im about to put a 3.25" pulley on my girls 03 bonnie with only a K&N air filter, what are some ways that i can keep what ya'll call knock retart down............and what is krand how does it hurt performance

Do NOT put that on there without many more supporting mods. You should be putting on a 3.5 if you aren't going to do anything else but a filter. A 3.25 can damage that engine. You are guaranteed a lot of KR with that size. You will need a lot of exhaust work, colder plugs, and even rockers or an IC to keep the KR down to 0.

Agreed! Not only would you hurt the motor, but the KR will tell the computer to kill horsepower anyway. Basically, it would feel like the engine just fell over itself.

Or out the bottom of the car

To answer your question about what KR is. KR is "knock retard." The engine has knock sensors in it that can hear when the engine is getting spark knock (predetonation), which is when the mixture in the cylinder ignites before the plug sparks. It retards the ignition timing when it hears this knock to try to reduce this spark knock to save your engine. Spark knock if not controlled can damage your engine badly. KR is a good thing for your engine, but bad for performance because it gets rid of timing. With a 3.25" pulley, the blower will be making so much heat with your mods that it will cause the mixture in the cylinder to ignite before the plug sparks, causing KR, pulling your timing, and therefore slowing your car down a lot, therefore basically getting rid of any gain you would've seen from the pulley. If you don't plan on doing any more mods than what you have, a 3.5" pulley is as small as you want to go. You might even see a little KR with that pulley, but it will probably only be a degree or two if you do which can be destroyed with colder plugs or something to that effect.

If that didn't help you understand what KR does and why it is both good and bad, then I can link you to a great article about it that should make it really clear.

Shawn