[gritz45]

Originally Posted by Steve Levin

Something to keep in mind with any engine changes -- they rapidly cost engine life, and typically disproportionately to the amount of extra power generated.

I've worked with the 3.0 litre Cosworths for vintage F1 cars, and the rule of thumb is that for every 1,000 rpm you pull back redline (from, say, 10,000rpm) you double engine life. And the difference in power between 9,000rpm and 10,000rpm is not all that high.

So whilst I don't have a good anecdote about taking a 425hp engine to 560hp, my gut says that, all engineering aside, that a 30% increase in engine power without reworking the engine internals is going to end up being very, very costly.




It appears to me that there are two major problems with supercharging these engines. The first is lack of tuning capabilty (particularly fuel management) over the entire rev range, and the second is powdered metal connecting rods. If you check with the Mustang crowd(I still have one) where SC or turbo is the preferred power adder, you will find that the non forged motors with cast pistons don't tolerate forced induction very well above about 6-8 psi(about 360 CSHP). On those motors running higher boost a bent/broken connecting rod was almost a certainty at some point. With forged internals reliability has been good up to 600+ HP with proper tuning. My personal feeling is that a motor capable of 500+ HP and 6500 rpm needs forged rods, crank, and pistons. But that's just me.

Steve