Ya essentially three main things are taking place to make that power.
-It's stronger in many areas than the M54 allowing it to rev up to 8000 RPM safely. Given that horsepower is simply work completed as related to time, if you can keep making good torque at faster RPMs, you are making more power.
-It has the flow capability to flow enough air to make power at 8000 RPM. (higher flowing intake/heads/exhaust).
-It has a cam profile to match and make power up to 8000 RPM.
The key to making big horsepower n/a in these cars would be to rev them higher and support that with enough flow.
Check out my band - The Marked
1999 BMW 328i (Daily Driver) - m54b30 intake manifold, ebay headers, Rebirth Motorsports CAI, Rogue Engineering underive pulleys, Epic Motorsports Remote Dyno Tune, Custom 3 inch exhaust with Burns Merge, Schrick 264/248 Cams
1967 Buick Skylark - 430 Buick Big Block Swap.
Last edited by jared_wiesner; 01-14-2013 at 08:43 AM.