AutoX terrible understeer

[e30gentry]

Attended my first SCCA autocross event with the 135
While setting relatively good times there was terrible understeer on sharp corner entry.
2008 135i auto MHD XHP3 PSP goodies
Sport Alignment settings
Stock wheels and brakes
Steering and suspension is in well working order
225F 255F Firestone Firehawks.

I started my run at 38PSI square
Reset to 40F and 38R
This is where my fastest and consistent times were but I feel there is still a second or so with the terrible understeer.

Any suggestions on alignment or tire pressures for those autoXer's out there.

 

[chris_flies]

Try disconnecting or removing the front sway bar. It's at least worth a shot; takes 10 minutes to do, and another 10 to undo. I did it in my 128i, and it CLEARLY doesn't have any understeer, unless I drive like an idiot...

 

[e30gentry]

Try disconnecting or removing the front sway bar. It's at least worth a shot; takes 10 minutes to do, and another 10 to undo. I did it in my 128i, and it CLEARLY doesn't have any understeer, unless I drive like an idiot...

I'll give that a shot tomorrow. I'll go through the garage and look for my ground down thin wrenches tonight.

 

[chris_flies]

I'll give that a shot tomorrow. I'll go through the garage and look for my ground down thin wrenches tonight.

Also, keep in mind that the 1-series is infamous for its built-in understeer characteristic. I'd also try to dial out a lot of camber in the rear. My car is wonderfully neutral, sitting at -2.3 degrees of camber up front, and -0.5 in the rear. You won't be able to get that front number without camber plates, but you can get the rear setting.

 

[ShocknAwe]

What made you decide on 40 psi front? And is that hot or cold?

 

[Bnks334]

Good suggestions so far. Removing a front endlink is a quick and cheap way to make a big suspension change. You can even do it in-between heats.

Are you trying to stay in street class? That will help steer further suggestions...