First Autocross with the 128i in STX

[Rexpelagi]

Here's my fastest run in the 128i at the first event of the season. I ended up first in STX, but the course was a bit unusual for us with all the slow transitions so I'll have to see how it does on a more typical course.

^No, I'm not Jamie Tyler.

Car:
2009 sport package 128i

Setup:
-Stock shocks/springs/rear ARB
-Hotchkis 32mm front ARB
-Vorshlag camber plates
-D-Force LTW5 17X9's
-245/40R17 RE-11's (square setup)
-BMW 'performance' muffler

I didn't have time to get an alignment before the event and I maxed the camber in the front so I'm sure my toe is way way out. I don't know what the rear is at either. I should have that sorted this weekend.

I was fairly happy with the car, although it struggled in the slow corners and the sweepers. The rear of the car was too planted and it wouldn't rotate on throttle, which I'm sure is partially due to the power and partially due to the lack of a differential. I'm not sure if I will prep this car as it's a really nice daily and I'd hate to make it uncomfortable, but I definitely had fun with it and I was pleased with the results. Time will tell how it does on a less transition-heavy course.

[pixelblue]

nice driving! that look like a lot of fun. makes me want to go to one

[Hops128i]

Good driving there! Just went to a scca autocross practice sunday. There were 4 1's there, and a 128i got 2nd in STX. The other 1's (including me) were in DS.

I'm new to autocross, and trying to keep my stock for this season, do you have any pointers for stock wheels/ tires? Or did you start in STX from the get go?

[yandy]

nice driving! looks like an great fun time

[Rexpelagi]

Originally Posted by Hops128i

Good driving there! Just went to a scca autocross practice sunday. There were 4 1's there, and a 128i got 2nd in STX. The other 1's (including me) were in DS.

I'm new to autocross, and trying to keep my stock for this season, do you have any pointers for stock wheels/ tires? Or did you start in STX from the get go?

I've done this for a few years now and I needed another set of wheels for summer (I don't like to switch summer and winter tires on the same wheels) so I went straight to STX.

For the stock classes you have keep the same width/diameter/offset (offset within 0.25") but I'm sure there are some lightweight options out there. However, it probably isn't worth it unless you need a second set of wheels anyway. For tires at a national event you generally need Hoosier A6's to win, but they are big money and I would never recommend race tires like that to someone starting out. Race tires give minimal feedback (if any) and the extreme levels of grip can create bad habits.

My recommendation would be either the Hankook RS-3's or Dunlop Z1 Star Specs, and the size isn't restricted directly, only the rim is. Either of those would be a great tire to start on. The Dunlop is probably the best all-around budget autocross tire available.

A 128i and a good set of street tires would be a great setup to learn autocross on. You will definitely have fun with it!

[Hops128i]

Originally Posted by Rexpelagi

I've done this for a few years now and I needed another set of wheels for summer (I don't like to switch summer and winter tires on the same wheels) so I went straight to STX.

For the stock classes you have keep the same width/diameter/offset (offset within 0.25") but I'm sure there are some lightweight options out there. However, it probably isn't worth it unless you need a second set of wheels anyway. For tires at a national event you generally need Hoosier A6's to win, but they are big money and I would never recommend race tires like that to someone starting out. Race tires give minimal feedback (if any) and the extreme levels of grip can create bad habits.

My recommendation would be either the Hankook RS-3's or Dunlop Z1 Star Specs, and the size isn't restricted directly, only the rim is. Either of those would be a great tire to start on. The Dunlop is probably the best all-around budget autocross tire available.

A 128i and a good set of street tires would be a great setup to learn autocross on. You will definitely have fun with it!

thanks for for the advice! I'm glad the 128i is a good car to autocross, I'm definitely hooked on it. To stay stock in both scca and bmwcca I have to keep stock tire and wheel sizes. It's too bad the sport package has staggered wheels and tires, i wanted to have a easily rotatable setup.

Couldn't find your tire recommendations in the staggered sizes. Do you have any thoughts on the hankook v12, or Cont. extreme contact ? These are level below the RS-3's or Z1's aren't they?

[Rexpelagi]

Originally Posted by Hops128i

thanks for for the advice! I'm glad the 128i is a good car to autocross, I'm definitely hooked on it. To stay stock in both scca and bmwcca I have to keep stock tire and wheel sizes. It's too bad the sport package has staggered wheels and tires, i wanted to have a easily rotatable setup.

Couldn't find your tire recommendations in the staggered sizes. Do you have any thoughts on the hankook v12, or Cont. extreme contact ? These are level below the RS-3's or Z1's aren't they?

Yes, neither of those would be as effective as the ones I suggested. I take it the BMWCCA has different rules regarding tires? Any size is fine in SCCA - only the rim is restricted which makes finding tires a lot easier.

The sport package front tires are a bit of an odd size for a sporty tire so it's not surprising that they aren't available in the ones I listed.

Taking a look at Tirerack the Bridgestone RE-11's (what I'm running) and the Yokohama AD08's are both very good tires and appear to be available in the stock size, but they are a bit more expensive than the Star Specs and the RS-3's. Either tire would be an improvement over the ones you found and should perform very close to the ones I listed previously.

http://www.tirerack.com/tires/tires....omCompare1=yes

http://www.tirerack.com/tires/tires....omCompare1=yes

[Hops128i]

thanks again for the tire advice, keep us posted how the season progresses!

[Bimmer-Bob]

FWIW, I find the rear end to step out pretty willingly if pushed. At least it did so for me on the track last weekend - I've only been to one autocross, but have many more planned for this year.

I'm not on stock suspension, so that could be the main issue.

[Rexpelagi]

Originally Posted by Bimmer-Bob

FWIW, I find the rear end to step out pretty willingly if pushed. At least it did so for me on the track last weekend - I've only been to one autocross, but have many more planned for this year.

I'm not on stock suspension, so that could be the main issue.

On this particular course I was a bit out of the powerband in several tight corners so I couldn't really get the rear loose with the throttle and I didn't notice much action with trail braking. It didn't necessarily have a lot of understeer but the rear also didn't want to slip. I'm sure the upgraded suspension will help you out, although the stock sport suspension didn't seem too bad. Once I get an alignment I'll see how it is as I know the front is completely out.

[Impervious]

Awesome looks like fun!

[jb2178]

I loved autocrossing my 128i, wish I had camber plates. Maybe when I get back into it. It's definately not the best platform for autocrossing but it could be competative. My problem always seemed more to do with the driver than the car.

What wheels are you running for your square setup? I always ran my stocks but I did switch to star specs and upped my fronts to 225/45s and my rears to 235s which helped. The M3 front sway bar helped to but your hotchkis should be even stiffer.

[Rexpelagi]

Originally Posted by jb2178

I loved autocrossing my 128i, wish I had camber plates. Maybe when I get back into it. It's definately not the best platform for autocrossing but it could be competative. My problem always seemed more to do with the driver than the car.

What wheels are you running for your square setup? I always ran my stocks but I did switch to star specs and upped my fronts to 225/45s and my rears to 235s which helped. The M3 front sway bar helped to but your hotchkis should be even stiffer.

I'm running the D-Force LTW5 17x9 ET41 wheels with a 5mm spacer up front. I should be able to fit 255's on the front and rear but without a roll the rear may rub apparently. I figured I'd start with 245's and I didn't notice any rubbing with them, but I'm running a lot of negative front camber (I'll know how much on Saturday).

[jb2178]

Originally Posted by Rexpelagi

I'm running the D-Force LTW5 17x9 ET41 wheels with a 5mm spacer up front. I should be able to fit 255's on the front and rear but without a roll the rear may rub apparently. I figured I'd start with 245's and I didn't notice any rubbing with them, but I'm running a lot of negative front camber (I'll know how much on Saturday).

Good luck on Saturday, make sure to post a new video.

[JimD]

Congratulations! Thanks for the description of your setup and the tire recommendations. I've thought of running some scaa events but haven't yet. I've run 3 BMWCCA events at the performance center and they were a lot of fun. My 128i cabrio is totally stock and I finish in the middle but closer to the slowest than the fastest. Last year I primarily just stuck it in second and shifted only near the finish. I hit the rpm limiter briefly a couple other places but it works better for me than trying to shift and turn at the same time. My skill level needs to improve in other words.

I will have the stock run-flats worn out very soon. I may look at the tires you suggest but it isn't terribly important to me where I finish so I may just get the ultra performance all seasons (contis) I have planned on. They will hold me back a little but I still have room to improve as a driver too. I've also thought about camber plates - or at least the pin removal to get a bit more negative - but haven't done anything yet. Any comments on what mod helped the most would be welcome.

Jim

[Rexpelagi]

Originally Posted by jb2178

Good luck on Saturday, make sure to post a new video.

Nice pictures!

The next race is actually on 4/15. This Saturday (tomorrow) is my alignment so I can see what maxing my camber actually did to my toe settings and correct it.

Originally Posted by JimD

Congratulations! Thanks for the description of your setup and the tire recommendations. I've thought of running some scaa events but haven't yet. I've run 3 BMWCCA events at the performance center and they were a lot of fun. My 128i cabrio is totally stock and I finish in the middle but closer to the slowest than the fastest. Last year I primarily just stuck it in second and shifted only near the finish. I hit the rpm limiter briefly a couple other places but it works better for me than trying to shift and turn at the same time. My skill level needs to improve in other words.

I will have the stock run-flats worn out very soon. I may look at the tires you suggest but it isn't terribly important to me where I finish so I may just get the ultra performance all seasons (contis) I have planned on. They will hold me back a little but I still have room to improve as a driver too. I've also thought about camber plates - or at least the pin removal to get a bit more negative - but haven't done anything yet. Any comments on what mod helped the most would be welcome.

Jim

It's tough to tell as I never raced it stock. However, running any car (especially a strut car) at autocross without negative front camber tends to lead to excessive outside shoulder wear on the front tires. I installed the camber plates partially for this reason and partially to fit the tires/wheels. The front bar is there just to help manage the front end geometry so it won't roll as much and give me positive camber. The camber plates might be a good first mod but removing the pin would be simpler and faster. The front bar is a pretty easy job.

Honestly the best mod you can do for autocross is always tires, but beyond that camber was probably the next best thing if for nothing else besides extending tire life.

[Rexpelagi]

As expected, the front was a bit off.

Front Before:
Camber (L/R) -2.5°/-2.3° (maxed on the camber plates with stock ride height - I did expect a bit more)
Caster (L/R) 6.5°/6.5°
Toe (L/R) -0.31°/-0.23° (-0.54° total toe)

Front After:
Camber (L/R) -2.5°/-2.3° (didn't adjust this - left it at max)
Caster (L/R) 6.5°/6.5°
Toe (L/R) 0.00°/0.03°

Rear Before:
Camber (L/R) -2.0°/-1.4° (good to know that with the work I had done the unaligned front had basically equal camber while the rear was over half a degree different and I'd never touched it )
Toe (L/R) 0.14°/0.12° (0.25° total toe)

Rear After:
Camber (L/R) -1.7°/-1.6°
Toe (L/R) -0.02°/0.01°

We will see if I notice any difference at the event next week.

[3liter1]

nice driving! that course is much larger than the few I have run at. I would consider doing more if I could find some like that in NJ. I do have one question.What camera and mount are you using? I have a track day coming up and am looking for something to mount a compact camera that also shoots video (canon s90)

[Rexpelagi]

Originally Posted by AudiS4

nice driving! that course is much larger than the few I have run at. I would consider doing more if I could find some like that in NJ. I do have one question.What camera and mount are you using? I have a track day coming up and am looking for something to mount a compact camera that also shoots video (canon s90)

I have a GoPro HD that works great for autocross but the mounting system wouldn't really work with another camera. I'm not sure what people are using to mount a compact camera like that.

[Rexpelagi]

Well, I had the second event today and I was again the fastest STX car, but only by ~0.020 - my co-driver was pretty close.

Our regular STX guys were in DC this weekend for the national event there so I didn't have the same competition but the car did ok. I was hoping the alignment might help the car rotate a bit more coming out of some of the corners but either the lack of diff or the lack of power made it difficult.

My fastest run:

Overlay with my co-driver:

[Hops128i]

like the video, that looks like a really fun coarse.