A Closer Look at the Schirmer E92

[AP3X_FTW]

I know I’m not the only one who has drooled over Tom Schirmer’s acclaimed E92 M3 Ring monsters over the years. The cars configuration has been discussed at a high level many times, but in effort to take a page out of their playbook I’m looking to uncover more details on the suspension and diff/gearing setup. I understand a lot of in-house R&D and engineering has been performed, especially on the suspension bits and geometry, and the only true way to achieve their results would be to work with them directly.

With that said, does anyone have any more details on suspension, bushings, diff and gearing? Even small details like the CF door panels and floor boards are very cool. Any further information would be interesting to discuss, as these cars are truly the benchmark of what this platform is capable of.

There are a handful of these cars, and not all are built the same in terms of power and interior details, but they do share most of the same trade secrets from what I can tell.


Known Specs

E92 M3 Coupe
- DCT transmission
- CF roof
- Non navigation / stripper model

BBS E88 Wheels F. 18x10 R 18x11
Various compounds used in F. 265/35-18 R. 295/30-18
Custom Nitron 3-way suspension w/ modified axle kinematics by Schirmer
AP Racing BBK F. 6 piston 378mm R. 4 piston 356mm
Akra titanium exhaust
Roll cage
Recaro seats - some with custom upholstery
Carbon door panels
BMW GT4 front splitter
BMW GT4 wing
Significant weight reduced reduction and much more

Feel free to share photos, videos or anything else related. Just looking at these cars raises my heart rate.

[dparm]

Per this post, it sounds like the car's performance is mostly down to the secret suspension work. It seems like they've totally reworked the entire suspension.

https://www.m3post.com/forums/showpo...7&postcount=17

[jid2]

^^^^ Not sure on that one, they've posted pictures on their instagram and I can't see any magic. More like 3 way shocks, and replacing all the links with solid bushing versions, and maybe a custom control arm - maybe. Maybe a custom subframe, but doesn't seem like it. I think it's custom wordsmithing like "our race kinematics" and a sprinkling of hype.

[dparm]

Custom control arms is still pretty nuts. Not exactly something you can whip up in your garage on a weekend.

[SYT_Shadow]

Originally Posted by dparm

Custom control arms is still pretty nuts. Not exactly something you can whip up in your garage on a weekend.

Doesn't BW and I think SPL sell the same type of thing?

[///Mobbin]

Can someone post some pics here for discussion? I'm quite curious.

[jid2]

Instagram: Team Schirmer, AlexHardt7

Photos on Alex's page show basic parts with the notion of "Schirmer Axle Kinematics" aka hype.

[AP3X_FTW]

Appreciate the feedback thus far. I don’t know how much hype is involved, the cars do chase down / keep up with GT3RS’s afterall. The BTG Ring times they are putting down aren’t possible with your run of the mill E92. With that said, my assumption is that with the right mixture of parts an E92 could be prepped to a similar degree.

They use the Drexler diff from the GT4, correct? I’ve been reading Florian’s “Master Diff Thread” which is a must read for any diff newb like myself. I’m trying to get a better understanding if an ATB or clutch style diff is best for my application.

I just picked up another E92 as a weekend / track only car, and here is the current list I have in terms of the suspension and diff categories.

• APEX Race Parts JRZ RS PRO Suspension Package
• Hyperco 2.25” ID Race Springs
• Ground Control Race Camber Plates
• Fall Line Motorsport Front Monoball Conversion
• Fall Line Motorsport Adjustable Front & Rear Endlinks
• Fall Line Motorsport Rear Toe Links
• Fall Line Motorsport Solid Subframe Bushings
• PowerFlex Purple Poly Diff Bushings
• Undecided Engine & Tranny Mounts
  
• Wavetrack or Drexler GT4 diff

[slicer]

Originally Posted by SYT_Shadow

Doesn't BW and I think SPL sell the same type of thing?

Yes, SPL has replacement arms for most of the suspension. I believe that Schirmer uses a true rear coilover with a replacement for the main rear LCA. Smaller and lighter without the need to accommodate the divorced spring. I have noticed that M24 sells that LCA. M24 also has Carbon door panels that look the same or similar to what Schirmer uses.

[nicksm3]

Originally Posted by slicer

Yes, SPL has replacement arms for most of the suspension. I believe that Schirmer uses a true rear coilover with a replacement for the main rear LCA. Smaller and lighter without the need to accommodate the divorced spring. I have noticed that M24 sells that LCA. M24 also has Carbon door panels that look the same or similar to what Schirmer uses.

Speaking with Schirmer himself about 5 years ago via email, said clearly cannot disclose anything they do in house but yes it is a true rear coilover, custom suspension components they build/design in house, custom full cage, gutted interior with custom carbon trim with alcantara, ecu remapped and upgraded diff. They did disclose the rim specs to me and I had them built by BBS asap after that info.
The e92 that got sub 7 at the Ring runs a blower as of 2 years ago
Also to add ......as you can see their camber, it is aggressive and I’m assuming they are running atleast -4 upfront and -2rear. Just good the pics

[roastbeef]

i don't think they are hyping it up. obviously its not magic, but i think they are adding some lightness, adjusting the track width, and correcting some geometry so they can run fatter tires without a ton of built-in scrub. spl has some cool parts, but m24 is the only place i know of that sells a rear lca designed for a true rear coilover. also, in a few pics, i see bladed swaybars...

[UPSROD]

[eternallx]

@nicksm3

I pretty sure they did sub 7mins just on their stroked NA s65.
I dont think they ever posted a time for their Harrop S/C setup.

[AP3X_FTW]

Originally Posted by slicer

Yes, SPL has replacement arms for most of the suspension. I believe that Schirmer uses a true rear coilover with a replacement for the main rear LCA. Smaller and lighter without the need to accommodate the divorced spring. I have noticed that M24 sells that LCA. M24 also has Carbon door panels that look the same or similar to what Schirmer uses.

I thought M24 only had the universal CF door panels, but after looking again you are right. The front and rear "molded" CF panels are very nice, and I agree they are likely the same ones found in the Schirmer cars.

Originally Posted by eternallx

@nicksm3

I pretty sure they did sub 7mins just on their stroked NA s65.
I dont think they ever posted a time for their Harrop S/C setup.

Correct.

[slicer]

Originally Posted by AP3X_FTW

Appreciate the feedback thus far. I don't know how much hype is involved, the cars do chase down / keep up with GT3RS's afterall. The BTG Ring times they are putting down aren't possible with your run of the mill E92. With that said, my assumption is that with the right mixture of parts an E92 could be prepped to a similar degree.

They use the Drexler diff from the GT4, correct? I've been reading Florian's "Master Diff Thread" which is a must read for any diff news like myself. I'm trying to get a better understanding if an ATB or clutch style diff is best for my application.

I just picked up another E92 as a weekend / track only car, and here is the current list I have in terms of the suspension and diff categories.

• APEX Race Parts JRZ RS PRO Suspension Package
• Hyperco 2.25" ID Race Springs
• Ground Control Race Camber Plates
• Fall Line Motorsport Front Monoball Conversion
• Fall Line Motorsport Adjustable Front & Rear Endlinks
• Fall Line Motorsport Rear Toe Links
• Fall Line Motorsport Solid Subframe Bushings
• PowerFlex Purple Poly Diff Bushings
• Undecided Engine & Tranny Mounts
  
• Wavetrack or Drexler GT4 diff

Sounds like a great plan. I will say that I think the SPL arms are a bit better than fall-line. Both are great but the clamp type of lock that SPL used is far easier to work with. That being said, I know of at least one forum member saying he had a difficult time getting the SPL arms to stay locked in place. I can't confirm or deny as I haven't had mine long enough. I did strip the head of one of the SPL titanium bolts. I think I will grab some stainless replacements as the weight savings is negligible. I spoke with SPL and they told me the size, plus stainless is stronger in that application.

I have the BW Group-N motor mounts and have zero complaints. You might want to do the full SPL kit while you have the rear SF out to install the SF mounts. The rear arms are impossible to install with a torque wrench when the SF is in the car (can install with a ratchet but head of torque wrench is too large). Might as well install an adjustable rear sway bar while you are at it. The SF needs to be dropped to install a rear sway.

[xander_g]

I thought this car has a stroker build?

[slicer]

Originally Posted by xander_g

I thought this car has a stroker build?

It does have a motor build. Not sure if it's a stroker or not.

[AP3X_FTW]

Originally Posted by slicer

Sounds like a great plan. I will say that I think the SPL arms are a bit better than fall-line. Both are great but the clamp type of lock that SPL used is far easier to work with. That being said, I know of at least one forum member saying he had a difficult time getting the SPL arms to stay locked in place. I can't confirm or deny as I haven't had mine long enough. I did strip the head of one of the SPL titanium bolts. I think I will grab some stainless replacements as the weight savings is negligible. I spoke with SPL and they told me the size, plus stainless is stronger in that application.

I have the BW Group-N motor mounts and have zero complaints. You might want to do the full SPL kit while you have the rear SF out to install the SF mounts. The rear arms are impossible to install with a torque wrench when the SF is in the car (can install with a ratchet but head of torque wrench is too large). Might as well install an adjustable rear sway bar while you are at it. The SF needs to be dropped to install a rear sway.

Great information. After more thought, I think I will hold off on the control arm upgrades for now. I really like to modify cars one part or region at a time, that way I can get a clear understanding of what has changed for better or worse. Too many enthusiasts throw everything and the kitchen sink at the car, and at that point you have created a bit of a Frankenstein. Pretty difficult to disseminate which part contributed to which improvement, pitfall or added NVH. On the other hand, the downside of doing things step by step is increased labor cost. I certainly get the "while you are in there" approach.

Good note on the Bimmerworld Group N motor mounts as well. I was going to stick with OEM for the whole driveline in fear off major NVH, but it looks like I'll take the opportunity to upgrade knowing OEM mounts fail pretty quick (~40k - 50k mile intervals). Did you leave the transmission mounts OEM? I know if you go with solid motor mounts you will want to upgrade the tranny mounts as well, but I am not sure if the same rule applies for the Group N motor mounts.

Originally Posted by xander_g

I thought this car has a stroker build?

You are correct, this particular car had a stroker kit when he set the sub 7 min BTG time. There are a number of Schirmer E92 and E90 M3's out there, and they range from stock motors, CF airbox and tune, to full stoker builds and/or Harrop superchargers.

[jid2]

Bimmerworld motor mounts were too stiff for me as a car I drive on the street. Others say it's ok, but for me it was a shakey, noisy deal breaker. I pulled them out and went back to stock.

[AP3X_FTW]

Originally Posted by jid2

Bimmerworld motor mounts were too stiff for me as a car I drive on the street. Others say it's ok, but for me it was a shakey, noisy deal breaker. I pulled them out and went back to stock.

Appreciate the feedback. My car is only a weekend / track car, so I am willing to live with a little NVH. From what I have heard, it is very minimal.

Next time slicer is at MRF I will have to take a seat in his car

[slicer]

Originally Posted by AP3X_FTW

Appreciate the feedback. My car is only a weekend / track car, so I am willing to live with a little NVH. From what I have heard, it is very minimal.

Next time slicer is at MRF I will have to take a seat in his car

Definitely! I should be there in a few weeks. PM me your number and I will let you know when I will be there next. My car is DCT and I did not change the trans mounts along with the motor mounts. Not necessary to my knowledge as GroupN mounts are far from solid.

[dparm]

Originally Posted by xander_g

I thought this car has a stroker build?

It was my understanding that the motor is mostly stock, save for a tune.