Observations on suspension settings

[OwensRacing]

http://www.turnfast.com/tech_handling/handling_weightxfr


Good read. Notice more links at that top.

I applied some real world shock tech I had researched last night. Dropped a second and made my car sooooo much better. placebo? I dont think so, I was slipping off Suzuka every other lap. Changed the shocks relevant to springs and instantly driving like a Super GT in my RX7 TC. No offs or even close. Can't wait to race the car today.

Just gotta try things and what works stick with it.

 

[CSLACR]

CSLACR, do you come here looking for a fight? If didn't react so sensitively to others' posts, we'd be able to concentrate more on GT5 tuning, and without the venom, too.


What happened is you said "by raising the ride height to maximum". This is ambiguous, people assumed you meant both ends. It's not anyone's fault, can't you just accept there was a misunderstanding and move on please?


I wasn't trying to flame you, so why was this in your reply to me?

Chill, dude! If you think everyone is out to put you down (which isn't true), then it seems strange that you would want to keep coming back here...


Anyway...about actual tuning stuff:

(note: below is a calm statement of ideas, not an attempt to flame/belittle/anything else)
4 inch raise on a 106 inch chassis gives an angle of 2 degrees
2 degree angle means the CG moves forwards/backwards 0.07%, this is why I believe the effect is negligible.

Speak of the devil, it wasn't to you. 💡

Just because I quote you at the top doesn't mean the whole post is entirely about you. I'd thought it was obvious what it was about, to anyone that read the thread.

I guess I can't help but assume people will figure out more on their own than they will, I will certainly try to lay everything out more in the future though.

http://www.turnfast.com/tech_handling/handling_weightxfr


Good read. Notice more links at that top.

I applied some real world shock tech I had researched last night. Dropped a second and made my car sooooo much better. placebo? I dont think so, I was slipping off Suzuka every other lap. Changed the shocks relevant to springs and instantly driving like a Super GT in my RX7 TC. No offs or even close. Can't wait to race the car today.

Just gotta try things and what works stick with it.

I'll have to read that later, what shocks did you end up with?

 

[OwensRacing]

9/4 Front 8/4 Rear Shocks

10 Front. 5 Rear Ride

14.5 Front. 14.0 Rear Spring

 

[Scaff]

Anyway...about actual tuning stuff:

(note: below is a calm statement of ideas, not an attempt to flame/belittle/anything else)
4 inch raise on a 106 inch chassis gives an angle of 2 degrees
2 degree angle means the CG moves forwards/backwards 0.07%, this is why I believe the effect is negligible.

That would only be the case if the static weight distribution of the car was 50:50 and it also assumes that the cars weight exists only on a flat plane along that angle. The first is not always the case and the second is never going to be the case.

A four inch lift to the front of an Audi A4 would have a significant effect on the height of the COG (as an A4 is nose heavy) while it would have a minimal effect on the COG of a 911 (for the exact opposite reason).

The COG is also only one factor in how suspension will react to ride height changes, and Roll Centre's will most certainly change at a given end with a 4" lift, that's going to increase you Roll Centre (and potentially its location - add too much height and it could go outside the track width - which is very bad news) for just about any suspension type and its not going to make the suspensions job any easier. Particularly given the increase in camber changes its now going to go through for a number of suspension set-ups.

Little of the above is going to be modelled (or is modelled in a very basic form) in GT5, however please don't imply that real world ride height changes of 4" (either at a single end on overall) will have a minimal effect on a car, because that's simply not true.


Scaff

 

[nomis3613]

Here's the problem with that statement. It has nothing to do with GT5.

Totally agree. PD could have modelled the Corvette with a 10 inch wheelbase, for all we know! (But, in case they've done it correctly, I was just explaining why the angular effect on longitudinal CG location is negligable)

Speak of the devil, it wasn't to you. 💡

Just because I quote you at the top doesn't mean the whole post is entirely about you

Just a friendly tip: if a sentence is between 2 other sentences which are replies to a specific post, people will assume that the sentence in the middle is related.

That would only be the case if the static weight distribution of the car was 50:50 and it also assumes that the cars weight exists only on a flat plane along that angle.

Totally agree. And these mean that my calculation is actually over-predicting! (I based it on the CG being located at the other end of the chassis from the pivot point)

A four inch lift to the front of an Audi A4 would have a significant effect on the height of the COG...

Yes, but the discussion was about longitudinal CG location.

 

[CSLACR]

So we know raising the rear itself adds traction on RWD, and it shouldn't.
While debatable in how much, raising the whole car could potentially add some traction.

Does raising the whole car in GT5 add more traction than just raising the rear at all?
Seems like the question that should be asked atm.

 

[Rotary Junkie]

So we know raising the rear itself adds traction on RWD, and it shouldn't.
While debatable in how much, raising the whole car could potentially add some traction.

Does raising the whole car in GT5 add more traction than just raising the rear at all?
Seems like the question that should be asked atm.

Not really, no. Front ride height on a RWD car usually means fairly little, with higher settings usually being preferable due to gain in the top end.

It seems as though rear ride height is "god" where traction is concerned regardless of drive type, though FWD and AWD vehicles benefit from dropping the nose as low as it'll go as well.

Oh and FWDs also like the front springs as soft as possible for launch quality. Peak Gs will generally be the same, but it seems traction is worse on initial launch with stiffer front springs (though this should be a damper correction).

---

But then, thinking of this...

If traction = grip, why aren't all cars running min/max ride height instead of max/min? min/max provides as much traction as possible at both ends of the car while max/min provides the least, for all drive types.

 

[CSLACR]

Not really, no. Front ride height on a RWD car usually means fairly little, with higher settings usually being preferable due to gain in the top end.

It seems as though rear ride height is "god" where traction is concerned regardless of drive type, though FWD and AWD vehicles benefit from dropping the nose as low as it'll go as well.

Oh and FWDs also like the front springs as soft as possible for launch quality. Peak Gs will generally be the same, but it seems traction is worse on initial launch with stiffer front springs (though this should be a damper correction).

---

But then, thinking of this...

If traction = grip, why aren't all cars running min/max ride height instead of max/min? min/max provides as much traction as possible at both ends of the car while max/min provides the least, for all drive types.

Because you get better cornering traction from a high front end. You also get better cornering traction from a high rear end.
It's quite simple, raise the front, and the front turns easier, raise the rear, the rear slides less.
Max/min works so commonly in offline mode because many cars have massive amounts of under steer at normal settings. If you take notice, on cars that over steer people don't run max/min setups.
Now if it were just extra speed that made these setups work, and they don't make the car rotate more, wouldn't we run that setup on every single car in the game? Including online?

Those couple of tenths here and there gained from extra speed due to max/min setups mean virtually nothing on the race circuit. If it were all from speed gains, and didn't actually increase over steer, there wouldn't be a limit to how much you can use before the rear spins out in every corner.

 

[Will27]

I have been finding that the high ride height increases early corner grip and responsiveness but lower height increases grip later in the corner.

Some cars seem to benefit from the entry corner grip so much that it’s not worth running any other setting. It varies massively depending on the car.

I would like to be able to adjust roll center independently because I think this would give a much clearer picture of what is going on.

 

[Rotary Junkie]

Because you get better cornering traction from a high front end. You also get better cornering traction from a high rear end.
It's quite simple, raise the front, and the front turns easier, raise the rear, the rear slides less.

Cornering traction? What is this, I don't even.

I use "traction" to refer to, well, longitudinal loads, and "grip" to refer to lateral loads.

Max/min works so commonly in offline mode because many cars have massive amounts of under steer at normal settings. If you take notice, on cars that over steer people don't run max/min setups.

Okay.

Now if it were just extra speed that made these setups work, and they don't make the car rotate more, wouldn't we run that setup on every single car in the game? Including online?

Maybe.

I read at one point that if a car works better when you set the nose higher (and suspension travel/ground clearance isn't an issue in the first place), it's not stiff enough, and the same to a lesser extent for the rear. This was in reference to real-world tuning, and much of it actually seemed to check out in GT5 as well. That'd actually be my "gauge" of sorts. The only setup I've ever gone nose-high with was my Atenza for the FF shootout, and it wasn't by much. Then again, it was impossible to go as stiff as would've potentially been needed/wanted by that car in the front.

Oh, well, that and my tunnel drag tune for my Z06 because rocking whoolies was epic in the tunnel... Until it went uphill and the car quit accelerating.

Those couple of tenths here and there gained from extra speed due to max/min setups mean virtually nothing on the race circuit. If it were all from speed gains, and didn't actually increase over steer, there wouldn't be a limit to how much you can use before the rear spins out in every corner.

A couple of tenths mean nothing?

What in the world are you talking about?

 

[Sail IC]

Interesting thread. But I think its difficult to move forward and understand what is happening in this simulation if discussing details before coming to a common understanding of the basics.

Does overall ridehight has an impact of a cars handling?

Take a car that has a balanced handling using a level ridehight, ie same front/rear ridehight. If now running it with the ridehight front/rear:
- Max-low
- In the middle
- Max-high.
When I do this, I get the same lap times, the car feels the same, ie no difference.

If you agree with this, then the ridehight cannot impact the springs, dampers or any of the other suspension settings. Also it cannot impact the overall CG placement above the road surface.

 

[Scaff]

Totally agree. And these mean that my calculation is actually over-predicting! (I based it on the CG being located at the other end of the chassis from the pivot point)


Yes, but the discussion was about longitudinal CG location.

Strange because I don't see the thread topic asking for it to just be just the effect longitudinal CG location has on load transfer?

As far as I'm aware its a discussion on how changes to ride height (and other suspension settings) will affect a cars balance via the distribution of load to each contact patch. If you wish to throw real world observations in then sticking to just the longitudinal CG location and dismissing CoG height and Roll Centres is quite strange, and also will result in some rather inaccurate observations.


Scaff

 

[Blood*Specter]

FORGIVE THE LENGTH OF THIS POST

My question to all. Are any suspension settings in GT5 simply window dressing? Which suspension settings actually work and have positive/negative affect on car performance?

Perhaps understanding those settings that "make no difference" (If there is any such thing) will help simplify setup and interpreting what is felt when driving a car. Or what I witness when looking at replay of my car.

Use "KIS" method; Take a premium Honda S2000 from the New Car Dealership in GT5.
These cars have 50/50 front to back balance. Even the standard models share that trait.

Run the S2000 all stock except for FC suspension. Then apply what you would consider correct “Real World” settings to the suspension package. Take a “Photo Mode” shot of your cars profile with your “Real World” suspension settings.

Now, test the car at "MONZA" (off-line and on-line) and record (but do not make public) your best lap for each (off-line/on-line) environment.


Next, put the car in the hands of an agreed upon test driver who can not be either person who tuned the suspension. Have driver test the car at "MONZA" (off-line and on-line) and post his/her best on-line/off-line lap time results.


Then the suspension tuners will apply settings known to work within GT5 according to the “games” physics. Tune the cars suspension with goal of achieving the best lap time. When you feel the car is ready, take another “Photo Mode” shot of your cars profile with your “Real World” suspension settings. Then call upon the same test driver to test each car.


Finally, post or otherwise share the times, setups and photos. This could be very interesting outcome to this test. Not so much speed/times as much as handling/feel and physical appearances of the cars.

 

[OwensRacing]

FORGIVE THE LENGTH OF THIS POST.

Many have been testing and tuning daily for almost a year. CSL has shared his findings with lower lap times being the common result.

He has plenty of proof for himself with seasoned racers going faster with his tips/tunes.

I use CSL as an example cause I race with him and seen it first hand.

Personally. I use what works.

 

[CSLACR]

Cornering traction? What is this, I don't even.

You must be kidding now, saying you don't know what cornering traction is.

I use "traction" to refer to, well, longitudinal loads, and "grip" to refer to lateral loads.

That's fine.

Maybe.

I read at one point that if a car works better when you set the nose higher (and suspension travel/ground clearance isn't an issue in the first place), it's not stiff enough, and the same to a lesser extent for the rear. This was in reference to real-world tuning, and much of it actually seemed to check out in GT5 as well. That'd actually be my "gauge" of sorts. The only setup I've ever gone nose-high with was my Atenza for the FF shootout, and it wasn't by much. Then again, it was impossible to go as stiff as would've potentially been needed/wanted by that car in the front.

Oh, well, that and my tunnel drag tune for my Z06 because rocking whoolies was epic in the tunnel... Until it went uphill and the car quit accelerating.

Why just maybe?
If it doesn't make the car rotate more, and people use it for TT's because it makes every car faster in a straight line, common sense says people would use it on every TT they ever run.

A couple of tenths mean nothing?

What in the world are you talking about?

The hair length difference between +40/-20 and +30/-20 is not what makes me decide between the 2 ride heights, or anything else. The handling balance of the car is.
You're looking at the straight-line time difference between +40/-20 vs 0/0, or something much more extreme. That will give you false results, because the options for a good TT setup aren't 0/0 or max/min, because if you can drive max/min, 0/0 will get destroyed in the corners.

I have tried making setups with max/min, or as much reverse ride height as possible, intentionally using camber, toe and everything else possible to keep the speed gain from max/min setups, but without the car being an uncontrollable over steer monster, and it was slower than using less reverse ride height, with a more normal camber/toe setup.
Max/min is only the fastest setup when you need the extra rotation it brings.

 

[Blood*Specter]

Many have been testing and tuning daily for almost a year. CSL has shared his findings with lower lap times being the common result.

He has plenty of proof for himself with seasoned racers going faster with his tips/tunes.

I use CSL as an example cause I race with him and seen it first hand.

Personally. I use what works.

Understood

CSL has tuned a car for me, and I read his input, because I generally understand the way he relates things. However, sometimes I think you will agree people want something concrete. I will most likely not race with CSL or you because I am not really fast.

The same can be said for other tuners and superior drivers on GTP. They would not consider the rooms I play in and I would most likely be kicked from room they frequent because I would be in the way. No problem with that, life goes on.

So my question/suggesting was not to call into question CSL or anyone else’s knowledge of the game or real automotive fact.

I just wanted to see these dynamics captured by folks who understand what does and does not happen within the game.

 

[MrGrado]

The amount of travel in a suspension DOES matter if you're not bottoming out. The lower car with the same springs has more compression at neutral and therefore tighter springing since springs are non-linear. (If I remember my Hooke's law and elasticity mechanics correctly)

In short, when you lower the ride height and reduce travel you're increasing the effective spring rate. Whether it bottoms out or not, lowering the car without changing the springs will increase the force required to compress the springs farther, thus, effectively stiffer springs.

But you get a lower ride height only by changing springs or cutting your springs shorter.

(or I guess you could change the structure of the car where you mount your springs to your car: make that part of your car higher off the ground, then when you re-attach your springs, your car will sit lower to the ground. Your springs will still compress the same amount with the car at rest because the car is still the same weight.)

 

[OwensRacing]

But you get a lower ride height only by changing springs or cutting your springs shorter.

(or I guess you could change the structure of the car where you mount your springs to your car: make that part of your car higher off the ground, then when you re-attach your springs, your car will sit lower to the ground. Your springs will still compress the same amount with the car at rest because the car is still the same weight.)

Adjustable Coilovers?



http://www.youtube.com/watch?v=tPAJ7egwweM&feature=youtube_gdata_player

 

[Motor City Hami]

Adjustable Coilovers?



http://www.youtube.com/watch?v=tPAJ7egwweM&feature=youtube_gdata_player

That's a really dumb way to go about adjusting the coil overs. No need to take the wheel off. Jack one side up, use two jackstands along the body pinch weld, crawl under and adjust. Don't be affraid to get a little dirty.

Or you can go MrGrado's getto way of cutting the springs short.

 

[MrGrado]

Anyone notice that the top car in round 1 of 400PP shootout is nose down, higher rear spring rate and higher rear anti roll bars?

 

[praiano63]

Anyone notice that the top car in round 1 of 400PP shootout is nose down, higher rear spring rate and higher rear anti roll bars?

Yes anyone can explain??

><(((((ô>°°°°°°°

 

[Nicktune]

Lower front end to knock the oversteer/Higher spring rate to support the higher amount of weight at the back ( 43/57).

 

[praiano63]

Lower front end to knock the oversteer/Higher spring rate to support the higher amount of weight at the back ( 43/57).

Right in the middle my friend... , this was the idea and apparently it work, for the low grip tires and this kind of weight repartition.👍

><(((((°>°°°°°°°°°°°°°//

 

[CSLACR]

What needs explaining?

Cure over-steer, drop front or raise rear.
Cure under steer, drop rear or raise front.

The top 3 cars in the shootout display this perfectly, I think.

Anyone notice that the top car in round 1 of 400PP shootout is nose down, higher rear spring rate and higher rear anti roll bars?

Say what now?

 

[MrGrado]

but high rear and/or low front = more oversteer.

 

[CSLACR]

but high rear and/or low front = more oversteer.

So the MR2 was tuned for more over steer, and the FF was tuned for more under steer?
I think that would make my Teggy might impressive if that were true, don't you?

I'd also have to ask how in the world testers could not complain of horrid under steer on mine, yet also not complain of horrid over steer on the MR2?

 

[MrGrado]

You got toe out on the front and rear wheels. That will help it not understeer. But I haven't driven your Integra. All I drove was the 2000GT and the MR2. The 2000GT does understeer horribly because it's set up to understeer with front spring rate at max. The MR2 drives nice because it has sharp steering with high rear spring rate and low front ride height.

 

[Nicktune]

but high rear and/or low front = more oversteer.

Not in this game.

 

[CSLACR]

You got toe out on the front and rear wheels. That will help it not understeer. But I haven't driven your Integra. All I drove was the 2000GT and the MR2. The 2000GT does understeer horribly because it's set up to understeer with front spring rate at max. The MR2 drives nice because it has sharp steering with high rear spring rate and low front ride height.

So that small amount of toe I used counteracted the entire suspension balance of the car huh?

 

[MrGrado]

Not in this game.

All the tests I run say different.

So that small amount of toe I used counteracted the entire suspension balance of the car huh?

Yes. No matter how wrong you get ride height and spring rate, you can mask it all with toe settings.