BMW M3 E36 Saloon, weight reduction

[isee]

What sort of weight saving can one expect by slimming it down?
I am talking, no sound system, no back seats, no spare, no aircon, no stock dashboard and plastic windows.

A mate wants to get a vx220 as a track car and I feel I will get a lot more value for money, not to mention replacemnt part avilability by buying an m3 saloon and slimming it down to similar weight of the vx220 and a performance to exceed, non?

[swtmerce]

Doing exactly what you say plus removing sound deadening, trimming loom, plastic boot and bonnet and putting in two light buckets will probably see you under 1250kg.

[benny.c]

My E36 325 saloon track car was 1,145kg last time I weighed it, but I've recently completed some more weight saving so it will hopefully be around 1,125kg. Not sure what's actually possible but 1,100kg would be a nice round number

Edited by benny.c on Tuesday 30th November 23:08

[isee]

benny.c said:

My E36 325 saloon track car was 1,145kg last time I weighed it, but I've recently completed some more weight saving so it will hopefully be around 1,125kg. Not sure what's actually possible but 1,100kg would be a nice round number

Edited by benny.c on Tuesday 30th November 23:08

nice, what sort of 0-60 are you getting any idea?

[E36GUY]

getting rid of the front seats is probably the biggest saving. They must weigh in at nearly 40 kgs each

[rassi]

Would you install a (half) cage or leave it as is? That would be an additional 15-25 kg.

[benny.c]

isee said:

nice, what sort of 0-60 are you getting any idea?

Not sure sorry. It's only used as a track day tool so it only ever gets a rolling start from the pit lane. The cornering and braking are far more impressive and useful than the acceleration though. It has a full FIA approved cage in BTW.

Going up to Oulton on Saturday so will weigh it again then.

Edited by benny.c on Wednesday 1st December 14:58

[trackm3]

My old Saloon which went on to win the Kumho bmwrdc this year was 1268 kg when i sold it, that had drilled doors, carbon kevlar seats, alloy pro harness's, GRP boot and bonnet both pinned, Carbon boot spoiler, slimmed down wireing loom, lightened bumpers but still in ABS, 12 point cage in CDS, it still ran a heater and ABS and im sure it still does today

[isee]

i'd be looking to have a cage in it yup.
And yes I would definitely be looking to replace the front seats with more appropriate ones too.

do you think a lightened m3 evo would corner as well as a standard vx220 though? Wold be surprised if it did.

[rassi]

Also some weight to be saved if you were to run with one of these batteries:

http://shop.edoperformance.co.uk/tomioka-racing-pe...

[dan101smith]

E36GUY said:

getting rid of the front seats is probably the biggest saving. They must weigh in at nearly 40 kgs each

Coupe ones yes, but saloon ones aren't nearly as heavy as Vaders.

[benny.c]

Weighed the car today up at Oulton and it is 1,130kg with 1/3 of a tank of fuel. So I make that 1,109kg dry

Still got the back doors to chop down, sound deadening to remove and some structure to come out of the rear bumper. 1,100kg is looking like a nice round figure to aim for.

[sniff diesel]

benny.c said:

Still got the back doors to chop down, sound deadening to remove and some structure to come out of the rear bumper. 1,100kg is looking like a nice round figure to aim for.

I seem to remember mine weighing about 1120kg when it had the old M50 engine. With the S50 and EVO axle it weighed 1200kg last time I had it on the weigh bridge, since then it's lost nearly 6kg from the flywheel. That's with ABS still working and BBS wheels, reckon there's 5-6kgs of ABS pump and ECU, plus a kg per wheel to be saved if I went for some lighter ones.

The lightest 3 litre M3's in the Kumho championship are around 1200kgs with driver.

[benny.c]

So you reckon about 80kg extra weight in an M3 block and drivetrain or had you added anything extra in too? Oil cooler and bigger rad? I found a website giving all BMW engine weights and it says there is only 16kg between the M50 and S50 but that doesn't factor in gearbox, trans etc.

[sniff diesel]

benny.c said:

So you reckon about 80kg extra weight in an M3 block and drivetrain or had you added anything extra in too? Oil cooler and bigger rad? I found a website giving all BMW engine weights and it says there is only 16kg between the M50 and S50 but that doesn't factor in gearbox, trans etc.

I'd guess that 20 kgs of that is the EVO axle, large casing over a medium casing. Using a 3l axle would be lighter. 5 speed gearbox and prop would have negligable weight difference. I also swapped to M3 front hubs and brakes at the same time and they're bigger and heavier too. Added about 10kgs of rollcage turret bars and a GT lower brace at the same time.

Is that 16kg difference for a fully built engine or just the short block? I'd be suprised if the difference was that little considering the bigger, wider head, ITB's etc. M3 exhaust is bigger and heavier too (60mm diameter instead of 50mm IIRC) suppose all these things add up, and what with the rad and oil cooler it's easy to pile on the pounds.

What I can tell you is, when I did the first trackday with the M3 running gear fitted the car was prone to understeer badly. With the same suspension settings and the 325i lump it was very neutral at the limit.

[benny.c]

That's interesting thanks Rich. Did a track day at Oulton yesterday and the car felt great with the Aplina lump in. Noticabley more power than the 325 and no longer any issues picking up speed exiting slower corners. It was wet and icey all day so we never got to test properly though.

This is the website I was looking at with the weights on:

http://www.bimmerforums.com/engine_faq.php


M50/M50TU
Straight 6 DOHC 24V/Straight 6 DOHC 24V with Single VANOS. 1989-1998. 136kg 299lbs
Used in E36 320i/325i, E34/39 520i/525i, Variation of this was used in the Early US E36 M3
2.0 (150bhp), 2.5 (192bhp), 3.0 (240bhp) Sometimes referred to as S50US. Engine shares more common parts with M50 than Euro S50, but is a motorsport engine.


S50
Straight 6 DOHC 24V Solid Lifter Valvetrain with Single VANOS and Individual Throttle Bodies. (Dual Vanos on 3.2Ls) 1992-2000. 152kg 333lbs
Used in non-US E36 M3
3.0 (286bhp), 3.2L (321bhp)

[Renn Sport]

This is an interesting thread.

Sorry O/T

Do you chaps insure these cars as road cars SPFT and drive them to events? Or are these track cars trailered to events?

Just curious.
Cheers.

[dan101smith]

I used to insure mine fully comp and drive it to/from trackdays.

Which was horrendous.

[Renn Sport]

Thanks.. I don't have room for a trailer.

I was thinking I would much prefer to track my 328 then my 911. Although I would like to take the 911 on track eventually.

A road going, insured taxed track car would be the only option for me. Hmmnn I wonder if this is feasable? The car will be so modified. Insurance may pose a problem.

[dan101smith]

Mine was race spec but still road legal.

Insurance was peanuts with Richard Egger.

It's certainly possible, but with a completely bare interior, cage, no heater, 5 speed M3 box and short ratio diff it was in no way fun.

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