If you want that down low torque, nothing beats a twin-screw. The K&N filter is good for exactly 0 hp.

 

Agreeing with everyone else. K&N won't gain you anything over a clean paper filter. They're just pushing a product. Unless you plan on going with a cold air intake AND TUNE over the stock intake, just get the paper filter.

For superchargers, based on my research they're built for two different purposes. The twin-screw will get you torque at the low end of the RPM range, whereas the centrifugal builds power similar to a turbo. Both are capable of a lot of horsepower and torque, the difference is where you want to feel it on the powerband and how you want to drive the car.

 

I can confirm everyones answer for your second question. After a small dust storm had a very filthy filter for my JLT intake, cleaned and reoiled it and it made zero difference in performance besides being clean. And that's with an aftermarket intake. Can imagine drop in filter will make zero difference in stock intake. Watch out for those quick lube places. One guy brought me the PCV valve off my Impala claiming it was bad, which I had already changed out only a few hundred miles prior. I was pissed!

 

Unless you got loads of cash your willing to spend on installs the first thing you gotta think about is can you afford a supercharger? IE, are you gonna install it and can you work on your car? I only ask this cause you took your car to Jiffy Lube. Oil changes are done by the dumbest dudes with the least experience in the shop..........Just saying..... the dudes at Jiffy Lube might not be the smartest guys in the biddness, thats all. Learn to do all that sh*t yourself.

You will see a lot of the HP/TQ numbers in the 400-450 range because a lot of us want to stay under the grenade limit of the motor and trans. I have no desire to spend the cash on a built motor and trans hence the reason I am staying at the 425 mark. Yes I could add the smaller pulley and fuel pump upgrade but why.....it will only put me that much closer to the limit and my car is already extremely consistent and reliable right now.

More isnt always better.

 

If you read around, a lot of people think that the K & N filter lets a little more air and a lot more dirt past compared to the stock filter. I would stay with a paper filter until I went to a CAI.

I have been wondering the same thing about a supercharger though. Just enough to get into the lower 400s