S50 swap soon, whats performance mods can i do?

[AirplaneBuilder]

I got a 95 m3 that ill be tearing down and pulling the motor, tranny, LSD, autothority intake autothority exhaust and an autothority chip. What basic mods can I do that won't drain my wallet? Maybe bigger injecters, headers... I also need a new maf sensor, is it better to get oem or after market one? Any help would be nice, thanks all!

[MaxBell]

BMW generally builds very highly tuned engines from the factory. Even more so when you consider the M Power engines.

Generally a chip/tune, and utilizing higher octane fuel will net the most gains. Intake, exhaust, larger injectors, etc will net minimal increase per dollar.

Turbos are the best and most cost effective power increase, however, they can be labour and cost intensive.

[rlddlr53]

chip for/with >> 24lb injectors, 3.5 maf
underdrive pulleys
headers/no cats

I presume your premium gas is 93 out in WA?

[AirplaneBuilder]

^^our premium gas is 92 I think, never paid attention. We need cats here for emissions/smog testing. So far i have the autothority exhaust, intake, chip that came with the m3 and it needs new maf sensor so I might as well get the 3.5 maf and also 24lb injectors and get headers... simple to install.

[Leo_328i]

M20 flywheel and clutch is best bang for buck whilst the motor is out.

[AirplaneBuilder]

^^ how is the m20 flywheel and clutch better then the stock m3 parts? i have a good running m3 so i was thinking to use the motor and tranny thats stock on it...

[matthugie]

My opinion, somewhat related to the above, is ltw flywheel and clutch kit. You can use the M20 clutch and fly combo, but it's best to upgrade the clutch kit. The reason to use is that the m20 fly is a bit lighter, and can easily be lightened more. The stock m20 clutch can handle roughly as much power as you're putting down, but dies under abuse. A good aftermarket clutch (like southbend) can stand up to a beating.

For power, 24# injectors and MAF are a decent way to go, I already had them for my s52 and the do make a difference. You don't need to go aftermarket for the MAF, you can use the 3.5" out of a 540 or a porsche i believe, and be relatively inexpensive. You can get some replica headers (racelands or such) for pretty cheap, and they aren't useless (thought like others i had to beat the shit out of mine to get them to fit). High flow cat for sure, and probably a custom exhaust.

No matter how you go, it'll be pretty damn quick. Having had the s52 in my m3, the fly/clutch combo was the best mod for me. The quicker revving and feel is amazing.

[e30rapidic]

I have a lightened M20 flywheel with heavy duty stage 1 clutchmasters clutch and pressure plate. I ripped my stock M20 pressure plate apart the first time I really got into it.

Also have a TRM tune, 3.5 MAF, 21 pound injectors and headers with 3 inch exhaust. The jump from 21# to 24# injectors isn't really noticeable but if you are going to buy a set anyway, get whatever is optimized for your chip.

[Adrian_Visser]

24lb injectors are seriously overkill and won't gain you anything, unless you have cams. Honestly cams or forced induction are what's Gunna get you a real bump in power. Lightweight pullies will get you 2-4whp at most, good header maybe 15whp (maybe).