[E91Swagger]

Originally Posted by Biginboca

Hey,

I tried doing it through the Bimmergeeks Pro Tool but couldn’t get it to work, so my buddy had to do it with his laptop. He had to use winkfp to change the VO to add “+SPBR”

The use NCS Expert to code the entire car so all the modules will change settings to reflect the new change on the VO.

Did you notice any improvement in braking after the coding?

[Biginboca]

Originally Posted by E91Swagger

Did you notice any improvement in braking after the coding?

I didn’t notice any difference. I suspect the coding is more for ABS, DSC, and Traction Control to work better. I’ve read some guys saying it helped pedal feel but I didn’t notice any change and I can’t see how it would change that.

[The Nightman]

Originally Posted by tetsuo111

That might be me, Al. I think I brought those rear strut tower M3 side braces to the attention of the community. They are a welcome addition for stiffening the chassis further.

Sorry to beat a dead horse but after wasting a lot of time trying to figure out how to retrofit these shock tower braces to my E90, I found out that the E90 M3 doesn't even have them. Not the best photo but you can see that they are missing and that the bottom mounting hole isn't threaded:


https://www.m3post.com/forums/showthread.php?t=1158445

Another photo with no braces. It also shows sound deadening covering where the mounting holes should be exposed:

https://www.flickr.com/photos/59241080@N03/8555822358/

Since these braces are only found on coupes, I'm guessing the rear door frames provide enough rigidity so that they're not required on sedans. This also suggests that the E90 chassis could be inheritly more rigid.

[Biginboca]

Tambohamilton I know you recommended this somewhere in this thread and I’m taking you up on your advise. I ordered some XD front strut mounts and standard perches to replace my Lowering Perches set up. Thanks for that recommendation!

After doing my track days I decided I wanted to add a little more front camber, hopefully get to -3.0. I’m taking the cheap and easy way going to try stacking some Dinan camber plates on top of my strut mounts. They don’t play nice with the lowering perches the mounting hardware can rub the perch under load. feuer even said he had steering issues during hard autocross style turns when the hardware contacted.

So this will allow me to ditch the lowering perch and have the parts play nice together. Also I think it will allow me to bump back up to a 255 front tire again from the 245 I have now.

I found at the very limit on the last track day I was having a little under steer, hence the motivation for all this. I read a post on M3Post where a guy said with all Uniballs up front he was able to run the -3.0 camber and not get weird tire wear, but when he had stock rubber bushings he had increased wear. So I’m hoping I can pull off the -3.0 without too much issue there!

[Tambohamilton]

I've done similar recently, and found a couple of potential snags (literally):
https://www.e90post.com/forums/showp...8&postcount=38
Let me know if the pics don't work for you.

[Phil325i]

Originally Posted by Biginboca

I didn’t notice any difference. I suspect the coding is more for ABS, DSC, and Traction Control to work better. I’ve read some guys saying it helped pedal feel but I didn’t notice any change and I can’t see how it would change that.

If you've got the software, a firmer brake pedal is possible according to this:

[Biginboca]

Originally Posted by Tambohamilton

I've done similar recently, and found a couple of potential snags (literally):
https://www.e90post.com/forums/showp...8&postcount=38
Let me know if the pics don't work for you.

On the Dinan website they list their camber plates as working on the X Drive models so I’m thinking their hardware must clear the spring perch with XD mounts. Is that the snag you are referring to?

[Tambohamilton]

Basically, yeah. I'm guessing they will have covered it, but worth just checking everything as you assemble

Edit: Just looked at their plates - they have a nut on the underside of the strut top, which I'd say would be cutting it fine.

[ENintyTwo]

Unreal

[Biginboca]

Originally Posted by ENintyTwo

Unreal

Thanks! This car has really been transformed!

[The Nightman]

Originally Posted by Biginboca

Update! I installed Condor Speed Shop UHMW subframe inserts and E92M3 front and rear swaybars this weekend. Front Swaybar super easy, 30mins job I didn’t even take the front wheels off. Rear swaybar super PITA! I didn’t remove the subframe I just lowered it as far as possible on loosened bolts and wrestled with it. Scratched the hell out of the bottom of my car but 3 hours later I got it in. I would say this is one of the most frustrating jobs you can do in this car

After that time for the subframe inserts. I was expecting this to be hell but it was actually really easy! Here’s a short write up on how I did it...

This is as low as I could get this corner subframe to drop with 3 bolts still in. The trick is to support the subframe with a jack and get all 4 subframe bolts all the way out (only remove one at the time so the subframe stays in place!!) and then give them each like 5 turns reinserted. Then you can remove your jack and go back to remove the one bolt from the bushing you want to work on and then tighten the mounting screw diagonal from the screw you removed. The subframe teeter totters and as you tighten the diagonal screw the corner of the subframe with the missing screw will lower more.

...

Are the subframe bushings worth the effort over the inserts? I recently upgraded from M3 to GAS monoball tension struts and am now considering upgrading the subframe from poly inserts to full poly bushings

On one hand, the inserts are likely sufficient for my usage. On the other hand, I am bored

[Biginboca]

Originally Posted by Guy Fieri

Are the subframe bushings worth the effort over the inserts? I recently upgraded from M3 to GAS monoball tension struts and am now considering upgrading the subframe from poly inserts to full poly bushings

On one hand, the inserts are likely sufficient for my usage. On the other hand, I am bored

Yea for sure! The whiteline inserts are garbage. It’s some added work for the solid inserts but there is a noticeable improvement. The improvement is the gradual and controllable breakaway in the rear, very predictable vs the spongy feeling rear that has a snap back feeling when it regains traction. There is a reason why all the new M cars do not use rubber subframe mounts.

I honestly wish I had never bothered with the whiteline inserts. To me they are complete garbage. Maybe the new 034 aluminum ones are noticeably better than whiteline but I doubt it lol

[The Nightman]

Beating a dead horse part 2: front subframe reinforcement info dump

I've attached some information from BMW's technical training on chassis dynamics that supports reinforcing the front subframe using the M3 plate. However, I'm not sure how much rigidity is compromised when cutting the M3 plate as BMW emphasizes transverse rigidity.





The E90's V-brace is identified but there is no commentary on it. Maybe there is something to gain by adding a transverse brace across the rear of the subframe?

[Biginboca]

Originally Posted by Guy Fieri

Beating a dead horse part 2: front subframe reinforcement info dump

I've attached some information from BMW's technical training on chassis dynamics that supports reinforcing the front subframe using the M3 plate. However, I'm not sure how much rigidity is compromised when cutting the M3 plate as BMW emphasizes transverse rigidity.





The E90's V-brace is identified but there is no commentary on it. Maybe there is something to gain by adding a transverse brace across the rear of the subframe?

The M3 plate installed the way I did definitely made a felt difference. Some of the bracing I added I didn’t notice anything (front convertible bracing and rear strut brace), but the M3 chassis plate was totally worthwhile.

[Biginboca]

Did a mod today! At my last track day I felt like the car was really dialed in but I noticed some understeer at the limit and the front could use a little more grip. So I wanted to bump my camber from -2.4 to -3.0 which is what a lot of the track focused M3 builds I see are running.

A side benefit is I think a little more camber would allow me to swap from 245/35r18 front tires to 255/35r18 which is would also help under steer and would also match what I have on the rear.

So a little camber added gets me a nice reduction in understeer by 2 mechanisms.

-3.0 is aggressive camber for sure but from the research I did tire wear on these cars should be ok if you have all Uniballs (which I do) and get the toe dialed in. So away we go!

I decided to use the Dinan camber plates to get the camber. I have slotted strut mounts already and with the E92M3 control arms and the M4 spindle was able to achieve -2.4 camber without any plates. So adding the Dinan plates would get me around -3.1.

The downside is the added stack height of the Dinan plates:



So that Dinan camber plate would raise the front ride height by ~6mm.

But that’s not all… On top of that, the Dinan plates don’t play nice with the SRP front drop perches I have installed because the Dinan mounting bolts rub the top of the drop perches under load and can make the steering lock up. So I had to deal with also raising the front ride height an additional 15mm (on top of the 6mm from the Dinan plates) because I had to take off the drop perches and swap to normal spring perches.

I decided to use the X Drive strut mounts instead of the OEM sport mounts. Those take away a little ride height, maybe 4mm, because they are shorter than RWD strut mounts.



After assembling the new stack on top of a strut I took some measurements and found the new assembly would still leave 17mm of ride height to compensate for even with the X Drive strut mounts:







I decided to just sink the strut 17mm deeper into the Spindle (Steering Knuckle) by cutting a V in the strut adapter I’m running and it worked perfectly.



So the car is now sitting same ride height and aligned to:

-3.0 front camber
-2.0 rear camber

Best of all now I can get some wider front tires… and also in any brand I want! There were only 2 tires that came in the 245/35r18, the Michelin PS4S and Falken FK510. After a bunch of searching I found none of the decent more track/performance oriented tires came in that size.

So now that I can go to a 255/35r18 front I can pretty much run any tire because they all seem to come in that size.

[The Nightman]

Good stuff. Interesting that the xdrive mounts are reinforced too. How are the gussets oriented? ie transverse or longitudinal?

[Biginboca]

Originally Posted by Guy Fieri

Good stuff. Interesting that the xdrive mounts are reinforced too. How are the gussets oriented? ie transverse or longitudinal?

Both I guess lol

[CalvinNismo]

I know this information is a bit late for you Biginboca, but the E85/E86 Z4 top mounts have a 10mm lower stack height than the regular E9X non-M top mounts. Could've saved a few millimetres of grinding!

[Biginboca]

Originally Posted by CalvinNismo

I know this information is a bit late for you Biginboca, but the E85/E86 Z4 top mounts have a 10mm lower stack height than the regular E9X non-M top mounts. Could've saved a few millimetres of grinding!

Oh man now you tell me haha! Good info none the less!

[Biginboca]

So after doing some reading last night it’s come to my attention that I can likely fit 265’s up front with this new spec. Looking at the car there is definitely quite a bit of room this is from this morning with the 245’s up front…



Not sure I need 265’s. In the PS4S I was shopping for my next set of tires they are 2lbs heavier than the 255’s.

Although there is definitely some allure to running 265’s square on a e92 haha

Here’s a pic to show how the ride height ended up with the modified strut collar:

[Tambohamilton]

Here's my source on strut mount info:
https://www.e90-forum.de/forum/threa...er#post1510042

Just out of interest, why have you (seemingly) aimed for the same fender gap front and rear, rather than any other measure of ride height?

Also what top spring perch is that you've used?

[Biginboca]

Originally Posted by Tambohamilton

Here's my source on strut mount info:
https://www.e90-forum.de/forum/threa...er#post1510042

Just out of interest, why have you (seemingly) aimed for the same fender gap front and rear, rather than any other measure of ride height?

Also what top spring perch is that you've used?

I’m now running the standard e9x front spring perch (p/n 31336759452) which gives plenty of clearance for the Dinan Camber Plates nuts.

As far as ride height, it’s actually not ideal for what I want. I’d actually like to run the car flat to maybe even a bit of negative rake. I know shirmer likes the cars set up like this, and I have been taking a lot of cues from their builds this year.

I will say I like the front height where it is because #daily but the rear about ~10mm lower would be fine by me. From what I have researched these cars seem to handle best with zero to slight negative rake.

It arrived where it is now because the rake increased a bit after weight reduction because more of the weight loss was from the rear (lithium battery took 45lbs off the rear and rear seat delete took 40lbs off the rear). Most of the other mods were even reductions front to rear.

I cut the rear springs a bit when I did the rear uniballs and that seemed to get me back to about factory rake. At this point without doing coilovers (which I don’t really want to do yet) only way I know to take the rear down a bit more is cut the springs a little more, which I would prefer not to do because this increases the spring rate, or maybe try some of those adjustable rear springs/perches. I need to check the spring rates on those but I might be doing that next if they are in the 500-550 lb/inch range.