Ive been working on my tune and it wont take more than 5 degrees of timing up top without getting 5+ counts of knock. Air fuel is 11:1 and boost is 23psi. Is there something i'm missing here? Tune is on 91 octane.

here is my mod list:

Cosworth 272s
denso 720s
walbro 255
Buschur cast manifold turbo kit with sc61
Ebay FMIC
dc sports downpipe
aem intake
invidia catback
dejon tool mbc
Denso iridium 1 step colder plugs

I've tried everything I can think of, but it just doesnt want more than 5. Any ideas?

 

HMM. 5* is obviously low. can you post up a log? So your saying if you go bellow 5* of timing the knock goes away?

 

i have a log, but im not sure where to host it. I can tell you when I had it peak at 6 i was getting 8 counts of knock at 6k+

 

what do you run at peak tq?

 

at peak torque im at 1*, then it gradually increases to 5 by redline.

 

Is boost to high for 91?

 

boost seems fine, there are 8's that run 24-25 pounds with more timing then you on 91

 

hmm try to run a little less boost and see if you can push timing further just out of curiousity?

 

It sucks having to figure out knock issues. Is it knocking from 6k all the way till you let off the throttle? also does it just instantly go from 0 knock to a higher value or does it gradually climb before 6k?

 

Once it starts knocking it doesnt stop til I let off, and it comes on strong. It goes from 0 knock to like 8. I tried running less boost but it didnt really make a difference.

 

Keep in mind you can drop the timing so low the knock will stay. Diminished timing will not give the charge enough time to combust and it will burn where it can or cause weird hotspots.

Since you are running a 61mm, 23psi is more with that than 23psi is with a stocker. I still think you should be in the 9*+ range though even on 91. Throw in 100 and turn the timing up and see if it still does it at the same boost. There are many things that the knock sensor can think are knock whether they are or not.

JB

 

25...26....27....whatever

 

Yeah I agree, and I thought of that, but the knock was consistent in the same place for about 8 pulls on different stretches so I concluded that it is real knock. That and the fact that reducing the timing also reduced the knock. I turned the boost down to 21psi and could only run about 1* more timing up top.

 

try 21psi for cali 91 octane

 

general rule is every 2psi increase, retard timing 1 degree