Knock Question
 

I just hooked up my scan guage in my car today and was using the knock learn function on it. it displays as a number but i don't know if its degrees of knock retard or what. when im crusing along at like 2100 rpm's or so and like -2 to 0 psi of boost and a little bit of engine load the knock learn will move from 0 to about 2 and even up to like 3.4 and back down it moves up and down real quick but doesnt seem to go up past like .5 to 1 under full throttle and boost... I really don't understand this, and the car is stock except for a CAI. i would appreciate some help understanding bacause i plan to do mods and a pulley soon but this scared me a little bit tonight and i dont need to scatter an engine on the ground

RE: Knock Question
 

what kinda scan tool?

If your only mod right now is a CAI, you've got quitea few mods to go before you should even consider doing a pulley. Could definitely be KR though- most stock L67s have some knock even stock.

RE: Knock Question
 

The more air you put in the engine(Lean Condition)
The more fuel you put to the engine ( Rich Condition )
You need to get this mixture out (bigger exhaust system )
You have to remember you are going through a computer. So you have to reprogram the computer for the new perameters you put to the engine. If this motor is not in balance with all of this you can hurt the engine.

RE: Knock Question
 

Ya im not just gonna bolt a pulley on cuz that scares me, im looking into a magnaflow catback it think and maybe pacesetter headers. i think it will be a while for the pulley, but i would like to take the right steps in the right order

RE: Knock Question
 

O sorry, the scan tool is one of them aeroforce scan guages...i dont know how great they are, but i had one layin around so i hooked it up

RE: Knock Question
 

I disagree to a point. I'll definitely agree that a custom tune specific to your mods will help tremendously, however doing something to add more air to the engine (such as a smaller supercharger pulley) will not make the engine run lean. Your mass airflow sensor is fueling based on how much air is being sucked in- so it is able to compensate by adding the proper amount of fuel to match by adjusting IPW's.

The further away from stock you get though, the further your fuel trims will be locking in from 0 (which is bad), so the more a tune will help. But there are many people running gtps with basic bolt ons on a stock pcm. Its not really like those off the shelf 'cookie cutter' pcms help tremendously either, they can get you much closer (like stock is) but they can never perfectly dial ina car.