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      08-20-2013, 05:07 PM   #235
Ant Man
United Kingdom

Drives: E92 M3 Santorini Competition
Join Date: Jun 2008
Location: East Anglia

iTrader: (1)

Originally Posted by lukester View Post
Great thread. But the issue with removing weight from the M3 is that it changes the car.
If you go through it like I did - basically the stuff which makes sense - only removes weight from the rear of the car which changes the handling.

I did:
Full Akrapovic Exhaust (~23kg/50lbs)
rear seat delete & remove all unnecessary parts and insulation from the trunk (~28kg/61lbs)
55Ah Battery (~11kg/ 24lbs)
Recaro Pole Position seats driver and passenger (~29kg/ 64lbs)
OZ Ultraleggera Wheels with Michelin Pilot Cup tires (~7kg/ 15lbs)

All mods make sense for me as I love track days and would have done it even if it doesn't make the car lighter (e.g. the seats, wheels, tires, ...)

My M3 should be +/- 216 lbs (98kg) lighter than stock at the moment.

But....the car switched from a slightly oversteering M3 to an more understeering M3. There's no power steering available any more as it just
pushes over the front wheels.
(you can still drift it but you have to force it)

It's logical. A lot of the stuff has been removed from the rear or the center of the car.
Nothing from the front or under the hood. So the weight balance moved away from were it should be.

Will weight my car within the next weeks and I'm really interested to see the final results.

What can be done against this new handling?
I'm gonna try some 265/35-19 Michelin Pilot Cup on the front, too. At the moment the setup is 235 and 265 which is not perfect if you like an oversteering M3.

But I'm missing ideas what to do with the front.

A carbon hood will only help with ~4kg/ 8.8lbs. Not really worth it.

What I saw ... but I'm not sure if it's a good idea. Replace the big underfloor plate (it's directly under the engine) with a more lightweight part as this thing is really massive (and we do have good streets in germany so there's no need for such a engine protection).
I'm trying to understand how moving the weight from the rear increases understeer? If there is less weight pushing the rear into the tarmac, wouldn't the rear slide more, especially under power as there is effectively less grip? On the other hand, cars that have a lot of weight over the front axle tend to understeer more than cars with a more equal front-to-back weight distribution.

Also, are you running OEM GTS aero?