Correcting Understeer

[Dave B]

I have a stock 2020 CTR with Hardrace ball joints in the middle setting for about neg 2.65 camber using 200 UTQG tires. I still find that the car understeers, not badly, but coming from a rear driver, I would like the rear to rotate more than it does, even if it is just on corner entry. I already run the front tires about 3 PSI cold lower than the fronts but by the time they heat up, the pressures are pretty equal. I have zero rear toe.

My choices are either to get a somewhat stiffer rear sway bar or potentially run a bit of rear toe out. I feel the latter choice could really bite me so would prefer to use the former. I think for my choice of tire, going to a very aggressive front setting of neg 3.7 camber may not be the right decision.

What has been your experience and how have things gone with stiffer rear sway bars on stock suspensions? Any brand recommendations?

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[booost]

Just chiming in, I track my SI and I made it a mission to try to ride myself of understeer. Currently I'm running:

Parts:
— SPC -1 camber front ball joints
— Fortune Auto coilovers with Fortune Auto front sway bar endlinks. Camber set to max in the front
— SPC rear camber arms almost maxed out
— Eibach rear sway bar on stiffest setting
— Eibach front sway bar on soft setting
— Eibach subframe brace in the rear
— Eibach endlinks on the rear sway bar

Alignment:
— I usually run a slight toe out in the front and a slight toe in within the rear.

Tires:
— 200tw Hankook RS4's


I now can get the rear to move on the track if I really push it with traction control off and the setup is fine for my daily commute (50 miles per day on average) including harsh rain here in South Florida.

There's also some techniques where you can let off the gas to induce the oversteer.

It's a challenge. The track is something I am still trying to improve and get better lap times.

Just figured I would share, it may be relevant to you.

 

[AlphaDigital]

I have a stock 2020 CTR with Hardrace ball joints in the middle setting for about neg 2.65 camber using 200 UTQG tires. I still find that the car understeers, not badly, but coming from a rear driver, I would like the rear to rotate more than it does, even if it is just on corner entry. I already run the front tires about 3 PSI cold lower than the fronts but by the time they heat up, the pressures are pretty equal. I have zero rear toe.

My choices are either to get a somewhat stiffer rear sway bar or potentially run a bit of rear toe out. I feel the latter choice could really bite me so would prefer to use the former. I think for my choice of tire, going to a very aggressive front setting of neg 3.7 camber may not be the right decision.

What has been your experience and how have things gone with stiffer rear sway bars on stock suspensions? Any brand recommendations?

could you try upping the rear tire pressures a bit more? I ran one of my autox runs with a 5psi difference between the front and the rears and just about lost the rear end going around a faster corner. could it also be that you just have to get used to FWD more? haha

Ill be installing a whiteline RSB before my next event in Sept. Interested to see how the car responds to it.

 

[Dave B]

could you try upping the rear tire pressures a bit more? I ran one of my autox runs with a 5psi difference between the front and the rears and just about lost the rear end going around a faster corner. could it also be that you just have to get used to FWD more? haha

Ill be installing a whiteline RSB before my next event in Sept. Interested to see how the car responds to it.

There is certainly some getting used to front wheel drive vs rear wheel although I ice race Ice Racing | CASC Ontario Region a front driver. Certainly there, low traction and inducing oversteer is pretty easy. I am aware of trailing throttle oversteer but have issues getting it to work on my car. It may well be my driving style that needs to change as well. I also endurance race a much slower front driver with significant suspension mods and it understeers significantly less with a 3 PSI difference in pressures, front lower than rear.

And no, I always use the long push VSA in R mode. No nannies trying to prevent oversteer.

 

[Lust]

Pickup the RV6 rear sway bar + end links and set it to full stiff. Your next option would be to play with rear tire pressures a little or bite the bullet and get coilovers

 

[metal_driver]

Dave, I am no expert but many in the past on this forum have installed a stiffer rear sway bay to help with this. It seems to be a preferred solution throughout mutiple past FK8 threads.

 

[NightFuryEXT]

I have found staggered tire size to help a lot in all my fwd cars. On my EXT its 235/40/17 up front, 215/50/17 in the rear in Nitto NT555 G2. I dont get any understeer with a nice bit of lift off oversteer that's easy to correct.

 

[Kotaas]

Just chiming in, I track my SI and I made it a mission to try to ride myself of understeer. Currently I'm running:

Parts:
— SPC -1 camber front ball joints
— Fortune Auto coilovers with Fortune Auto front sway bar endlinks. Camber set to max in the front
— SPC rear camber arms almost maxed out
— Eibach rear sway bar on stiffest setting
— Eibach front sway bar on soft setting
— Eibach subframe brace in the rear
— Eibach endlinks on the rear sway bar

Alignment:
— I usually run a slight toe out in the front and a slight toe in within the rear.

Tires:
— 200tw Hankook RS4's


I now can get the rear to move on the track if I really push it with traction control off and the setup is fine for my daily commute (50 miles per day on average) including harsh rain here in South Florida.

There's also some techniques where you can let off the gas to induce the oversteer.

It's a challenge. The track is something I am still trying to improve and get better lap times.

Just figured I would share, it may be relevant to you.

Have you considered beefing up your Eibach rsb to whiteline 26mm rsb?

I’m thinking it might be too stiff for the rear ?

 

[MoodySara]

When you're chasing a balance problem, understeer in this case, it's usually better to try to improve the end of the car that's not working.
With understeer, the rear is sticking while the front is sliding. If you can improve the grip at the front you'll have more total grip.
As a last resort you can improve the balance by taking grip away from the rear - with a bigger rear bar, for example. The total grip will be lower, but the balance will be better.
More toe out in the front will help with initial turn-in. The car will be less stable in a straight line, but the driver can deal with that.
A smaller front bar can help improve the grip on that end by reducing the load transfer to the outer wheel.

 

[booost]

Have you considered beefing up your Eibach rsb to whiteline 26mm rsb?

I’m thinking it might be too stiff for the rear ?

I haven't yet but that's not a bad idea.

 

[Kotaas]

I haven't yet but that's not a bad idea.

I’ll do it if you do it

 

[booost]

I’ll do it if you do it

Hahaha!

 

[Dave B]

When you're chasing a balance problem, understeer in this case, it's usually better to try to improve the end of the car that's not working.
With understeer, the rear is sticking while the front is sliding. If you can improve the grip at the front you'll have more total grip.
As a last resort you can improve the balance by taking grip away from the rear - with a bigger rear bar, for example. The total grip will be lower, but the balance will be better.
More toe out in the front will help with initial turn-in. The car will be less stable in a straight line, but the driver can deal with that.
A smaller front bar can help improve the grip on that end by reducing the load transfer to the outer wheel.

I agree that increasing front end grip is the real answer but I don't really have the option of having more than neg 2.7 camber unless I go to neg 3.7 which is likely too much. I am ok with the car rolling a bit as it may actually add some compliance to the suspension. Does anyone make a smaller front sway bar?

 

[TypeSiR]

Give Karcepts a try:

http://www.karcepts.com/shop/product.php?id_product=131

 

[Oddwayne]

If you have coil overs, you can lessen dampening in the front and turn it up a bit in the rear. That should help with weight transfer when you brake. Then it’s a matter of lifting off the throttle and a lil flick of the steering wheel to make it lift off oversteer. You could also try an si or ex front sway bar to keep the front from being so planted. Like someone said earlier, work on the end that’s problematic for you.

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