Official 135i/128i SCCA FS/STU/STX Chat thread

[Ginger_Extract]

It seems that a number of us have decided to prep our cars for SCCA Autocross Street Tire classes, with the 128i being in STX, and the 135i in STU. Discussion on setup, questions, events, etc. is on the forums, but is scattered. In the same direction taken by other forums, I have decided to make an "official" chat thread. This way, autocross discussion can be easily tracked, and referenced, if need be, or if people have any questions.

I'll get started with some basic info on my 135i. It's a dual function car, prepped in line with STU rules, but also geared towards track use.

- Intake, Exhaust, Tune (changed as necessary for SCCA)
- TCK Singles + Vorshlag, Eibach big front bar, Whiteline RSFB inserts
- MFactory Torsen Diff
- 17x8.5 wheels with 255/40 RS3
- Race weight is just a hair under 3400# w/ 3/4 tank of gas and my 185# self in the driver's seat.

Here's a pic as she sits:


My goals for 2015 is to get more wheel/grip under the car and learn more about reactive shock and tire tuning after watching my competitors destroy me at the last ProSolo.

[Kgolf31]

Good idea, I like this.

2012 BMW 128i
M Sports Package, No Sunroof

Modifications
TCKline Dual Adjustable Suspension + Camber Plates
APEX 17x8.5 ET40 w/ 245/40 Hankook RS3s
Recaro SPG w/VAC Mounting Hardware
Diffsonline 3-Clutch Custom Ramp LSD
Active Autowerke Headers + Tune
Eibach 28mm Front Bar
Turner Motorsports Adjustable Front Endlinks
UUC 19mm Rear Bar
M3 Subframe Bushings
Powerflex Race Differential Bushings
Hawk HP+ Pads
Muffler Delete

I'm sure I'm missing something here or there.


Race weight currently 2991 with 1/4 tank and without me in it.

Car currently has 1 National Win under it's belt (Toledo ProSolo)

Goals for this year:
Install Braile LTW Battery
Get 17x9 w/255 Tires to fit w/out compromising ride height.

As she sits:

[The Nebulizer]

I think the 135i best fits in FStreet. Here is my new car:

2011 M-sport 135i
Manual

Modifications:
Eibach 20100.310 FSB
18x7.5/8.5 Breyton GTS-R (may shave the rears hub down a few mm)
245/275 BFG Rivals (not mounted yet)

Future (possibly):
Koni yellows
lightweight muffler

(with my main FStreet car in the background)

[M. Holtmeier]

I just got my track wheels fitted yesterday. This will be my first a-x season where I had a car ready to go before the season started. Not looking forward to losing in STU, but I bet it will be fun no less. I've already picked up a few pointers reading Kgolf's posts. (Thank you!)

'12 135i M-sport DCT
Mfactory helical LSD- stock gearing
Eibach Multi-Pro R1 coil overs
300# front springs, 600# rear
2.75* front camber, 2.25* rear- zero toe
Ground Control camber plates
M3 RSFBs
Muffler delete
TRM c2 17x8.5 et40 wheels
245/40 RS3s

I have a question: Are the aluminum n55 charge air pipes legal in STU? Mine just broke at the TB last night while doing some test driving with the track wheels. I'd like to avoid that at the track.

[Ginger_Extract]

Small update: Will be testing an 18x9 w/ 255/35 RS3 fitment up front in the next week. Will report with clearance and fitment impressions and pics.

[Kgolf31]

Originally Posted by Ginger_Extract

Small update: Will be testing an 18x9 w/ 255/35 RS3 fitment up front in the next week. Will report with clearance and fitment impressions and pics.

Please do.

Where does your perch sit currently? Mine is basically at the tire height, so my min clearance needs to be to the perch, not the shock body.

[Kgolf31]

Originally Posted by M. Holtmeier

I have a question: Are the aluminum n55 charge air pipes legal in STU? Mine just broke at the TB last night while doing some test driving with the track wheels. I'd like to avoid that at the track.

I need to find where it states, but I'm fairly sure you can change the piping to and from the intercooler

[M. Holtmeier]

Cool. I read "silicone hoses." But was unclear on this. At the moment I'm still "sponsored" by BMW, so I'll put a stock one on for now.

[Ginger_Extract]

Originally Posted by Kgolf31

Please do.

Where does your perch sit currently? Mine is basically at the tire height, so my min clearance needs to be to the perch, not the shock body.


From my rough calculations, I think an ET35-33 is required to have clearance

Clear out your PM box.

My perch is situated higher than yours, just above the tire. Still getting -3.2* camber, so not much compromise there if you need to raise it up. For reference, I too run 17x8.5 ET40 ARC8 w/ 255/40, no spacer, and I clear the strut just fine. My math is that we may be able to get away with a 9" ET35-37 with a 245 or 255. We shall see.

[Kgolf31]

Originally Posted by Ginger_Extract

Clear out your PM box.

My perch is situated higher than yours, just above the tire. Still getting -3.2* camber, so not much compromise there if you need to raise it up. For reference, I too run 17x8.5 ET40 ARC8 w/ 255/40, no spacer, and I clear the strut just fine. My math is that we may be able to get away with a 9" ET35-37 with a 245 or 255. We shall see.

No PM because full. Send again please

I'm going to try and throw my wheel up there w/out a spacer and see what my clearances are and my perch this weekend.

[M. Holtmeier]

You're running front spacers, correct? My 17x8 et40 wheels look like this with the Eibachs:

[M. Holtmeier]

I added a 10mm spacer on the strut to clear the perch.

[Ginger_Extract]

The warranty is voided if you remove those lock collars? That's silly, it doesn't look like you need them, and you're ceding a lot of wheel clearance in a crucial area...

[M. Holtmeier]

I had them rebuilt and the stickers came on there to identify them, since I have a year warranty on the dampers.

Yeah, the sway bar mounts take up some room.

[Ginger_Extract]

Originally Posted by M. Holtmeier

I had them rebuilt and the stickers came on there to identify them, since I have a year warranty on the dampers.

Yeah, the sway bar mounts take up some room.

Oh, it's a sway bar mounting point, I see that now, that's weird. I wonder why they didn't do the welded tab style mount like the OEM shocks??

[Kgolf31]

Here is my current ride height and perch on DD tires. I might need to go to shorter springs

[Ginger_Extract]

you need to take a pressure washer to your suspension. how do you do any work in there and not come out the other end being filthy?! also, your suspension makes it easier to detect leaky shocks.

[Ginger_Extract]

May have lucked out, found a friend with a C5Z with a spare pair of C5Z front wheels, which are 17x9.5 ET55. Corvettes effectively share the same bolt pattern as Bimmers, going to try and bolt them up to the rear and see how the fitment looks.
Beyond that, picked up a set 255/35R18 RS3V2 take offs for cheap locally, going to mount one up to a spare 18x9 wheel I have laying around and measure front clearances. Should have all of this done by the upcoming weekend. Stay tuned on that front.

[Kgolf31]

Originally Posted by Ginger_Extract

you need to take a pressure washer to your suspension. how do you do any work in there and not come out the other end being filthy?! also, your suspension makes it easier to detect leaky shocks.

LOL, sorry for winter.

I threw a pressure washer to it this weekend.

[M. Holtmeier]

Nice. What are the offset of those wheels?

[Ginger_Extract]

Originally Posted by M. Holtmeier

Nice. What are the offset of those wheels?

x2, trying to find wheels/specific specs on TireRack is so tedious. I'm guessing that it it's the same as the 5x114 wheel it's 17x9 ET45?

[Ginger_Extract]

How did you find the wheel on tirerack, i.e. what model of car did you plug in to find the wheels? Please post pics and all the gory details. Getting my 18x9 + 255/35 mock up wheel mounted/balanced this weekend, will report back ASAP.