Author Topic: Preventing understeer. (Read 3957 times)

Danny707 · « **on:** August 11, 2008, 12:03:19 AM »

Lets chat.

At today's AutoX I was understeering really badly to the point where I had to get out of the power band and lose precious 10ths.

Any advice to reduce this?

I have Bilstein Sport shocks in front with KYB GR2s in the back H&R race springs bav auto strutbar and 215/40/17 Yokohama EVS100 tires.

e30 4cyl · « **Reply #1 on:** August 11, 2008, 12:15:43 AM »

Are you running any camber plates?

Danny707 · « **Reply #2 on:** August 11, 2008, 12:19:12 AM »

No i'm not.

Danny707 · « **Reply #3 on:** August 11, 2008, 12:34:32 AM »

I also have a medium case LSD from a 325is Automatic

Ruger · « **Reply #4 on:** August 11, 2008, 12:53:24 AM »

Are you running any swaybars and if so are they adjustable? Stiffening the rear sway bar up will make it more oversteery but in your case probably just stop the understeer. Front negative camber would also help aswell as offset m3 caster bushes

Danny707 · « **Reply #5 on:** August 11, 2008, 01:09:25 AM »

I have just stock sway bars.

What about ONLY a thicker rear sway bar?

e30 4cyl · « **Reply #6 on:** August 11, 2008, 01:12:51 PM »

Not sure about the sway bars but I think if you kept the stock front bar and added a stiffer rear bar it would help your situation.
I think getting some camber plates and setting them on full negative camber would also make a huge difference.

John W · « **Reply #7 on:** August 12, 2008, 04:24:08 PM »

What tire pressures are you running front/rear?

Danny707 · « **Reply #8 on:** August 12, 2008, 08:47:08 PM »

I ran 32 all around

John W · « **Reply #9 on:** August 13, 2008, 10:20:07 PM »

The 91 318is has something like a 54/46 weight distribution. It's not a hard and fast rule, but generally, starting with about 5-8 percent more psi up front is a good place to start with this much weight over the front wheels. I haven't autocrossed my 318is yet, but with my old 318ti that I autocrossed about a dozen times I ran something like (IIRC) 35 or 36 psi cold front, 32 or 33 rear (215/45/17 Hankook Ventus RSII).