Car unstable at high speeds

[Nate047]

Well I have an e39 m5 which is definitely not low as this and driven a 997 with 4.0 L engine which is low but still doesn’t feel unstable at high speeds.

Im running a stock setup. 19 inch rims in the front on 225/40/19

That looks a bit low, but it’s hard to tell from pics. If you can, measure from the center of the wheel hub straight up to the edge of the fender. If memory serves,13.5” front and 13” rear is a good starting target, you *should* ideally have the car corner balanced, but that’s another couple hundred bucks.

But again you might just not be used to how it feels to drive a low car with lots of camber. It does definitely suck in some ways. Tramlining is how it feels when the car is jumpy and twitchy, like in freeway ruts, things like that. It’s just a natural side effect if you want low ride height and lots of camber.

[Leafsrule531]

Oddly enough, I guess it’s not as low as I expected. Just measured it and it’s 13.5 inches all around. The rears are closer to 13.25 inches.

shouldn’t I be able to get more positive camber if they aren’t that low ??

[Nate047]

What upper mounts do you have? Can you post a picture of the top mounts how they are positioned in the car?

[DJAM3]

It doesn't look excessively low to me. Not sure why the shop can't get less than -3. My car was lower than that and I could get -2.

edit: Just re-read that you don't have camber plates. Maybe your top hats are swapped. That will get you -3 camber.

[Leafsrule531]

It doesn't look excessively low to me. Not sure why the shop can't get less than -3. My car was lower than that and I could get -2.

edit: Just re-read that you don't have camber plates. Maybe your top hats are swapped. That will get you -3 camber.

This is exactly what I’m questioning. The alignment was done after I installed the camber plates and the car isn’t too low so not sure why the best I can get is -3.

[Leafsrule531]

Pretty frustrated to be honest - I just called the alignment tech back and he claimed that the camber plates that I have (ground control race plates) are already set to the most positive camber possible. So the only options I have is raise the car both sides by about an inch and get an alignment done again OR he said I should buy new / different camber plates that allow more flexibility 🙄

[elbert]

You might have non-M camber plates, which are different than specific M3 plates.
The non-M cars need plates with a lot more negative camber due to differences in spindles.

[Leafsrule531]

They are def for for the m3 - i actually bought them off of a forum member here who used them on his e46 m3. I dont think ground control makes non-m camber plates

[jayjaya29]

Those camber plates are clocked wrong. They should be installed with the ground control engraving towards the front of the car. So rotate them one hole clockwise. The caster will need to be adjusted.

[elbert]

I dont think ground control makes non-m camber plates

Actually, they do. But it sounds like jayjaya29 figured out your problem.

[Leafsrule531]

i just called ground control and they confirmed that the fitment of the plates are correct. The pictures i have sent are from me standing next to the fender looking at the plates.

[jayjaya29]

Look at these plates. The pointer is for adjusting camber, the slots allow the camber to be adjusted easily. The allen head screws adjust caster and are harder to adjust since its not adjusted as much as camber is. You can also just barely make out the arrow on the bottom plate that is supposed to point towards the front of the car.

[jayjaya29]

Here is the correct orientation:

[fattycharged]

Edited for incorrect info, these actually look to be installed correctly

[Leafsrule531]

Just to confirm, right now they are installed the same way shown in the picture below with the “ground control” lettering showing horizontally if I am looking at them from the fender side. If I rotate them one hole clockwise the “ground control” lettering will essentially be vertical and that’s the correct orientation?