I've got a 99 323i, I'm looking for performance with looks being secondary. I've found a number of things I can do to increase the speed, handling, and overall driveability.
I went with the ECIS intake (
www.ecisbmw.com), because of the heatshield and the easy installation (takes 15min). I'm going with the UUC Motorwerks (
www.uucmotorwerks.com) exhaust mainly because I think it looks cool. I would like to replace the headers, but I haven't found any out there (anyone know of some?). Okay, so now the car can breath.
I couldn't stand the extremley long throw of the manual so I went with the UUC Motorwerks short shifter with the ball bearings.
To increase the power throught the power curve and remove the top speed governor I'm going with the Shark Injector. You can get that from a number of places.
IMHO the 323 revs slow, so I plan to go with a lightweight flywheel from Rogue Engineering (
www.rogueengineering.com). This also drops about 15lbs from the weight of the car.
I also plan to go with a dry cell battery to further remove weight (
www.performancedistributors.com/batteries.htm), this should drop 30+ pounds according to stuff I've read.
I haven't decided what coil over system I want to go with yet, but to reduce body roll and the unsightly gap between the wheel well you've got to lower the car. I also plan to go with a front shock tower brace (
www.racdyn-usa.com), and sway bars from UUC Motorwerks. All of this should dramatically reduce body roll and increase the cars cornering capability.
I'm also going to do rims, just trying to find some nice looking lightweight one (hopefully around 15lbs-18lbs for 17's).
Brakes should be done also. You can get lighter rotors since the stock ones are really heavy.
Okay so all in all, after all of this, you should have a car that should be able to hang with a 330. If a shop does the work you've spent a few thousand dollars.
If that's not enough, go with a Supercharger (
www.esstuning.com).
Sorry for the long reply. Do you feel better now?
:-)