[Atomic Ed]

Originally Posted by Daves1SS

Well I finally got some good logs. I went out during lunch today and got many WOT logs. It was 86 degrees out with a DA of 2200'. Humidity is around 60%. I saw a max IAT or 71 C which is 160 F. The car felt strong most of the time, but sometimes I felt a bit of lag in the power (barely noticeable). This would have been the KR that I saw from time to time (not always, just at times). Most of the time it was under 1 degree, but had a few times where it got to 2 degrees with a peak of 2.7 degrees. At that time, timing was probably 4 or 5 degrees at most. Peak timing at 0 KR was 15.

The KR is a little concerning to me. I just sent the logs to Edelbrock so they can review.

Glad to hear that you are able to pull logs now.

It does sound like the KR is hitting a little high. Where they occasional spikes or multiple spikes during a single run? Timing sounds a little low so I assume the knock pull left you with the low overall timing. 91 or 93 Octane tune? Posting the IAT, timing and KR graphs would most helpful. It will be interesting to hear what Edelbrock says.

Your 160 F max IAT is better than my 185 F max. The ambient was comparable, but my DA was more like 700 and probably a 15% humidity, so I need to dive into my temp management issue.

[Daves1SS]

Originally Posted by Atomic Ed

Glad to hear that you are able to pull logs now.

It does sound like the KR is hitting a little high. Where they occasional spikes or multiple spikes during a single run? Timing sounds a little low so I assume the knock pull left you with the low overall timing. 91 or 93 Octane tune? Posting the IAT, timing and KR graphs would most helpful. It will be interesting to hear what Edelbrock says.

Your 160 F max IAT is better than my 185 F max. The ambient was comparable, but my DA was more like 700 and probably a 15% humidity, so I need to dive into my temp management issue.

Upon further analysis, most of my KR was in the high/WOT load, lower rpm range (2500-3000 rpms). In the upper rpms there was no KR. There were maybe 10-12 frames at a time where I would consistently see under 1 degree, and only momentary spikes to 2 degrees with only 2 frames showing 2.7.
I'll have to spend some time with this software and see if I can figure out how to view graphs as opposed to excel data. Will let you know what Edelbrock says.

[Atomic Ed]

Originally Posted by Daves1SS

Upon further analysis, most of my KR was in the high/WOT load, lower rpm range (2500-3000 rpms). In the upper rpms there was no KR. There were maybe 10-12 frames at a time where I would consistently see under 1 degree, and only momentary spikes to 2 degrees with only 2 frames showing 2.7.
I'll have to spend some time with this software and see if I can figure out how to view graphs as opposed to excel data. Will let you know what Edelbrock says.

I had to do screen shots of the graphs expanded out. Couldn't see a way to copy graphs otherwise.

[Speedy1975]

Originally Posted by Daves1SS

Upon further analysis, most of my KR was in the high/WOT load, lower rpm range (2500-3000 rpms). In the upper rpms there was no KR.

This is pretty typical in a PD supercharged setup. You're getting all that boost at a lower RPM where it's more prone to detonate prematurely.

A custom tune would pull a bit of timing in that area to prevent it and ramp up the timing with RPM.

Can you tell from the DL what the timing advance is where the knock occurs?

[Daves1SS]

Edelbrock says my scans look fine, and the peak 160 degree IAT's made sense to them due to me testing in upper 80 degree weather. Ed, their response to me saying yours had gotten up to 185 degrees in similar weather was maybe your IC system could use more bleeding and/or not enough gentle good air flow drive time between the WOT runs.

Here's what they said about my scan:



As for the spark values we are seeing in the logs they look correct in comparison to the data we have collected from our vehicles. Disregard the knock retard you are seeing because LiveLink isn’t reading that value correctly for the new E92 ECM’s in these vehicles. We compared the spark values being commanded in your log at low and high rpm to ours and you are within .25-.5°. To put it simply everything looks good considering the warm weather you’re in.

[Daves1SS]

Originally Posted by Speedy1975

This is pretty typical in a PD supercharged setup. You're getting all that boost at a lower RPM where it's more prone to detonate prematurely.

A custom tune would pull a bit of timing in that area to prevent it and ramp up the timing with RPM.

Can you tell from the DL what the timing advance is where the knock occurs?

I'll look in the morning when I'm back at work and let you know what the timing was right before it started knocking a bit. I recall it being pretty low though before it even showed KR.

[Atomic Ed]

Originally Posted by Daves1SS

Edelbrock says my scans look fine, and the peak 160 degree IAT's made sense to them due to me testing in upper 80 degree weather. Ed, their response to me saying yours had gotten up to 185 degrees in similar weather was maybe your IC system could use more bleeding and/or not enough gentle good air flow drive time between the WOT runs.

Here's what they said about my scan:



As for the spark values we are seeing in the logs they look correct in comparison to the data we have collected from our vehicles. Disregard the knock retard you are seeing because LiveLink isn’t reading that value correctly for the new E92 ECM’s in these vehicles. We compared the spark values being commanded in your log at low and high rpm to ours and you are within .25-.5°. To put it simply everything looks good considering the warm weather you’re in.

Thanks for the feedback Dave. Interesting comment about the KR not being accurate across liveLink. If I remember right, the SCT scanner can either request PID or OBD information. Can't remember which channel type the KR is on.

Also thanks for asking about my IAT for me. I checked the flow on my heat exchanger and its fine, no air in the system. Regardless of what Edelbrock says, I still think the IATs are too high.

I would like to know what the IAT table looks like for this ECM, but I would bet a cold beer that 185 F is high enough to pull some timing and torque, unless Edelbrock tuners tuned around the stock table.

I have a few ideas on getting the IAT down. On my Audi, I added a nylon insulator spacer/gasket between the intake and the head. This little insulator trick did lower the measured IAT around 15-20 F. So I'm thinking of cutting some nylon insulation spacers and putting them in between the SC and the heads, like a thick gasket. Should reduce heat transfer from the heads and maybe help the IATs.

The other improvement I see is getting air through the three layers of radiator, condenser, and heat exchanger. A larger/more efficient fan that kicks on earlier might also help.

Another option is to add a secondary heat exchanger to the Edelbrock one. But right now, I don't see a spot to put one that doesn't interfere with airflow to the other coolers. Maybe a bigger heat exchanger to replace the Edelbrock?

And of course, a 170-180 F t-stat.

I'm gonna try the t-stat and the nylon insulators first, then move on to the more difficult later. I want to be able to run this thing hard for more than 15 seconds.

[Speedy1975]

I'll wager Edelbrock adjusted the timing pull to something closer to 150 IAT. I'd do the 180 T-stat for starters. That won't help the IAT but will help over all performance. Also, adjusting the fan speed to come on higher sooner would also help. I'd go with those first.

[Daves1SS]

Originally Posted by Speedy1975

This is pretty typical in a PD supercharged setup. You're getting all that boost at a lower RPM where it's more prone to detonate prematurely.

A custom tune would pull a bit of timing in that area to prevent it and ramp up the timing with RPM.

Can you tell from the DL what the timing advance is where the knock occurs?

Looks like timing advance is consistently in the single digits when the KR occurs, again always below 3,000 rpms at WOT, and as low as 2 degrees but no more than 7 degrees. I'm even seeing timing still slowly but consistently increasing as RPM's increase despite the knock retard showing on the scan. I hope Edelbrock is right, that the KR showing on the scan is not really happening. Because 2.7 degrees of knock on a 540 whp car is like licking a tootsie roll. After so many licks.......

The car feels great now though.

[Speedy1975]

Originally Posted by Daves1SS

Looks like timing advance is consistently in the single digits when the KR occurs, again always below 3,000 rpms at WOT, and as low as 2 degrees but no more than 7 degrees. I'm even seeing timing still slowly but consistently increasing as RPM's increase despite the knock retard showing on the scan. I hope Edelbrock is right, that the KR showing on the scan is not really happening. Because 2.7 degrees of knock on a 540 whp car is like licking a tootsie roll. After so many licks.......

The car feels great now though.

They may be right, the information you provide is a little vague for me to make any real determination, but at the initial hit of the throttle below 3,000 RPM single digit timing is what I'd expect, and then ramping up quickly with RPMs. If you're getting STKR of 3° with single digit, that would seem strange.

93 or 91 octane and what brand of gas? I only run Shell, but it's the best in my area. Chevron I've heard is another good one. You may run the tank almost dry and try a different brand to see if you get different results. It DOES matter believe it or not.

[Daves1SS]

Originally Posted by Speedy1975

They may be right, the information you provide is a little vague for me to make any real determination, but at the initial hit of the throttle below 3,000 RPM single digit timing is what I'd expect, and then ramping up quickly with RPMs. If you're getting STKR of 3° with single digit, that would seem strange.

93 or 91 octane and what brand of gas? I only run Shell, but it's the best in my area. Chevron I've heard is another good one. You may run the tank almost dry and try a different brand to see if you get different results. It DOES matter believe it or not.

Shoot me an email at dmoore@superior-mason.com and I will email back an excel file with the logs so you can glance it over and see if you agree with them. I would appreciate someone else knowledgeable backing up their findings.

I use 93 octane only, and either Chevron, BP, or Shell is all I will run in my car. The last several tanks have been Chevron and BP.

[Speedy1975]

Originally Posted by Daves1SS

Shoot me an email at dmoore@superior-mason.com and I will email back an excel file with the logs so you can glance it over and see if you agree with them. I would appreciate someone else knowledgeable backing up their findings.

I use 93 octane only, and either Chevron, BP, or Shell is all I will run in my car. The last several tanks have been Chevron and BP.

Email sent. I've had excellent success with Shell 93 in my area and I run it explicitly in my Challenger and have for 7 years. I had the car tuned on it as a matter of fact.

I had to do a major retune on my buddy's Challenger. He was having all kinds of problems with AFR and STKR. I told him to try Shell and things got markedly better, I retuned and fixed everything else. He told me he was running BP prior and I told him to never run that again. Could have been the station he was getting it from as it was always the same one, but it wasn't worth the risk.

[Daves1SS]

Originally Posted by Speedy1975

Email sent. I've had excellent success with Shell 93 in my area and I run it explicitly in my Challenger and have for 7 years. I had the car tuned on it as a matter of fact.

I had to do a major retune on my buddy's Challenger. He was having all kinds of problems with AFR and STKR. I told him to try Shell and things got markedly better, I retuned and fixed everything else. He told me he was running BP prior and I told him to never run that again. Could have been the station he was getting it from as it was always the same one, but it wasn't worth the risk.

Interesting info! I sent the log, and it's 6 MB. Let me know if you didn't get it for any reason.

[Speedy1975]

I got it Dave. It's CSV so will take me a bit of fiddling to get it where I can have some feedback. I'll see if I can get a minute to work on it today in between meetings.