Red SS Barchetta

Just wondering what some of the more common causes of knock retard are. I have seen posts about the ASP UD pulleys causing it and headers. But I was just wondering if you had come across any other "common" LS1 areas.

Mike K.

sometimes the exhaust banging could cause or worse case it is actually detonation in which case you better get it taken care of.

Fastt Gunn

Anyone else that's had KR and found a way to fix it?

I just had heads and cam done and I have the dreaded KR according to the data logs. I too have an ASP pulley. But arent there a ton of folks running that piece no prob?

I was getting KR both with the exhaust going through the catback and when the cutout is open. I've had the headers on for quite a while and I've never felt any banging at all.

Any suggestions/ comments?

HumpinSS

iTrader: (1)

Try some high octane gas to rule out the posibility of it being real detonation

Fastt Gunn

Great idea! I could just dump in a can of octane boost right?

Red SS Barchetta..... I apologize... I'm not trying to hijack your thread but when I read what you wrote, it's an answer Im looking for too

marc_w

I hear octane booster stuff only raises octane about half a point...

I consistantly get around 2* KR when I roll into the throttle in OD, at about 65-70.

I've got as high as 9* of KR in some occasions. I don't know how to duplicate it.

It drives me crazy... I have no idea how to get rid of it. I run nothing but 93 octane.

CHRISPY

no use racegas: 100 or 104 unleaded

Fastt Gunn

Thats what my car does too! Comes and goes. Sometimes alot and sometimes a little. From the data logs, it seems to happen a lot when tipping into the throttle. It happened on the dyno too at WOT. Im losing power and am trying to help the guys who work on my car get it figured out.

Next step... put in some race gas and log some data....

Red SS Barchetta

I have yet to try high octane gas, but I figured maybe some of the tech guys might have ran across some more common issues. I had mine dyno tuned at LS1speed and am only putting down 360rwhp - with MAJOR KR. Tuner felt it was a possible bent valve(s) - I had some problems with a set of PP S2 heads with the old springs on them.
I sahould be around 420.........................