[Sluttypatton]

Cutting your compression ratio is a step that is optional if your engine is a low compression engine. I'd say anything more than 9.5:1 and you should probably cut the compression ratio, if you are going to intercool the charged air then you will be able to run a higher compression ratio. The main concern in this is to avoid detonation, detonation is usually a result of excess heat, and since turbos are run by exhaust gas they heat up the charged air before it enters the engine. Intercooling the charged air will drop its temperature and reduce your chances of detonation. Now if you dont want to cool the charged air, then cutting the conpression ratio can be a costly venture, but its your choice, it will cut the power your engine makes naturally aspirated, but will allow you to increase the boost level that you want to run (7psi is a typical boost with stock compression ratio). Another issue is will your fuel system be able to supply enough fuel for it to run without "leaning out" (running with too little gas), if you engine leans out the worst that will happen is that you will "window" one or more pistons(put holes in them...thats bad). If your fuel system is a returnless system you may have to pay for pricey ecu's or reprogramming, if it isn't you should be able to use a rising rate fuel pressure regulator, that monitors the MAP and adjusts fuel accordingly. Detonation will window your pistons just like leaning out so make sure you have enough fuel, and that your air is cool. So onto cooling, oil cooling shouldn't be a problem but incorporate a large oil cooler to be safe. make sure to keep up on your oil changes, and another thing, unless you invest in a turbo timer, make sure you let the engine idle for 5-10 minutes after driving so that the ceramic turbine has a chance to cool or elso it will crack or shatter. Remember, compression ratio is subjective, the guys at sport compact magazine turboed a matrix with 11.5:1 compression ratio and ran 7 psi boost, without cutting the ratio at all...and they ran the car on pump gas. That reminds me use high octane gas only to help resist detonation...sorry i kinda rambled but there is a lot of stuff to know about turbos, and i only scratched the surface, hope ive been help. And by the way, turbos are the most cost effective way of boosting power. but you will probably have to ditch those headers you have for som turbo headers. Have a good time with the turbo, i know i do.