I would like some suggestions on the best way for me to reduce kr. First ill start with the mods- (2005 monte l67 supercharged) 3.5 pulley, 180 t-stat, zzp powerlog front header, zzp down pipe, full 2.5" catback exhaust with magnaflow mufflers, ngk tr6 plugs gapped at .055" throttlebody spacer, and i always run 93 octane. I have a scanner to read kr, but more importantly i can feel the computer pulling timing when i get on it, mainly in second gear. First gear is usually fine, im sure it is due to the increased load in second. I think its safe to assume its actual spark knock and not just false knock, however with the supporting mods ive done i would not expect this much kr. As for possible solutions im thinking of the zzp short stack intercooler, or a tuned pcm. The intercooler is the pricier option, however im not sure if a tuned pcm would reduce my knock or not. Does anyone have any expirience with a pcm lowering their knock? Also any suggestions on the best pcm? ive heard the zzp one is no good. Or any other options/ suggestions to lower my knock? Any info would be appeciated, Thanks.

 

Are you really not tuned? I would put your stock supercharger belt on until you get a tune. The best way to get rid of your KR is going to be to add more fuel, because you've added more air and the computer isn't making the adjustments well enough.

Overkill is out of the 3800 game I believe, he was always my recommendation for a mail-order tune. ZZP is a good starting point, a local shop would be your best bet though. They would dial you in properly, put a wideband in, get you where you need to be and be good.

 

Thanks for the response. Do you have any expirience with a zzp pcm? Ive been hesitant about a tuned pcm mainly because ive heard they completely eliminate the torque management which is still beneficial to have in some cases.
Also, any input on pcms from intense for 3800performance? thanks

 

Maybe I missed it, but how much KR are we talking? If it's pulling so much you can noticeably feel it, it must be a ton.

May as well prove it before you starting chasing a phantom. Run the tank low, dump in a few gallons of unleaded race gas, and go for a pull. No KR = it was real. Still have the KR, it's false and you need to figure out what's causing it.


An IC would be far better at reducing KR, but I woudnt do a short stack. All of the work to install, all of the risks, most of the cost and only part of the benefit.

With that said, you really should tune it too though. A stock pcm leaves a lot to be desired. I don't do canned pcms though, so I don't have any experience with who is best. I've just heard lots of bad storis about all sorts of canned pcms - too little timing, too much fuel, too many safeties disabled, etc etc.

Lots of other options, but you've certainly hit on some of the big ones. Could do rockers, could open up the inlet path (ported blower, bigger tb, etc. E85 could be an option, so would meth injection. Could do full headers. Lots of routes to go from where you are now.