3" exhaust with hi-flow cat
272I/264E
~20psi on a MBC
Walbro 255lph
93 octane
~70 degree day

Note: subtract 20 from the timing values. The XML was wrong in the EcuEdit logger. I've since fixed it.

What do you guys think?

 

Bump and... Note that the Timing values are 20 degrees off in the log graph. The XML data was wrong in the EcuEdit file. I've since corrected it.

 

Bump for movment into the EcuFlash forum. This thread didn't get any love in the general tuning forum. Help me out a little here guys. Should I be knocking with that AFR and timing?

This was using 93 octane on about a 70* day.

 

Would be better to see the actual excel scan

 

93 octane? no I would not expect to see that level of knock at all.

Your AFRs look pretty good, but the amount of knock you have below 5000 is problematic.

I have the same knock levels at 5000, and I have been able to get rid of most of it or at least prevent the knock from going over a 6-7 count past 5000 rpm.

The difference is my tune is on 91 cali crap gas.

Notice on your timing map on the 5000-5500 rpm row. See the trough forming around 140 load range? That is where most of your knock begins. You need to pull more timing in those areas of the map. If pulling the timing does not reduce the knock, then you need to add more fuel in those affected load cells.

It's interesting to note that your '03 has similar knock issues that mine does. I don't know if I can completely rid myself of the knock, my focus has been to minimize it as much as possible. To do this you need to minimize the timing jumps when moving from one load cell to another.

I wish I could offer more assistance, but I am still learning like you.

 

Thanks for the input Chris.

Is my spool up area too lean? I know that I should be able to go to about 11.5 on boost, but I'm not sure about where the AFRs should be during spoolup.

I do have a problem with my Buschur downpipe hitting my transfer case that I could not get Dave to fix for me. I'll post pictures of the contact when I get home this evening. I'm going to have to find a way to tell if the downpipe is causing the knock. Any suggestions other than high octane gas and changing the DP?

 

There are a few ways to do this. You already mentioned one obvious way by running race gas with the same exact settings and see if the knock goes away.

The other way is to remove say, 3 degrees or timing from the cells where you are getting knock. If the knock goes away, it was most likely real knock. If the knock is still there in the same amount, then it is most likely phantom knock, probably due to your downpipe.

Eric

 

I would also add that you should do several runs with your current settings to see if it's real.

I always get some knock values < 6 between 4800 - 6000, and it's always in that trough area in the timing map that I pointed out. If I change the timing by a couple of degrees in the affected load cells, I can get the knock instance to move up and down the RPM range. I am pretty sure it's phantom knock, but I have not run all the suggestions that Eric provided to narrown down if it is or not.

 

My knock seems to be fairly random. Is it safe to remove the crossbars to eliminate the downpipe from hitting them as a source? I think it's safe, I just wanna pass it by you guys first. They're just to tighten the suspension/unibody up, correct?

I still think it's the downpipe hitting the transfer case. But it's not as easy to eliminate that as the source.