Any advice on this? I'm thinking that it may be a drastic vvti map that is causing the knock.

2 runs done a few minutes apart. 3rd gear pull on flat ground.

My AFR's are fine so I left them out of this.

What would you guys do to your timing maps to fix this?

 

your timing is pretty high, is this pump gas?

stock timing is 1 degree at 3500rpms then works its way up as boost fails..

 

back down between 3000-5000 1 count of timing from 200-260 load

and 2 counts from 5000-7k

 

Try bringing it down to 4* at 3000-3500 and less mivec advance at 3500. Also try 1* less 4k-5.5k rpm

What is your AFR at 3500-4000 and 6000rpm?

 

My AFR's are 11.5-11.6 pretty solid.

 

Well try doing what I suggested and see if it cleans the logs up. Then you can add back in from there.

How much boost are you running? You might have to run the car a little richer too to get it more stable.

 

Thanks for the tips.
I'm running from 20-22psi peak.

 

your timing in the higher load columns as rpm increases is a bit higher than i run the cars i have been tuning...

you may want to decrease them a little, and also look at ur vvt map.... i had done some tapering the jdm style map and played and it worked well...

you may find you can run slightly less timing and slightly more fuel.. ill tip into 11.6's just at/after peak and then to 10.8 by redline..

cb

 

hehe .. just richen the fuel to 11.2 .. you'll get rid of the knock almost immediately

 

Use your log. See what the timing dropped to because of knock and subtract one degree in those loads at XXXX rpm. It looks like 4-6* is what your motor is looking for, not the 7+ that it has. Well at least in that particular section of that particular log. I really havent found aggressive MIVEC to cause knock, if anything it seems to help somewhat because of increased scavenging.

 

Your peak timing is not much less than what I use on a VIII with methanol and only 23 lbs of boost

 

u should be doing 18 counts of timing on meth at only 23 pounds... i've even done 20 be4 with 11.5 and no problems at all... how far can i go with a/f towards lean?

cheers!

 

Here's some more info.

This is a datalog I took on the way home.
Same drive. 2 different 3rd gear pulls and very different knock results.

AFR is around 11.4 - 11.5

So what I'm trying to finger out is why I get knock in one pull, and not in another.

 

It's a very aggressive tune that's why. Bring it down a bit and it should become a bit more consistant.

 

I understand you think it's aggressive. I'm currently richening up across the board.
but it is the same tune, same drive, same gear and very different results. I should get similar results.

I appreciate the tips though. Very helpful.