E92C63

Hello All,

My warranty is up in october on my 09 M3. I'm thinking about getting into a P31 C63.

I was wondering if there is any way to get more power out of the P31 car without voiding warranty and cutting primary cats.

The first thing i'd do to the car is set it up with some decent rubber, 255 in the rear on a car with this much power is a joke.

Can I do 245/35/19 Front on what 8.5 width rims?
275/30/19 Rears on 10 inch or 9.5 width rims.

Anyone have any lighter weight rim recommendations? I've been searching, but the information on the board is all over the place. Theres no designated Wheel/Rim section

Thank you all for the help.

_AMG_

Those wheel/tire sizes work perfect with the C63.
Id recommend looking into some lightweight 18" or 19" CCW, Volk, or HRE Comp wheels.

Since the P31 already has the power bump a tune would always add some additional power but you wont see the same gains as the non P31 engines since they are de-tuned. Fyi a tuned non P31 is as fast as a standard P31.
I would look into these following mods....
-Tune
-Charcoal filter delete
-Drop in filters (K&N, AFE, BMC)
-ROW airbox
-Long tube headers
These mods will definitely give you the power bump your looking for.

E92C63

Thanks for the response. I saw a post that had a negative horsepower gain after deleting the charcoal filters on a P31 car.

I will look into the others. Drop in filters are probably a go.

Any custom offset on wheels that you particularly like? I need to start looking at some pictures.

derspi

Tuning a P31 car is a waste of money. You're better off spending that money towards going catless & a header where you'll actually see &, more importantly, feel some gains. Fiddling with the air of in any manner is moot also - again, nothing you can feel even with your butt dyno.

But none of this should even matter to the OP if he is serious about keeping his warranty. As soon as you open up the ECU and do header work you can kiss your warranty goodbye if your dealer is a dick.

E92C63

Aright, well thats not too bad, especially since I'm reading the P31 package comes pretty under rated from the factory.

Maybe I'll just do a set of P43s wheels and call it a day. Doesnt need anything else!

Merc63

There isn't much ou can do without voiding warranty

CampioniShop

+1

The true gains on the C63 P31 are from the long tube headers and cats removal. That will certainly a dealer to deny any warranty claims on the powertrain.

Regarding wheels - we can make a custom set of wheels for your car from the biggest brands in the industry. Send us a PM and let's see what fits your budget, desired style, weight target and finishes!

We usually do 19x8.5+45 19x10+50.