all 500pp MR cars ovetster or understeer?

[DolHaus]

@DolHaus sorry, don't have a link to a specific article. It's from notes I made when trying to get my head round tuning in GT5. I foolishly started out reading articles on real world tuning which ended up with me being totally befuddled when trying to apply the theory to the game.

Google Friction Circle, Slip Angle, Loose & Poosh and you'll find lots of reading.

I will have to give it a look, there's always something new to be learned.
I've started tracking down real world stuff about camber to try and figure out how its supposed to be working and I think its pointing me in some new directions so maybe the answer to how ride height affects things is out there somewhere as well.

 

[Ceolix]

You guys say low ride height on front will induce understeer
but when i watch WTCC, all their cars are low ride height and they
corner incredible good.
so i dont know whats happening here

 

[Ridox2JZGTE]

It's reversed in GT6. In real life, front lower, rear higher aid in giving better rotation on entry, not in GT6.

 

[DolHaus]

Its to do with roll angle and its quite complicated but accurate to some degree in terms of physics. It skips over a few influential factors but its a good enough model to work with if kept sensible, if taken to extremes it does have unrealistic outcomes though.
With the cars in GT the suspension geometry is identical at both ends, on a real life race car the ride height may look level but the springs/dampers stroke length may be longer or shorter which is what the ride height represents in game.

 

[Ridox2JZGTE]

There are some cars in GT6 that has different suspension ride height in order to make it level visually, and I found on at least 1 car that replicates real life ride height that has rake on stock ride height, but sadly the intended effect in real life is not to be found in GT6. The car is Ferrari F430 Scuderia, have a look at my latest replica, the high rake ( front lower by 22mm ) on stock ride height in real life is to give the car better turn in and rotation as Ferrari F430 ( even on Gen II ) runs pretty low spring rate even though it has low motion ratio - most F430 Scud when driven on track day will have high chance of hitting the bump stop at the front on stock suspension.
When real Ferrari F430 Scuderia owner tuned the suspension with stiffer springs ( higher front/rear spring ratio difference - almost compulsory when often do track driving ) and fitted sticky semi slick or slick, they often lower the rake to balance the car - easier to control snap oversteer and manage over rotation. Do that in GT6, the Ferrari will oversteer even more or easier to rotate ( the opposite ), so I if I ran original rake in GT6, the car will understeer even more - completely opposite.

 

[Ceolix]

But if you're saying lower front end gives better cornering
why won't would understeer?
lower front end, more pressure on wheels and springs and dampers
and it would understeer

 

[Ridox2JZGTE]

Lower ride height alone won't make it better, in real life, the rest of the suspension are optimized, stiffer spring, stiffer damper contributes to better balance. The Ferrari F430 Scuderia example I used has distinct motion ratio, with very close to 1 at the front strut and about 0.6 to 0.9 at the rear. Stock Ferrari ride height has 22mm higher at the rear, this gives the relatively soft stock springs ( even on Gen II Scud ) at the rear more travel as the actual wheel rate is lower than the spring rate due to the motion ratio. The rake gives better balance toward neutral on stock suspension. Lowering the rear ride height closer to equal will make the rear end slower to respond and lazy on mid corner to exit. This has been proven on the track by Ferrari owners Stock suspension on F430 Scud has also proven to be too soft for serious track driving, with many complained about the front hitting bump stop too often on hard braking/cornering even on stock ride height ( not lowered ). Serious track racer fitted stiffer springs with higher front to rear ratio, which gives more tendency to oversteer, to reduce this, they also lower the rake ( difference between rear and front ), most running with 8 to 12 mm higher at the rear, and large toe in to reduce snap oversteer ( F430 rear has suspension geometry that goes toe out when loaded, so toe in is necessary to compensate ). Those who run much stickier tires often run with close to level ride height ( 2-5mm rake ).

The rake also prominently used on Lancer Evos to help with rotation, due to similar situation, much lower rear motion ratio and relatively soft stock springs which leads to low wheel rate

 

[DolHaus]

Lower ride height alone won't make it better, in real life, the rest of the suspension are optimized, stiffer spring, stiffer damper contributes to better balance. The Ferrari F430 Scuderia example I used has distinct motion ratio, with very close to 1 at the front strut and about 0.6 to 0.9 at the rear. Stock Ferrari ride height has 22mm higher at the rear, this gives the relatively soft stock springs ( even on Gen II Scud ) at the rear more travel as the actual wheel rate is lower than the spring rate due to the motion ratio. The rake gives better balance toward neutral on stock suspension. Lowering the rear ride height closer to equal will make the rear end slower to respond and lazy on mid corner to exit. This has been proven on the track by Ferrari owners Stock suspension on F430 Scud has also proven to be too soft for serious track driving, with many complained about the front hitting bump stop too often on hard braking/cornering even on stock ride height ( not lowered ). Serious track racer fitted stiffer springs with higher front to rear ratio, which gives more tendency to oversteer, to reduce this, they also lower the rake ( difference between rear and front ), most running with 8 to 12 mm higher at the rear, and large toe in to reduce snap oversteer ( F430 rear has suspension geometry that goes toe out when loaded, so toe in is necessary to compensate ). Those who run much stickier tires often run with close to level ride height ( 2-5mm rake ).

The rake also prominently used on Lancer Evos to help with rotation, due to similar situation, much lower rear motion ratio and relatively soft stock springs

The toe changes under compression? Never heard of that happening before

 

[Ridox2JZGTE]

The toe changes under compression? Never heard of that happening before

Ferrari 360, 430, CS, and Scuderia all have low spring rate ( stock ) and low rear wheel rate due to the same reason - low motion ratio at the rear. This cause a lot of body roll and squat when loaded, and this leads to dynamic toe ( happens to a lot of cars both front and back ). The 360, CS, 430 and Scuderia all share similar geometry on rear control arms and pick up point, and based on tests by Ferrari tuner/owner, even a little travel at the rear can cause toe out with close to neutral rear toe.

The stock Ferrari F40 alignment used by real owners also share similar setup with toe in both front and rear, shared with F355 alignment


Dynamic toe is pretty common, on FF car, the front usually set with toe in, as the front wheel tend to toe out when pushed hard around corner Lots of body roll, dive or squat

 

[DolHaus]

Ferrari 360, 430, CS, and Scuderia all have low spring rate ( stock ) and low rear wheel rate due to the same reason - low motion ratio at the rear. This cause a lot of body roll and squat when on loaded, and this leads to dynamic toe ( happens to a lot of cars both front and back ). The 360, CS, 430 and Scuderia all share similar geometry on rear control arms and pick up point, and based on tests by Ferrari tuner/owner, even a little travel at the rear can cause toe out with close to neutral rear toe.

I'm not doubting it, just curious about the process. Always looking to learn something new

 

[Ridox2JZGTE]

I'm not doubting it, just curious about the process. Always looking to learn something new

It's something I learned myself long ago from real life experience, used to wonder why my mates advised me to run more toe in at the rear Some cars do have close to neutral rear toe on stock factory alignment, like Lancer Evo - to help with rotation

 

[DolHaus]

It's something I learned myself long ago from real life experience, used to wonder why my mates advised me to run more toe in at the rear Some cars do have close to neutral rear toe on stock factory alignment, like Lancer Evo - to help with rotation

So basically the more compression experienced on a spring, the more toe out encountered?

 

[Ridox2JZGTE]

So basically the more compression experienced on a spring, the more toe out encountered?

Depends on the suspension geometry, I think this mostly happens to multi link rear suspension which often have low motion ratio, the actual wheel rate ( spring rate on the wheel ) is lower. When cornering, the body roll and travel ( the rear goes lower ) will make the wheel toe out. The more the travel, the more the toe out, so in a way, yes, spring compression also contributes - cause changes to the geometry.

I also remembered that R34 GTR rear multilink also experience the same thing, which is why stock alignment is at 4mm toe in

 

[Ceolix]

Could you explain easier?
i am kinda noob in mechanics, i didn't understand half what you said
lol

 

[DaBomm4]

Could you explain easier?
i am kinda noob in mechanics, i didn't understand half what you said
lol

In real life, ride height works one way, in GT6, it works backwards. That is about the extent of what I understand with what they are saying pertaining to your confusion. I hope this helps.

 

[Ceolix]

In real life, ride height works one way, in GT6, it works backwards. That is about the extent of what I understand with what they are saying pertaining to your confusion. I hope this helps.

yes but which one is real?

low front ride height = understeer -> gt6 or real life?
high front ride height = understeer -> gt6 or real life?

to me the high front ride height would get a better cornering ability because springs
wouldn't get too much stress from a low ride height

 

[rams1de]

yes but which one is real?

low front ride height = understeer -> gt6 or real life?
high front ride height = understeer -> gt6 or real life?

to me the high front ride height would get a better cornering ability because springs
wouldn't get too much stress from a low ride height

In GT6 high front, low rear gives oversteer.

As for the reason why. No-one knows, not even PD. Read the in game description and you'll see they expected it to be the opposite. You'll see lots of theories round here but that's all they are.

 

[Ceolix]

so in real life
a low ride height will understeer/oversteer right?

 

[DolHaus]

so in real life
a low ride height will understeer/oversteer right?

It will bring your centre of gravity closer to the road, whether this is a positive/negative thing depends on how the shortened suspension travel and slightly increased spring rate affects the car overall. Its generally a good thing but it can screw up your suspension geometry and/or lead to bottoming out, multiple other changes will be needed to make it work 100%.

 

[Ceolix]

yes but in real life lower ride heigh will understeer.
i dont get much of that mechanic talk you're writting lol
because lower heigh = more pressure on springs.
thats my theory.
but also dont make sense having pretty high ride height
because in WTCC they only use low ride height thats why im confusing

 

[DolHaus]

Ride height has no direct effect on handling unless other settings are correctly utilising the physics. Its extremely complicated.

Lower ride height = lower centre of gravity
Lower centre of gravity = more resistant to changes in state (if you are travelling forward, it will be less willing to change direction)

As with all suspension settings it is the best compromise to suit the needs at hand, there is no ideal setting for all cars.

 

[Ceolix]

so low or high ride height
has the same effects?
people keep saying high ride height
improves front wheels grip :s

 

[DolHaus]

so low or high ride height
has the same effects?
people keep saying high ride height
improves front wheels grip :s

In GT6 if you raise the front end higher than the rear you will get more turn in, if you raise the rear higher than the front you get more stability.

In real life it is complicated

 

[Ceolix]

In GT6 if you raise the front end higher than the rear you will get more turn in, if you raise the rear higher than the front you get more stability.

In real life it is complicated

that's why i dont get it.
shouldn't low ride height improve the car on close turns?
or is it the dampers get pressure and the car understeers?
but if it's that all the cars should have a monster truck suspension.
so they would get good turn in.

so confused lol

 

[DolHaus]

that's why i dont get it.
shouldn't low ride height improve the car on close turns?
or is it the dampers get pressure and the car understeers?
but if it's that all the cars should have a monster truck suspension.
so they would get good turn in.

so confused lol

All a low ride height does is lowers your centre of gravity and shorten your springs.
A low centre of gravity is inherently more stable whilst in motion which means that it will be less likely to lose control but also less willing to make sharp direction changes. Shorter springs mean you have to run stiffer spring rates in order to deal with the forces of cornering without bottoming out.
Shorter stiffer springs tend to be less suited to quick direction changes and are more effective for faster, more open corners due to their added resistance to body roll and high lateral forces.

In short, lowering the ride height of your car is good for stability and predictability but if you lower it too far you will have to drastically increase your spring rates in order to prevent bottoming out. This increase in stiffness and stability can spoil low speed handling by inducing understeer.

The ideal setting is as low as is possible without having to specifically alter your suspension to suit the ride height. The other thing to watch out for is curbs, if you are too low to the ground then you can beach the car when going over them. This will lead to a sudden and non-recoverable loss of grip as the tyres are no longter touching the track.

 

[Ceolix]

so basically low ride height = makes springs shorter = more front turning ability but = bottoms out easily

but in wtcc their cars never bottom out.so its kinda strange this phenomon

 

[Ridox2JZGTE]

How do you know they never bottom out at all ? Most race cars uses helper/tender/assist springs + stiff main springs that are often over the max value on most cars in GT6. This allows low ride height, and won't easily hit the bump stop as well as staying safe ( springs in place ) when on full droop ( when the wheel lift off the ground )

 

[DolHaus]

so basically low ride height = makes springs shorter = more front turning ability but = bottoms out easily

but in wtcc their cars never bottom out.so its kinda strange this phenomon

Lower ride height = shorter springs = more stable = bottoms out easily if springs are not stiff enough

In the WTCC they will be running suitably stiff springs to prevent them bottoming out as much as possible. They will change elements of the suspension to suit each and every race track they visit

 

[Voodoovaj]

Like everything in the tuning department, there is no absolute. Lowering does help as stated above, but there are limits to how low you can go and what side effect you are willing to accept.

On the 73 Skyline for instance, it grips really nice slammed to the bottom...just keep it off the rumble strips. There isn't enough suspension movement (on this car) to soak up those bumps with composure. I raised mine a little, gave up some lateral G in favour of keeping it on the track.

 

[Ceolix]

Lower ride height = shorter springs = more stable = bottoms out easily if springs are not stiff enough

In the WTCC they will be running suitably stiff springs to prevent them bottoming out as much as possible. They will change elements of the suspension to suit each and every race track they visit

but i thought the harder the springs would get the more understeer or oversteer you would get