#33861, "RE: lets answer this once and for all" In response to In response to 10
I started this thread to understand the choice of higher or lower compression pistons on a boosted car, and the tuning issues that go along with that. Here's my theory (correct me if I am wrong). The tuning issues that come from a higher compression engine, come not from the fact that it has higher compression (that you would create anyway with more boost), but from the fact that you are starting with a smaller space, and increase the compression more rapidly (it is faster to increase pressure in a small space than it is in a larger one). Therefore with lower compression you are easier able to increase boost in smaller increments, creating an environment that is less sensitive to slight fluctuations, (a small spike will increase the compression a smaller percentage with a lower compression piston) making it more forgiving of your tuning. RIGHT?