Autocross Car Setup ???s

[D. Hitchcock]

Howdy all: I've got a season or two of autocrossing under my belt in my e30 325i.

I run in DSP but my car is very lightly modified and is also a daily driver. It's got Koni SAs, M3 springs and CABs, a front strut brace, stock swaybars. Next season I'll be running on 15X7 wheels with 225 Kumhos all around. Last season I ran basketweaves with 14-inch Hoosiers, 205s front, 225s rear.

So far, I've sought and followed anecdotal advice from other owner/drivers on car setup issues. E.g., Higher tire pressures in front and lower in rear to counter oversteer; hard shocks front, soft rear for same reason.

I guess I want thoughts on a very basic question: How do you describe the specific handling characteristics of an e30 (or for that matter an e36)?

Also, how do you set your car up for autocross? Hard springs front or rear? Both? Hard shocks front or rear? Or both? Swaybar setups? Ride height? Tire sizes & pressures, etc.

Can coilovers be practical for a car driven on the street? Can autocross alignment settings (say, at least -2 degrees camber front ... )?

Sorry to be so vague, but any thoughts on these questions would be of great assistance.

xo,
D. Hitchcock

[jmott]

You can have a competitive DSP suspension that is liveable on the street. The best way to do it is by using or 15 or 14 inch wheels for daily driver with some comfy, cheap, long lasting tires. This will offset the stiff springs and give you a comfy daily ride. The cheap long lasting tires will also allow you to run a serious autocross alignment without as much worry. You may kill the tires faster, but at least they were cheap =)

Then when its time to race bolt up the serious tires.


FYI, I've seen a couple different E30 DSP cars experiment with small wheel sizes, but the only one that was nationally competitive was on 18x10s with 285 Hoosiers. 18x9s or 17x9s with 245s also works well.

Howdy all: I've got a season or two of autocrossing under my belt in my e30 325i.

I run in DSP but my car is very lightly modified and is also a daily driver. It's got Koni SAs, M3 springs and CABs, a front strut brace, stock swaybars. Next season I'll be running on 15X7 wheels with 225 Kumhos all around. Last season I ran basketweaves with 14-inch Hoosiers, 205s front, 225s rear.

So far, I've sought and followed anecdotal advice from other owner/drivers on car setup issues. E.g., Higher tire pressures in front and lower in rear to counter oversteer; hard shocks front, soft rear for same reason.

I guess I want thoughts on a very basic question: How do you describe the specific handling characteristics of an e30 (or for that matter an e36)?

Also, how do you set your car up for autocross? Hard springs front or rear? Both? Hard shocks front or rear? Or both? Swaybar setups? Ride height? Tire sizes & pressures, etc.

Can coilovers be practical for a car driven on the street? Can autocross alignment settings (say, at least -2 degrees camber front ... )?

Sorry to be so vague, but any thoughts on these questions would be of great assistance.

xo,
D. Hitchcock

[robweenerpi]

You don't need hugenourmous tires to go fast in autox. Depending on how dedicated you are at this 245's should be more than adequate. And there's nothing wrong with running 225's under stock fenders you can still make it a fast car locally. Sure there are alot of autox cars out there mounting giant rubber but most don't seem to have the suspension or prep to handle them, at least from what I've seen.

You can run 2 degrees of camber without wearing the tires too bad, it's still not enough to be ideal though.

Swaybars vary pretty wildly in setup and options. It really seems to come down to what springs you are running and how you like the car to drive.

Coilovers can be just fine on a streetcar, and there aren't that many lowering springs for an E30 that are really going to be stiff enough to work well. I'd say it's probably the way to go. You can make a E30 pretty loose pretty easy in autox so don't go overboard with the rear spring but it does need to be firm.

[jmott]

You don't need hugenourmous tires to go fast in autox.

Yes, I didn't mean to imply you have to get 285s. 245s are plenty to lay waste to everybody in a 100 mile radius in fact. 225s may be as well on an E30.

I was more referring to playing with smaller wheel diameters. I've not seen those experiments work out well at all on other DSP E30s.