DV 993tt

I want to get some opinions on a possible direction for my 930 engine.

I have been thinking about the possiblity of a high compression low boost engine. I can maybe use 95mm 9.3:1 Carrera 3.2 P&Cs and run .5-.7 bar boost. I heard somwhere that actual compression ratio of these US spec 3.2 P&Cs are actually below 9:1.

I don't really want ultra high horsepower. I want the engine to drive like a really really powerful NA engine. Has anyone done anything similar?

Geoffrey

I think you would be fine as long as you have proper engine management and tuning done on a dyno. I've done some supercharged applications on stock compression 964s which are about 10.7:1 true compression.

JBH

So why is this not done more often? It seems logical to try to get the low end performance of a high compression engine and the increased hp/tq as the boost comes on. What am I missing?

Brent 930

Sounds fine as long as the turbo you use will operate in the boost range your runnning not to mention the tuning.

PT

Geoffrey - your supercharge 964 experience: does or can the car run reliably on track with extended boost period? Will it cause any heat/detonation issue?

thanks...

Geoffrey

The supercharged car is running non intercooled with 6-7psi of boost (falls off at the higher RPM) and is controlled with MoTeC which ensures proper timing and fuel. 350rwhp, runs like a champ. Cylinder head temps are about 150 degrees C which is well below the 180 degrees C my turbo car runs at.

PT

I guess the magic here is the MoTec? There are kits out there that claims to be bolt on & work with factory DME - those I believe will not be able to sustain track-use? Any comments/experience?

Thanks again for your input...