Too much rear camber? The cause of my oversteer?

[mindspin311]

Car is a 96 E36M3.

TRM coilovers, E36 non-M sport front swaybar connected to the control arms, no rear swaybar.

Hankook RS3 tires at 36psi hot.

Camber is -3.4F, -2.6R
Toe is 0"F, and 0.13"R


Road Atlanta this past weekend had the following issues.

• Low speed power oversteer out of T7.
• Mid-corner to corner exit oversteer in high speed corners like T1, T6, T12.

Front end of the car felt great, lots of grip.

I know some of it is just general throttle application, but especially in T1, I felt like the rear of the car was on edge the whole weekend.

Too much rear camber, not enough toe?

[4ABHGE]

Negative toe is toe out. Might explain what's happening in the back

Everything else seems good from what i can see

[mindspin311]

Negative toe is toe out. Might explain what's happening in the back

Everything else seems good from what i can see

Oops, thats not correct then. Definitely have toe in. My mistake.

[Inflame]

Car is a 96 E36M3.

TRM coilovers, E36 non-M sport front swaybar connected to the control arms, no rear swaybar.

Hankook RS3 tires at 36psi hot.

Camber is -3.4F, -2.6R
Toe is 0"F, and 0.13"R


Road Atlanta this past weekend had the following issues.

• Low speed power oversteer out of T7.
• Mid-corner to corner exit oversteer in high speed corners like T1, T6, T12.

Front end of the car felt great, lots of grip.

I know some of it is just general throttle application, but especially in T1, I felt like the rear of the car was on edge the whole weekend.

Too much rear camber, not enough toe?

T7 is a common oversteer turn, nearly every single car come out of that turn oversteers. Coming out of T6, which is a high speed, banked turn, you're carrying quite a bit of exit speed into T7.

The rest of the turns are fairly high speed, so having oversteer in those locations is quite scary, especially T12 which is probably the fastest "turn" of the whole track. I'd look into changing your ride high as your camber seems to be fine (I run -3.5, -2.0) on my car. I'd consider dialing back some camber, but you'll have to look at your tire temps.

One of the easiest ways to shift grip is to adjust your ride high. Raise your from to give yourself faster weight transfer to the rear upon acceleration. This will induce some understeer which is what you ideally want, but it's all preference.

[Def]

Maybe up your front bar motion ratio or stiffness? If the wear is even in the rear, I don't think camber is an issue since that's pretty standard for a track car.

[=BA=]

Really need more info on the car, ie what springrates are on those TRM coilovers.

[mindspin311]

Really need more info on the car, ie what springrates are on those TRM coilovers.

780lb Front, 895lb Rear

[=BA=]

That setup with no rear bar is actually quite front biassed (ie it should understeer) and I see no real issue with how much camber you run.

Out of the box thinking but have you tried reinstalling the rear bar? Some setups feel a bit funny without a rear bar and your spring differential is not very big. Ie you might perceive the additional rear roll as the rear giving away.

Alternatively, these TRM socks are adjustable as far as I know, turn up the fronts or turn down the rears.

[Def]

If those are in the stock position, I agree, very front biased.

You might have so much rear roll that the rear grip actually goes down since that axle has much less roll stiffness. I would put a rear bar on and see how it feels. I'm honestly not a fan of the "no rear bar" typical setups, as I think they generally lack roll stiffness in the rear and that causes some odd handling or just terminal understeer.

[exvitermini2]

My car is rather the opposite. It pushes like no tomorrow, was very frustrating last time out. Running the same TRM coilovers, though my springs are the original rates of 670/895. I can't recall but I think I had less camber in the front, which I need to fix. Good news is it will put down power with no issues in almost any situation, bad news is if it gets loose and you overcorrect there is no getting it back it just snaps.

[=BA=]

My car is rather the opposite. It pushes like no tomorrow, was very frustrating last time out. Running the same TRM coilovers, though my springs are the original rates of 670/895. I can't recall but I think I had less camber in the front, which I need to fix. Good news is it will put down power with no issues in almost any situation, bad news is if it gets loose and you overcorrect there is no getting it back it just snaps.

Your car seems to have more rear bias so it shouldn't really be a problem (but it is more than what I would run if you still had a rear ARB), but lack of camber can hurt you. Same here, correct your camber and have a play with the shock settings. I have played with the shocks on my car for ages (different from TRM but same adjustment principle) and it makes a lot of difference.

Ie when I was running rain setup it behaved just like your's, oversteer and no way of ever getting it back. Turn up the front shocks a few clicks and the balance came back.

For your needs you most likely need to turn up the rears or back off the fronts a bit.

Most of the shocks that have the adjustment principle where you adjust compression and rebound with one knob, only adjust the low speed area of the damping curve, ie the transitions and you can influence the balance of the car a lot with these. Also noteworthy is that they don't always adjust in the same rate, ie on mine I believe compression is only 50% from rebound adjustment so your primairy adjustment mechanism is still rebound.

Also you could try to raise the rear rideheight, but I'm not sure of that is the way to go if it's so difficult to catch.

[exvitermini2]

Much appreciate the input. I have no rear sway. The car felt pretty bouncy/stiff, so I did back the shocks way off in hopes of helping that some early on in the weekend. It had been a few years since I'd been on track and fresh car, so I didn't really go back to playing with things as much as trying to get reacquainted. I will play with that stuff some this next trip out.

One scenario i was sitting here pondering, entry to the snake at VIR. Every car I've been able to lift throttle it a bit to get the car pointed into the turn better, this car I lifted and it straight pushed. Had to pick up the throttle some to make it quit, quite the odd feeling.

[Def]

If the car feels "floppy" over to steady state, usually feeling like it's one extreme, then over the other like understeer then oversteer - try turning the shocks UP in damping. It can indicate you're under damped, and turning the damping up will tend to control the sprung mass better.

My S2000 is definitely like this, where it's way more under to oversteer through a corner as I correct than with the shocks turned up.

[scooper]

toe in more rear? thought 0.20 total toe in rear is minimum even for a track car...

[chikinhed]

Kind of an OT question but has anyone noted how much the rear toe changes per degree of rear camber change?

I have Turner adjustable camber arms. I usually have rear camber set at 1.0° for the street. I'd like to increase the camber to 2.0° for autox but don't want to mess with the toe.

[NotoriousJJE]

how much rake do you have? Ride Heights?

If you have too much, would explain some of these symptoms.

[mindspin311]

how much rake do you have? Ride Heights?

If you have too much, would explain some of these symptoms.

Are you talking to me? or the other guy?

[NotoriousJJE]

I think you. Corner exit oversteer could be a rake issue. Could also be your rear shocks bottoming out...

[mindspin311]

I think you. Corner exit oversteer could be a rake issue. Could also be your rear shocks bottoming out...

Ride height/rake is something I need to look in to. I know it needs improvement.