[cwmizner]

likely getting a 06 330i sedan 6 speed very soon.

while i want the car because it's a nice car, not specifically for autocross, i do plan to autocross it.

been autocrossing for about 10 years, but mostly just locally (in phx az).

plan to run in DS in our local street tire class

will probably get some dunlop star specs soon and maybe a front sway bar.

1. sway bar a good idea? looks like Hotchkis might be a good choice???

2. thinking of putting a 255/35/18 on the FRONT stock wheels, thoughts on that???

thx!

[eltoshan]

Hotchkis is probably your best bet for stock class. I don't see a problem in fitting 255 star specs in the front either, assuming that the front wheel is 18x8 et34.

[Chowbow]

You should be fine with the 255s up front. Sure you don't want to run slicks though?

Definitely need a front sway bar on a stock height / stock class car. There's so little negative camber up front that the front swaybar actually HELPS with the understeer because it maintains the contact patch through corners. Are you going to do the dampers too? Vorshlag has AST shocks that are stock class legal, FYI.

[cwmizner]

keeping it simple, don't have a lot of extra cash and don't like swapping wheels on 'race' day. no dampers for a while, just the 255 star specs all around and maybe the Hotchkis bar and whatever I can do with alignment, should be enough for local street tire class, the ultra competitive folks are in different classes, so I should be good,

[Porschefile]

You can definitely fit 265's or possibly 275's on the stock rears. I had 265 Hankook RS-2's on my stock rears and they work well. DS you can run any tire though, I ran Yokohama R compounds when I had a 325i in DS. Now I run the Hankooks in FS because I don't think auto-x is worth spending that much on tires. It's fun on any tire really.

[cwmizner]

don't want too much tire in back do you?

i the idea of 255s all around (although only 8 inch wheel in front vs. 8.5 in back obv)

maybe 265s in back, 255s in front?

Porschefile, what do you run in FRONT?

[eltoshan]

For autocross, especially the e90/e92 in stock class, squared tire setup is preferred. Especially considering the total lack of camber in the front, a bigger rear will not lessen understeer plus you are giving up longitudinal grip. Ideally for autocross you will want something like 285+ on all four corners, but the front of our cars probably will only be able to fit 255s under stock class rules.

[Chowbow]

Originally Posted by cwmizner

keeping it simple, don't have a lot of extra cash and don't like swapping wheels on 'race' day. no dampers for a while, just the 255 star specs all around and maybe the Hotchkis bar and whatever I can do with alignment, should be enough for local street tire class, the ultra competitive folks are in different classes, so I should be good,

Understand. Heck, stock classes can be so expensive to run in when you get serious tires and dampers, I'd hate to see what happens to be competitive in SP.

[eltoshan]

Originally Posted by Chowbow

Understand. Heck, stock classes can be so expensive to run in when you get serious tires and dampers, I'd hate to see what happens to be competitive in SP.

Yeah, not looking forward to replacing like 3 drive axles a year in a couple seasons down the like. Most SP classes are much cheaper than BSP though.

[Porschefile]

Originally Posted by cwmizner

don't want too much tire in back do you?

i the idea of 255s all around (although only 8 inch wheel in front vs. 8.5 in back obv)

maybe 265s in back, 255s in front?

Porschefile, what do you run in FRONT?

I run 235's up front without much understeer at all. Tire pressures and the right tires go a long way. I was running 38 psi rear 39-40 psi front (both hot pressures) at my last couple of track days and it handled very neutrally.

[cwmizner]

keep in mind the tires will be the only tires on the car and daily driven.

235s are .3 in higher
265s are also .3 in higher

hmmmm, maybe with stock ride height, that'll look ok, only 'cheat' is 265s list as needing 9 in rim.

options:

1. stock, 225/255
2. 235/255 (little high in front)
3. 235/265 (little high on both ends, rear rim little narrow)
4. 255/255 (front rim a little narrow)
5. 255/265 (both rims little narrow, rear little higher)


I think it's one of those 5 options, beats me what to choose!!!

actually got the car last night, so putting the RFTs up for sale and will need to decide which route to go.

the run flats do 'catch' road imperfections in front i noticed a couple times already (driven the car less than 100 miles), so maybe I don't want to go wider in front from a daily driver perspective?

[cwmizner]

is going taller at one end but not the other going to mess up the DCT at all?

[Chowbow]

Originally Posted by cwmizner

is going taller at one end but not the other going to mess up the DCT at all?

I'm running 235/40/18 F and 255/35/18R RE10Rs without issue. But, I only use those at the autoX so DSC is always off.

Actually, I drive to the track like that too, it's really no issue, the difference is so minimal.

[cwmizner]

if i go 255s in FRONT, how is it going to drive on the street? will it be a handful?

[Chowbow]

Doubt it'll be much of an issue at all, I doubt it'll feel much different on the street.

[cwmizner]

quite a bit wider...

let me ask it this way, why do run 235s in front vs. 255s?

thanks!

[Chowbow]

Originally Posted by cwmizner

quite a bit wider...

let me ask it this way, why do run 235s in front vs. 255s?

thanks!

Because I got them for $400, brand new. It was the size that they had available as a set at the time, so I bought them.

[Porschefile]

I run 235's front because they were cheaper and 255's are a stretch for the front rim. It's an 8" and the rear is 8.5" if I remember correctly.

[cwmizner]

yes, it's a 1/2 inch 'cheat' as specified rim width for the 255 is 8.5 to 10 (this for the star spec according to tire rack)

so yes a bit of a stretch, think I'm going to try them through, here is post to local autocross forum:

http://www.azsolo.com/forums/index.p...=0&#entry94725

[eltoshan]

265/275 is like the norm for competitive autocrossing on 8 inch rims, and people do 285/295 on 8.5 inch. IMO 255 is the lowest you should go on the front. You will want every bit of contact patch you can on the camber challenged BMW, plus the 255s will likely wear slower than the 225-245 tires.

[Porschefile]

Originally Posted by eltoshan

265/275 is like the norm for competitive autocrossing on 8 inch rims, and people do 285/295 on 8.5 inch. IMO 255 is the lowest you should go on the front. You will want every bit of contact patch you can on the camber challenged BMW, plus the 255s will likely wear slower than the 225-245 tires.

True, but if you're running a tire that large on an 8" rim it will be balooned like crazy. Just like the C5 z06 guys here that run 315's or so up front and yeah it works but it looks ridiculous.

[cwmizner]

pretty much going with 255s all around, will be my daily driver/only wheels/tires, so think that's a good compromise.

do you think the 255s will look ridiculous??

it's only a 1/2 inch 'cheat', so doubt it will balloon much, i think it'll look fine???