Originally Posted by GRILLCRAFT
High Compression FI motors are on the trend to popularity and a few local guys have have done some really bad damage to their motors. Some precautions to doing it:
-Watch/Limit your boost
-Know how much power your bottom end can take
-Dont over do the turbo size
A friend in particular built an entire block 11:1 compression, went FI with it and basically his crankshaft said I'm out of here. That was with a decent sided GT42R. Other guys can get more out of a paticular engine, but never lose mind that your build can only handle so much power.
Naturally you have to build for your goals, that goes for any compression ratio.
High compression ratios will need a different tuning strategy, less boost and better intercooling as a rule but these are basics for any build IMO.
You also have to be reasonable with the compression ratio, for most engines 9-10:1 is the sweet spot, newer engines can run higher ratios then older ones as a rule.
With the ability of guys to use E85/water/meth injection now days high compression is the choice more then ever. Just look at all those stock block 5.3 GM truck motors making 800-1000whp with stock 9.5:1 compression. Or all the supras making even more with 10:1 builds.
It is about the whole package, got to make sure everything is working together properly.