GB for SLON Workshop CF Rear bulkhead, which can (optionally) be a back seat delete

[repoman89]

Sublime made and installed a good friend's CSL roof. They're not cheap at all. They use to build/still build most of Turner's cars lol

Oh interesting .. How is the quality and pricing of his roofs compared to something like a Karb? I wasn’t sure which direction to go

haha figured they weren’t cheap but nonetheless I’ve been surprised at how reasonable smaller jobs at least have been through them.

[Epoustouflant]

Hey guys.

Just chiming in to thank you for participating in the GB and for SYT_Shadow to put me up to speed on the forums.

Man - gone are the days of E46fanatics and m3forums.net eh?

I'm glad to be here. If you have any questions on the GB itself, let me know. You guys visibly have the product information figured out.

I'm also thinking of expanding Slon's Advanced Retrofit BBK to the E46 in the current E9X GB. Let me know your thoughts!

[heinzboehmer]

Hey guys.

Just chiming in to thank you for participating in the GB and for SYT_Shadow to put me up to speed on the forums.

Man - gone are the days of E46fanatics and m3forums.net eh?

I'm glad to be here. If you have any questions on the GB itself, let me know. You guys visibly have the product information figured out.

I'm also thinking of expanding Slon's Advanced Retrofit BBK to the E46 in the current E9X GB. Let me know your thoughts!

Just wondering, has the group buy gotten to 20 people yet?

Also, as long as you and Slon are open to it, you should consider waging interest for a CSL trunk group buy. OE trunks are currently not available from BMW and the vendors that do have them are selling them for crazy prices. I'm sure that many people here would be interested in a high quality cf trunk.

[nextelbuddy]

39% increase in chassis stiffness for $1400 has to be one of the best performance/$ increases available for the car!

to be fair, the m3 coupe was stiffer than non Ms already by far and stiffer than a non M sedan albeit only 50 units stiffer according to their posted data.

the M3 coupe with FOLD seats was 18500 units of stiffness compared to non M sedan NON FOLD at 18000 units of stiffness. besides the rear reinforcement wall, there isn't much difference in chassis between M3 and NON M that i can think of? but i could be wrong and missing something. the m3 has strut brace in the front and the rear lower diff V brace over the NON M cars. are those 2 items really the cause for the 48% additional stiffness between non M FOLD and M3 fold chassis? is there that much difference in stiffness with the design of the A, B and C pillars over the sedan counterparts?

I just dont see this CF back seat panel adding yet another additional 38-39% of stiffness to the already stiff m3 coupe at 18500.. so afterwards the m3 coupe would possible be at 25,500ish units of torsional rigidity?

[Epoustouflant]

Just wondering, has the group buy gotten to 20 people yet?

Also, as long as you and Slon are open to it, you should consider waging interest for a CSL trunk group buy. OE trunks are currently not available from BMW and the vendors that do have them are selling them for crazy prices. I'm sure that many people here would be interested in a high quality cf trunk.

We are at 17!

Yes on E46 CSL trunk. I will chat with him about it. He's incredibly surprised by the speed we filled all 3x GBs (pan, wall, bbk). Trust factor is great and I can sweet talk him into things now

I'll put in on my to-do and circle back.

[repoman89]

I'm also thinking of expanding Slon's Advanced Retrofit BBK to the E46 in the current E9X GB. Let me know your thoughts!

Details on this? Calipers, discs, pads etc? I’m in the market for brakes as well since I sold my 996 kit ...

[Epoustouflant]

Details on this? Calipers, discs, pads etc? I’m in the market for brakes as well since I sold my 996 kit ...

https://docs.google.com/forms/d/12CWs-s5eGEzJF1IcIw5vCGJRM-r-J72CaWKZx0WW-jA/edit

Check the Advanced Kit section. Basic Kit doesn't fit E46.

The Advanced also features the same brand new 6 piston Brembo caliper fitted with a machined and anodized bracket for easy mounting on the E9X M3 - no new spindles or hubs required.

The Advanced Kit includes Slon's 2 piece 380mm slotted Brembo rotor. It is machined in house from Brembo blanks for usage on this caliper. All of Slon's rotors are made with the same dimensions as Brembo GT rotors.

The replacement rotor rings will cost 730$ per pair including shipping, cheaper than Brembo's own 2 piece 380x28 mm rotors which retail at 1,445$ US at Turner Motorsport. Many of Slon's customer that were originally using the Brembo GT BBK switch to Slon's rotors and use on their kits.The complete replacement rotors with hats and rings are 1,300$ per pair.

Note: we highly recommend you go with the optional Ferodo Racing DS2500 or equivalent quality pads. The Advanced Kit was developed with such pads in mind for street usage.

Pad size and sweeping surface:
- 380mm Slon 2 piece rotors you can use 57.5mm height for a nearly full sweeping coverage (60mm total)

If you will track the car, use your preferred pads using the pad shape below:

Front pads for 380mm 2pc:

https://ecat.ferodoracing.com/product-line/car-racing/brake-pads/code/FRP3098

Rear pads for 380mm 2pc:
https://ecat.ferodoracing.com/produc...s/code/FCP1348

[Obioban]

to be fair, the m3 coupe was stiffer than non Ms already by far and stiffer than a non M sedan albeit only 50 units stiffer according to their posted data.

the M3 coupe with FOLD seats was 18500 units of stiffness compared to non M sedan NON FOLD at 18000 units of stiffness. besides the rear reinforcement wall, there isn't much difference in chassis between M3 and NON M that i can think of? but i could be wrong and missing something. the m3 has strut brace in the front and the rear lower diff V brace over the NON M cars. are those 2 items really the cause for the 48% additional stiffness between non M FOLD and M3 fold chassis? is there that much difference in stiffness with the design of the A, B and C pillars over the sedan counterparts?

I just dont see this CF back seat panel adding yet another additional 38-39% of stiffness to the already stiff m3 coupe at 18500.. so afterwards the m3 coupe would possible be at 25,500ish units of torsional rigidity?

As far as I know, the differences that make the M3 stiffer than the non Ms are...
-Rear V brace
-Front thrust plate
-supposedly some seam welding from the factory, though I've never seen any specifics on that.

I don't think the strut tower brace is likely factored into the 18,500, since it wasn't there on launch year.

Sounds like he's buying a chassis twister, so we'll get actual numbers on what this provides, though after the GB period is over.

The e39s start out in the ~25,000 range and still get a significant bump from not having fold through (I've never seen what that bump is listed, but I can easily feel it from behind the wheel). I don't know if the M3 starting out stiffer means the gains will be less. And, are we defining less as a smaller percent (as in, perhaps the plate adds 5000 nm/deg, regardless of the starting point-- which would mean the "same" gain on the M3, but a smaller percent gain (27%)). In which case we'd end up at 23,500,

Whatever the absolute number ends up being, I'm pretty much certain it will be a SIGNIFICANT increase in chassis torsional rigidity. Short of a cage tied into the chassis, I don't know of a better way to make the car more rigid than a product like this. I've been wanting something like this in my car for years now, but couldn't figure out any way to DIY it in a way that would be functional.

I look forward to seeing the test results when he does them, but the concept here is sound enough that I'm completely willing to pay for and install this before seeing the data.

[usdmej]

I suppose if one didn’t care about being able to add in another one, you can cut it out and leave a rim of CF in place. Definitely would need to make sure you’re wearing appropriate PPE and clean up adequately when doing that

curious how cutting a hole like you said would reduce the stiffness, hopefully not too much

losing ability to pass things through from trunk to passenger compartment is a pretty significant detriment to the functionality of the car. i don't see why you don't just go with a half cage at that point for the money involved

[Obioban]

curious how cutting a hole like you said would reduce the stiffness, hopefully not too much

losing ability to pass things through from trunk to passenger compartment is a pretty significant detriment to the functionality of the car. i don't see why you don't just go with a half cage at that point for the money involved

I use the back seat pretty often, for people and tires (4 track tires fit perfectly back there), and will be even more in the coming years now that I have a kid.

... and a half cage is pretty dangerous when not wearing a helmet or 4/5/6 point, so pretty ruinous to a car that sees street use.

[nextelbuddy]

As far as I know, the differences that make the M3 stiffer than the non Ms are...
-Rear V brace
-Front thrust plate
-supposedly some seam welding from the factory, though I've never seen any specifics on that.

I don't think the strut tower brace is likely factored into the 18,500, since it wasn't there on launch year.

Sounds like he's buying a chassis twister, so we'll get actual numbers on what this provides, though after the GB period is over.

The e39s start out in the ~25,000 range and still get a significant bump from not having fold through (I've never seen what that bump is listed, but I can easily feel it from behind the wheel). I don't know if the M3 starting out stiffer means the gains will be less. And, are we defining less as a smaller percent (as in, perhaps the plate adds 5000 nm/deg, regardless of the starting point-- which would mean the "same" gain on the M3, but a smaller percent gain (27%)). In which case we'd end up at 23,500,

Whatever the absolute number ends up being, I'm pretty much certain it will be a SIGNIFICANT increase in chassis torsional rigidity. Short of a cage tied into the chassis, I don't know of a better way to make the car more rigid than a product like this. I've been wanting something like this in my car for years now, but couldn't figure out any way to DIY it in a way that would be functional.

I look forward to seeing the test results when he does them, but the concept here is sound enough that I'm completely willing to pay for and install this before seeing the data.

my sedan is a non FOLD car and i could feel the difference as well compared to the M3 coupe i had last year as well as the convertible I had briefly. the sedan I have feels very planted when taking hard turns.

[Obioban]

my sedan is a non FOLD car and i could feel the difference as well compared to the M3 coupe i had last year as well as the convertible I had briefly. the sedan I have feels very planted when taking hard turns.

Yes sir. That's why I'm so excited about this!

[repoman89]

my sedan is a non FOLD car and i could feel the difference as well compared to the M3 coupe i had last year as well as the convertible I had briefly. the sedan I have feels very planted when taking hard turns.

The rigidity numbers as quoted in this thread at least suggest that the stock M3 coupe is slightly more rigid than the non-folding sedan though .. maybe you were feeling suspension differences between the two cars perhaps?

[usdmej]

I use the back seat pretty often, for people and tires (4 track tires fit perfectly back there), and will be even more in the coming years now that I have a kid.

... and a half cage is pretty dangerous when not wearing a helmet or 4/5/6 point, so pretty ruinous to a car that sees street use.

i personally think deleting the entirety of your passthrough ability is pretty ruinous to a street build type of car but thats just me.

[Obioban]

The rigidity numbers as quoted in this thread at least suggest that the stock M3 coupe is slightly more rigid than the non-folding sedan though .. maybe you were feeling suspension differences between the two cars perhaps?

His sedan is M3 converted-- so it has the M3 V brace, thrust plate, and shock tower brace (the items that make the M3 coupe stiffer than the non M coupe). So, his M3 sedan should be stiffer than an M3 coupe.