OK, here's my take on this:
At WOT the vacuum in the intake manifold is (or should not be) more than 1.5" and the PCV valve is closed anyway. The PCV really is doing it's job at idle and steady state cruise by evacuating the crankcase of water vapor from condensation/combustion as well as unburnt fuel and whatever blow-by gets past the rings. No engine has a 100% seal (0% leakdown). The lighter distillates in oil will also tend to evaporate and mix with water and fuel then solidify on the inside of the valvecover, rockers, etc causing problems down the road. When I lived out east, I saw enough condensate in the engine oil to almost look as though it had a head gasket leak. Pull the VC's, clean them ip, and change out the PCV and poof, problem solved. That water plays havoc on your longblock causing sludge and oil delivery problems which as mentioned before, can cause leaks and other nasty stuff. :)
Back in the day their was no PCV system, just a so called "Draft Tube" that hung under the car and evacted under speed. So in a nutshell. here's my response:
Q: Do I have to have a PCV system on my street/strip driven car?
A: NO, but your engine will last longer
Q: Will a PCV make my car faster?
A: NO, but it won't slow it up any appreciable amount either. Depending on the state of tune of the engine, you may have to make jet/idle mixture changes if changing to a PCV or open breather but most likley not.
Strip only cars should have a header evac system as that is the only type that positively evacs under WOT and may reduce windage but that's debatable. Some guys run vacuum pumps with great results over 5 or 6k rpm.
Circle track cars run open evacs because as Memike says, the oil is changed every race and it's just one more thing that won't break causing a lost race.
I hope this is the type of response you were looking for.
Now, back to work bleeding my brakes.
Joe
