Bernooo's E92 M3 Clubsport Build

[911r]

Originally Posted by Lienrocs

Yup. I see where I went wrong. I have an oe GTS cage waiting to go in and the slon carbon panel coming. I'm having a hard time between going as light as possible or fill GTS.

GTS>>

[slicer]

Originally Posted by Lienrocs

Yup. I see where I went wrong. I have an oe GTS cage waiting to go in and the slon carbon panel coming. I'm having a hard time between going as light as possible or fill GTS.

Originally Posted by DRLane

This cage bolts to the chassis via rear mount points. The slonik panel fills that in.

GTS cage doesn't enter the trunk area - there's no bolting to the chassis via "rear mount points". The mount points reside in front of the trunk pass through and are welded in place brackets that come with the cage. You could run both without modifications to the slon piece. The only issue would be the seat delete panel. That has bolts that would penetrate the panel unless you modified.

[macdude357]

Just to close on the Trophy ST60 vs. Trophy ST40 weight differences, I finally did the swap. ST40 caliper, bracket, pads and rotor came to 33lbs. Same parts for the ST60 came to 35lbs. So a whopping 2lbs per corner.

[berns]

Dad life and work life = the slowest updates, but here we go.

Last time I left off, I'd made some changes to the StopTech kit to try to improve braking feel / ditch the knockback I was feeling at Buttonwillow.

I also finally swapped the inner barrels of two of my 18x10 Fikse's and added an inch inside to make them 18x11, so I could try to run the Falken 275/35 on 10" up front and the massive 315/30 on the 11" out back. This wide staggered setup is only due to the availability of sizes from Falken right now. I think staggered can work well on this car, but they need to be closer in size, like 295 front / 315 rear, or 265/295... you get it.







Naively, I suppose, I slapped this new tire setup on and headed out to Buttonwillow for Round 2 of Bimmer Challenge. Following my 2nd place finish at Rd. 1, I was confident going to my "home" track, and I was (overconfidently) expecting to dip into the 1:53's. Oops.

I assumed I'd need to stiffen up the rear of the car to compensate for the newfound grip, but figured the lateral grip and grip on-power would be enough to shave off massive time. You can already tell where this is going. Major. Fucking. Failure.

I was frustrated all day. ABS felt like shit. Front grip was all over the place. Turn-in was trash. The car that literally never understeered, all of a sudden, now became a push monster. Without a ton of time for test and tune, I really used up the time I had on the staggered setup in the first two sessions with no luck, and decided to throw on my 2-day old 285/30's out back, while keeping the new 275/35's up front.



Instantly, the car felt better. I had my balance back, and the car was rotating again, but of course, rear grip was just not there. Still, I managed to set my best lap of the day like this, but anyone who spent some time behind me came up to me afterwards and asked if all of my fast laps look that insane... Maybe I just like being sideways. My best was a full second off my previous Buttonwillow PB, on fresh 285s, on a damp track, with major brake issues. What a bummer. At this rate, temps are getting warm and I probably won't be able to get that 53 any time soon. Here's my best lap from the day which was only good enough for 4th out of a massive 23-driver B3 class.

A bit discouraged, I headed home and parked the car. It sat in the garage untouched until Bimmer Challenge Round 3 at Chuckwalla. With zero time to even swap wheels, or wash the car, I decided to just give the staggered setup another try, since Chuckwalla is such a different track with a way better surface and a higher premium for lateral grip with all the massive high speed sweepers. I also felt that, while I had an annoying day at Buttonwillow, I learned more about what the car would need to overcome the rear grip of the 315s, which meant starting with new base tire pressures as well as base suspension settings on the MCS 1WNR's.

I hit the road at 10pm the night before and made the 3+ hour drive to sleep at the track.



Traditionally, I'd been running about 10 clicks front and 6 clicks rear on a square setup. Even still, as you've seen, the car loves to rotate and drift, and while sideways isn't the fastest, the car feels the best moving around like that, to me. I'd also always run even pressures front and rear, usually around 33 hot on the RT660's.

Starting my day, I set the rear tires 2psi higher than the fronts, and went out with 8 clicks front, 10 clicks rear. Car felt OK in the first session but it wasn't sideways at all, which meant I had to go further. I kept pressures the same and went for 12 clicks out back. BINGO. Front end was working, and the car was finally swinging around the turns the way I liked, except when it was time to get on power... man, there is just so. much. grip. The newfound traction paired with the taller sidewalls made the ol' E92 feel kind of sluggish. It's the first time I was missing the power of my old 1M-clone build. If the car were to stay on this tire setup, I'd for sure go for the 4.10 gearing, where on the 285/30's or 295/30's the stock gearing feels perfect.

Of course, I decided to try a new camera location and external mic setup for this day, and I have no video to show you. IS the staggered setup faster than the square setup though? At this track, I think they'd be close. But I'd need to go back in the same conditions with equally fresh 285s to find out. Regardless of getting the car to do what I wanted, which was a victory in itself, I still prefer the sidewall stiffness, balance and overall agility of the short sidewall square setup, but hey, it's cool to have learned any of this, and have made changes for the better to mitigate the understeer and adapt my driving to the new setup. This is all stuff I'd never been able to do before, so seat time and patience has been paying off, I think!

So... I grabbed 1st place in B3 at Round 3 out of 14 drivers! New PB in CW format of 1:56.91. Previous lap time here was a 1:59.29. And this moved me up to P1 in the series, too. Bimmer Challenge counts the 10 best performances over the season, so I'm going to take some time off, skip Vegas & Sonoma, and pick back up soon. Having a ton of fun with this car, and competing in such a simple build is seriously a blast.





Thanks for following along.

[//steve\\]

Keep it up! I love this car.

[derbo]

Nice update Berns on the square/staggered situation. Keep it up!

[b4hand]

Do you think the corner exit traction issue is more of a diff thing and no so much a tire thing?

[berns]

Originally Posted by b4hand

Do you think the corner exit traction issue is more of a diff thing and no so much a tire thing?

So many things at play when trying to put power down. I don't think the stock diff is great, but I don't think it's the main culprit either. At this point, the cost investment for a diff, and the chance of it working against me in regard to lockup, turn-in and throwing the balance off, isn't worth it right now. I'd like to get the car to do exactly what I want before making that change.

Every arm, mount and bushing is still stock in the rear, so that'll all be changed soon to give me a more direct feel and open up some alignment possibilities.

[Redd]

I noticed big traction difference going from stock diff to OS Giken, especially on corner exit. You just get on the power earlier and harder with a good clutch type LSD. No additional understeer at turn in either.

[berns]

Originally Posted by Redd

I noticed big traction difference going from stock diff to OS Giken, especially on corner exit. You just get on the power earlier and harder with a good clutch type LSD. No additional understeer at turn in either.

Which setup did you go with?

[Redd]

Originally Posted by berns

Which setup did you go with?

I have OS Giken Superlock stock setup with 3.45 FD. I don't know enough about setting up a custom diff so I just went with the stock setup. Very happy with it. Smooth, not intrusive at all and locks up well.

[Rochen_00]

Incredible, I really like your explanations. I'm going to run a 265/35/18 and 285/35/18 tiered configuration shortly. We'll see what senation is going to give me on track

[iamtrashman]

This is a great build! Really enjoy reading these updates.

[_X]

Originally Posted by Rochen_00

Incredible, I really like your explanations. I'm going to run a 265/35/18 and 285/35/18 tiered configuration shortly. We'll see what senation is going to give me on track

I run these sizes with Hankook RS4s. Good grip, good balance, and a stiff sidewall.

Coming from Michelin PS2s, the grip is greatly improved, as is the turn in, but the rear isn’t as communicative. It seems as though they step out before you really notice or feel them start to step out, as opposed to the Michelin’s where you knew they were breaking free in a nice progressive, gradual manner.

[m3gang]

Mind sharing your rear wheels spec? Curious on how you are able to fit 315s without rubbing.

[berns]

Update time? Sure.

The car has stayed the same for a while now and I can confidently say I've gotten what I could out of it in its current state. That doesn't mean I've gone as absolutely fast as I can go and I've reached my limit as a driver, but just that I've driven the piss out of it, competed, improved on personal records and am super, super comfy in the car.

The rear end has always wanted to come around, and mixed with my driving style, I prefer that over understeer any day, but there is a fine line here, and I'm certain the lack of rear grip in cornering, transitioning and on-throttle is slowing the car down.

As I've said 100x, I'm taking this build slow in the sense that I'm making changes that I can feel and pinpoint, whether they're for better or worse. You might remember I took care of the front-end with all the SPL arms and some powerflex swaybar bushings early on. The front of the car has felt amazing....

The rear, on the other hand, has felt squishy and washy and unpredictable and loose to the point where I question the diff is even functioning properly. It's possible it isn't in the best shape, but we'll get there.

So, with all that, I set out to handle the rear of the car all at once. I went with the trusted brands I've worked with for the last few years on my e82, e90 and e46, but this time, I replaced literally everything that might be showing its age or softness all at once.

Here's what I used:

SPL Rear Swaybar Endlinks
SPL rear upper arm links
SPL rear toe arms with eccentric lockout
SPL outer spring arm spherical bearing (NEW PART!)

Then I hit up my buds at BimmerWorld for the rest of the bits I needed. James, Phil & Kevin are always so great to deal with.

BimmerWorld Solid Aluminum Subframe Mounts
BimmerWorld Spherical Rear Trailing Arm bearings
BimmerWorld Rear Camber Arm Bearing kit
PowerFlex Black "Track" front/rear diff bushings and rear Swaybar bushings

Also ordered some Revshift Rear Trailing Arms (these were supposed to be black, and they took 1.5 months to arrive. Not impressed.) ECS was out of stock and I wasn't aware of the new Fall Line arms till it was too late. Truth is, they all do the same thing and the benefit here is pretty negligible.















I dropped the car at my favorite shop, European Auto Source with a pile of parts as usual. Just want to thank all the dudes there... Steve & Tom, TJ, Nick -- they hustled and did an awesome job with the quickness!




Everything went smoothly and the car was back on the ground on day one. The pile of parts removed looks like it was dug up somewhere by an archeologist.









The second I started driving I felt a difference. A little bit of diff whine, not nearly as much as solid diff bushings (this is why I go poly for the diff), but even shifting felt smoother and more direct right off the bat. Rowing through the gears accelerating on the freeway, hitting an offramp at speed and feeling the rear end just be there with the car rather than needing to "settle" into the turn. In fewer words: direct, immediate, responsive... Really blown away.

So, will this translate to more grip, more control and quicker laptimes? I have no idea. I hope it does. If it doesn't, I know at least I'll like the way the car feels more than before, but its behavior is definitely TBD.

I do have some track time coming up, but not at tracks I frequent, so the Buttonwillow PB will have to wait till later in the year when the weather cools down and Bimmer Challenge heads back there.

On that note, I missed the last two events, so my 1st place became 3rd place, and I have two turbo cars to try to beat at the rest of the events this season. An M4 and an A90 Supra. Fair? Not sure. Fun? Definitely. It says Nick is in an E46, but he's in an F82 M4 on MCS 1WNR's. He works at EAS currently and "helped" out with the install. Hopefully he didn't do anything to sabotage me.



I'm going to ACS this Sunday, followed by Big Willow on the 26th and Laguna on July 31st. If work allows, I'll be stoked to make it out to all of these! I've only been to ACS once about 6 years ago, and Big Willow I have one day at as well a few years back. Same for Laguna... Should be interesting.

Finally, I mounted up some fresh 285's, tossed them on the car and it was time to corner balance and align the car at Chewerks. I've never corner balanced it, but surprisingly enough, it was really close.







Curb Weight - 3255 with half a tank of gas
Not bad! Could be better, though. I have some plans for a brake kit swap and a custom Ti exhaust, maybe some lightweight door cards and maybe I'll replace the carpet with some perlon felt to keep it clean but light.



And here's the weight with me in it.



I've thought about a carbon driveshaft, light flywheel, but that's where weight reduction starts getting really expensive and I'm not sure I want to deal with any of that, especially a failing driveshaft.

As for the diff, I'm going to run the stock one for now and I'm waiting on OS Giken to get more diffs in from Japan, and they're going to set it up for me for my car/driving style. Looking forward to testing that out!

I'll let you guys know how ACS goes... Going to have to show up with some big balls to keep it flat on the Roval.

[DRLane]

Nice updates. Not going back to the 315 stagger setup?

[911r]

looks better w/o the rear diffuser

[//steve\\]

Originally Posted by 911r

looks better w/o the rear diffuser

I've already told him the same too.

[Exclusivs]

Nice updates Alex!

Those are hot dates for summer. Keep up the great build

[berns]

Originally Posted by DRLane

Nice updates. Not going back to the 315 stagger setup?

It's still here but will mostly be my street setup so I can keep the 285's fresh for track time. I'm not 100% opposed to running it again but I really think the front end needs more rubbing to compete with the massive 315. 275 just doesn't compliment the car up front. a 295/315 setup would probably be best, but Falken doesn't make the sizes. Hopefully they just come out with a 295/30 so I can run those all around.

Originally Posted by 911r

looks better w/o the rear diffuser

I agree and have been meaning to pull it off for a while. There's a small piece of the bumper material missing on the left side exhaust outlet, but you really can't see it. Very happy without that thing on there and I sold it in minutes on IG. Win!

Originally Posted by //steve\\

I've already told him the same too.

Yes, yes, yes.

Originally Posted by Exclusivs

Nice updates Alex!

Those are hot dates for summer. Keep up the great build

Thanks dude! Not looking forward to driving in the heat. I'll probably run the morning two sessions and just go home haha.

[kyippee]

The weight of the car is good! I should remove my passenger seat and rear seats too!

Anything else that got you down to 3255 half tank aside from battery? I'm at 3550 with a full tank of gas, still full interior.