My ultimate tuning guide

[nomis3613]

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THE WAFFLE
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Aims
This guide is aimed at people who are familiar with Gran Turismo 3 or tuning settings in other racing games and want to get maximum performance from their cars on the road tracks. Sorry to sound elitist, but it's not a beginners guide, but people new to GT3 tuning may need to start with more simple guides before they can understand some of the stuff in this one.

Method
While there are some excellent GT3 tuning guides on the net, this one was made by testing each setting in a way that isolated its effects (ie specific straight-line testing of the effects of camber on power-down (straight line acceleration). The method used was to carefully read the scrolling text in the settings menus, then do specific testing to check their claims and fill in the gaps. Many other guides describe real-world tuning effects, which may or may not be relevant to GT3. I started with the scrolling text because they are (hopefully!) written by someone who knows how GT3 physics works.

The specific testing was done in a way so that improvement could be measured with numbers (ie max speed at high speed ring for aero testing, 0-400m for camber vs straight line acceleration testing) and not lap times usually, so that driver inconsistency could be removed. Tests were repeated until a trend emerged (lordy, the braking tests were difficult!!! have you ever tried to hold 250km/h in a Speed 12, then brake at EXACTLY the 600m line of the 0-1000m test?? This took lots and lots of repeat runs to figure out a trend for each setting.

Like most guides, I have broken it up by going through each setting. However, I have also bolded the main effect of each setting in the text, so if you have a particular problem, you can skim through the text looking at the words in bold (kinda like cross-referencing). The first paragraph in each section is a summary of how to tune that setting, then the next paragraphs go a bit deeper into discussion.

COMMENT ON TUNING OVERALL
I strongly believe that in GT3, the amount of mechanical grip and braking power is set for a car, and there is nothing you can do to change it. So why bother tuning? Well, the balance of understeer/oversteer can certainly be changed through tuning, as can trade-offs like steering response vs loss of grip later in turns (front toe-out). But as for the steady-state overall cornering grip, if the car is balanced, there are no other tuning settings (aside from downforce) that will increase this grip. I started this guide in the search for settings that would maximise grip (eg "the car is balanced and drives nicely but if I softened the springs and stiffened the stabilisers, would this give more grip?", "does lower ride height give more grip?"). But these "magic tuning combinations" do not exist, which makes tuning simpler. Once you are happy with how a car reacts on a certain track, then you have the best settings for that track. That is it. Easy!

A small general point is that GT3 works on ratios, hence if you want to increase something both front and rear but keep the balance the same, then increase each of the values by say 20% (not by 5 clicks each).

Tyre Wear
This has not been tested much. Each tyre wear test would take at least 5 laps, so it's very time consuming. Also, driving style will effect tyre wear so the results are often not consistent. However, I personally believe that most settings (except for TCS) do not effect tyre wear rates. The percieved difference in tyre wear due after changing settings is because your are going slower or faster through the turns, hence using less or more tyres (but of course your lap time has decreased or increased). Tyre wear is greatly effected by driving style, so think smooth smooth smooth!

Please Contribute
I actually encourage you to criticise my guide. Where you have a better understanding of something, please send me details of the car, settings and track, and I will test it then revise the guide. Please try to come up with as specific a situation as specific as possible, because saying “more rebound at the front in car X at track Y increases understeer”. Different drivers have different styles leading to different effects of tuning, so we need to find a way to test the effect in a controlled, measureable environment. However, there are sooo many possibilities for tuning in GT3, so I welcome your ideas, which will help us understand tuning better and get the most out of our cars!!

TBC
Although most of the principles apply to all vehicles, this guide has been based on RWD cars. Checking the theories on other drivetrains and tyres is on the To Do list.

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THE GUIDE
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Spring rate
In theory, softer springs would give more grip (coz of better weight transfer), with the trade-off being slower reactions and more body roll. But I couldn't find any difference in in steady state grip (so the scrolling text about "stiffened springs...cornering performance improved” is perhaps just referring to more responsive handling). So adjust the overall stiffness based on how smooth or sharp you like the handling to feel overall.

Stiffer front or softer rear can be used to reduce oversteer (and the opposite for understeer) but it is better to try to fix the balance using camber and ride height before messing with spring rates.
With regard to setting the front/rear rates, there are 2 theories in GT3 land: set according to the car's weight distribution, or increase spring rate whenever ride height is lowered (which could be at the front or rear only). Either method seems to work, and will produce similar results (because of the simplifications in the GT3 physics).

Ride Height
Lower ride height will cause less yaw and pitch. For less understeer, make the front ride height higher than the rear (10mm higher max), and use the opposite settings to reduce oversteer.

Overall grip is unaffected by ride height settings , but if the car makes you feel seasick or feels too rigid, then decrease or increase the ride height respectively.
Altering the cars weight balance by using different front/rear ride heights is a good way to change the overall balance of the car slightly. This is recommended as the second thing to adjust (after camber) to cure oversteer or understeer.
While moving the weight forward by raising the rear will reduce steady-state oversteer, it has been found (thanks, Parnelli!) that this will actually increase the chance of spinning when you start to turn with hard braking (entry to a hairpin). Brake balance and dampers can be used to reduce this effect.
One last thing, when experimenting with low ride, stiff springs but soft dampers; the car would drift though corners with shuddering noises (ie screee....eee....eee....eee...eech instead of a smooth, constant slide). This could be GT3s way of saying that the wheel is rubbing the guard or the suspension is fully compressed (both bad), but it could also just be a result of the dampers being too soft for the springs and ride height.

Damper Bound / Rebound
Start with bounds at 4, rebounds at 8. Reduce front bound and rear rebound in equal amounts if the car wants to spin when braking. Do the opposite if it won't turn when braking. Reduce front rebound and rear rebound in equal amounts to reduce power oversteer. Do the opposite to reduce exit understeer. Then adjust all of the dampers equally to tune how the car responds to bumps/kerbs. If it feels too "floaty" stiffen everything equally. If the car bounces around, soften everything equally.

Dampers are quite complex! They effect weight transfer during braking + accel, response to bumps, and weight transfer in cornering. You may find that the overall understeer/oversteer has changed once you change damper settings. Use the camber or stabilisers to fix the balance.

Camber Angle
Set front and rear to 1.5 as a starting point. Increase (but not past 4.5) the front to reduce understeer, ditto for the rear re oversteer.

Unlike real life, GT3 just compares the front and rear camber angles to determine how much understeer/oversteer you have. There is no optimal camber angle for maximum grip. Within the above range, camber angle will not reduce braking, in fact below 1 degree, straight line acceleration on racing tyres will decrease!
Camber angle is the best way to fix oversteer and understeer because there are no side effects.
There is a theory that high rear camber causes snap oversteer, but I did not find this effect within sensible camber angles.
Different tyres respond differently to camber. For example, on Sport Tyres reducing front camber from 1.5 deg to 1.0 will actually reduce understeer. Sport Tyres seem to prefer lower camber angles than Super Hard racing tyres (where the peak seems to be up near 3 deg)
If GT3 is like real life, camber angle should effect tyre wear. But like I said at the start, I doubt that effects of suspension settings on tyre wear are modelled in GT3.

Toe Angle
More negative front toe means steering is less responsive, but less understeer at corner exit (max -1.5 deg). More negative rear toe (max 1.0 deg) means less understeer at corner entry.

In theory, positive rear toe could be used to reduce power oversteer for RWD cars, but I'd be looking into the general balance of the car before fiddling with this.
The effect of toe on straight line acceleration/braking is negligable, just tune it to get the handling you want and don't worry about any decrease in straight line power/braking.
Use rear toe carefully, too much will suddenly make the car very oversteery but negative rear toe is especially useful in FWD cars.

Stabiliser
Start with them at 2 or 3 and increase front and rear together only if there is too much body roll in corners (only after setting the spring rates and ride heights properly first). Use as little stabiliser strength as possible.

If reasonable camber and ride height tuning is not enough to fix the understeer or oversteer, then adjust the stabilisers in the same way you would the springs.
Stronger stabilisers make the car react worse to bumps, so minimise their strength where possible to avoid being thrown off the course when you hit a kerb!

Brake Balance
Increase front brake (or decrease rear) if the car wants to spin-out when braking. Decrease front (or increase rear) if the car will not turn while braking. While brake balance is just relative, keep both front and rear between 4 and 20.

There were a few surprise results when I tested brake balance settings:
- moving the brake balance towards the front does not reduce stopping distances! In fact, stopping distance seems to be unaffected by any suspension or brake settings.
- once past a certain strength, increasing the strength further will not cause any change to the handling at all.
- when front or rear is below 4, the car will skid when braking below 30km/h (whether this has any effect on races – except maybe pitstops – is doubtful).
Engine braking (downshift to the redline in each gear) decreases stopping distances by a couple of car lengths, so do it!
There is a theory that using Sports brakes does not reduce stopping distances on Hard Tyres. This is not the case for GT3, so Sports brakes are well worth getting!

LSD Initial
Set to midway. Increase if inside wheel spins when accelerating, decrease if steering becomes unresponsive. Increase if you have an MR car which keeps spinning out (add an equal amount of LSD Deceleration, too).

This has been debated on the internet, but I believe that when accelerating, the LSD effect is Initial + Acceleration. Therefore you set the accleration to max and the Initial to the minimum that will prevent wheelspin, so that the car maintains good steering response.
Another theory I tested is that setting Initial to the maximum or minimum means that LSD Accel and Decel have no effect, I do not think this is true.

LSD Acceleration
Set to maximum in a RWD car. Always (unless you are lacking power and want to power oversteer). In FWD, increase to remove wheelspin, but there will reduce if exit understeer increases.

Basically, I recommend setting up a RWD car with a locked diff to maximise power down (acceleration) when turning. LSD acceleration could be decreased to improve the steering response, but there are better ways to achieve the same thing.

LSD Deceleration
Set to minimum. Always. Well, except in MR cars that keep spinning out, where you should increase it until the car is stable enough.

Theoretically, a higher LSD Deceleration could be used to increase stability under braking, but why?? You'd be normally better off fixing stability with brake balance, toe angle or aerodynamics.

Gear Ratio
NEVER USE AUTO-SETTING. Here's how to do it properly:
1)Drive manual and use the analogue sticks for accleration/braking (if you don't already, go away and learn how to drive GT3 properly before doing anything else in your life!!)
2)Set TCS to 1
3)Set 1st and 2nd all the way left, 3rd 30% to the right (of the moveable range, not the overall position of the yellow bar on the line), 4th 60%, 5th and 6th 100% right.
4)Tune 6th for top gear: go to Grand Valley and adjust the Final setting until your top speed on the straight is at redline in top gear.
5)Find your “starting gear” (not 1st gear usually!!): go to machine test, 400m test. Hold the revs at redline in 1st gear and full throttle as soon as you start. If TCS is flashing the constantly until you change gear, start the test again in a higher gear. If TCS does not come on, start the test again in a lower gear. The correct starting gear is when TCS flashes at the start, but stops flashing about 1000 revs before the gear change. You may need to adjust the gear ratio of the “starting gear” to achieve this
6)Once you have found the “starting gear”, adjust all gears below it to fully left and evenly space the gears after it (ie 25%, 50%, 75%, 100%). This will put the gears as close together as possible and keep the engine in its power band.
7)If you are mostly using 2 or 3 gears on a track (ie 2nd, 3rd, 4th are mostly used, and 5th and 6th are only used on the main straight), it might help to put these gears close together (ie 3rd 30%, 4th 60%) and set 5th and 6th fully to the right. This will sacrifice some acceleration in 5th and 6th but keep your engine closer to peak power in 2nd, 3rd and 4th (ie the majority of the time)
8)The gear below your “starting gear” can be used for very low speed turns when power oversteer is required (ie hairpins)
9)The above instructions are hard to explain, but really easy in practice, so don't be scared!!

Downforce
Set both front and rear to maximum where possible. Decrease front downforce if car oversteers at high speed, decrease rear downforce if car understeers at high speed.

The difference between mechanical and aerodynamic grip needs to be understood. All of the suspension, brake and differential settings affect low and medium speed grip. For medium and high speed corners, aerodynamic grip becomes a bigger factor. So if a car handles nicely at low speed but understeers at through fast corners, you need to be looking at the downforce. High speed handling is also effected by other settings than downforce, but the best way is to tune the other settings for low and medium speed, then tweak high speed handling using aerodynamics.
The tradeoff between reduced speed and improved handling (ie the lift to drag ratio) heavily favours handling, so use as much overall downforce as possible when fixing oversteer or understeer at high speeds.
Changing ride height and spring rates has not caused any noticeable effects on aerodynamics and since it's not mentioned in the scrolling text, it's safe to assume GT3 doesn't include ground effects, aero compressing springs, etc; so the downforce can be adjusted independantly to everything else.

Active Stability Manager
0, at the very least while you're tuning your car.

ASM masks the handling of the car and generally introduces understeer. Try to drive without it. If you adjust settings with ASM on, you won't get the proper understanding of the effect of the changes, so turn it off when tuning.

TCS Controller
Can be used to control wheelspin in high power cars. Set to 0 and increase until you are happy with with amount of wheelspin during acceleration. Use as little TCS as possible, because a higher TCS setting will reduce acceleration (since the TCS more often detects slip and reduces engine power)

Wheelspin can sometimes be handy (especially in RWD), so having a low setting can help. Also, a higher TCS setting will slow your car down more when you run off the road, drive along a bumpy kerb, etc.

 

[Parnelli Bone]

Good lord what a massive post! 👍

You may have noticed by now, GT3 is super-slow. Matter of fact, it's the slowest of the slow, which is unfortunate. If this were 4 or 5 years ago, you would have no doubt had a page full of comments by now. Don't feel bad about being "elitist"...all the people that don't "get" this sort of tech talk are out punting real drivers in the GT5P world.

But i read it. And i dig it because i'm a bit of a car-nut. A few areas where i've drawn my own conclusions (in reference to your guide)

1. I almost always stagger spring rates front to rear, the main reason (real-life and in the game) is because most cars have an uneven weight balance (typically where the engine and/or transaxle or transmission is bolted up). If i've got more weight up front, for instance, i'll typically use stronger springs there. Well, 95% of the time i will.

2> there are ALWAYS exceptions to the rule when i'm tuning. Sometimes, these exceptions are extremely rare, but you'll see what i mean. Some cars demand eccentric rules because they display eccentric behavior, different from anything you've ever driven before. 💡

How new are you to GT3, and gT in general by the way? Just curious.

3> Cars in GT2 and GT3 don't truely "bottom out", which is unfortuante. Nor do tires ever meet their wheelwells...PD didn't go this far with chassis programing. The reason i know this is: there are times i've driven a super-low car over some bumpy areas. In real-life, a car will slow as its wheels find any additional resistance (contact with a wheel well will certainly do it. However, this is not true in the game. Unfortunately. So setting springs, dampers, stabilizers, and ride height is merely a way to effect weight transferrence under braking and cornering and acceleration. In this respect, Pd is striving for realism, and for the most part, they certainly get it better than some other racing sims i've tried.

Now in GT4, there is additinal chassis tuning. Set your car too low, and it will bottom out. Sparks will fly. However, all that is happening is the car is slowly losing its chassis stiffness when such bottoming occurs, which after an X amount of miles, can be retooled back to full stiffness for $50,000.. There is no slowing-down of speed like there should be, again, PD didn't go this far with chassis tuning in gT4.

A car with super low ride height and super-stiff springs in GT1, on the other hand, WILL slow down. The effect is not 100% realistic, but at least it is THERE. In many ways, GT1 is therefore different from any ohter Gran Turismo.

5>. I'll agree with you on camber and toe stuff. Basically, there's a window with which you can use either of these where they "work" the way you want them too. Get outside this window, and that extra cornering grip (or whatever you're trying to achieve) also goes out the window. 💡

6> Brakes. You should know PD programed all cars in all gran turismo games to have a rudimentary ABS-type system, which is why you never see brakes & wheels truely lock in these games like you would in real-life; therefore, using stronger brakes front or rear won't make a car stop any faster. Instead, the brake-balancer should be used as a tool aid cornering (less understeer, less oversteer, or whatever). this kinda sucks.

I heard a rumor that in GT5, PD is gonna include an option to get rid of the ABS, which means (if you choose) you'll actually have to KNOW and use brakes with as much care as you use the gas pedal to avoid wheelspin. I really hope they include this option.

Now in GT4, they've gone half-way. Cars in this game don't truely lock wheels. However, if you set the balancer too stong, now it's obvious the brakes are trying to lock. Tires start chirping like mad once you set the balancer anywhere over about 12. However, they never truely lock. In some cars, actual brake distances ARE affected in this game..mostly if that car had sucky brakes to begin with when stock. I'm sure GT3 brakes have some effect over distances, but i'm not sure how far they went with this when they were programing.

7> LSD. Personally, i try and use it only when absolutely necessary. I'm talking about the device that determines play between 2 axles, now...not anything illegal. lol. Anyways, i prefer my cars NOT TO HAVE any sort of limited-slip. I dig flexibility. However (of course) many cars eventually need something to tame them. I typiclaly only use the "fixed" differentials for most passenger-car racing. Only for rally trakcs and full-blown professional racing will i start delving into LSD tuning.

Why? because i don't like having too many advantages over the Ai. This goes for suspension tuning as well...i prefer my "pedestrian" cars to have a stock suspension in the absolute easiest Beginner Level races, and a sports or semi-racing suspension for more challenging stuff.

I agree with you on everything except LSd decel. Yes, i prefer to keep it minimum as possible to keep understeer while braking to a minimum, however , there are times (and you'll eventually find) some cars that require decel in massive doses...especially once you're rallying or driving a super-swivelly mid-engine car, for instance.

9> I forget what number i'm supposed to be on. Oh well. transmission tuning. Yeah, i try not to use Auto settings, too. There is no such thing in real-life (not without spending additional tens of thousands on a new set of gears) so i try not to use it. There are some extreme cases where i have used it, tho. After awhile, you'll find a car in which you HAVE to use it.

That's a neat trick with the TCS, tho, i never heard of that. Learn something new everyday.

132> Yup. TcS and ASM OFF OFF OFF. very good. Some real-life professional race cars nowadays use traction controls (not so much stability, tho), so i have used them in very rare cases. But for 99% of my racing, all that crap is off.

Since real-life cars often have TCS and/or ASM nowadays, i will drive a brand-new car in the game with these effects on "1" briefly around a track with sim tires on (or in GT4, N2 or N3 tires to simulate all-seasons or summer radials). This is an effort to try and simulate the car when it's handling at its suckiest...straight from the dealer. However, i always research cars online before i drive them this way. I won't drive a '91 Silvia, for instnance, with these effects on because they weren't used back in 1991. Instead, i'll drive the '91 Silvia briefly around on sim or N tires.

Real-life car magazines and online car sites nowadays sometimes drive a car with these effects ON, and then do a seperate test with them OFF (if the car actually features a manual kill-switch that turns off traction & stability controls from the dash).

Man, you got me hungry. Think i'll go make some waffles.

 

[nomis3613]

Good lord what a massive reply!

I'm actually pleasantly surprised to get an reply at all, so thanks. GT3 is certainly off the radar now, but I went back to it recently and am now hooked on trying to squeeze maximum speed via tuning.

About 4 years ago, I almost completed GT3, then played GT4 until I got stuck at 80% needing a much more expensive car to win the next tournament to go any further (and that damn Nurburgring 1 Lap Challenge got the better of me). Your comparison of physics between the games is really useful, it provides great insight in flaws in each game that you can exploit (if you're so inclined...)

1. I almost always stagger spring rates front to rear, the main reason (real-life and in the game) is because most cars have an uneven weight balance (typically where the engine and/or transaxle or transmission is bolted up). If i've got more weight up front, for instance, i'll typically use stronger springs there. Well, 95% of the time i will.
I've never thought of this, but sure I'll give it a go. Makes sense in real life. As an engineer, I'm obsessed with testing individual parameters in a controlled environment, so what I'm thinking is lap times on Super Speedway with FR, MR and RR cars with spring rate set to a) equal front and real b) in proportion the car's weight balance (of some guess thereof).

2> there are ALWAYS exceptions to the rule when i'm tuning.
Amen.

3> Cars in GT2 and GT3 don't truely "bottom out", which is unfortuante. Nor do tires ever meet their wheelwells...PD didn't go this far with chassis programing.
Agreed. Although, I suspect stiffer, lower cars get more unsettled on kerbs and other bumps, but this is hard to quantify.

Now in GT4, there is additinal chassis tuning. Set your car too low, and it will bottom out. Sparks will fly. However, all that is happening is the car is slowly losing its chassis stiffness when such bottoming occurs, which after an X amount of miles, can be retooled back to full stiffness for $50,000.. There is no slowing-down of speed like there should be, again, PD didn't go this far with chassis tuning in gT4.
Interesting! I'll keep that in mind when I go back to GT4. I have seen sparks fly off the F1 cars in GT3. Dunno if it's just a pretty visual effect or actually means anything, though.

6> Brakes. You should know PD programed all cars in all gran turismo games to have a rudimentary ABS-type system, which is why you never see brakes & wheels truely lock in these games like you would in real-life; therefore, using stronger brakes front or rear won't make a car stop any faster. Instead, the brake-balancer should be used as a tool aid cornering (less understeer, less oversteer, or whatever). this kinda sucks.
Cool, good to hear you think my theory is ok, because I was really surprised at the results I got during brake testing. Next on the agenda is testing brake settings vs tyre wear, although this will be very time consuming.

Just to sidetrack for a minute, most of my testing has been with 800+ HP RWD cars on Super Hard tyres, so it's possible that other tyres, drivetrains and less power could change the effects of tuning. I'll look at drivetrains and less power soon, but not so concerned about tyres because once you get far enough into the game, tyre wear kicks in and I've found using anything less than Super Hard isn't needed in most cases.

I heard a rumor that in GT5, PD is gonna include an option to get rid of the ABS, which means (if you choose) you'll actually have to KNOW and use brakes with as much care as you use the gas pedal to avoid wheelspin. I really hope they include this option.
Me too. At first I thought this was why they made seperate front and rear brake adjustment, instead of a single bias bar. But, alas, it is not so clever!

7> LSD. Only for rally trakcs and full-blown professional racing will i start delving into LSD tuning. Why? because i don't like having too many advantages over the Ai. This goes for suspension tuning as well...i prefer my "pedestrian" cars to have a stock suspension in the absolute easiest Beginner Level races, and a sports or semi-racing suspension for more challenging stuff.
Kudos for being a very fair gentleman racer!!

I agree with you on everything except LSd decel. Yes, i prefer to keep it minimum as possible to keep understeer to a minimum, however , there are times (and you'll eventually find) some cars that require decel in massive doses...especially once you're rallying or driving a super-swivelly mid-engine car, for instance.
True, I'll put in a note about MR cars, I forgot about this, so thanks.

That's a neat trick with the TCS, tho, i never heard of that. Learn something new everyday.
Thanks! I spent a while trying to think of the best way to explain the balance between excessive wheelspin and engine bogging. I suspect most people use terrible gear ratio (auto) settings and don't realise it because of TCS.

132> Yup. TcS and ASM OFF OFF OFF. very good. Some real-life professional race cars nowadays use traction controls (not so much stability, tho), so i have used them in very rare cases. But for 99% of my racing, all that crap is off.
I just prefer the 'raw' feel of a car, anyway. But trying to tune a car with ASM on is like entering a boxing match with the wrong contact lenses!!

I've gotta say I'm pretty happy with the results I'm getting using this guide. Yesterday, I managed to beat the F1 cars significantly using a Toyota GT1 Race Car mainly through some wikkid tuning. Once I got an F1 (wheee!!!), I've discovered that it's at least 8 seconds a lap quicker at Laguna Seca so clearly I'm doing something right. Hate to brag, but I reckon a 1:08.3 at Laguna Seca in a Toyota GT1 on Super Hard tyres is pretty impressive!!!

Thanks heaps for taking the time to share your thoughts.
Simon

Man, you got me hungry. Think i'll go make some waffles.
Mmmmm....waffles...

 

[Scaff]

nomis3613 - You may find the link in my signature to GT4/5 tuning guides of interest.

Almost everything in them can be directly applied to GT3 (you are quite right that GT3 is more simplistic in many of the settings and results).

The guides consist of two .pdf documents (around 80 pages in total) and should help out with your testing in a big way.


Regards

Scaff

 

[Parnelli Bone]

Cool, i was hoping Scaff would show up. :tup:


You are right, nomis. One hing they got right was stiffer, lower suspensions do get cantankerous over curbing, bumps, etc.

check out my website, too, nomis, it's the gt car reviews site in my sig below.

Most of my driving and testing occurs in "pedestrian" cars that i can research heavily. I haven't tested too many professional race cars. Most full-racing cars...it's hard to find specs for them. I have a weird thing about specs (length, weight, type of steering, etc). If i can't find specs for a car online or in a book somewhere, or at least read about its racing history, it doesn't seem as "real" to me. Therefore, i tend to avoid racing LM cars, most of which are PD "fantasy" machines. I'll race an Oreca Viper for instance (which is an actual real-life car i can read about) rather than a Camaro LM (which is fictional....i did alot of online searching to make this conclusion, too.

What type of engineering do you do in real-life? I'm a mechanic...not a super-mechanic like some of the guys i work with, but i'm learning plenty as i go.

....finally, and sadly...i didn't make waffles yesterday. Turns out all we had in the pantry is soem very heavy corn syrup. which i used to love as a kid, but as an adult, i prefer real maple syrup. And we didn't have any maple. I did make an omlette, tho.

 

[KAMKA-Z]

Lots of good food for thought. Good to see GT3 active again.

On differential settings, if I understand right, as the initial torque slider moves up, it acts more like a "Locked Diff". The accell and decell are to ballance it's action on accell and decell. With the initial maxxed, the figures of accell and decell are voided.
Right? That's how I understand it from Scaff's tuning guide.

And if you move the Accell all the way to the right by itself it acts like the "One-Way Diff" that I use on front-wheel-drive cars.

While playing with the Cobra, I found that LSD settings were critical to getting down the power with harder tires.

Maple Syrup. Good indeed. My neighbor across the road lets us tap his maple trees for sap in the spring. It's a bit of work boiling it down but the results are excellent. Hmmm. Waffles do sound good.

 

[Parnelli Bone]

Lots of good food for thought. Good to see GT3 active again.

On differential settings, if I understand right, as the initial torque slider moves up, it acts more like a "Locked Diff". The accell and decell are to ballance it's action on accell and decell. With the initial maxxed, the figures of accell and decell are voided.
Right? That's how I understand it from Scaff's tuning guide.

And if you move the Accell all the way to the right by itself it acts like the "One-Way Diff" that I use on front-wheel-drive cars.

While playing with the Cobra, I found that LSD settings were critical to getting down the power with harder tires.

Yup, that's pretty much the way i see it, too.

Maple Syrup. Good indeed. My neighbor across the road lets us tap his maple trees for sap in the spring. It's a bit of work boiling it down but the results are excellent. Hmmm. Waffles do sound good.

Cool! Well, i'll be right over! :idea:

 

[breakpoint]

Pretty much the people that you see reply here are the handful that will always look through the GT3 section and feel sad when they see there hasn't been a new post in at least one month. ( i do anyways ) That being said, they are dedicated and playing the game how it was meant, like a challenge. Check out PB's car page in his sig, massive amounts of stats for allot of cars in GT, could be useful for you in some test's. Im ready to get my PS3 and get the new GT because after i got 4 i just didn't like it and switched back to 3, and im ready for some new tracks!

 

[Parnelli Bone]

What up there, breakpoint? Still travelling around? Lemme know when you're in Maryland if you are.

Finally had some waffles tonite at a local Double T Diner. Nice and crispy on outside, but fluffy inside. But no maple syrup. guess i should just buy some.

 

[nomis3613]

Thanks, guys. Looks like I've got some GT3 homework to do!!

I'm not much of a maple syrup expert, so I dunno how I can contribute to this thread. Other than to say that real maple syrup kicks the arse of maple "flavoured" syrup!!!

 

[Parnelli Bone]

Thanks, guys. Looks like I've got some GT3 homework to do!!

I'm not much of a maple syrup expert, so I dunno how I can contribute to this thread. Other than to say that real maple syrup kicks the arse of maple "flavoured" syrup!!!

Hey you're the one that started all this with your "waffle" stuff. lol

 

[nomis3613]

I have done some more testing and updated the guide. I actually encourage you to criticise it! If you think something is wrong, let me know why, I'll check it out, and the guide will be improved. For regular readers, here are just the updates (I think the first sentence will stir up some responses!)

COMMENT ON TUNING OVERALL
I strongly believe that in GT3, the amount of mechanical grip and braking power is set for a car, and there is nothing you can do to change it. So why bother tuning? Well, the balance of understeer/oversteer can certainly be changed through tuning, as can trade-offs like steering response vs loss of grip later in turns (front toe-out). But as for the steady-state overall cornering grip, if the car is balanced, there are no other tuning settings (aside from downforce) that will increase this grip. I started this guide in the search for settings that would maximise grip (eg "the car is balanced and drives nicely but if I softened the springs and stiffened the stabilisers, would this give more grip?", "does lower ride height give more grip?"). But these "magic tuning combinations" do not exist, which makes tuning simpler. Once you are happy with how a car reacts on a certain track, then you have the best settings for that track. That is it. Easy!

A small general point is that GT3 works on ratios, hence if you want to increase something both front and rear but keep the balance the same, then increase each of the values by say 20%, but by say 5 clicks.

Tyre Wear
This has not been tested much. Each tyre wear test would take at least 5 laps, so it's very time consuming. Also, driving style will effect tyre wear so the results are often not consistent. However, I personally believe that most settings (except for TCS) do not effect tyre wear rates. The percieved difference in tyre wear due after changing settings is because your are going slower or faster through the turns, hence using less or more tyres (but of course your lap time has decreased or increased). Tyre wear is greatly effected by driving style, so think smooth smooth smooth!

Spring rate
In theory, softer springs would give more grip (coz of better weight transfer), with the trade-off being slower reactions and more body roll. But I couldn't find any difference in in steady state grip (so the scrolling text about "stiffened springs...cornering performance improved” is perhaps just referring to more responsive handling). So adjust the overall stiffness based on how smooth or sharp you like the car to feel.

Stiffer front or softer rear can be used to reduce oversteer (and the opposite for understeer) but it is better to try to fix the balance using camber and ride height before messing with spring rates.
With regard to setting the front/rear rates, there are 2 theories in GT3 land: set according to the car's weight distribution, or increase spring rate whenever ride height is lowered (which could be at the front or rear only). Either method seems to work, and will produce similar results (because of the simplifications in the GT3 physics).

Ride Height
Lower ride height will cause less yaw and pitch when cornering. For less understeer, make the front ride height higher than the rear, and use the opposite settings to reduce oversteer.

Overall grip is unaffected by ride height settings , but if the car makes you feel seasick or feels too rigid, then decrease or increase the ride height respectively.
Altering the cars weight balance by using different front/rear ride heights is a good way to change the overall balance of the car slightly. This is recommended as the second thing to adjust (after camber) to cure oversteer or understeer.

Damper Bound / Rebound
Start with rebound in the middle of the slider, and bound 1 click less. Then set the rebound to adjust how the car recovers from bumps/kerbs. Less rebound will make the reactions slower and more fluid. More rebound will make the car react quicker but more sharply/jittery. Once the rebound is set, concentrate on how the car reacts to the start of the first bump. Mushy? increase rebound. Harsh, sudden impact? less. The scrolling text says rebound should be 2-4 times bound. I'd just say that bound should be at least less than rebound.

Dampers can be used to reduce understeer/oversteer (same method as spring rates), but it is better to tune them for bumps and adjust the balance with other settings so there's no unwanted side effects when you hit a bump.
(yes, I totally changed my mind about dampers since the last edit!!)

Camber Angle
Set front and rear to 1.5 as a starting point. Increase (but not past 4.5) the front to reduce understeer, ditto for the rear re oversteer.

Unlike real life, GT3 just compares the front and rear camber angles to determine how much understeer/oversteer you have. There is no optimal camber angle for maximum grip. Within the above range, camber angle will not reduce braking, in fact below 1 degree, straight line acceleration will decrease!
Camber angle is the best way to fix oversteer and understeer because there are no side effects.
There is a theory that high rear camber causes snap oversteer, but I did not find this effect within sensible camber angles.
If GT3 is like real life, camber angle should effect tyre wear. But like I said at the start, I doubt that effects of suspension settings on tyre wear are modelled in GT3.

Stabiliser
Start with them at 2 or 3 and increase only if there is too much body roll in corners even after the spring rates and ride heights are ok. Use as little as possible. When there is too much bodyroll in corners, but the overall stiffness (on bumps etc) is good, increase the front and rear stabilisers the same amount. If reasonable camber and ride height tuning is not enough to fix the understeer or oversteer, then adjust the stabilisers in the same way you would the springs.

Stronger stabilisers make the car react worse to bumps, so minimise their strength where possible to avoid being thrown off the course when you hit a kerb!

Brake Balance
Increase front brake (or decrease rear) if the car wants to spin-out when braking. Decrease front (or increase rear) if the car will not turn while braking. While brake balance is just relative, keep both front and rear between 4 and 20.

There were a few surprise results when I tested brake balance settings:
- moving the brake balance towards the front does not reduce stopping distances! In fact, stopping distance seems to be unaffected by any suspension or brake settings.
- once past a certain strength, increasing the strength further will not cause any change to the handling at all.
- when front or rear is below 4, the car will skid when braking below 30km/h (whether this has any effect on races – except maybe pitstops – is doubtful).
Engine braking (downshift to the redline in each gear) decreases stopping distances by a couple of car lengths, so it is worth doing. There is a theory that using Sports brakes does not reduce stopping distances on Hard Tyres. This is not the case for GT3, so Sports brakes are well worth getting!

LSD Initial
Set to midway. Increase if inside wheel spins when accelerating, decrease if steering becomes unresponsive. Increase if you have an MR car which keeps spinning out (add an equal amount of LSD Deceleration, too).

This has been debated on the internet, but I believe that when accelerating, the LSD effect is Initial + Acceleration. Therefore you set the accleration to max and the Initial to the minimum that will prevent wheelspin, so that the car maintains good steering response.
Another theory I tested is that setting Initial to the maximum or minimum means that LSD Accel and Decel have no effect, I do not think this is true.

TCS Controller
Can be used to control wheelspin in high power cars. Set to 0 and increase until you are happy with with amount of wheelspin during acceleration. Use as little TCS as possible, because a higher TCS setting will reduce acceleration (since the TCS more often detects slip and reduces engine power)

Wheelspin can sometimes be handy (especially in RWD), so having a low setting can help. Also, a higher TCS setting will slow your car down more when you run off the road, drive along a bumpy kerb, etc.

 

[Parnelli Bone]

I have done some more testing and updated the guide. I actually encourage you to criticise it! If you think something is wrong, let me know why, I'll check it out, and the guide will be improved. For regular readers, here are just the updates (I think the first sentence will stir up some responses!)

Cool. A nomis post. Thanks to our f:censored:ed up economy (thanks so much PRes. Bush...it's not like i NEED to work ), it's another slow day at work, so at least i have something to do as i reply to this.

COMMENT ON TUNING OVERALL
I strongly believe that in GT3, the amount of mechanical grip and braking power is set for a car, and there is nothing you can do to change it. So why bother tuning? Well, the balance of understeer/oversteer can certainly be changed through tuning, as can trade-offs like steering response vs loss of grip later in turns (front toe-out). But as for the steady-state overall cornering grip, if the car is balanced, there are no other tuning settings (aside from downforce) that will increase this grip. I started this guide in the search for settings that would maximise grip (eg "the car is balanced and drives nicely but if I softened the springs and stiffened the stabilisers, would this give more grip?", "does lower ride height give more grip?"). But these "magic tuning combinations" do not exist, which makes tuning simpler. Once you are happy with how a car reacts on a certain track, then you have the best settings for that track. That is it. Easy!

I agree. Grip is really the job of whatever tires your car is equipped with, you really can't increase total grip until you upgrade tires. Suspension settings (particularly toe and camber) can affect grip during cornering. A car with lots of front-end camber, for instance, won't have much of a footprint while the car is going straight. But when it starts turning (and the entire leans to one side) that tire is now hopefully getting a larger footprint as its contact patch increases.

Lower ride height does not increase grip (you are correct), which is an error many novice players think. All it does is lower your car's center of gravity, which helps in some cases because now there isn't so much weight being transferred to and fro and from side to side. In theory, lowering a car also means there is less air travelling beneath that car, which can aid high-speed cornering. In GT, however, it's debateable how much effect air has under a car. I don't think PD went into extensive detail when programming here.

A small general point is that GT3 works on ratios, hence if you want to increase something both front and rear but keep the balance the same, then increase each of the values by say 20%, but by say 5 clicks.

Yea, that's what the tuning guide that comes with the game suggests i think. Personally, i don't follow this sort of logic, i've always been a guy who tunes and tunes till the car starts to drive the way i want it to. But there's no harm in being super-technical....it just takes alot of time. And i already spend loads of time before races making sure i've got a car taht races fairly against the Ai.

Tyre Wear
This has not been tested much. Each tyre wear test would take at least 5 laps, so it's very time consuming. Also, driving style will effect tyre wear so the results are often not consistent. However, I personally believe that most settings (except for TCS) do not effect tyre wear rates. The percieved difference in tyre wear due after changing settings is because your are going slower or faster through the turns, hence using less or more tyres (but of course your lap time has decreased or increased). Tyre wear is greatly effected by driving style, so think smooth smooth smooth!

I would agree. As we discussed earlier, dRiving wussier during races can extend your tire life the most, but only to a limited extent....settings dont' have much to do with it. And if you drive wussier during an endurance, you are really making a gamble because the outcome of wussy driving (less pitstops) gets displaced by the fact that you're now going SLOWER. So you have to make a judgement call: is it really worth it to try and pit less? In some cases, the answer is no. I've lost some endurnace races by mere seconds, the reason being that i drove slower thru vast portions of the race in an effort to pit less. On the other hand, i've also WON a few races by mere seconds, as my initial gamble (less pit stops) actually DID pay off since i avoided that extra pit stop during the 2 hours.

Keep in mind that in GT (unlike ToCA and some other games) what is being represented so far as tires go is PERFECT tire wear. You'll never see tires go flat, heat unevenly, or wear unevenly in GT. YOu'll never have a tire, for instance, that is burned to the core on its sides, but still has a healthy tred in the center, know what i mean? Not entirely realistic at all, but at least it's better than not attempting to model wear at all.

Spring rate
In theory, softer springs would give more grip (coz of better weight transfer), with the trade-off being slower reactions and more body roll. But I couldn't find any difference in in steady state grip (so the scrolling text about "stiffened springs...cornering performance improved” is perhaps just referring to more responsive handling). So adjust the overall stiffness based on how smooth or sharp you like the car to feel.

Stiffer front or softer rear can be used to reduce oversteer (and the opposite for understeer) but it is better to try to fix the balance using camber and ride height before messing with spring rates.
With regard to setting the front/rear rates, there are 2 theories in GT3 land: set according to the car's weight distribution, or increase spring rate whenever ride height is lowered (which could be at the front or rear only). Either method seems to work, and will produce similar results (because of the simplifications in the GT3 physics).

Yup. All this stuff winds up being a very subtle process. I really wish Sucahyo and Scaff still posted..you'd no doubt have more discusssion on this topic! Suc never shows up anymore, and Scaff seems preoccupied with gT5, perhaps.

Newbs sometimes think "well if i lower my car all the way and boost springs to 20/20, i'll go faster, right?" THen they get discouraged to find all this has little to do with actual speed and lap times.

Ride Height
Lower ride height will cause less yaw and pitch when cornering. For less understeer, make the front ride height higher than the rear, and use the opposite settings to reduce oversteer.

Overall grip is unaffected by ride height settings , but if the car makes you feel seasick or feels too rigid, then decrease or increase the ride height respectively.
Altering the cars weight balance by using different front/rear ride heights is a good way to change the overall balance of the car slightly. This is recommended as the second thing to adjust (after camber) to cure oversteer or understeer.

Hmm, i've always lowered the front to reduce understeer (in the case of a front-engine car, weight is now more solidly planted over the front tires, which sometimes means increased front-end grip. And lowered the rear if the car has a habit of getting too "squirrely" with oversteer. Whatever, tho...carry on!

Damper Bound / Rebound
Start with rebound in the middle of the slider, and bound 1 click less. Then set the rebound to adjust how the car recovers from bumps/kerbs. Less rebound will make the reactions slower and more fluid. More rebound will make the car react quicker but more sharply/jittery. Once the rebound is set, concentrate on how the car reacts to the start of the first bump. Mushy? increase rebound. Harsh, sudden impact? less. The scrolling text says rebound should be 2-4 times bound. I'd just say that bound should be at least less than rebound.

Dampers can be used to reduce understeer/oversteer (same method as spring rates), but it is better to tune them for bumps and adjust the balance with other settings so there's no unwanted side effects when you hit a bump.
(yes, I totally changed my mind about dampers since the last edit!!)

Yeah, dampers have several functions, and not everyone agrees with just what they're supposed to be. I tend to tune them specifically to affect weigth transfer for braking & accelerting. They also come into play over bumps and such, but i specifically use them to affect transfer first, and then i may compensate for how bumpy a track is, and bring that into play as well.

My understanding is that the higher the number, the slower the reaction of bound dampers. With rebounds, a higher number makes them extend faster.

Bound=resistance

Rebound=extension

In other words, if you have a high bound setting, the car will resist pitching to and fro and side to side as weight is being applied. If you have a low bound setting, the car now allows for lots of movement as you brake, corner, and accelerate.

With rebound, a higher number willl "throw" the car in whatever direction. A lower number means the rebound damper is now wimpyer, and doesn't throw as forcefully.

So if you've got a car with high front bound and a low rear rebound, when you brake, that high front bound will put up lots of resistance, and weight is transferred slowly towards the front of the car. The low rear rebound isn't throwing weight forward much either, as fluid in the damper is exiting its chamber slowly. I would use such settings if i had a car that has a habit of lifting its rear under braking too much, for instance. Such a car would be prone to spins under hard braking.

Now if i had a car with a low front bound, and high rear rebound, what happens now (in theory) is there is lots of weight being thrown forward more quickly, increasing front-end traction under braking. I would use such settings if i had a car prone to lots of entry-understeer, as i'm now making an effort to get such a car to "trail-brake" and turn into the corner (rather than plow into it).

Camber Angle
Set front and rear to 1.5 as a starting point. Increase (but not past 4.5) the front to reduce understeer, ditto for the rear re oversteer.

Unlike real life, GT3 just compares the front and rear camber angles to determine how much understeer/oversteer you have. There is no optimal camber angle for maximum grip. Within the above range, camber angle will not reduce braking, in fact below 1 degree, straight line acceleration will decrease!
Camber angle is the best way to fix oversteer and understeer because there are no side effects.
There is a theory that high rear camber causes snap oversteer, but I did not find this effect within sensible camber angles.
If GT3 is like real life, camber angle should effect tyre wear. But like I said at the start, I doubt that effects of suspension settings on tyre wear are modelled in GT3.

Agreed on all except one point: a car with zero camber (all 4 tires sitting at a perfect angle on the ground, basically) will get better traction during a straight-line acceleration run than one with camber added. It takes some angling before you'll notice any difference, however (perhaps, over 2 degrees for most cars ive tested).

High rear camber does increase snap oversteer in some cases, but such settings won't be used in most cases, of course. I have used tons of rear camber on occasion, tho. I had a Datsun 240Z in GT2, for instance, that i was trying to rally. You'd think (since this is a rear-drive auto) taht the 240Z would be all fishtaily in the dirt. Not so. Matter of fact, it UNDERSTEERED so heavily, it wasn't fun to drive, and i was getting TROUNCED by the Peugeot 306 i was competeing against. The ultimate solution (after much tuning) happened to be ALOT of rear camber...like 5 or 6 degrees of it! Now the 240Z finally would slide its rear and get better angles in the dirt!

Stabiliser
Start with them at 2 or 3 and increase only if there is too much body roll in corners even after the spring rates and ride heights are ok. Use as little as possible. When there is too much bodyroll in corners, but the overall stiffness (on bumps etc) is good, increase the front and rear stabilisers the same amount. If reasonable camber and ride height tuning is not enough to fix the understeer or oversteer, then adjust the stabilisers in the same way you would the springs.

Stronger stabilisers make the car react worse to bumps, so minimise their strength where possible to avoid being thrown off the course when you hit a kerb!

Yea, the main service anti-roll bars provide is to make the car stiffer from side-to-side. A car with a stabilizer set at "7" should handle as though it's suspension is no longer independent (in theory, anyways). Stabilizers don't have as much effect in GT3 as they should, tho. But in general, stiffer stabilizers mean a bumpier ride, they act sort of like springs.

GT1 is king here. In this first game, PD modeled springs, dampers, and stabilizers with alot more variability. A setting of damper setting "10" in this game, for instance, realy made a huge differnce (in a BAD way), so you really had to be more careful with maximizing settings in this game. This goes for springs and stabilizers as well. In later GTs, this, of course, aint true in most cases; PD has really dumbed down the effect suspension settings have, perhaps in an effort to make their games more freindly for the casual racer. 👎 In GT4, it is possible to buy an "Org" suspension for some cars, which can give you greater variability with springs, ride height, etc...greater than a regular full-racing suspension. But personally, i haven't done much driving on Org suspensions yet.

Brake Balance
Increase front brake (or decrease rear) if the car wants to spin-out when braking. Decrease front (or increase rear) if the car will not turn while braking. While brake balance is just relative, keep both front and rear between 4 and 20.

There were a few surprise results when I tested brake balance settings:
- moving the brake balance towards the front does not reduce stopping distances! In fact, stopping distance seems to be unaffected by any suspension or brake settings.
- once past a certain strength, increasing the strength further will not cause any change to the handling at all.
- when front or rear is below 4, the car will skid when braking below 30km/h (whether this has any effect on races – except maybe pitstops – is doubtful).
Engine braking (downshift to the redline in each gear) decreases stopping distances by a couple of car lengths, so it is worth doing. There is a theory that using Sports brakes does not reduce stopping distances on Hard Tyres. This is not the case for GT3, so Sports brakes are well worth getting!

Interesting. Sucahyo used to do extensive testing with brakes and such, too...

I almost always buy sport brake packages by default, except for the easiest races, so it's good to know they actually affect braking distance. GT games don't feature brake fade, but if they did, surely the sports brakes would be a good buy to get rid (or vastly reduce) fade. The less fade there is (real-life), the more consistent and cooler your brakes are running overall. 👍

LSD Initial
Set to midway. Increase if inside wheel spins when accelerating, decrease if steering becomes unresponsive. Increase if you have an MR car which keeps spinning out (add an equal amount of LSD Deceleration, too).

This has been debated on the internet, but I believe that when accelerating, the LSD effect is Initial + Acceleration. Therefore you set the accleration to max and the Initial to the minimum that will prevent wheelspin, so that the car maintains good steering response.
Another theory I tested is that setting Initial to the maximum or minimum means that LSD Accel and Decel have no effect, I do not think this is true.

I don't think it's true either. Initial, accel, and decel work together as we brake, coast, and accelerate in a corner. Whether they switch from one effect to the other (initial works seperately from accel and decel), or if their effects compound atop one another (initial + accel = total lsd effect under acceleration, in other words, or initial + decel = total effect under braking) is what is often debated. Personally, i think the effects compound.

I need to seriously study how limited-slips work, tho, to draw my own conclusion here. To this day, i haven't really sat down and done this.

TCS Controller
Can be used to control wheelspin in high power cars. Set to 0 and increase until you are happy with with amount of wheelspin during acceleration. Use as little TCS as possible, because a higher TCS setting will reduce acceleration (since the TCS more often detects slip and reduces engine power)

Wheelspin can sometimes be handy (especially in RWD), so having a low setting can help. Also, a higher TCS setting will slow your car down more when you run off the road, drive along a bumpy kerb, etc.

Yea, like i said before, i have used TCS before in GT3...either to simulate a brand-new car when stock, or if i've found myself in a desperate situation. In gT4, i almost never use TCS.

Cool what a long post. I did finally get some work in (1990 Pontiac Grand Am needs 3 drive belts changed) so hurra!

 

[nomis3613]

Thanks Parnelli for your thoughts, and equally long post!!

If I may quote you...

Hmm, i've always lowered the front to reduce understeer (in the case of a front-engine car, weight is now more solidly planted over the front tires, which sometimes means increased front-end grip. And lowered the rear if the car has a habit of getting too "squirrely" with oversteer. Whatever, tho...carry on!

I also noticed that the car also felt more squirrely when the weight was moved rearwards (just ask any 1970s 911 owner!). So, you've found the opposite works?! I was testing in an MR car, I'll check it out in FR. Can you suggest any cars to try this in?

Bound=resistance

Rebound=extension

In other words, if you have a high bound setting, the car will resist pitching to and fro and side to side as weight is being applied. If you have a low bound setting, the car now allows for lots of movement as you brake, corner, and accelerate.

With rebound, a higher number willl "throw" the car in whatever direction. A lower number means the rebound damper is now wimpyer, and doesn't throw as forcefully.

So if you've got a car with high front bound and a low rear rebound, when you brake, that high front bound will put up lots of resistance, and weight is transferred slowly towards the front of the car. The low rear rebound isn't throwing weight forward much either, as fluid in the damper is exiting its chamber slowly. I would use such settings if i had a car that has a habit of lifting its rear under braking too much, for instance. Such a car would be prone to spins under hard braking.

Now if i had a car with a low front bound, and high rear rebound, what happens now (in theory) is there is lots of weight being thrown forward more quickly, increasing front-end traction under braking. I would use such settings if i had a car prone to lots of entry-understeer, as i'm now making an effort to get such a car to "trail-brake" and turn into the corner (rather than plow into it).

Interesting! My understanding of dampers in general was that Damping Force = damping co-efficient x damper velocity), which I think is the opposite of what you've said for rebound. I'll reread your post to make sure I understand it, look to the scrolling text for clues, then do some more testing and get back to you...

Agreed on all except one point: a car with zero camber (all 4 tires sitting at a perfect angle on the ground, basically) will get better traction during a straight-line acceleration run than one with camber added. It takes some angling before you'll notice any difference, however (perhaps, over 2 degrees for most cars ive tested).

That's what I would assume too! But doing acceleration testing starting at 0 degrees, the times improved up until 1 degree then stayed constant. Maybe other cars behave differently. Any specific cars you should suggest I should test the 0 camber = more powerdown theory (more like real life...) on?

High rear camber does increase snap oversteer in some cases, but such settings won't be used in most cases, of course. I have used tons of rear camber on occasion, tho. I had a Datsun 240Z in GT2, for instance, that i was trying to rally...The ultimate solution (after much tuning) happened to be ALOT of rear camber...like 5 or 6 degrees of it! Now the 240Z finally would slide its rear and get better angles in the dirt!

Wow, that's not high rear camber, that's very high rear camber!! Any similar experiences in GT3? I should also make a disclaimer that I haven't been offroad for a while in GT3 so my guide is actually only for track work...

I need to seriously study how limited-slips work, tho, to draw my own conclusion here. To this day, i haven't really sat down and done this.

I believe that "initial" is actually preload in diff-speak, and my testing seemed to confirm this (ie changing initial while leaving accel constant did make the diff tighter when accelerating)

Yea, like i said before, i have used TCS before in GT3...either to simulate a brand-new car when stock, or if i've found myself in a desperate situation. In gT4, i almost never use TCS.

Who needs TCS when you use the analogue stick for acceleration + braking!!

Have fun with the Grand Am. Maybe it'll need an LSD soon, so you can pull one apart and have a play!!!

 

[Parnelli Bone]

Thanks Parnelli for your thoughts, and equally long post!!

If I may quote you...


I also noticed that the car also felt more squirrely when the weight was moved rearwards (just ask any 1970s 911 owner!). So, you've found the opposite works?! I was testing in an MR car, I'll check it out in FR. Can you suggest any cars to try this in?

Well, the squirrelyness a 911 owner feels is of a different quality from that of a car which has a light rear end, like a Trueno or certain muscle cars. And this is different from the squirrelyness a mid-engine Elise was exhibit.

But up above, I was specifically talking about what happens sometimes when you lower a car's front too much, leaving the rear high (like a funny car). The trunk area now starts dancing under brakes (like a squirrel running from a cat, its tail goes haywire), and to tame this, you'll sometimes need to lower the rear, to keep it planted down during braking.

Interesting! My understanding of dampers in general was that Damping Force = damping co-efficient x damper velocity), which I think is the opposite of what you've said for rebound. I'll reread your post to make sure I understand it, look to the scrolling text for clues, then do some more testing and get back to you...


That's what I would assume too! But doing acceleration testing starting at 0 degrees, the times improved up until 1 degree then stayed constant. Maybe other cars behave differently. Any specific cars you should suggest I should test the 0 camber = more powerdown theory (more like real life...) on?

Huh. Interesting. This is exactly the kind of stuff Sucahyo would do a cuople years ago...he'd do like 10 acceleration runs..each one with an added degree of camber. Or toe. Or whatever. He was the testing god.

I'm not sure at the moment of any specific cars you should test..i'll have to think about it.

Wow, that's not high rear camber, that's very high rear camber!! Any similar experiences in GT3? I should also make a disclaimer that I haven't been offroad for a while in GT3 so my guide is actually only for track work...

Well that Datsun was the only extreme case i can think of. I normally never put more than 3.5 degrees of rear camber on an all-wheel drive, or 2 (if that) on a rear-drive car. The Datsun stands out in my mind cuz the solution to the prob was so unusual.

In my gT1 days, i regularly put like 6 or 7 degrees of front camber on my Viper. But this worked in gT1. It doesn't work in later games...anything more than 5 degrees, and the front-end starts getting too inaccurate.

I believe that "initial" is actually preload in diff-speak, and my testing seemed to confirm this (ie changing initial while leaving accel constant did make the diff tighter when accelerating)

yea like i said, i need to sit down and study how a limited slip works, and then apply what i've learned towards the game. Funny thing is: i've known how open diffs work since i was 13. Being a mechanic, you relly do learn something new everyday. lol

Who needs TCS when you use the analogue stick for acceleration + braking!!

Have fun with the Grand Am. Maybe it'll need an LSD soon, so you can pull one apart and have a play!!!

Yup. Taht Grand Am was a challenge. But i got a couple hours for it, and got it done. The litlte old lady who drove it has had it since 1990, and has only put 22,000 miles on it! CAn you imagine? So its drive belts were all cracked up, and i was like YES I GOT WORK TODAY!

 

[Parnelli Bone]

Sorry for the double post, i need to amend something.

I meant to say dampers affect the speed of a car's weight transfer, not weight transfer altogether.

So if you have a car with all high bound dampers, the speed with which weight gets resisted to and fro and from side to side is slower becuase high bound dampers put up more resistance in their compression chambers. 💡

If you have a car with low bound dampers, these shocks now offer less resistance during compression, allowing for a faster transfer of speed to and fro and side to side.

REbounds, on the other hand, affect a shock's speed during extension, rather than compression / resistance. So if you have a car with high rebounds, the deal is it'll "throw" weight to and fro and side to side faster than if the rebounds are set lowish.

Springs & stabilizers, of course, limit the overall suspension travel a car exhibits, while dampers affect the speed of that travel.

...there, that's better.

 

[nomis3613]

Hmm, i've always lowered the front to reduce understeer (in the case of a front-engine car, weight is now more solidly planted over the front tires, which sometimes means increased front-end grip. And lowered the rear if the car has a habit of getting too "squirrely" with oversteer. Whatever, tho...carry on!

I went back and checked this in a turbo Miata at the Super Speedway (Miata because I wanted a "slow" FR so that aero effects would be minimised, turboed because I found stock I was able to drive the lap full throttle so lap times wouldn't vary enough with tuning changes). Still found that steady-state grip was increased at the lower end. But then I went to Apricot Hill to test on a range of corners for subjective testing. I think the effect you're describing is the initial weight transfer on braking. If the rear is higher, the car will dive more in the transition from full throttle to full braking, making it initially feel more "nervous". But once this weight transfer is done, the actual grips level is more understeery. Thanks for making me test this!

Although I'm trying to view GT3 tuning in a bubble and not make assumptions based on what happens in real life, here is one possible explanation: basically you use ride height to push weight balance closer to neutral (ie like an MR car). Due to weight transfer, the front tyres get "overloaded" in braking (ditto the rears in acceleration). Moving the static weight rearwards reduces the amount that the fronts become overloaded. Also, a car with neutral static weight balance will have balanced grip (ie no understeer or oversteer) in steady-state cornering.

All this means that by moving the weight distribution rearwards (eg lower rear ride height), you're decreasing oversteer during weight transfer but actually increasing steady-state oversteer. What a conundrum!! I'd say just experiment till you're happy with the compromise. But moving weight forwards in an FR car seems a bit silly (the fronts are already overloaded, this will just make it worse!), probably best to fix the nervousness in this case with diff/brakes/camber or even lower ride height overall and it might made you less scared when you slam on the brakes!

Have you noticed that the spring rates (kg/m) are not always the same at the middle position? I think this is an indication of the weight distribution in GT3.

Yeah, dampers have several functions, and not everyone agrees with just what they're supposed to be. I tend to tune them specifically to affect weight transfer for braking & accelerating. They also come into play over bumps and such, but i specifically use them to affect transfer first, and then i may compensate for how bumpy a track is, and bring that into play as well.

I totally agree now! Before you showed me the light, I thought it was just for bumps in GT3, but now I've seen how they affect weight transfer. Seems the scrolling text isn't gospel in this case. Read on...

Bound=resistance

or "compression"

Rebound=extension

In other words, if you have a high bound setting, the car will resist pitching to and fro and side to side as weight is being applied. If you have a low bound setting, the car now allows for lots of movement as you brake, corner, and accelerate.

With rebound, a higher number willl "throw" the car in whatever direction. A lower number means the rebound damper is now wimpyer, and doesn't throw as forcefully.

So if you've got a car with high front bound and a low rear rebound, when you brake, that high front bound will put up lots of resistance, and weight is transferred slowly towards the front of the car. The low rear rebound isn't throwing weight forward much either, as fluid in the damper is exiting its chamber slowly. I would use such settings if i had a car that has a habit of lifting its rear under braking too much, for instance. Such a car would be prone to spins under hard braking.

After some testing at Apricot Hill in the Miata, I totally agree with you. Except I believe rebound is the other way around: lower rear rebound means the stroke can extend faster so the weight is transferred to the front quicker during braking (=less understeer, same effect as decreasing front bound).
Here's some better explanations than I could come up with:
http://www.saabnet.com/tsn/bb/performance/index.html?bID=121502
http://www.ozebiz.com.au/racetech/theory/shocktune1.html
http://www.ozebiz.com.au/racetech/theory/shocktune.html (a good summary table down the bottom)
Sorry, I couldn't find any diagrams. Yes, it is possible the Polyphone got rebound the wrong way around.

But I did find that reducing rear rebound decreased understeer under braking. And softer front rebound reduced power oversteer. So now my strategy is to adjust the dampers for corner entry and exit. Then tweak the level overall to get it to feel nice over bumps and kerbs.

It should also be remembered that shocks also effect the car in roll. The inside dampers are extending as the car rolls, so softer front rebound will increase oversteer in theory. Similarly, stiffer rear bound will increase oversteer. Whether this has a noticeable effect in GT3 hasn't been specifically tested, though. If it does upset the balance, what I'd do is tweak the stabilisers to cancel this out.

Thanks for reading. Dissent is encouraged, try to prove me wrong please!!

 

[Parnelli Bone]

I went back and checked this in a turbo Miata at the Super Speedway (Miata because I wanted a "slow" FR so that aero effects would be minimised, turboed because I found stock I was able to drive the lap full throttle so lap times wouldn't vary enough with tuning changes). Still found that steady-state grip was increased at the lower end. But then I went to Apricot Hill to test on a range of corners for subjective testing. I think the effect you're describing is the initial weight transfer on braking. If the rear is higher, the car will dive more in the transition from full throttle to full braking, making it initially feel more "nervous". But once this weight transfer is done, the actual grips level is more understeery. Thanks for making me test this!

well there are certainly different degrees of understeer and oversteer taht show up at different points of any corner...hence the terms "entry-corner understeer" or "mid-ccorner sliding" or "exit/oversteer" or whatever.

So yeah, i lower the front of a car, keeping its rear higher, when i want weight to be over its front tires more consistently. In theory, this means there is greater traction up front overall, but in practice, our results certainly do vary

Although I'm trying to view GT3 tuning in a bubble and not make assumptions based on what happens in real life, here is one possible explanation: basically you use ride height to push weight balance closer to neutral (ie like an MR car). Due to weight transfer, the front tyres get "overloaded" in braking (ditto the rears in acceleration). Moving the static weight rearwards reduces the amount that the fronts become overloaded. Also, a car with neutral static weight balance will have balanced grip (ie no understeer or oversteer) in steady-state cornering.

All this means that by moving the weight distribution rearwards (eg lower rear ride height), you're decreasing oversteer during weight transfer but actually increasing steady-state oversteer. What a conundrum!! I'd say just experiment till you're happy with the compromise. But moving weight forwards in an FR car seems a bit silly (the fronts are already overloaded, this will just make it worse!), probably best to fix the nervousness in this case with diff/brakes/camber or even lower ride height overall and it might made you less scared when you slam on the brakes!

You can look at it that way. The reality is, front-engine cars sometimes understeer no matter what you do....lowering the front helps sometimes. It's one of my solutions, and i find it useful. But certainly, overloaded tires will prohibit these actions, becoming the absolute limit.

Have you noticed that the spring rates (kg/m) are not always the same at the middle position? I think this is an indication of the weight distribution in GT3.

Spring rates vary between different makes & models. This much i know. I forget how GT3 structured racing suspensions, tho...if they're generic or based on the car's stats.

I totally agree now! Before you showed me the light, I thought it was just for bumps in GT3, but now I've seen how they affect weight transfer. Seems the scrolling text isn't gospel in this case. Read on...

I only learned about shocks & weight transfer in the game from all the reading i've done at this (and other) GT sites. One thing you'll learn is there's always lots of stuff PD leaves out, gets wrong, etc. They're just a bunch of game programmers...i'm not convinced all of them are car-experts by any means.

or "compression"


After some testing at Apricot Hill in the Miata, I totally agree with you. Except I believe rebound is the other way around: lower rear rebound means the stroke can extend faster so the weight is transferred to the front quicker during braking (=less understeer, same effect as decreasing front bound).
Here's some better explanations than I could come up with:
http://www.saabnet.com/tsn/bb/performance/index.html?bID=121502
http://www.ozebiz.com.au/racetech/theory/shocktune1.html
http://www.ozebiz.com.au/racetech/theory/shocktune.html (a good summary table down the bottom)
Sorry, I couldn't find any diagrams. Yes, it is possible the Polyphone got rebound the wrong way around.

But I did find that reducing rear rebound decreased understeer under braking. And softer front rebound reduced power oversteer. So now my strategy is to adjust the dampers for corner entry and exit. Then tweak the level overall to get it to feel nice over bumps and kerbs.

Okay. Dang, there's a chance i got it wrong then. I'm talkin about rebounds. I gotta do some research.

PD definately did not get rebounds (or their description of them) wrong. If anything, i am at fault here. There have been some legendary arguments on this very subject in the past.

But it has been well-documented that they got toe backwards in GT2. Sucahyo did some tests long ago in which he boosted toe via an emulator far past the values PD offers us. Negative toe (which should point the front of a wheel inwards) instead pointed the front of tires outward.

It should also be remembered that shocks also effect the car in roll. The inside dampers are extending as the car rolls, so softer front rebound will increase oversteer in theory. Similarly, stiffer rear bound will increase oversteer. Whether this has a noticeable effect in GT3 hasn't been specifically tested, though. If it does upset the balance, what I'd do is tweak the stabilisers to cancel this out.

Yes. I implied that but didn't say...shocks afffect roll as well as diving and pitching. What i forgot to say (and added later in my previous post) is that dampers also affect the speed of these transistions, whereas springs & stabilizers affect the total amount of play in said transition.

This has all been tested here in the land of GT3...that's why i wish Scaff would spend more time here. All the pertinent threads are well-buried here, of course, since nobody discusses GT3 much anymore.

Thanks for reading. Dissent is encouraged, try to prove me wrong please!!

It's not really about proving you or anybody wrong, it's about seeking the truth.

 

[nomis3613]

You can look at it that way. The reality is, front-engine cars sometimes understeer no matter what you do....

👍 Although I was surprised at how taily the Miata was (admittedly, I was running a lot more power than stock). I had to run stupidly high front camber to "de-grip" the front end so I could test settings that would reduce understeer!!

But it has been well-documented that they got toe backwards in GT2. Sucahyo did some tests long ago in which he boosted toe via an emulator far past the values PD offers us. Negative toe (which should point the front of a wheel inwards) instead pointed the front of tires outward.

Wow! I also remember reading some debate about spring stiffness being backwards (so using softer front springs to reduce oversteer), maybe for GT4(?). Are there any mistakes like this in GT3 you can think of?

I'm think I'll be starting up on GT4 again soon. Will I see you in the forums over there, Parnelli?

It's not really about proving you or anybody wrong, it's about seeking the truth.

Amen, brother. We are all just seekers of the GT3 Truth here!!

 

[Parnelli Bone]

👍 Although I was surprised at how taily the Miata was (admittedly, I was running a lot more power than stock). I had to run stupidly high front camber to "de-grip" the front end so I could test settings that would reduce understeer!!

I've forgotten how Miatas tail-drift lightly in GT3. In GT4, they don't do this much but they ARE great with trail-braking and general cornering, still.

Wow! I also remember reading some debate about spring stiffness being backwards (so using softer front springs to reduce oversteer), maybe for GT4(?). Are there any mistakes like this in GT3 you can think of?

No no no no no. Do not pay attention to any of that nonsense.

Long ago, some people somehow got the notion that dampers in GT2 (not any other game) are given with backward specs. The debate was heavily..debated. My opinion is that everything is as it should be, EXCEPT toe in gT2, which Sucahyo conclusively proved is backwards in GT2 and only GT2. In all other games, it has yet to be proven anything else is amiss.

I'm think I'll be starting up on GT4 again soon. Will I see you in the forums over there, Parnelli?

Yes sir. I've been going thru GT4 very slowly over the past 2 years....driving and exploring as many different cars. I'm not even half done with the game yet! Just started the EXTREME races not long ago, matter of fact. so no doubt, i'lll be seeing you over there, which is good.

I'm hoping to be done with GT4 by the time GT5 finally comes out, so that i can finally catch up with the rest of the world.