Help me control understeer, a sway bar question

[Fender13Bender]

To make the story short.

I have a 135i with the following mods:

MPSS tires, 235/18 265/18
Apex wheels, 18X8.5 18X9.5
VRSF intercooler and downpipe
Metal charge pipe
MHD stage 2 plus tune
Dinan camber plates with fresh alignment (-1.2 degrees of front and rear camber)

Whiteline rear subframe inserts are in the mail and I will be installing them in the next few days.

I've done two auto xs with this car. The car is still understeering pretty badly even after the camber plates and alignment.

So, WHAT'S NEXT??

I was thinking maybe M3 front sway bar, or aftermarket front and rear sway bars. I was considering M3 front control arms, but I don't want to pay for another alignment since I just got it done. I also may throw on some front 10mm spacers.

Also, I do not want to do struts and springs. I like the ride height and at the end of the day, this is a DD and is holding me over at auto x until my LS swap E36 is finished.

Below is my last auto x course. I am new to it and i know I probably am coming into turns too quickly and causing more understeer than needed. However, I still feel the car is lacking serious grip up front compared to the rear.


I've read a ton of threads and have come to the conclusion that no one has a solid answer on sway bars. Any help is much appreciated, thanks!

[bbnks2]

Originally Posted by Fender13Bender

To make the story short.

I have a 135i with the following mods:

MPSS tires, 235/18 265/18
Apex wheels, 18X8.5 18X9.5
VRSF intercooler and downpipe
Metal charge pipe
MHD stage 2 plus tune
Dinan camber plates with fresh alignment (-1.2 degrees of front and rear camber)

Whiteline rear subframe inserts are in the mail and I will be installing them in the next few days.

I've done two auto xs with this car. The car is still understeering pretty badly even after the camber plates and alignment.

So, WHAT'S NEXT??

I was thinking maybe M3 front sway bar, or aftermarket front and rear sway bars. I was considering M3 front control arms, but I don't want to pay for another alignment since I just got it done. I also may throw on some front 10mm spacers.

Also, I do not want to do struts and springs. I like the ride height and at the end of the day, this is a DD and is holding me over at auto x until my LS swap E36 is finished.

Below is my last auto x course. I am new to it and i know I probably am coming into turns too quickly and causing more understeer than needed. However, I still feel the car is lacking serious grip up front compared to the rear.


I've read a ton of threads and have come to the conclusion that no one has a solid answer on sway bars. Any help is much appreciated, thanks!

The first thing you need to decide on is if you're going to stick with the staggered wheel setup... Give the spacers a try. Also, try dropping front tire pressure a few psi.

[Fender13Bender]

Yes, sticking with these wheels and tires. They are brand new and look great IMO. Of course a square setup would be better, but then I'd have a smaller tire size in the rear.

[Ginger_Extract]

Learn to experiment. There is no one size fits all solution.

- Tire pressures
- Unhook the front sway bar
- Alignment

[MightyMouseTech]

You need more front camber. Period.

Suck it up and get the front M arms.

[Fender13Bender]

So, I went in install the whiteline inserts and saw these were already installed:





20180531_164459 by Matt Bender, on Flickr

[lakefront]

Originally Posted by MightyMouseTech

You need more front camber. Period.

Suck it up and get the front M arms.

This is it. Had the M arms installed, went from -2.5 to -3 degrees camber. Difference in front end grip was unreal.

[Gangplank]

You're at -1.2 with the Dinan camber plates installed? I have the M3 arms and pins knocked out and I'm at -1.4. Front grip is much better than stock.

Alignments aren't that expensive. The TRE M3 arm are also not too bad. Plus you get stiffer bushings up front.

[MightyMouseTech]

Originally Posted by Fender13Bender

So, I went in install the whiteline inserts and saw these were already installed:





20180531_164459 by Matt Bender, on Flickr

Damn, lucky man!

[MightyMouseTech]

Originally Posted by lakefront

This is it. Had the M arms installed, went from -2.5 to -3 degrees camber. Difference in front end grip was unreal.

I am at -2.2 with Dinan plates and M3 arms. Perfect for a street car, would want significantly more for a track car.