E36 M3 chassis reinforcing plates

[sniff diesel]

I've heard that the differences in the floorplans between regular E36's and M3's are that the M3 models have about 4 extra plates welded in to strengthen the diff mounts, and that these should still be available to order from the dealers. As I'm doing an M3 running gear transplant in a few weeks I think it's worth me adding them, I'm struggling to find the appropriate parts numbers for them. Can anyone help?

[TheEnd]

They are known as spacer rings (ve did not hav a design fault!!)

41.00.2.256.495 FL
41.00.2.256.496 FR
41.11.2.256.497 RL
41.11.2.256.498 RR

[sniff diesel]

Many thanks for that, anything else worth upgrading whilst transplanting the running gear from the M3 into my 325i trackcar?

[naetype]

Road speed sensor?

If you know what I mean you'll be fine... otherwise send me a PM.

ETA, as you can see from the Turner site, those plates are only really required if you're running M3 power along with M3 ARB's....

To put that in perspective I've been running M3 'across the board' in a 328 shell without any problems both at UK track days and on the 'ring...

Edited by naetype on Thursday 1st October 22:04

[TheEnd]

I'd put those plates in any 325, as they suffer from ripped diff mounts with the 2.5 in, let alone anything more powerful.

[sniff diesel]

naetype said:

Road speed sensor?

If you know what I mean you'll be fine... otherwise send me a PM.

I'll be swapping the entire running gear from the M3 so as to benefit from the bigger brakes, LSD, driveshafts etc. Not sure if I need to swap steering colulms or brake servos and master cylinders too?

[sniff diesel]

TheEnd said:

I'd put those plates in any 325, as they suffer from ripped diff mounts with the 2.5 in, let alone anything more powerful.

I've heard some horror stories (never seen any evidence yet though) the car's having a bit of welding done anyway as there's a bit of rust in the engine bay and a couple of extra bars added to the rollcage so whilst everthing's in bits it wont be much extra effort to add the plates.

[TheEnd]

The rear axle swap is a bolt on affair, but you will need to keep hold of your original 325 diff input flange, and swap this onto the M3 diff. The M's use a CV joint instead of a UJ, so have a cup shaped 6 bolt flange. That way you'll be able to use your original propshaft. You won't be able to use an M3 one, as the 325's gearbox has a smaller output / donut on it, and there isn't any props to match at both ends.

If you are using an evo diff, then there might be a few more glitches, as i can't find out if you can swap the input flange for a 325 4 bolt type. I had a custom prop made up to keep the rear cv joint and use a small donut at the front.

At the front, M3 3.0 hubs are a direct swap, and identical to the evo ones except the evo one seems to have built in negative camber (which would cancel out with the evo top mounts), the calipers are the same on both, and you can use the evo floating discs if you find some.

The final piece is the master cyl, i swapped a complete m3 3.0 MC and servo on mine, so everything is back in sync.
There does appear to be plumbing differences with 3.0 and 3.2 master cylinders which should correspond to pre or post 95.
So, for a 320/325 use a 3.0 mastercyl, for a 323/328, use the evo version

the steering racks and columns won't need to be changed. the 3.0 had a variable ratio rack, with a slow centre, and quicker sides, the evo returned to the same non M single ratio rack.

[scz4]

Check the "Diff Mount Reinforcement Kit" kit lower on the page. Think I'll get these when I replace my diff, only £50.

http://www.bmsport.com/e-shop4(2008).asp



Edit, link doesn't seem to work. Go to e-shop, BMW > M3 > Drivetrain

Edited by scz4 on Friday 2nd October 18:28

[sniff diesel]

TheEnd said:

The rear axle swap is a bolt on affair, but you will need to keep hold of your original 325 diff input flange, and swap this onto the M3 diff. The M's use a CV joint instead of a UJ, so have a cup shaped 6 bolt flange. That way you'll be able to use your original propshaft. You won't be able to use an M3 one, as the 325's gearbox has a smaller output / donut on it, and there isn't any props to match at both ends.

Being as I've got a complete rusty 3.0l M3 coupe going spare I was planning on using the entire running gear from it in the 325i, so will use the M3 gearbox and prop as I imagine they'll be heavier duty items and it keeps things simpler when ordering parts in the future as it'll be essentially a 4 door M3.

[TheEnd]

If you are using the M3 box, you might have to do some research into clutch combos.

If my memory serves me correctly, the M3 and 328 use a larger 240mm clutch disc, so you'll need a suitable flywheel, and i have a feeling the PCD on the crank is different, so a 328/m3 flywheel won't just bolt on.

I can't be 100% sure, but it needs to be checked out beforehand.

As for the BM sport diff mount reinforcement, that's only suitable for the 3.2's 210mm diff, which has the famous alloy boomerang. If there will be a problem with the 3.0 188mm diff, it'll be the front nose bolt breaking instead.

[naetype]

sniff diesel said:

naetype said:

Road speed sensor?

If you know what I mean you'll be fine... otherwise send me a PM.

I'll be swapping the entire running gear from the M3 so as to benefit from the bigger brakes, LSD, driveshafts etc. Not sure if I need to swap steering colulms or brake servos and master cylinders too?

Don't need to swap the steering column,
May need to do the servo though.. I had to on mine for a 328 setup.
You'll need the road sensor signal. It'll be fine up to about 70mph then, if this is not hooked up, it'll start to run and idle rough. Clear the DME errors (or disconnect the battery) and it'll run fine until you go over 70mph again.

ETA. The 328 and M3 box's are the same, so if you're doing a straight swap over you'll be fine.

Edited by naetype on Friday 2nd October 20:54

[sniff diesel]

TheEnd said:

If you are using the M3 box, you might have to do some research into clutch combos....

As for the BM sport diff mount reinforcement, that's only suitable for the 3.2's 210mm diff, which has the famous alloy boomerang. If there will be a problem with the 3.0 188mm diff, it'll be the front nose bolt breaking instead.

I'll be using the engine, clutch, gearbox, driveshafts, etc from the M3 so it's not an issue, I'll be keeping the standard M3 clutch for now.

I might have to swap over to an EVO rear axle setup as I'd like to swap the diff internals for a 3.64 setup from the E46 M3 as it gives a nice ballance between top end and acceleration topping out at around 150mph in 5th. Apparently the E46 internals need the wider casing from the EVO diff.

[TheEnd]

Yep, i've heard of the e46 m3 diff swap, you'll also get the M variable slip diff, and i think the crown wheel and pinions can come from the older e34 535's

The evo diff needs the evo carrier, but despite being bigger, the front flange is in the same spot so the 3.0 prop will fit.
Essentially it's the same set up as the european M3 GT.