M3P owners: Anyone tried remove rear sway bar?

[wenkan]

I have MPP sport coilovers and OEM sway bar on my M3P. In my few track and autocross experience, I feel it quite easy to spin. Either too much throttle, or too much regen will lose my rear traction. I have a square setup of tires.

Someone told me removing the rear sway bar will make the rear traction better. Is that a good idea? I know most of the people are going for stiffer sway bars, but I have coilovers to reduce body roll already. Is there any unwanted side effect of not having a rear sway bar, than more body roll in corners?

 

[jjrandorin]

I dont have the answer, but giving you a free thread bump so the thread doesnt get buried too fast, as well as tagging @MasterC17 @Mash @cOoTeR who might be able to provide some input.

 

[dsgerbc]

Plenty of people have aftermarket front/rear bars.

Have you tried softer shock settings?
Instead of removing the rear bar, personally, I'd install a thicker/adjustable one up front.

 

[MountainPass]

Could you share your alignment specs with us?

 

[Mash]

I have MPP sport coilovers and OEM sway bar on my M3P. In my few track and autocross experience, I feel it quite easy to spin. Either too much throttle, or too much regen will lose my rear traction. I have a square setup of tires.

Someone told me removing the rear sway bar will make the rear traction better. Is that a good idea? I know most of the people are going for stiffer sway bars, but I have coilovers to reduce body roll already. Is there any unwanted side effect of not having a rear sway bar, than more body roll in corners?

I'm sure that you going to make your traction way worse without a rear sway bar. On a track, it's actually have not enough force at the rear.
MPP sport doesn't have stiffer springs at the rear, so "no" to that as well.

Regen makes it harder for me to control a car on high-speed curves and since it overheats the battery I'm just turning it off completely.

Removing most of the front and rear control arms rubber bushings in favor of the uniball bearings eliminated the rest of this uncertainty.
The front lip and rear wing removed high-speed traction decline.

In your particular case, you might have too much toe or too much/not enough camber - you should check that as well.
Weird small chance - something wrong with tires or suspension arms are not connected well.

 

[wenkan]

Plenty of people have aftermarket front/rear bars.

Have you tried softer shock settings?
Instead of removing the rear bar, personally, I'd install a thicker/adjustable one up front.

That sounds a better idea. Eibach ones good enough?

 

[MasterC17]

If anything I think people have found the opposite - a thick rear bar and stock front bar is a good, balanced setup. I would not remove the rear sway bar. That may have worked on some platforms (RWD), but I don't think it's going to do you any good here.

What I will say is that after driving my 2021 for the past week I forgot how easy the car rotates with stock camber. Getting the Red 2018 with MPP Comforts and Camber Arms on the not-at-all-sticky 18" MXM4's to rotate requires some effort. Getting the stock 2021 on more-sticky Hankook Evo3's to rotate is surprisingly easy - to the point I almost failed to correct it because it was very unexpected.

I would be curious to know what your alignment specs are for starters. I'm running roughly -3 degrees of camber in the front and -2 in the rear.

 

[Dolemite]

Could adjusting the rear shock rates help?

 

[wenkan]

Could you share your alignment specs with us?

If anything I think people have found the opposite - a thick rear bar and stock front bar is a good, balanced setup. I would not remove the rear sway bar. That may have worked on some platforms (RWD), but I don't think it's going to do you any good here.

What I will say is that after driving my 2021 for the past week I forgot how easy the car rotates with stock camber. Getting the Red 2018 with MPP Comforts and Camber Arms on the not-at-all-sticky 18" MXM4's to rotate requires some effort. Getting the stock 2021 on more-sticky Hankook Evo3's to rotate is surprisingly easy - to the point I almost failed to correct it because it was very unexpected.

I would be curious to know what your alignment specs are for starters. I'm running roughly -3 degrees of camber in the front and -2 in the rear.

So I found my alignment, camber front -1.15 rear -1.3, toe front 1.7mm rear 2mm.
I may not go that far to -3/-2, but probably need more front camber? Do I need MPP adjustable FUCA to get -1.5 front?

 

[MasterC17]

So I found my alignment, camber front -1.15 rear -1.3, toe front 1.7mm rear 2mm.
I may not go that far to -3/-2, but probably need more front camber? Do I need MPP adjustable FUCA to get -1.5 front?

You would need adjustable arms to change the camber any further - it is fixed from the factory and lowering it will add a little bit of negative camber but not too much. So, you would need MPP or UP Adjustable FUCA's and Rear Camber Arms to dial it in. For a dual purpose car, I would probably target a hair over 2 degrees in the front and 1.5 in the rear.

Also, I don't like your toe settings. I would set the front toe to 0 degrees. Even the rear toe is off quite a bit if my mm to degrees conversion is correct (not sure if that is total or each side). I would set the rear toe to .25 degrees on each side.

 

[gearchruncher]

@wenkan- have you played with the Track mode torque bias? I was at a very wet AutoX this weekend and was running too much rear bias- about a 20% shift to the front made a huge difference to stability and my lap times.

A bit less tire pressure in the rear can also help (or more in the front).

Where do you AutoX around Seattle? Don't see many Teslas out at my local track here (Monroe).