Autocross video

[KWM338R]

Dolly Sprint in action State side.

http://www.youtube.com/watch?v=XFwyz9pIR4k

Results here.
http://www.boston-bmwcca.org/results/20 ... ?event=523

Ned to work on minimising body roll. I currently run 400 lb front springs with a 24mm ARB, thinking maybe 600lb springs will be nice.

Cheers
Mark

[trackerjack]

Nice one Mark over here we call those events autosolo or ghymkhana as autocross used to be outrite racing in a grass field!
Seems you guys over there like BM's.

[KWM338R]

thanks Jon. I run with the Boston BMW club so there's a good turnout of BMW's.

Cheers
Mark

[DaveMc]

Not exactly what I'd call an autocross...............more of an elongated autotest!

[straylight]

that looked like fun. Thanks for posting the vid. Sounds like a dolomite too

stu

[ponchoj]

Dolly Sprint in action State side.

http://www.youtube.com/watch?v=XFwyz9pIR4k

Results here.
http://www.boston-bmwcca.org/results/20 ... ?event=523

Ned to work on minimising body roll. I currently run 400 lb front springs with a 24mm ARB, thinking maybe 600lb springs will be nice.

Cheers
Mark

Is this your car?

Great video. The americans do use the term autocross for what we call autosolo. It's just a terminology thing.

You say you're going to stiffen the front, but it looks like the back end is too soft to me. It's understeering more often than not. You're often putting in a lot more steering angle than others and more than I'd expect to see.
Personally, I'd look at stiffening the rear up instead and bring some grip back to that front end, you'd have a spot more forward bite too, though a stiffer ARB might make it more predictable and less skitty. I'd introduce a bit more toe in aswell if there's room...just to improve turn-in.
It's hard to see from the video, but it looks at its worst under acceleration, which backs up the rear being too soft.

Anyway, you want to start bringing that back end round a bit better.

I used to do a spot of autosolo...did it in a 2.8i capri. My mate laughed but it turned out a very good 2nd place on my first outing. It's good fun for the money, I'd do it again but I'm not sure how the trans am will be received in the tiny courses we have here. lol
I may give it another go in the dolomite though.

[KWM338R]

Yep thats my car. thanks for the input, I put the standard rear springs back in last night, they are stiffer than what I had in there. Going out again on Sunday, so we'll see if any improvement has been made.

Cheers
Mark

[ponchoj]

Way ahead of me then.

Try raising the rear tyres pressures too and see if that improves things. Sometimes it's a nice way of seeing if you need to go up or down on spring rates. Remember, raising tyre pressures a bit is like increasing your spring rate on that wheel. Don't go mad or you'll have a smaller contact patch or start rolling the tyre...but going 5 psi each way will start to give you an idea.

Make sure they're put back before going home though. lol