FF tunes don't make any sense

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Greyout

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I see all these tunes posted with spring rates way stiffer in the front then the rear.

Will someone please explain to me why this is. I am tired of, after 5 versions of the game, PD refuses tacid corporate basic tuning principles, and insists on going against the laws of physics.

You can set up a FF car with maxed out rear springs and dampers, a soft front, and you still get grinding, miserable understeer.

Gran truismo tuning physics are, still, crap.
 
Ok, I'm no physics expert nor tuning god, so bear with me. I think it's to do with weight transfer, the stiff front will stop the weight from pushing the car into any further understeer, while the softer rear will let the back follow the front and help it rotate a bit more. Bear in mind that this will only work with a very low front anti roll bar setting with a high anti roll bar setting.

That's my take of it, anyway. Though I did get all this from Rotary Junkie, who did teach me this indirectly, so he would probably explain it clearer. I just try to put it into practice.
 
That is incorrect.

A stiff rear reduces weight transfer in the front and increases weight transfer in the rear.

That is why real FF and AWD race cars frequently lift the inside rear tire off the ground.

Real front wheel drive race cars run rear springs over 1,000lbs/inch, which the GT5 spring rate slider doesn't even approach (15kg/mm is only about 800)

Even the in-game description says a stiff rear should increase oversteer, but no matter how Agressive you tune a FF car (full soft front, full stiff rear, soft front bar, max rear bar) you can't get a FF's rear to break loose.
 
Greyout
I see all these tunes posted with spring rates way stiffer in the front then the rear.

Will someone please explain to me why this is. I am tired of, after 5 versions of the game, PD refuses tacid corporate basic tuning principles, and insists on going against the laws of physics.

You can set up a FF car with maxed out rear springs and dampers, a soft front, and you still get grinding, miserable understeer.

Gran truismo tuning physics are, still, crap.
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It doesnt make any sence but thats just how it is in this game. There is definately something wrong with the tuning physics in game, maybe an error or something they didnt see before release but now dont want to admit it because they feel embarressed and may lose customers & fans for the next series.

Setting a stiff front and very soft rear on fwd cars makes them oversteer in this game and can be a problem when you spin out on nearly every corner, (Happened to me online in an FTO with 14kg up front and 3kg at rear). Now its impossible to explain how that would happen without making up you own laws of physics.
 
ANY FF car with toe out in the rear and front, springs 3x stiffer in the rear then front, 100lbs of ballast in the rear, stiff rear sway bar, and proper camber should oversteer ass-first off the track in the first corner, even when on the throttle. Off the throttle, it should be even worse.

No.... In GT we always get FF cars that do not respond to correct tuning

Jackthalad
It doesnt make any sence but thats just how it is in this game. There is definately something wrong with the tuning physics in game, maybe an error or something they didnt see before release but now dont want to admit it because they feel embarressed and may lose customers & fans for the next series.

Setting a stiff front and very soft rear on fwd cars makes them oversteer in this game and can be a problem when you spin out on nearly every corner, (Happened to me online in an FTO with 14kg up front and 3kg at rear). Now its impossible to explain how that would happen without making up you own laws of physics.
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That's fine if they want to program the game that way, but if you read the suspension hints in game, it SAYS they designed it correctly - stiff rear for oversteer
 
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Greyout
ANY FF car with toe out in the rear and front, springs 3x stiffer in the rear then front, 100lbs of ballast in the rear, stiff rear sway bar, and proper camber should oversteer ass-first off the track in the first corner, even when on the throttle. Off the throttle, it should be even worse.

No.... In GT we always get FF cars that do not respond to correct tuning
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It should but it doesnt what can we do about it?

Nothing.

Greyout
That's fine if they want to program the game that way, but if you read the suspension hints in game, it SAYS they designed it correctly - stiff rear for oversteer
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I know yeah, I have an additional guide for gran turismo and it says the same just in more depth. Stiffer springs in rear etc. increases grip at front, reduces oversteer. It explains how and why everything happens, everything about weight transfer and how to control it and change it, but when you do it in game it doesnt do as what they tell you it should.

Thats why I think they made a mistake somewhere, maybe they cant fix it, and just dont want to but their hands up and admit to it.

Its a shame but thats just the way it is, you can still tune the cars just have to do it 'backwards' as they say.
 
Greyout
Even the in-game description says a stiff rear should increase oversteer, but no matter how Agressive you tune a FF car (full soft front, full stiff rear, soft front bar, max rear bar) you can't get a FF's rear to break loose.
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So…I take it that this, done with no handbrake, no ballast adjustments, isn't 'breaking loose'?



It is possible to get it a FF to break loose, just set the diff at something stupid like 5/60/5 and you're nearly there.

And why do we do it? Because it works in the game. It's GT5, not real life. What might work for real life won't translate as expected into GT5, GT5 has its own physics, its own rule book. Regardless what's wrong with it, if it gets the desired effect, we'd use it. We play by GT5's rules.
 
Let me guess, that integra has a super-stiff front?

Onboy123
So…I take it that this, done with no handbrake, no ballast adjustments, isn't 'breaking loose'?



It is possible to get it a FF to break loose, just set the diff at something stupid like 5/60/5 and you're nearly there.

And why do we do it? Because it works in the game. It's GT5, not real life. What might work for real life won't translate as expected into GT5, GT5 has its own physics, its own rule book. Regardless what's wrong with it, if it gets the desired effect, we'd use it. We play by GT5's rules.
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Ok so does that mean FF cara play by a different physics rule book in GT5 then FR? Or has the greatest driving simulator in the known universe blah blah blah screwed up the most basic concepts of suspension tuning?
 
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Onboy123
So…I take it that this, done with no handbrake, no ballast adjustments, isn't 'breaking loose'?

And why do we do it? Because it works in the game. It's GT5, not real life. What might work for real life won't translate as expected into GT5, GT5 has its own physics, its own rule book. Regardless what's wrong with it, if it gets the desired effect, we'd use it. We play by GT5's rules.
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No offence onboy but that doesnt really answer the question. We know its a game but it still dont make sence, you can try to explain why a stiff front and soft rear causes oversteer but really there is no explanation.
 
A good way to make an ff oversteer is whatever tyres you have on the front EG. Sports Softs, you put Sports hards on the rear, set Braking Sensitivity to 5. That will guaratee you drift round every corner.

Explain how 11.0 up front and 3.5 at rear causes oversteer, its impossible, not even Einstein could do it. :lol:
 
Jackthalad
A good way to make an ff oversteer is whatever tyres you have on the front EG. Sports Softs, you put Sports hards on the rear, set Braking Sensitivity to 5. That will guaratee you drift round every corner.
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Yes, but for the record, that was done with Sport Hard tyres front and rear.
 
Onboy123
Yes, but for the record, that was done with Sport Hard tyres front and rear.
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Im just saying how i get my FF's to oversteer, wasnt saying that is how you done it in the pic. :)

Onboy my friend, there is no explantion in how spring rates of 11kg up front and 3.5kg at rear causes oversteer. The front tyres would have no grip because the weight of the vehicle would fall onto the soft rear springs to easily.
 
There are definitely some things messed up with the tuning physics on the game. Most theories are that they just got the front and rear mixed up, but I'm not convinced it's that simple.

For offline (practice mode) physics, Everything in the front at Max (Including ride height) and everything in the rear at Min is the way to go for most FF cars. That will maximize performance of the car. That's not to say it makes sense in the real world, but it's what works.

The tuning issues are not just limited to FF cars. The ride height settings are completely backwards from what really works, higher front and lower rear is the most effective tuning method for all drive trains.

Then there's the issue of offline vs. online. If you try taking that extreme offline setup online, chances are you won't be able to get past the first corner. But that's not to say the tuning methods for online are correct, according to real life. Instead, they are just less extreme than those used offline.
 
Greyout
Those diff settings would not promote oversteer in anything, FWD or RWD
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Actually, they would in both cases, even in the real-world. It would delay wheelspin in the case of RWD but it would also make wheelspin-induced oversteer much more pronounced when it does happen.

In FWD's case, well... Ever played around with the XF GTI in LFS? Ever put a spool in the front of it (100% locked at all times)? Massive understeer off throttle, oversteer on throttle. Same thing applies to a strong accel setting on a FWD car in GT5, though too strong will be a bad thing at certain points on track despite the benefits at others.

Now then, your chief complaint seems to be that oversteer can't happen with normal methods in a FWD vehicle...

Which is where you are quite wrong. Stiffer rear springs + stiff rear anti-roll does induce lift-off and braking oversteer in FWD cars, PROVIDED the front is not so soft as to cause understeer.

However, the soft rear spring + stiff rear anti-roll/stiff front spring + soft front anti-roll setup myself and others use doesn't cause off-throttle oversteer without forcibly provoking it... But it reduces on-throttle understeer by a large amount, and when coupled with the correct front differential setting in the right car, oversteer can be had on-throttle.

Edit: @Scaff: I started tuning FWDs the way I do in GT4 because of exactly this. It's nothing new. Ride height is very strange in GT5 where it wasn't in GT4, but the rest of tuning is pretty much exactly how it had been in GT4. Then again, nose-down always seemed to cause understeer on entry in GT4 as well, it just didn't benefit traction.

@EDK: I very strongly disagree with that. For one, "proper" oversteer inducing anti-roll bars work (1/7 is my go-to), dampers should be treated on their own, and the ride height thing doesn't hold much water either if the rest of the setup is properly done.

Drag racing has introduced me to how oddly ride height affects things now... It seems that rear ride height affects traction in all vehicles, where a lower number results in less forward bite, front ride height does the same to a lesser extent, and in reverse. On RWD cars with rear downforce, max front ride height makes no difference versus minimum, on those without it is a slight benefit but nowhere near as large as rear ride height. FWD? Minimum is winner. AWD? Minimum wins.

The effect of max/min ride height on top speed (and, indeed, acceleration above any speed that is not traction-limited) is still here in GT5, and that is the only real reason I can see to use it on a FWD (or indeed, any) vehicle. It massively reduces rear lateral grip, massively reduces traction, and is generally a bad thing anywhere the track is not straight.
 
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Jackthalad
Onboy my friend, there is no explantion in how spring rates of 11kg up front and 3.5kg at rear causes oversteer. The front tyres would have no grip because the weight of the vehicle would fall onto the soft rear springs to easily.
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In the real world spring rates don't change load transfer front to rear, they change how its distributed between the tyres at that end.

:)

Scaff
 
Scaff
= Oversteer in a FWD car!

And this is why I don't tune in GT5 any more.

Seriously the mess that GT5 tuning is has totally ruined the title for me, which given the hours I spent developing and writing the tuning guides for GT4 is frustrating beyond belief.


Scaff
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Shame its ruined it for you, thats why I believe PD knows about it just dont want to come out about it because then many more people would not play the game anymore, and may not but the next GT.

Scaff
In the real world spring rates don't change load transfer front to rear, they change how its distributed between the tyres at that end.

:)

Scaff
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Yeah thats what i meant haha.
 
Rotary Junkie
Actually, they would in both cases, even in the real-world. It would delay wheelspin in the case of RWD but it would also make wheelspin-induced oversteer much more pronounced when it does happen.

In FWD's case, well... Ever played around with the XF GTI in LFS? Ever put a spool in the front of it (100% locked at all times)? Massive understeer off throttle, oversteer on throttle. Same thing applies to a strong accel setting on a FWD car in GT5, though too strong will be a bad thing at certain points on track despite the benefits at others.

Now then, your chief complaint seems to be that oversteer can't happen with normal methods in a FWD vehicle...

Which is where you are quite wrong. Stiffer rear springs + stiff rear anti-roll does induce lift-off and braking oversteer in FWD cars, PROVIDED the front is not so soft as to cause understeer.

However, the soft rear spring + stiff rear anti-roll/stiff front spring + soft front anti-roll setup myself and others use doesn't cause off-throttle oversteer without forcibly provoking it... But it reduces on-throttle understeer by a large amount, and when coupled with the correct front differential setting in the right car, oversteer can be had on-throttle.
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Provided the front is not too soft to cause understeer? How is that a concern?

Jackthalad
Shame its ruined it for you, thats why I believe PD knows about it just dont want to come out about it because then many more people would not play the game anymore, and may not but the next GT.



Yeah thats what i meant haha.
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They could just fix it in an update, which would make it much more likely I would buy GT6
 
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Maybe they could but then again maybe they cant, like EDK said it might be something major rather than a quick simple fix.

Either way I will still be buying GT6 if it does ever come out, I hate the driving & graphics on Forza.
 
Rotary Junkie
@EDK: I very strongly disagree with that. For one, "proper" oversteer inducing anti-roll bars work (1/7 is my go-to), dampers should be treated on their own, and the ride height thing doesn't hold much water either if the rest of the setup is properly done.

Drag racing has introduced me to how oddly ride height affects things now... It seems that rear ride height affects traction in all vehicles, where a lower number results in less forward bite, front ride height does the same to a lesser extent, and in reverse. On RWD cars with rear downforce, max front ride height makes no difference versus minimum, on those without it is a slight benefit but nowhere near as large as rear ride height. FWD? Minimum is winner. AWD? Minimum wins.

The effect of max/min ride height on top speed (and, indeed, acceleration above any speed that is not traction-limited) is still here in GT5, and that is the only real reason I can see to use it on a FWD (or indeed, any) vehicle. It massively reduces rear lateral grip, massively reduces traction, and is generally a bad thing anywhere the track is not straight.
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I'm basing my comments off of everything we learn in tuning events in WRS.

We have some of the fastest GT drivers in the world, and we commonly share tunes during the weekly events. The tactics I describe most often result in the tunes that can achieve the fastest times.

Here's my setup for last week's race, in the Alfa TZ2.

https://www.gtplanet.net/forum/showthread.php?p=6510353#post6510353

And here's the race winner's setup -

https://www.gtplanet.net/forum/showthread.php?p=6543053#post6543053
 
Greyout
Provided the front is not too soft to cause understeer? How is that a concern?
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How is it not? If the front lets go before the rear does, you get understeer, regardless of how stiff the rear is.


As for the "there is no way those spring rates could cause oversteer".

You're right. Aside from shock loading the rear tires (ever seen those crazy Saudis taking Accords, Camrys, and the like sideways? Yeah that). Or running a rear anti-roll bar that's extremely stiff.

Which is exactly how I've built my FWDs in GT since, oh, 2008. Too soft at the rear can be bad (either excessive oversteer or understeer transitioning into oversteer), too stiff can be bad, same for the front.

Traditional FWD setup for me is relatively stiff (anywhere from 9-14kg/mm) front and relatively soft (anywhere from 2.5-8kg/mm) rear springs, coupled with (usually) equal front/rear damper settings and 1/7 anti-roll bars. Some cars (Scirocco, I'm looking at you) require you to go less extreme on the spring rates, but then those vehicles also have very good weight balance.

Or am I wrong in thinking that the more weight at a given end, the stiffer it needs to be? ;)

Edit: Again, @EDK: I see those and I wonder why they've gone that route instead of less front anti-roll, more front spring, less rear spring, more rear anti-roll, etc. I think I'll pick that car up and give it a go, I'm no alien but I reckon I can beat those tunes with enough work. Might still need to go slightly nose-high due to limits of our available spring rates but...
 
I don't see what the problem is. This is a computer game, not real life. If you want a FF car to play nicely, firm springs up front and soft rear, no or little front ARB, fat ARB in the rear, etc, etc. There's so much of this game that doesn't translate to the real world. You'll go crazy trying to make one fit the other, I did...

{Cy}
 
Rotary Junkie
How is it not? If the front lets go before the rear does, you get understeer, regardless of how stiff the rear is.


As for the "there is no way those spring rates could cause oversteer".

You're right. Aside from shock loading the rear tires (ever seen those crazy Saudis taking Accords, Camrys, and the like sideways? Yeah that). Or running a rear anti-roll bar that's extremely stiff.

Which is exactly how I've built my FWDs in GT since, oh, 2008. Too soft at the rear can be bad (either excessive oversteer or understeer transitioning into oversteer), too stiff can be bad, same for the front.

Traditional FWD setup for me is relatively stiff (anywhere from 9-14kg/mm) front and relatively soft (anywhere from 2.5-8kg/mm) rear springs, coupled with (usually) equal front/rear damper settings and 1/7 anti-roll bars. Some cars (Scirocco, I'm looking at you) require you to go less extreme on the spring rates, but then those vehicles also have very good weight balance.

Or am I wrong in thinking that the more weight at a given end, the stiffer it needs to be? ;)

Edit: Again, @EDK: I see those and I wonder why they've gone that route instead of less front anti-roll, more front spring, less rear spring, more rear anti-roll, etc. I think I'll pick that car up and give it a go, I'm no alien but I reckon I can beat those tunes with enough work. Might still need to go slightly nose-high due to limits of our available spring rates but...
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That ruins the game for me. There are plenty of other good racing games that get it right. I don't need the song and dance of the GT circus if there isn't an attempt and making The tuning close to accurate.
 

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