Don't get me wrong, there are improvements to be had with these cars. Tightening up the worn bushings and suspension will probably be the most noticeable improvement in performance, but there's a ton of other stuff you could do to make the car funner to drive. A Z3 shift kit will make a noticeable improvement, as will a lightweight flywheel. A limited slip diff will wake up the rear end a little while putting better power to the road. If you have tools and experience, you could advance the cams a couple of degrees and stretch the powerband out over higher RPM's. Your engine can only suck in as much air as the MAF and throttle body will allow it to, so an intake is pointless unless you want to bore out your throttle body and run a larger butterfly. You can port match your intake and exhaust manifolds and port and polish the cylinder head. Heck, if you have the money and a good machine shop, you can increase displacement to 2.1L by over boring the cylinders, running bigger pistons, connecting rods, fuel injectors and a more aggressive crankshaft. Everything comes with a price, and part of that price is compromised reliability. The factory exhaust isn't really restrictive. In fact, it has just the right amount of backpressure. If you were to run an open header, you'd burn up your exhaust valves pretty quickly, so you need some backpressure. Plus with all these o2 and SAP simulators and stuff, you're tricking the car into running lean or rich. So it's either gonna run hot and fatigue everything or it's gonna run cold and gunk everything up with carbon. |