Thread: My Best Friend known as KR... Need Help

I had to run modded 1.9's on my car to run a 3.4 safely but I get what you mean about the tune being off.

Gen III blower and the car has around 160,000 miles on it and maintained very well. Lets end the "throw the cam in convo" because that is not an option for at least a year or so as I mentioned before the money is being saved for a supercharger for the charger. So I definitely think a solid tune could help.

Originally Posted by kyle91

I don't understand though... Plenty of people run headers, intake, larger cat back and a 3.4 and not have many issues after a tune. And I'd love to just throw a cam in it if my funds currently weren't being saved up for a slp loudmouth II and vortech supercharger for the charger

Most people that do that are going to see a few degrees of knock somewhere in the rev range and usually in 3rd gear. It's generally accepted as a few degrees of knock on a 3.4 setup isn't devastating. The problem is that as these cars age, we're less able to guess what will happen with any given set of modifications because it's strongly dependent on engine condition, maintenance, etc. Back in 2004 when most of the cars had under 50k on them it was easy but now we have cars that have anywhere from 20k - 200k on them and they can react vastly different to the same upgrades.

That said, perhaps sell the cam and put some rockers in there, dial back timing a few degrees or get a 3.5" pulley. Depending on how sporadic that knock is, the car might be stronger and more consistent with a 3.5" pulley. If you're getting a steady 4 - 5 degrees than go up a pulley size for sure. If it's just a couple degrees sporadically though then don't sweat it.

Also, as an aside, one thing we're seeing more is false knock as a result of vibration or resonating. Try removing the supercharger belt and see if you still get knock.

Originally Posted by Mike Kopstain

Also, as an aside, one thing we're seeing more is false knock as a result of vibration or resonating. Try removing the supercharger belt and see if you still get knock.

That came across to me this morning as I have all poly mount uppers, a solid brand new lower engine mount, and need a new solid trans mount. I'll have to try scanning again with the belt off.

Like it has been stated in here, I'd also check to see if there IS enough movement on the motor for the downpipe to be making contact with the swaybar under load...could be false knock...but I'm doubting it since you've replaced all the mounts...check the swaybar for contact though...as there will be obvious marks.

Having an MPS right now makes this an easy thing to figure out...I for one would be happy with the 4* of extra timing (since you said you were seeing 12*)...and toss a 3.6" on there and be done.

If you don't want to swap pulley sizes...then I'd pick up a wideband and go from there...also, a ported blower will help with flow...and lowering outlet temps...might help killing a little bit more KR as well when you do the re-tune.

And for the 3rd thing...there is TONS more load on the car in 3rd...than say 2nd or first...which is why when you see people popping pistons...they were running the ever living pee out of them.

absolutely no contact what so ever. I flipped the sway bar and relocated the O2 sensor so it won't smack the firewall or the sway or anything for that matter.