Project M3: Part 3 – Headers, software, dyno testing and more!
100whp per liter or bust!
This project is starting to get really fun. Building an E46 M3 is reminiscent of building cars in a Gran Turismo video game. Every little modification seems to release a little more power.
When we started, the car dyno’d a respectable 290whp on Modified by KC’s Dynojet 248C. After a fluids flush, new plugs, stock-box intake, software tune, pulleys and cat-back exhaust, we’re up to over 307whp. Our goal now is to reach the holy grail of specific output—100 wheel horsepower per liter—a feat in the O.E. world done only by big-dollar exotics such as the Ferrari 430 16M, Ferrari 458 and Porsche GT3/GT3 RS. Yes, their displacement is bigger, making their achievement even more impressive, but doing it with 3.2 liters would still be sweet.
We’ll be testing Fabspeed headers sold exclusively by VAC Motorsports. We sent these units to Swain Tech for their “White Lightning” treatment. Check out the video at the end of this article showing the sound differences between stock, with cat-back and then with full exhaust.
An ECU reflash will be necessary when catalytic converters are removed. Our previous tune in Part 1 came from Randy Mueller at Epic Motorsports. He’s known to be one of the best in the business and has not disappointed thus far. We’re working with him again today.
In anticipation of the extra power, we want to ensure optimal spark. I've tested Bavarian Autosport’s high performance ignition coils previously on a modified E36 M3, and hope to see similar results today.
Lastly, to prevent oil build up in the intake manifold, which will keep our fuel's octane optimal, we’ll be installing a nifty catch can setup from Radium Engineering.