[Michael Beard]

The effect of the filter +/- is going to depend on your tuneup. It's just like changing fuels: You can't just swap it in the tank and then assume that the new fuel is quicker or slower than the old. You have to tune for whatever you have changed in the system.

I have some Dynatech cone collector inserts that I have to run at one track due to a muffler requirement. First time I put them in the car, it slowed it down .03. Played with them again and it picked it up .05.... but I had the car jetted different.

In *any* case, it's a matter of tuning, and what you want to see. I specifically use my K&N to tune the car to what I want it to run, although I run it 95% of the time just to protect my engine.

IHRA is ok with the filtertop, and even the Quicktime air bell, but the "stub stacks" are a no-no.