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

[Obioban]

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

That's probably why BMW made it optional on sedan-- so people could choose if they prefer a stiffer chassis or the ability to transport long objects. No idea why they didn't on the coupe, as why would the less practical car shape have mandated increased practicality :P

I think your sentiment makes sense if the M3 is your only car. If it's one of a couple cars, just take a different car if you need to transport something long. I don't think I've folded down the seats on my coupe since I got the M3 wagon.

[usdmej]

I think your sentiment makes sense if the M3 is your only car.

whether or not you have another more functional car doesnt really change the fact that you've nerfed the cargo carrying abilities of the car we're talking about
which is fine really, i just personally don't consider this mod worth the trade-off

[Obioban]

whether or not you have another more functional car doesnt really change the fact that you've nerfed the cargo carrying abilities of the car we're talking about
which is fine really, i just personally don't consider this mod worth the trade-off

Then you probably shouldn’t get one 👍🏻

[old///MFanatic]

to be fair, the m3 coupe was stiffer than non Ms already by far and stiffer than a non M sedan

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?

Yeah the claim seems flawed. The M3 is like 18,750 Nm/D (Terra can confirm this). This rigidity is in BMW documents as from things like the additional reinforcements in the C-pillars, additional gusset plates and weld points. I'm sure this panel can aid the rear bulkhead, but since that rigidity was addressed by ///M it's very doubtful you can assume it would be near the same percentage of the non-reinforced designed E46 Sedan.

[old///MFanatic]

Ok not trying to be a buzz kill, just presenting things that seem to be overlooked and assumptions of how large an improvement this would add.

It should add some and to those wanting this it looks well made and weight savings a plus if seats completely removed.

[terra]

whether or not you have another more functional car doesnt really change the fact that you've nerfed the cargo carrying abilities of the car we're talking about
which is fine really, i just personally don't consider this mod worth the trade-off

I get what you’re saying, there will be a lot of utility lost. In the past I’ve used my M3 to move from apartment to apartment and the cargo capacity is a lot more than you would think. I’ve also frequently used the ski pass when I would go out to the slopes. But at this point my M3 no longer serves that purpose. I don’t really care about resale to someone who might care about those features since I’m never selling the car.

[Icecream]

This is the closest you'll see to OEM quality. It is a beautiful piece!

Some more info:
E46 Sedan (w/o folding seats) 18000
E46 Sedan (w folding seats) 13000
E46 Touring (w folding seats) 14000
E46 Coupe (w folding seats) 12500
E46 Cabrio 10500
What do we need to see here? Comparing two sedans' torsional rigidity – the difference between two chassis is limited to the steel wall behind the rear seats! 38% increase of torsional rigidity with only one chassis element difference!
Another interesting fact is that e46 coupes and even e46 m3s don’t have chassis options without folding seats (with the factory wall). Same for the next generation e9x chassis – bmw didn’t offer “w/o folding seats” option at all, so all versions have a hole instead of a wall.

Do the CSL Seats fold down?

[heinzboehmer]

Do the CSL Seats fold down?

Yup. No bulkhead either.

https://web.archive.org/web/20131022202715/https://www.cslregister.com/forum/showthread.php?t=4417

[usdmej]

I get what you’re saying, there will be a lot of utility lost. In the past I’ve used my M3 to move from apartment to apartment and the cargo capacity is a lot more than you would think. I’ve also frequently used the ski pass when I would go out to the slopes. But at this point my M3 no longer serves that purpose. I don’t really care about resale to someone who might care about those features since I’m never selling the car.

it looks like we've shared the same ownership experience with this car. while i no longer really use this car for anything other than weekend driving activities, it bugs me that this mod wouldn't allow me to incidentally transport something as simple as a broomstick. i can think of a lot of other -for fun- cars that i'd like to own if the bar for functionality is set that low

[usdmej]

Then you probably shouldn’t get one 👍🏻

i jumped in on the discussion of creating a bulkhead that retains some functionality in hopes that it might gain some traction

[terra]

it looks like we've shared the same ownership experience with this car. while i no longer really use this car for anything other than weekend driving activities, it bugs me that this mod wouldn't allow me to incidentally transport something as simple as a broomstick. i can think of a lot of other -for fun- cars that i'd like to own if the bar for functionality is set that low

Ideally for me it would have had a hole for the ski pass like the non folding sedans with the cold weather package do. That would at least allow transportation of broomsticks and the like. But I get that would probably be harder to manufacture and would probably limit the rigidity benefit.

[Icecream]

Y'all carrying a bunch of broomsticks for some reason?

[SYT_Shadow]

Ideally for me it would have had a hole for the ski pass like the non folding sedans with the cold weather package do. That would at least allow transportation of broomsticks and the like. But I get that would probably be harder to manufacture and would probably limit the rigidity benefit.

How about cutting a hole in it (and likely compromising the rigidity of the wall...) and then carrying your broomsticks happily? You can even choose the size/shape of the hole, personalize it to howevermany broomsticks you typically transport!

The wall's strength is precisely that it's a full sheet, in addition to the multiple planes it has parallel to each other (the 'deep X'). If you really need to carry those broomsticks you need to sacrifice the rigidity (there is no one without the other).

How about carrying those broomsticks on a roof rack?

[terra]

How about cutting a hole in it (and likely compromising the rigidity of the wall...) and then carrying your broomsticks happily? You can even choose the size/shape of the hole, personalize it to howevermany broomsticks you typically transport!

The wall's strength is precisely that it's a full sheet, in addition to the multiple planes it has parallel to each other (the 'deep X'). If you really need to carry those broomsticks you need to sacrifice the rigidity (there is no one without the other).

How about carrying those broomsticks on a roof rack?

No need to be a jackass. You realize the sedans maintain their rigidity advantage even having that hole right? Even the ones equipped without the ski bag just have a loosely attached piece of metal that can be knocked out with a rubber mallet.

[Cubieman]

Would installation of this impede the installation of say a vincebar or other topside RACP reinforcement later on down the road?
I know if that was the case one could simply do topside first, then rear bulkhead.