Help Requested on Knock Retard on My E85 Turbo Trans Am

[Megatron _ed]

Hi Everyone:

I own a 1989 Turbo Trans Am with less than 6,400 miles on it. Last year, I converted to E85 and this year, I had the car serviced and tuned by Rick (TurboBuRick), who knows a lot about these engines.

Here are a list of mods:

1. Upgraded "wide" intercooler
2. Down Pipe (closed for this test run)
3. 80lb Siemens Injectors
4. DW300 pump
5. TA49 Turbo built by Brian (Bison)
6. Adjustable wastegate
7. TurboTweak chip
8. LS1 MAF
9. MAF Translator
10. Scanmaster and Powerlogger
11. Beefed Up Trans from Jimmy's

THE BOOST IS SET AT 25LBS

During the summer, the car ran fantastic. Would haul ass and no knock retard. Recently, during hard acceleration, I register a little knock retard. So, I decided to hook up the Powerlogger to get detailed results; a file is attached below. Please note, I already adjusted the timing 1.75 degrees in high gear (parameter 4), but that does not seem to do anything since the knock is he same as it was before the timing adjustment.

Here are most of the readings on the file. I only measured the readings at peak knock retard (3.5). For safety, I let off the gas as I saw the knock retard pop up.

Boost - 23.8
IDC - 71.5
IAT - 96.8
TPS - 4.40
RPM - 4550
MAF - 254
LV8 - 255
IPW - 18.8
MAP - 265.5
BAT - 13.8
MPH - 52
O2V - .835
ADV - 22.9
BLM - 128
INT - 128

Knock counts were 7.

I do have a FP gauge, but could only keep my eyes on so many things at once. However, I am lost. My injectors seem to have a ways to go on capacity. Could this simply be that Chicagoland area stations have started converting to E70?

Thanks

 

[turbo89]

Hi Everyone:

I own a 1989 Turbo Trans Am with less than 6,400 miles on it. Last year, I converted to E85 and this year, I had the car serviced and tuned by Rick (TurboBuRick), who knows a lot about these engines.

Here are a list of mods:

1. Upgraded "wide" intercooler
2. Down Pipe (closed for this test run)
3. 80lb Siemens Injectors
4. DW300 pump
5. TA49 Turbo built by Brian (Bison)
6. Adjustable wastegate
7. TurboTweak chip
8. LS1 MAF
9. MAF Translator
10. Scanmaster and Powerlogger
11. Beefed Up Trans from Jimmy's

THE BOOST IS SET AT 25LBS

During the summer, the car ran fantastic. Would haul ass and no knock retard. Recently, during hard acceleration, I register a little knock retard. So, I decided to hook up the Powerlogger to get detailed results; a file is attached below. Please note, I already adjusted the timing 1.75 degrees in high gear (parameter 4), but that does not seem to do anything since the knock is he same as it was before the timing adjustment.

Here are most of the readings on the file. I only measured the readings at peak knock retard (3.5). For safety, I let off the gas as I saw the knock retard pop up.

Boost - 23.8
IDC - 71.5
IAT - 96.8
TPS - 4.40
RPM - 4550
MAF - 254
LV8 - 255
IPW - 18.8
MAP - 265.5
BAT - 13.8
MPH - 52
O2V - .835
ADV - 22.9
BLM - 128
INT - 128

Knock counts were 7.

I do have a FP gauge, but could only keep my eyes on so many things at once. However, I am lost. My injectors seem to have a ways to go on capacity. Could this simply be that Chicagoland area stations have started converting to E70?

Thanks

Check the downpipe for any potential rubbing creating a false knock ..

Not sure they have switched over yet .. I got some this week and it was still 82

 

[dvernst]

Looks like when you're getting your knock it's really rich.

 

[TurboBuRick]

Hi Emilio,

Do you have a test kit for the fuel?

Try to log a 3rd gear pull with no shift.

Rick

 

[Toby_Goodmk]

So is your timing 21 currently or 23? You may be a little high with 23. I know it says knock counts, but how many degrees was the sensor setting the timing back? I had some KR with 20lb and 22.5* so we took out a degree and it dissapeared. It was hot at balls that day as well. See logs for comparison. The little spikes in red are KR. Take your timing all the way out and see if you still have KR, if you do I would look for things rubbing. It's amazing that 1* could make a difference.

Now look at the next log. No KR

 

[turbo89]

So is your timing 21 currently or 23? You may be a little high with 23. I know it says knock counts, but how many degrees was the sensor setting the timing back? I had some KR with 20lb and 22.5* so we took out a degree and it dissapeared. It was hot at balls that day as well. See logs for comparison. The little spikes in red are KR. Take your timing all the way out and see if you still have KR, if you do I would look for things rubbing. It's amazing that 1* could make a difference.

View attachment 289242



Now look at the next log. No KR

View attachment 289243

Told him the same thing.. Pull a degree out and re-check downpipe or other false knock.. If its that on edge that going from E85 to E80 gives KR .. Its probably a bit aggressive

For the track .. I see no issues as you can control certain things, in the street
Gotta give a bit of room E70 shouldnt even give KR

 

[Megatron _ed]

Thanks everyone. The baseline number for parameter 4 (timing in high gear) is 128 which should correspond to 22-23 degrees timing.

I reduced it to 123. Each digit decrease equates to .35 reduction in timing, so I should be around 20.25-21.25 degrees now.

I'm first going to do a run tonight as Rick suggested (assuming the rain holds off) from about 60mph in 3rd and record that output.

That is the thing about knock retard. Could be motor mounts, dp, or bad gas or real knock.

 

[Megatron _ed]

So is your timing 21 currently or 23? You may be a little high with 23. I know it says knock counts, but how many degrees was the sensor setting the timing back? I had some KR with 20lb and 22.5* so we took out a degree and it dissapeared. It was hot at balls that day as well. See logs for comparison. The little spikes in red are KR. Take your timing all the way out and see if you still have KR, if you do I would look for things rubbing. It's amazing that 1* could make a difference.

View attachment 289242



Now look at the next log. No KR

View attachment 289243

Thanks. The knock retard was 3.5. If a recall though, it dropped off as boost increased.

 

[turbo89]

Thanks. The knock retard was 3.5. If a recall though, it dropped off as boost increased.

When were valvesprings done?

 

[Boost231]

Have you verified actual timing with a timing light? If not i would do that as well.

Sent from my SM-N930T using Tapatalk

 

[Toby_Goodmk]

Have you verified actual timing with a timing light? If not i would do that as well.

Sent from my SM-N930T using Tapatalk

Even my new build was advanced a couple degrees, it needed reset. Good point here.

 

[turbo89]

Even my new build was advanced a couple degrees, it needed reset. Good point here.

Guys .. Its a stock car .., what does it matter !!! It's just like a boost
Number or afr number.. Its just that A NUMBER

 

[Boost231]

True, however i like to know actual timing. Does it really matter no it's just a number but for my piece of mind i would like to know if my chip is commanding 22 deg but my car is really at 25 that's a big difference. That way when I'm looking at datalogs or i have someone else looking at them i can advise them the difference in timing

Sent from my SM-N930T using Tapatalk

 

[turbo89]

True, however i like to know actual timing. Does it really matter no it's just a number but for my piece of mind i would like to know if my chip is commanding 22 deg but my car is really at 25 that's a big difference. That way when I'm looking at datalogs or i have someone else looking at them i can advise them the difference in timing

Sent from my SM-N930T using Tapatalk

The guy looking at that log.. Doesnt care whether you tell him 21 or 23 right.. What he cares about is KR on that particular car on that particular tune.. DFI are a bit different

 

[TTA976]

Very timing first. Run the timing at 17* in 1/2 gear..and 16* up top. Your timing is way too high.
You need the A/F around 11:8 at that boost level.
Cars pig rich and tuned incorrectly.

 

[TurboBuRick]

from about 60mph in 3rd and record that output.

Do it from about 50mph.

 

[Megatron _ed]

So I go to the Shell gas station in schaumburg tonight to get some e85 and tested it. Think I may have found a culprit.

I also did a test run from 50. I'll upload the file soon. KR was 4.4.

But I've never seen e85 this low. Looks like e55!!!!! Anyone else ever seen this?

 

[Megatron _ed]

Very timing first. Run the timing at 17* in 1/2 gear..and 16* up top. Your timing is way too high.
You need the A/F around 11:8 at that boost level.
Cars pig rich and tuned incorrectly.

Thanks. When I got the car back in summer, it ran great with the stock timing. So must be something else and I think I may have found it. See my post below.

 

[turbo89]

So I go to the Shell gas station in schaumburg tonight to get some e85 and tested it. Think I may have found a culprit.

I also did a test run from 50. I'll upload the file soon. KR was 4.4.

But I've never seen e85 this low. Looks like e55!!!!! Anyone else ever seen this?

Ohh yeah.. that will do it ... that's really low ... E70 is the min

Get it out of there and put in some REAL Corn .. and that's why we test

 

[BEATAV8]

Fairly typical for Shell ClearFlex. Last time I checked it here, Shell was only 60%.