KR in First Gear Only
Thread Starter
Teching In
Joined: Nov 2006
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KR in First Gear Only Im a newbie to EFI tuning.. I did some logging on a 2000 C5 m6, only mod is the cable tie CAI and noticed that I am getting KR in first gear starting from about 1700 rpm and continuing all the way to the rev limit, but strangely no KR in second gear with more timing. I am also curious about a drop to 14* at 2200 and another to 11* at 2600 but only in first gear. I am running 93 octane, OAT is 89*, engine stock for cable tie CAI.
Is this normal or am I likely getting a false knock?
I will post the logs tomorrow.
Is this normal or am I likely getting a false knock?
I will post the logs tomorrow.
When I was tuning my heads/cam set up I was getting KR in first from a standing WOT run. Running lean was the cause. I found that each gear was a little richer. I don't know if this is because of load on the engine or what. I found that I had to tune it to around 12.7 in 4th to get 13.0 in first on the street. I am not an expert tuner but this is what worked for me.
Thread Starter
Teching In
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Thanks Code4. I am waiting to get the printouts from a recent dyno (unfortunately didn't have EFIlive to log with on the run) run but the dyno AFR monitor in the tailpipe indicated it was running quite rich. From memory it indicated that AFR started in the mid 11.X and went to low 11.X at higher rpm.
Also any ideas/explanation for the two significant drops in timing in first gear (see image below)?
Also any ideas/explanation for the two significant drops in timing in first gear (see image below)?
TECH Resident
Joined: Aug 2003
Posts: 970
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From: England UK
Just an idea, but before you pull away in first is the engine getting hotter? when you get to the 2nd/3rd gear runs the temprature has dropped?
IAT wasn't logged. Also I guess your fuel is getting hotter in the rails.
Extra heat causing detonation, therefore causing knock.
IAT wasn't logged. Also I guess your fuel is getting hotter in the rails.
Extra heat causing detonation, therefore causing knock.
Originally Posted by xSandbagger
Thanks Code4. I am waiting to get the printouts from a recent dyno (unfortunately didn't have EFIlive to log with on the run) run but the dyno AFR monitor in the tailpipe indicated it was running quite rich. From memory it indicated that AFR started in the mid 11.X and went to low 11.X at higher rpm.
Also any ideas/explanation for the two significant drops in timing in first gear (see image below)?
Also any ideas/explanation for the two significant drops in timing in first gear (see image below)?
It could also be false knock. If you can get some race gas put a bit in and see if it goes away. If the knock stays its probably false and desentizing the sensor might be what you want to do.
TECH Resident
Joined: Aug 2003
Posts: 970
Likes: 4
From: England UK
Talking of possible false knock, isn't there some newer knock sensors you an fit which dont react to false knock as much? I read this somewhere but cant remember where. Something along the lines of 98-99 are sensitive later years are less. Or perhaps its the location....
Last edited by RedWS6 00; Jan 8, 2007 at 09:27 AM.
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Might be false. Check the motor mounts and trans mount.
My Turbo TA would false knock in first gear because the engine torqued over so much, the down pipe hit the frame.
Just a thought.
My Turbo TA would false knock in first gear because the engine torqued over so much, the down pipe hit the frame.
Just a thought.
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Originally Posted by brad8266
You missed it, he said AFR was read on a dyno pull.
The OP got my drift and said so.
Originally Posted by Doc
That he doesn't have access to, and is at some shop not doing him any good. Furthermore having to read a printout and transcribe the events into the tuning tool is not necessary and time consuming, with EFI Live. With EFI Live you can highlight a recorded parameter (in this case the wideband O2)and have the corresponding affected cells in the VE, PE,...etc tables be highlighted for you in the Tuning Tool. I am merely pointing out that without the wideband input the OP is missing out on one of the coolest features of EFI Live.
The OP got my drift and said so.
The OP got my drift and said so.
Thread Starter
Teching In
Joined: Nov 2006
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Here is the latest:
I with the car indicating 50 miles to empty I added 5 gals of 104 unleaded fuel and drove about 30 miles then ran the 1/8th while logging. The first 2 passes I had KR then on a hard burnout I heard a load thump and haven't had any KR since.
I am still not getting maximum timing in first gear but atleast i'm not getting KR. However I am still getting a significant drop in timing between 1600 and 2000 rpm while transitioning to wot which I can't seem to find any reason for. The recorded timing is significantly lower than what the low octane table calls for. I noticed that even with the 104 in most cases I wasn't getting to the timing indicated in the high octane table, is this normal?
Btw, I received the wideband o2 late on Friday so will have that installed and logging in a few days.
I with the car indicating 50 miles to empty I added 5 gals of 104 unleaded fuel and drove about 30 miles then ran the 1/8th while logging. The first 2 passes I had KR then on a hard burnout I heard a load thump and haven't had any KR since.
I am still not getting maximum timing in first gear but atleast i'm not getting KR. However I am still getting a significant drop in timing between 1600 and 2000 rpm while transitioning to wot which I can't seem to find any reason for. The recorded timing is significantly lower than what the low octane table calls for. I noticed that even with the 104 in most cases I wasn't getting to the timing indicated in the high octane table, is this normal?
Btw, I received the wideband o2 late on Friday so will have that installed and logging in a few days.
