Z4 for Autocross/AX?

[nilfinite]

Has anyone tried using the e89 for AX? I have a stock z428 that I tried for the first time at a BMWCCA event and did really well with it. It was a top driver shootout with 80 drivers and I was in the top 10.

At the event, I found the car was a lot faster with DSC on than without. The rear of the car rotated really well with DSC partial on. Probably because I'm still learning the car.

I'm planning on autocrossing mine more in the coming year. It runs in BS in the SCCA. Against the Audi TT, C5 Z51 Corvette, 370Z, S2000 & WRX STI.

I haven't seen anyone in my region use the E89 so it'll be interesting to see how it does. Not holding my breath though. The C5 Z51 Corvette has similar weight but with 110 more hp and 100 more tq.

[nicknaz]

I think your observation on weight/power is why you haven't seen many E89

[nilfinite]

Yeah... That was my initial impression as well. The S2000 does pretty well in BS though.

I think locally the Z4 should do well in BS but it's definitely not capable of winning nationals.

[nicknaz]

2014 nationals results
http://scca.cdn.racersites.com/prod/...ls%20Final.pdf

As you mentioned C5 Vette and S2000 do really well in BS, and the 07 Miata MSR is there as well.

The Miata MSR that came in 3rd this year was for sale in San Diego for ~$11k, fully sorted out and ready to go.

I think that cost factor is probably another reason you don't see E89 to often. (i.e. why pay more for a platform that isn't or may not be competitive?)

That doesn't take away from E89 being fun to drive in AX (I took mine to a school last year for fun) or HPDE (other than limp mode/power reduction I get in my 35i each and every time I track it.....) but just doesn't seem like the right car if you are planning to go to Nationals. I think the 08 Boxster placing at the back of the pack in BS is potentially a hint as to how E89 will perform in that setting

[army_men]

I wouldn't go Nationals with E89 for the fear of damaging it. Having said that, any non-competitive events the E89 has been super fun to throw around in. I find it a little too heavy on the skidpad sessions and I couldn't consistently throw the tail out and remain under control.

I took it to BMW Advanced driving school on Mosport, ran in Class B and it can hang with the corvette and porsches with ease. But I don't expect it being the track star any time soon.

[nicknaz]

Originally Posted by army_men

I took it to BMW Advanced driving school on Mosport, ran in Class B and it can hang with the corvette and porsches with ease. But I don't expect it being the track star any time soon.

How were your oil temps? I'm surprised you didn't get power reduction / limp mode. You are full bolt ons right? Street tires?

I've passed very conservatively driven 997.2 GT3 and 991 Turbo S at TMP, but when there are used aggressively by experienced drivers, I think they are in a very different performance class

[army_men]

Originally Posted by nicknaz

How were your oil temps? I'm surprised you didn't get power reduction / limp mode. You are full bolt ons right? Street tires?

I've passed very conservatively driven 997.2 GT3 and 991 Turbo S at TMP, but when there are used aggressively by experienced drivers, I think they are in a very different performance class

I was running stock before. and I'm full bolt on now minus exhausts. No heat soak or limp mode actually. Yokohama AD08 tires. The car hauled ass but I don't think Class B drivers are very fast. They had a conservatively driven ferrari 430 scuderia too that we all passed for fun.

[nicknaz]

Originally Posted by army_men

I was running stock before. and I'm full bolt on now minus exhausts. No heat soak or limp mode actually. Yokohama AD08 tires. The car hauled ass but I don't think Class B drivers are very fast. They had a conservatively driven ferrari 430 scuderia too that we all passed for fun.

I'm so jealous you aren't getting heat related issues. I've had my car looked at a few times and techs keep saying its normal

Here's a pic from my last time out. 290F, after 1/2 a lap of cool down and driving through pits at Buttonwillow. It was at 300F when I started decided to cool down and pit

Timing was informal because I didn't rent a transponder that day, I was estimate I was in the 2:11-2:15 range at Buttonwillow CW13, based on the cars I was keeping pace with who had transponders. It was an open passing run group, car was stock with dunlop zii tires

[nilfinite]

The Z4 really surprised me when I ran with the BMWCCA. I was easily getting great times in the wet (left ESC on). Especially with stock everything and first event in the car. (My other AX car is FWD too)

When things dried up, I turned ESC off and noticed the car didn't like rotating as much.

Looks like the EDL system on our cars work really well per this thread: http://e89.zpost.com/forums/showpost...6&postcount=20

It's certainly an interesting car to AX but I think it has the capabilities of doing well locally. I'll give it a go for a season and see what happens. We don't have many C5 Z06s competing in BS in my region. I should be mostly racing against S2000s and Cayman/Boxters.

[Bossdog]

Hello,
I just purchased my first BMW, a Z4M roadster. I have tracked and autocross in recent years. I won't be tracking the roadster but I would like to autocross a bit just to get my driving jollies. I plan to stay stock, I guess she runs in B Stock? Anyway, I think I can add the front strut tower brace and still be stock?? The BMW rims are heavy and right now they have Goodyear fun flats on, a real killjoy to drive aggressively.
My plan is to purchase some Apex Arc 8's, 18x9 / 18x10. I am considering Bridgestone RE11,s and NT05's. I know the RE11's are stalwart when it comes to autocrossing. I have run NT05's on my STi and I really liked them. Any thoughts on whether the RE11's are with an extra $50 a tire over the NT05's?

[nilfinite]

Yup the Z4M is in BS as well. In stock class, you can't have the strut brace I believe. You can swap/modify/add one sway bar though.

Also the wheel width should match the width of the stock wheels. (8" F and 9" R). Diameter can be 1" wider or narrower (17"-19"). Offset can be 7mm +- from stock specs.

For tires, RE-11 is a good fit especially if you plan on doing both AX & DD. The best AX-focused tire is RE-71R or Rival S as of now. Don't recommend DD-ing them because they are crazy soft. Ran a season with the RE-11 and was happy with them. Was pleased with how they stayed sticky after multiple heat cycles from driving on them to and from work. It's not common to run the NT05's for AX. Hankook RS-3s are the favorite AX-only tire from last year. See lots of people doing DD & AX with the RS-3. Only issue is that they heat cycle and lose grip the more you drive em.

Reality is that if you are just autocross locally with the SCCA and you are there to have fun, no one is going to care about your wheel setup + other stuff. If you dominate in your class, then you should probably follow the rules. BMWCCA has a point system where your class goes up and down depending on your mods. So no problem there.

Here is a decent summary of SCCA rules: https://www.sff.net/people/dburkhead/prepcompare.htm

I've been mostly AX-ing my Abarth. Here is more detail that you can read tailored for other cars.
http://www.ft86club.com/forums/showthread.php?t=35855
http://fiattech.com/forum/fiat-motor...street-gs-mods

[Bossdog]

Originally Posted by nilfinite

Yup the Z4M is in BS as well. In stock class, you can't have the strut brace I believe. You can swap/modify/add one sway bar though.

Also the wheel width should match the width of the stock wheels. (8" F and 9" R). Diameter can be 1" wider or narrower (17"-19"). Offset can be 7mm +- from stock specs.

For tires, RE-11 is a good fit especially if you plan on doing both AX & DD. The best AX-focused tire is RE-71R or Rival S as of now. Don't recommend DD-ing them because they are crazy soft. Ran a season with the RE-11 and was happy with them. Was pleased with how they stayed sticky after multiple heat cycles from driving on them to and from work. It's not common to run the NT05's for AX. Hankook RS-3s are the favorite AX-only tire from last year. See lots of people doing DD & AX with the RS-3. Only issue is that they heat cycle and lose grip the more you drive em.

Reality is that if you are just autocross locally with the SCCA and you are there to have fun, no one is going to care about your wheel setup + other stuff. If you dominate in your class, then you should probably follow the rules. BMWCCA has a point system where your class goes up and down depending on your mods. So no problem there.

Here is a decent summary of SCCA rules: https://www.sff.net/people/dburkhead/prepcompare.htm

I've been mostly AX-ing my Abarth. Here is more detail that you can read tailored for other cars.
http://www.ft86club.com/forums/showthread.php?t=35855
http://fiattech.com/forum/fiat-motor...street-gs-mods

Thanks for your reply! I'll probably go with the RE-11's