135i Build - track toy with a license plate

[berns]

Originally Posted by gmx

Just realised you are bernb5 on AZ? I remember your A4GT30R vid from a decade ago!

EDIT:
Read the entire thread, this is awesome. Switched spring rates yet? I keep hearing this soft spring big bar theory - might try it out.
2F8F code is from left foot braking or probably even heel-toeing. Get tuner to turn it off, otherwise no big deal.
Have you turned off all the safeties/coding not in the DME but elsewhere and other modules? There are things like pad knock off, power reduction due to brake temperature etc
http://www.onelapx1.com/blog/how-to-...w-actually-fun

haha, small world!
I'm running 8k front, 14k rear, Eibach sway bars. Car feels great.

Originally Posted by spxxx

Lol Alex... You had a GT30R A4 1.8t?

I think we might be the same person? I had a GT28R 1.8t A4 like 10+ years ago in high school lol.

When's your next track day?

Haha, yes, I had a 30R A4. A 3071R GTI 337. A mk4 R32. Saab 9-2x Aero (saabaru), two Evo's, an E46 M3, E90 335i and I think a couple others...

My next track day.. I've been to a few! Went to Buttonwillow yesterday and finally accomplished my goal.

[berns]

I've been waiting to finish the rear widebody and add a rear wing and front splitter, but didn't want to do any aerodynamic or further grip enhancements till I went sub-2 minutes at Buttonwillow CW13.

Yesterday I finally did it, with a car in front of me to boot. 1:58.47 on street tires with no aero! Car definitely has a 1:57 in it with fresh tires. Here's my front left after two days...

[Ginger_Extract]

Congrats, Alex! Hitting the sub-2, after a million years, was very satisfying, so I know how you feel.

[trainerjon]

Nice job! Great driving man

[spxxx]

That's badass! Congrats dude.

Still convinced that the Rivals are the best choice? That seems like a crazy amount of wear for 2 days. I can't afford that kind of weekly HPDE investment lol

Most tests I've seen still show the RE71s as faster at the expense of slightly faster wear but I always get 5+ track days out of mine. They sure are wide though.

What's the ETA on the rear conversion?

[berns]

Originally Posted by spxxx

That's badass! Congrats dude.

Still convinced that the Rivals are the best choice? That seems like a crazy amount of wear for 2 days. I can't afford that kind of weekly HPDE investment lol

Most tests I've seen still show the RE71s as faster at the expense of slightly faster wear but I always get 5+ track days out of mine. They sure are wide though.

What's the ETA on the rear conversion?

Honestly, this wasn't normal wear. Two issues contributed to the premature failure of the front left tire:
1 - Ran Streets of Willow CW with no ABS for a day. Streets is a tight, technical course that eats up tires, especially the front left because it's almost entirely right-hand turns. Paired with no ABS, I had a few oh-shit moments and likely flat spotted a few of my tires, leaving massive skids on the track. Still managed to PB though with a 1:25.4!
2 - Fixed the ABS, but went back to buttonwillow and not only did I not rotate my tires because of the stupid staggered offsets, but I didn't flip them left to right, either. The remaining three tires have an easy two days left of them. I just messed up.

To top it off, I really feel like the car still doesn't want to rotate and am definitely still battling understeer. Either over-driving or just fighting the lack of front mechanical grip.

I'm not convinced the Rival S is better than the RE71R or the Sur4G, and definitely not convinced it's better than the A052. These four tires are undoubtedly the best and I don't think you can go wrong with either. If you're not competing for times or personal records, I'd probably just try to get a bunch of Federal RSR-R's to hang with until it counts.

Rear conversion will start this week or next, but I'm sure it'll be down for at least a month.

[spxxx]

Originally Posted by berns

Honestly, this wasn't normal wear. Two issues contributed to the premature failure of the front left tire:
1 - Ran Streets of Willow CW with no ABS for a day. Streets is a tight, technical course that eats up tires, especially the front left because it's almost entirely right-hand turns. Paired with no ABS, I had a few oh-shit moments and likely flat spotted a few of my tires, leaving massive skids on the track. Still managed to PB though with a 1:25.4!
2 - Fixed the ABS, but went back to buttonwillow and not only did I not rotate my tires because of the stupid staggered offsets, but I didn't flip them left to right, either. The remaining three tires have an easy two days left of them. I just messed up.

To top it off, I really feel like the car still doesn't want to rotate and am definitely still battling understeer. Either over-driving or just fighting the lack of front mechanical grip.

I'm not convinced the Rival S is better than the RE71R or the Sur4G, and definitely not convinced it's better than the A052. These four tires are undoubtedly the best and I don't think you can go wrong with either. If you're not competing for times or personal records, I'd probably just try to get a bunch of Federal RSR-R's to hang with until it counts.

Rear conversion will start this week or next, but I'm sure it'll be down for at least a month.

Ohhh I've heard Streets is horrible for tires, I ran a few laps there CCW and actually tore up some RSRR tires haha think I managed a 1:26 something. 1:25 is moving for sure.

Yeah I should have stocked up during Americas Tires eBay sale. Toally fine paying $200ea for RE71s. They wear about as fast as RSRR which are about $120ea so the price difference is negligible during these sales.

The smart move would be running the Federal FZ or NT01s and saving the 200s for GTA or Time trial events. The FZs are similar to NT01s (similar grip level to RE71/SUR4/Etc) but last twice as long and are $135ea.

Definitely document the rear conversion - I'm interested to see if going full quarter panel is easier or just the lower section.

[trainerjon]

1:25 is moving for sure at Streets. It's a bit disappointing to hear that you are still having a difficult time getting the car to rotate with all the work you've done. I'd be curious to see if you put on some really sticky tires to see if that helps at all with more mechanical grip in the front.
I had the same experience at Streets last weekend with a huge lack of mechanical grip in the front. My fastest time was a 1:31 with some old Pirelli's that were like ice skates out there. The front of the car would skip across the track and push real hard.

I've been wondering if I should put the money into an LSD, half cage, wide body, and some engine mods, weight reduction, seats, aero etc... OR should I just go buy an @30 race car or e36M3 race car and move on to a more predictable situation.

It seems like an endless journey with no end to get these cars to work the way we think they all should???

Here's some video - turn up the volume and you can hear the tires complain!!!

[berns]

Originally Posted by trainerjon

1:25 is moving for sure at Streets. It's a bit disappointing to hear that you are still having a difficult time getting the car to rotate with all the work you've done. I'd be curious to see if you put on some really sticky tires to see if that helps at all with more mechanical grip in the front.
I had the same experience at Streets last weekend with a huge lack of mechanical grip in the front. My fastest time was a 1:31 with some old Pirelli's that were like ice skates out there. The front of the car would skip across the track and push real hard.

I've been wondering if I should put the money into an LSD, half cage, wide body, and some engine mods, weight reduction, seats, aero etc... OR should I just go buy an @30 race car or e36M3 race car and move on to a more predictable situation.

It seems like an endless journey with no end to get these cars to work the way we think they all should???

Here's some video - turn up the volume and you can hear the tires complain!!!

Streets is a TOUGH track to find good manners in the car. All cars struggle there, but once you find a good setup at Streets, you will likely feel good at all tracks. My car is certainly the best it's ever been. I'm not a pro race team, I don't go out on big test days and make changes on the fly, look at data, temps, etc... still very much a learning process. You can see, at least, the work and seat time has paid off in the same chassis, result in 5+ seconds on a short track. That's huge between our cars, so not a waste to have fun with this chassis!

I will say, an E36 at 2800lbs with some nice rubber and good suspension, will be fun and predictable and just as fast or faster than a 135i.

I think about it often, ha, but I'm too far in at this point. I think with a 15 or 16k rear spring the front end would come further into check. The rear doesn't feel out of control by any means. it's playful but not scary. Would be interested to see, maybe I'll try for the hell of it.

[spxxx]

What spring rates are you running now?

[berns]

Originally Posted by spxxx

What spring rates are you running now?

8k/14k

[spxxx]

Originally Posted by berns

8k/14k

Cool, I'm 450/750 #imperialsystemsucks

Are you considering bumping to 9k/500lbs up front?

[berns]

Originally Posted by spxxx

Cool, I'm 450/750 #imperialsystemsucks

Are you considering bumping to 9k/500lbs up front?

Nope, I'm considering bumping to 15k/840lb rear and leaving the front as-is. Our rates are just about identical.

kg/mm to lbs/in
—————————–
16 = 896
15 = 840
14 = 784
13 = 728
12 = 672
11 = 616
10 = 560
9.0 = 504
8.5 = 476
8.0 = 448
7.5 = 420
7.0 = 392
6.5 = 364
6.0 = 336
5.5 = 308
5.0 = 280
4.5 = 252
4.0 = 224
3.0 = 168
2.0 = 112

[spxxx]

Originally Posted by berns

Nope, I'm considering bumping to 15k/840lb rear and leaving the front as-is. Our rates are just about identical.

kg/mm to lbs/in
—————————–
16 = 896
15 = 840
14 = 784
13 = 728
12 = 672
11 = 616
10 = 560
9.0 = 504
8.5 = 476
8.0 = 448
7.5 = 420
7.0 = 392
6.5 = 364
6.0 = 336
5.5 = 308
5.0 = 280
4.5 = 252
4.0 = 224
3.0 = 168
2.0 = 112

Heh, I meant rear rates... Long weekend.

I think some a tad more rear spring will help the car rotate for sure. Someone on here is running ~1,000lbs rear springs which seems pretty high. I might try ~800 rears sometime soon. Really just want to get out there while it's cool and dry to see what the car can do without overheating.

Just run 285 front and 275 rear tires to help balance it out lol

I can't wait to see your car with the rear bodywork done.

[arc_resistant]

I'm running a 6k/18k setup on YCW coilovers.
Square 235/40/18
Whiteline poly RSFB, M3 front arms
-2.5 deg camber up front. Slight toe out.
Everything else is factory stock, including sway bars.

I track the car 7-8 times per year, so have some experience with this setup.

Car is much closer to neutral now, but still has understeer.
In fact, when I first put the coilovers on, the handling was very similar to stock. I could trail brake same as before and car wasn't any more prone to rotate.

The thing that made a difference was lowering the front ride height by 1/4" or so. The car came alive. Easier rotation on corner entry and more importantly I could adjust rear slip angle on corner exit with the throttle instead of just having a choice of more or less understeer. Hard to believe such a small adjustment was enough to put the car in the "window" of proper handling.

That said, car still understeers too much for my taste. I want to try a SOFTER front sway bar an see if that neutrals things out a bit more.

Also, looking at post 244 above, video at Buttonwillow. Driver is putting a LOT of steering wheel into the car. Appears to be understeering heavily. I think rear spring rate could definitely be increased without risking it being crazy loose.

Originally Posted by spxxx

Heh, I meant rear rates... Long weekend.

I think some a tad more rear spring will help the car rotate for sure. Someone on here is running ~1,000lbs rear springs which seems pretty high. I might try ~800 rears sometime soon. Really just want to get out there while it's cool and dry to see what the car can do without overheating.

Just run 285 front and 275 rear tires to help balance it out lol

I can't wait to see your car with the rear bodywork done.

[bbnks2]

Originally Posted by arc_resistant

I'm running a 6k/18k setup on YCW coilovers.
Square 235/40/18
Whiteline poly RSFB, M3 front arms
-2.5 deg camber up front. Slight toe out.
Everything else is factory stock, including sway bars.

I track the car 7-8 times per year, so have some experience with this setup.

Car is much closer to neutral now, but still has understeer.
In fact, when I first put the coilovers on, the handling was very similar to stock. I could trail brake same as before and car wasn't any more prone to rotate.

The thing that made a difference was lowering the front ride height by 1/4" or so. The car came alive. Easier rotation on corner entry and more importantly I could adjust rear slip angle on corner exit with the throttle instead of just having a choice of more or less understeer. Hard to believe such a small adjustment was enough to put the car in the "window" of proper handling.

That said, car still understeers too much for my taste. I want to try a SOFTER front sway bar an see if that neutrals things out a bit more.

Also, looking at post 244 above, video at Buttonwillow. Driver is putting a LOT of steering wheel into the car. Appears to be understeering heavily. I think rear spring rate could definitely be increased without risking it being crazy loose.

Pull the front sway out and see if the stock bushings are stuck to the bar. If so, cut them off and get a set of aftermarket bushings that won't bind.

[drunkenup]

How's the clearance of your vrsf inlets with the CSF rad? Mine are basically touching the belt. Did you do any modifications to clear?

NVM saw your solution. I will try the same.

[Taskmaster]

Originally Posted by berns

If you're looking at the VERY first post in this thread, then no -- the car was not aligned in those photos. I had just installed the coilovers and test fitted the wheels at that point.

Running -3* up front and -2.9* out back right now.



265 front on a 9" wide wheel no-less! It is the +42 ARC8 from APEX with a 3mm spacer, and the rear is the 9.5" +58 with a 10mm spacer.

Camber is playing a big roll here, for sure, but up front the biggest factor is that with a 7" Swift spring, the lower coilover perch is just above the top of the tire. I am only running the 3mm spacer for piece of mind, but the wheel and tire fit without.

I know it seems like black magic, but this is a fairly simple setup to replicate, with minimal work. It just took some testing and calculating, and willing to waste time and money, to see if it worked. I'm glad I did.

Way too much camber our back - that’s ridiculous.

[berns]

Update time! Finally got going on the body work.

Ruined my beautiful Seibon hood with this Trackspec hood vent, built for the E92 M3. This should make a big dent in my temp issues, though, so I'm willing to sacrifice looks for glory.






I picked up a Seibon carbon trunk at the Seibon Garage Sale late last year. It was $65... You read that right! As you'd imagine, fitment isn't the best but I can't complain for the price. I got right to mocking up the new APR GTC-250 wing.

Shortly after that, we removed the rear glass and the rear quarter glass.



I stopped by APR Performance today with my front lip so we could trace it out, and my new carbon front splitter will be ready in the next week or so. Mounting that should be fun...

Got most of the interior out today, and since the rear glass is already removed, I decided I might as well do a carbon roof now. It was on my dream list, but I'm halfway through the labor and really don't want to come back to the body shop again. Too much down time during prime track season!

Went with an iND Distribution / RKP roof. Should be here by the end of the month! Need to source a 1M headliner... More soon.

[HyeWarrior]

Man I love this thing

And congrats on the Supra gig! So amazing!

[ajsmithvmi]

Your prime track season is my frozen nightmare.

How far behind the rad fan is that hood vent? I can't decide where to put mine.

[berns]

Originally Posted by HyeWarrior

Man I love this thing

And congrats on the Supra gig! So amazing!

Ah, thank you! Was a pretty incredible opportunity for me. Highlight of my career for sure.

Originally Posted by ajsmithvmi

Your prime track season is my frozen nightmare.

How far behind the rad fan is that hood vent? I can't decide where to put mine.

Ha, yeah, fortune to live in LA. But I miss my NY winters...

I was a bit limited on how far back I could place the vent because of the hood bulge. Ideally you'd like about 7" behind the radiator I believe. I'm at 5", so not perfect but should definitely have a big impact on ventilation and help with downforce as well. Would be really cool to build a duct underneath it but there is so little room in there for anything.