[ZephTheChef]

I've been doing some fun turbo-spool math based upon a spool data chart that we put together over on the 3000GT/Stealth forums. If the numbers from twins on a 3.0 can be directly related to a single on a 3.3, then I've come up with some shockingly quick spool predictions. The 16Gs on a 3/S will start seeing positive pressure around 1800rpm at full load. Divide that by 2.2 (10% more displacement, and twice the cylinders feeding the turbo) and you get 818 RPM. Max boost happens at 4700RPM on a 3/S, the same formula yields 2136 RPM with a single on the SVX. There are obvious flaws and things not considered here (compression ratio, differences in VE, differences in EGT, etc), but it should give a general idea of the spool characteristics anyway.

If that's even remotely representative of what I'll be seeing, then I should get positive boost off-idle, which will hit around 30psi by 2136 RPM, and make about 215 crank HP at that point. That'll ramp up to about 365HP at 4000RPM, at which point the turbo will be out of flow and the boost will start bleeding off, maintaining somewhere around that 365HP to redline (the boost falling off, but maintaining roughly the same CFM).

When plotting that on the compressor flow map it just BARELY stays right of the surge line, this is of course helped with higher VEs, as I'm sure I'll be seeing due to the boost. I think this turbo is going to be an incredibly fun match if the real-life numbers look anything like these guesstimates. 200+HP from 2000 RPM...hellz yeah! It's so borderline to being too small that it'll either fall on it's face, or spool fast and hard, I can't wait to see which.