Help me prepare for first 135 Auto-X

[oldskoolbmw]

Hey guys,

I've been autocrossing for about a year in my 1970 BMW 2002



Due to some issues with my 2002 this week (broken exhaust hanger, temperamental carb) I've decided to show up tomorrow morning in my 2011 135i. I have not driven this car competitively yet, and this will be my first Auto-cross event with it.

I was wondering what a good cold tire pressure was to start with on the stock runflats, and also what you guys like to do as far as turning off DTC, etc.... I tried the search and have found everything from 36psi to 50 psi. Maybe somebody who has raced regularly on stock tires can chime in....

Thanks!

[bluesunit]

Cool car. I want a 2002.

Go way high on the pressures in the front . . . the tires will still roll, even at max listed pressure. Prepare to plow.

On the run flats/street tires, I found that the car was faster with DTC off/DSC on . . . it helps keeps you out of death plow situations and will still let you wiggle the rear a bit.

Good luck!

[fboutlaw]

Been autoxing on the 1 for the last year. Agree with blues, go high on the front. With no camber and a thin tire, they roll over easily.

Try 40F/38R first run.

Bleeding the fronts down to 42 after your second run when they warm up. Keep the rears around 38-40.

If you're rolling the fronts (check with chalk) then go to 44psi front.

[CLV0009]

Originally Posted by fboutlaw

Been autoxing on the 1 for the last year. Agree with blues, go high on the front. With no camber and a thin tire, they roll over easily.

Try 40F/38R first run.

Bleeding the fronts down to 42 after your second run when they warm up. Keep the rears around 38-40.

If you're rolling the fronts (check with chalk) then go to 44psi front.

Im looking to get back into AutoX with my new 135i, I used to Autox my 2002 WRX and did one run with my 2006 Mazdspeed 6 (not very successful as the 6 is too hevy and too much body roll). I see you have been doing it with ur 135 for a while, any tips on cheap mods? do you have an extra set of wheels and tires, if so whta size and type? thanks for info, I just dont want to f***kup the car neither make a fool of my self out there.

[fboutlaw]

Originally Posted by CLV0009

Im looking to get back into AutoX with my new 135i, I used to Autox my 2002 WRX and did one run with my 2006 Mazdspeed 6 (not very successful as the 6 is too hevy and too much body roll). I see you have been doing it with ur 135 for a while, any tips on cheap mods? do you have an extra set of wheels and tires, if so whta size and type? thanks for info, I just dont want to f***kup the car neither make a fool of my self out there.

Good luck. The 1 isn't very forgiving in autox.

If you're getting back into it, don't mod anything. Learn how the car feels stock then you can make piece by piece changes and can actually gauge the effect.

After a few autox, I'd suggest:
- Front Sway Bar
- New Wheel/Tire combo to bring the ratio of rubber F/R closer to equal.

After this, the mods start costing a lot of points and will move you around classes in SCCA or BMWCCA autox events.

For me, the biggest gain I've had was swapping my wheel/tire setup to go as wide as possible (255/275) with a good set of max performance tires. Took me from below average to 3rd in category.

[Frampton]

fboutlaw what wheel tire combo are you running, and how can you stuff those in the wheel wells without other mods?

[BrokenVert]

I'll be trying out my new 245 square setup on star specs this month.

The front arb is a big help. I ran stock last year with 225s up front and I had a few digs because I entered a slaloms with a little too much speed and plowed past the first cone

Just work into it, scrub your first run and get a feel for it and work up from there. The car is prone to throttle oversexed so be careful about how much gas you give

[pjdvd]

I autocrossed last half of last year and 3 races this year. while I'm sure others will disagree, I've had better luck with grip up front when I start at 38 cold (41 in the rear). I did that this past weekend and only started to plow after my 3rd run (quick TAT of 7-8 minutes).

Best thing to do when you start plowing through a turn... next time around get on the brakes hard before the turn and go tight and "slow" around the curve. or, get some more negative camber or wider tires or non-runflats or ... I'm sure you know all this since you've been racing a while.

By the way, I'm not sure you'd want to run lower psi in the back. low means more grip which for me has always meant ... more plow.

Once the run flats have been removed, I expect it will be another couple weekends until I get the balance right with the new tires, whatever they may be.

[fboutlaw]

Originally Posted by Frampton

fboutlaw what wheel tire combo are you running, and how can you stuff those in the wheel wells without other mods?

Vorshlaq camber plates, although I'm pretty sure Dinan camber plates would work too with the +45 offset wheel.

[jvb6806]

what tire are you guys running with that high of pressures? that seems a bit high for modern autoX street tire. were they all-seasons?

i have been autoXing for about 9 years now, just bought a 128 and it will be making it's first autoX next week on a set of 225 RS3's. i was going to start at 36 up front and work my way down.

[Lubo]

Originally Posted by jvb6806

what tire are you guys running with that high of pressures? that seems a bit high for modern autoX street tire. were they all-seasons?

i have been autoXing for about 9 years now, just bought a 128 and it will be making it's first autoX next week on a set of 225 RS3's. i was going to start at 36 up front and work my way down.

People who run that much pressure are running mostly stock cars.
With -2.5* up front and 255s all around I start 32cold presssure and keep it around 34-35 hot all day long with best results during autox.

On the track day, I start with 28 front and 29 rear and come in 33-35 hot. No outer tire wear whatsoever and the Star Specs grip like there is no tomorrow at those pressures.

[Frampton]

i've gradually worked my way down to the exact pressures @Lubo is using on the star specs... spot on with camber plates

[jvb6806]

i will be in D-Stock i think for the rest of the year. from what i understand you can get maybe .5deg of camber out of the stock suspension. should i be expecting a ton of understeer? does the e93 front sway take are of most of that?

sorry for the new to BMW questions. i am trying to read as much as i can so if there is already a thread talking about this please point me in the right direction.

thanks,

[Focusedintntions]

Expect quite a bit of understeer. The new sway bar will only increase the understeer, however, you'll get less body roll and better turn in.

[Frampton]

m3 fsb will create more understeer but give you less body roll and more confidence to push the car. can you change the fsb in d-stock?

i run STU class so I;m not sure what you can and can't do in stock class. hopefully you ahve good tires and no run flats!

[jvb6806]

yeah. SCCA stock class allows you to change FSB, adjustable shocks, drop in air filter, stock sized wheels, cat back, and race rubber.

is it worth doing just the FSB?

there are rumors that next year stock class will give you the option to change either the front or the rear sway, but only one of them. i thought i heard something about being able to add eccentric bolts to factory suspension for camber, but that doesn't really help me at all.

i have been in BSP with the old car for three years, so i am just starting to figure all this stuff out. i don't think the car is anywhere near ready to play with the big boys in STX. i have a feeling i would get ROCKED by all the RX8's around here.

[Frampton]

the m3 fsb was my first mod after tires. it turned a well balanced stock car to a very very heavy understeering car. On the street the fsb is a perfect upgrade.

[jvb6806]

cool thanks. i plan to autoX this car at every event i can make it to, so maybe i will hold off on the FSB till i decide if i am going to make the jump to STX.

and maybe bite the bullet and do the rear if they change the Stock rules next year to allow owners to choose their sway bar.

thanks again for the input, i appreciate it.

[Frampton]

What about STU, have you thought about that class it allows a lot more upgrades without playing with the boost?

[jvb6806]

i didn't get that much money after my evo was stolen

i have a 128, i wanted to go back to NA RWD for a while. i have not had one since my freshman year of college. i got into the DSM thing back then and have had turbo AWD ever since.

i will probably pick up another evo in a few years and go nuts with it, for right now i want to keep the BMW pretty simple. but i said the same thing when i bought the evo 3 years ago, so who knows.

i did want a 135 but i figured NA was a change of pace and i could afford a newer one with more time left on the warranty. i didn't want to get into a BMW for the 1st time with an expired warranty. i have heard horror stories about how expensive these things are, but so far it doesn't seem to be any worse than the evo was. if anything it is cheaper.

[BrokenVert]

I dont know about SCCA, but there is a dun loophole in the BMW CCA class rules that allow you to consider your car stock so long as it has all BMW part numbers.

IE you can run an E93 swaybar package on your car without a points or class penalty because it is an OEM BMW part

[jvb6806]

Originally Posted by BrokenVert

I dont know about SCCA, but there is a dun loophole in the BMW CCA class rules that allow you to consider your car stock so long as it has all BMW part numbers.

IE you can run an E93 swaybar package on your car without a points or class penalty because it is an OEM BMW part

wow, that is one hell of a loophole!

SCCA is a bit more strict on that stuff. they added updating and backdating so you can put a 2.5l into your 2.0l WRX as long as you change everything else that came with the 2.5. it is usually a bigger PITA than it is worth.

i wish i could do the M3 control arms to get some more camber. i was thinking about going to a BMW CCA autoX if there are any around the chicago area this summer. should be a good time, and hopefully i could learn a lot about the car.