[ksfrogman]

Here are a few ideas I have:

(1) Change to lower (numerically higher) gear ratio.

. . . PROS: quicker acceleration

. . . CONS: slower top speed, more shifting, driveability affected

. . . ???: gas mileage may suffer



(2) Dyno-tuned Intake/Exhaust combination including ECU remapping, cold air vented intake, headers, mandrel-bent pipe and tuned rear exhaust system.

Intake contenders: Gruppe M, Simota.
. . . I am 95% certain I am going with Gruppe M. Why? Because Simota has not backed up their item with a dyno test, the air chamber volume containing the filter element is smaller, and the air filter element itself appears to have a smaller surface area than the one for Gruppe M. On the flip side, the Simota "air box" is completely enclosed, not allowing any warm engine air induction.

Simota:


Gruppe M:


To date, Supersprint is the only company that offers a "complete" exhaust system from headers to muffler:


Concerns: US models have a total of 4 catalytic converters (2 on the exhaust manifold, and 2 beyond that). This product is the Euro aftermarket version. The US version is not yet available. Will the Euro one pass emissions testing?

(3) Supercharger - not yet available. Larger bore and stroke --it's probably cheaper to just get a M3.

[just4kickz]

hey mr frogman can you tell me what exactly voids the BMW warrenty? like in all aspects including body, electrical (lighting?etc), engine... anything else..

[ksfrogman]

Originally Posted by just4kickz

hey mr frogman can you tell me what exactly voids the BMW warrenty? like in all aspects including body, electrical (lighting?etc), engine... anything else..

The answer probably depends on the particular dealership. I believe that a cause and effect relationship between the mod and failed part must be established.

[ward]

I think the diff is only a worthwhile mod if you spend the $$ for limited slip at the same time!

[foofighter]

magnussen's law...dealer has to prove that you did to the car caused that particular thing to fail.

Like you change the filter element to a K&N and it jacks up your MAF, they have to prove that it was the excessive oils in the filter is what jammed up your MAF is an example.

as for mods, i'm kinda of a "green" person when it comes to modding. I wouldnt do something that would bypass the normal smog equipment, i'd rather wait for the US spec version of the full exhaust.

So with that, I'd get a limited slip diff

[EVO_S4]

damn that $5k worth of parts you listed

[ksfrogman]

Just updating this thread.

[ksfrogman]

GruppeM Intake video and dyno:
http://e90post.com/forums/showthread...t=hear+gruppeM

Pre-mod dyno (best of 3 results) vs post-mod dyno (best of 3 results) done same day:

[AW330i]

where can you buy the rear diff?

[ksfrogman]

Originally Posted by AW330i

where can you buy the rear diff?

Bimmerworld.com. That's where the print screen image came from.

[Pyrat 2]

I'd go straight to the source for the rear end diff. Here are the options as I have been seriously investigating getting a new LSD for my car.

BMW parts. The e90 autotrans cars have a 3.64 gear ratio. You can order direct for about $1200. This is not an LSD. You can get this at realoem.com. It is a remanufactured factory unit.

Diffsonline. They will custom build a 3.64 LSD for you. About $3500. This is built off of a standard 3.64 open diff. This is a 3 disk setup with a 40% lock.

Koala motorsport. They will build a custom 3.46 or 3.64 LSD for about $4k. The 3.64 is built off of a standard open diff. The 3.46 again is built off the standard diff but has the gears swapped out. The 3.46 carries a $100 premium because of this gear swap. Both are 4 disc setups with a 40% lock.

Too much information to describe here on the detailed differences but this info should warm you up.

[ksfrogman]

Originally Posted by mdemange

I'd go straight to the source for the rear end diff. Here are the options as I have been seriously investigating getting a new LSD for my car.

BMW parts. The e90 autotrans cars have a 3.64 gear ratio. You can order direct for about $1200. This is not an LSD.

Diffsonline. They will custom build a 3.64 LSD for you. About $3500.

Koala motorsport. They will build a custom 3.46 or 3.64 LSD for about $4k.

Too much information to describe here on the detailed differences but this info should warm you up.

I surmised that the part Bimmerworld was selling was simply the stock E90 diff for the steptronic. Good to hear the BMW price is in line with Bimmerworld's price.