knock retard...
11-13-2001, 01:06 AM
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knock retard... i put in some maf ends at the track a couple of night ago and man i got alot of knock retard from just the ends...stock i ran 0.0 degrees to a 3.9 in 2nd and 3rd with the maf ends... looks like i'm going to pull them out and put the stock ones back in just wondering if anyone else has the same thing i guess it's the turbulence in the air or something that is setting off the knock?? that's the only thing i could think of..
11-13-2001, 01:40 AM
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Re: knock retard... what happens when a lot of people use the MAF ends is that it leans the car out real bad, thats what causes your knock. in my case it was the opposite, i have a ported TB and MAFS and i still had to lean the car out 4%
11-13-2001, 07:29 AM
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Re: knock retard... I got the same thing dude..
it was mainly in warm weather though...now that it's cold again, it has gone away.
I also heard that anything below 4.0 is normal? it even says we'll get it in the owners manual.
it was mainly in warm weather though...now that it's cold again, it has gone away.
I also heard that anything below 4.0 is normal? it even says we'll get it in the owners manual.
11-13-2001, 07:44 AM
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Re: knock retard... This KR thing has me confused. Last year I was showing up to 4.0 degrees of knock but this year there was none to be found as per autotap. The only change made to the car in that time was a cam. I'm thinking false knock from the Borla was the main culprite but really I have no idea.
11-13-2001, 08:45 AM
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Re: knock retard... Ok, question for you. What is your OVERALL timing? Overall timing is total timing advance - knock retard.
As an example, if you are getting 30 degrees of timing advance at WOT (which is kinda high) and 3.9 degrees of KR, that nets you 26.1 degrees of overall timing advance. Anything between 25-28 degrees of overall timing advance is excellent at WOT. So if this is the case, I think you're fine.
However, if you get 26 degrees of timing advance, 3.9 degrees of KR, that nets you 22.1 degrees of overall timing which ISN'T good.
Personally, I think 3.9 is a high amount of KR regardless, but as can be seen by the first example, could be perfectly legit.
As an example, if you are getting 30 degrees of timing advance at WOT (which is kinda high) and 3.9 degrees of KR, that nets you 26.1 degrees of overall timing advance. Anything between 25-28 degrees of overall timing advance is excellent at WOT. So if this is the case, I think you're fine.
However, if you get 26 degrees of timing advance, 3.9 degrees of KR, that nets you 22.1 degrees of overall timing which ISN'T good.
Personally, I think 3.9 is a high amount of KR regardless, but as can be seen by the first example, could be perfectly legit.
11-13-2001, 08:59 AM
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Re: knock retard... Where were you getting the KR at?
Between the shifts or at the top?
Lane your timing theory is good except for the fact that most of the '01-'02 cars are AVERAGING about 22* of timing at WOT. So his numbers may be low and still legit.
Edge made a good point also with the comment on weather. Too hot and you have a better chance of KR. Try some Octane Boost and see if it's false knock (Noise from headers, converter, etc...) or legit knock.
How long did you have the ends on when you autotapped. If you just put them on, the PCM might have some 'learning' to do also.
<img src="images/icons/smile.gif" border="0">
Between the shifts or at the top?
Lane your timing theory is good except for the fact that most of the '01-'02 cars are AVERAGING about 22* of timing at WOT. So his numbers may be low and still legit.
Edge made a good point also with the comment on weather. Too hot and you have a better chance of KR. Try some Octane Boost and see if it's false knock (Noise from headers, converter, etc...) or legit knock.
How long did you have the ends on when you autotapped. If you just put them on, the PCM might have some 'learning' to do also.
<img src="images/icons/smile.gif" border="0">
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11-13-2001, 09:09 AM
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Re: knock retard... I was unaware that the newer ones liked a little less timing. <img src="images/icons/smile.gif" border="0">
Either way, a few months ago I was laden with 2.3 - 4.0 degrees of KR at WOT and 12-15 degrees at slight throttle and throttle tip in.
I found the EGR system was turned off by Ed Wrong despite the fact that I didn't have the LS6 intake and a vacuum leak causing all that KR at slight throttle and throttle tip in. All gone now. My next battle was the KR I was getting at WOT throttle.
I made sure to eliminate any knocking coming from the exhaust hitting floorboards and then decided to go with the next size larger pushrods (7.450 I think) as I noticed my valvetrain "ticking" more than it should. When I installed these, there were too long as they hung the valves open bleeding cylinder pressure. I took them back out, put the Comp Cam 7.400's back in and virtually all the "ticking" went away! Go figure!
Took it out for a few full throttle run in the industrial park and averaged only .4 degrees of KR at WOT.
Point is, like Tony I've been there, done that, and bought the T-shirt chasing my knock retard down till it was next to nothing.
Did you do a PCM re-program with this?
Either way, a few months ago I was laden with 2.3 - 4.0 degrees of KR at WOT and 12-15 degrees at slight throttle and throttle tip in.
I found the EGR system was turned off by Ed Wrong despite the fact that I didn't have the LS6 intake and a vacuum leak causing all that KR at slight throttle and throttle tip in. All gone now. My next battle was the KR I was getting at WOT throttle.
I made sure to eliminate any knocking coming from the exhaust hitting floorboards and then decided to go with the next size larger pushrods (7.450 I think) as I noticed my valvetrain "ticking" more than it should. When I installed these, there were too long as they hung the valves open bleeding cylinder pressure. I took them back out, put the Comp Cam 7.400's back in and virtually all the "ticking" went away! Go figure!
Took it out for a few full throttle run in the industrial park and averaged only .4 degrees of KR at WOT.
Point is, like Tony I've been there, done that, and bought the T-shirt chasing my knock retard down till it was next to nothing.
Did you do a PCM re-program with this?
11-13-2001, 09:48 AM
#9
Re: knock retard... Knock Retard is the Devil!
If you are only getting it from switching MAFs, that KR is being caused by you running too lean. Put the other MAF back on.
From what I've seen doing 100s of dyno runs, we don't see any additional rwhp gains above 28 degrees total timing. I've had mine up to 31 degrees and no additional gains. Seems like 28 total is the "happy" number for most LS1 cars.
Someone else mentioned temperatures. Engine and air temp are very critical for maintaining KR. Our LS1s do not like coolant temps above 190F, so install a 160F T-stat to keep it around 185F. Also, catalytic converters tend to keep the head in the exhaust manifolds and cause knock. This is most prevalent on bone stock cars, you can hear them audibly ping on the dyno. I've never seen any cars with offroad headers and proper O2 readings make audible detonation.
If you guys want to learn more about Knock Retard and False Knock, I might have the solution for you. Check out my website:
Knockout Box
Tony
If you are only getting it from switching MAFs, that KR is being caused by you running too lean. Put the other MAF back on.
From what I've seen doing 100s of dyno runs, we don't see any additional rwhp gains above 28 degrees total timing. I've had mine up to 31 degrees and no additional gains. Seems like 28 total is the "happy" number for most LS1 cars.
Someone else mentioned temperatures. Engine and air temp are very critical for maintaining KR. Our LS1s do not like coolant temps above 190F, so install a 160F T-stat to keep it around 185F. Also, catalytic converters tend to keep the head in the exhaust manifolds and cause knock. This is most prevalent on bone stock cars, you can hear them audibly ping on the dyno. I've never seen any cars with offroad headers and proper O2 readings make audible detonation.
If you guys want to learn more about Knock Retard and False Knock, I might have the solution for you. Check out my website:
Knockout Box
Tony
11-13-2001, 10:04 AM
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Re: knock retard... Very good information guys.
FWIW, I had a lot of audible pinging and KR last year. Tinkering with the MAFT did not help. I took the car to Joe Prince and he found out the root of my problem, clogged cats.
I then had my T1 cam installed and everything was fine. I had the car dynoed and I put down 333 RWHP with only 20 degrees of time. I sent the PCM back to Ed Wright and he took care of it for me. It was fine, when I got the new PCM the car was noticeably stronger and I was seeing 28-30 degrees of timing. Within the last couple weeks though, the car has started to ping. I have to ATap it again and see what the timing is, and tinker with the MAFT I guess. Why would my car suddenly start pinging again? Also, I plan on running Macs w/offroads soon. Will the car run even leaner when I do that?
FWIW, I had a lot of audible pinging and KR last year. Tinkering with the MAFT did not help. I took the car to Joe Prince and he found out the root of my problem, clogged cats.
I then had my T1 cam installed and everything was fine. I had the car dynoed and I put down 333 RWHP with only 20 degrees of time. I sent the PCM back to Ed Wright and he took care of it for me. It was fine, when I got the new PCM the car was noticeably stronger and I was seeing 28-30 degrees of timing. Within the last couple weeks though, the car has started to ping. I have to ATap it again and see what the timing is, and tinker with the MAFT I guess. Why would my car suddenly start pinging again? Also, I plan on running Macs w/offroads soon. Will the car run even leaner when I do that?
11-13-2001, 10:59 AM
#11
Re: knock retard... Kenny, your car might run a bit leaner initially, but the PCM will adjust for it after you drive it for a few days. Resist the urge to mess with the MAF-T until the PCM learns the new header setup. That is, unless your numbers are totally off (which I doubt).
Tony
Tony
11-13-2001, 10:59 AM
#12
Re: knock retard... I showed 25 degrees of timing with the stock MAF on and 27 degrees with a set of fully ported ends. However, I had 0 KR w/ the stock unit and over 2 degrees of KR with the ported ends. I've gone back to the stock ends.
My PCM is at Ed's now, and we've been talking about timing. I asked him if he could set the timing at 28 degrees full advance, and he said that he can try. He said he's yet to see that kind of timing out of an '01+ car, but he's yet to tune a car with a "decent-size" aftermarket converter. The higher stall will net less load, so the chance of KR will be less. It might end up being a trial and error process, but what isn't? <img src="images/icons/smile.gif" border="0">
Like I said on the other board, I'd install the stock ends and spend the money elsewhere.
My PCM is at Ed's now, and we've been talking about timing. I asked him if he could set the timing at 28 degrees full advance, and he said that he can try. He said he's yet to see that kind of timing out of an '01+ car, but he's yet to tune a car with a "decent-size" aftermarket converter. The higher stall will net less load, so the chance of KR will be less. It might end up being a trial and error process, but what isn't? <img src="images/icons/smile.gif" border="0">
Like I said on the other board, I'd install the stock ends and spend the money elsewhere.
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11-13-2001, 03:11 PM
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Re: knock retard... Hey Trevor, how's the 10 bolt out back of your car? With that 60' time your 3rd member has to be upset. Just wondering if a 12 was in your future plan.
11-13-2001, 04:28 PM
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Re: knock retard... SSCamaro - My 10-bolt is doing just fine, and I'm getting ready to step up to 3.73's. <img src="images/icons/smile.gif" border="0"> It should be good for some high 1.5 60' times then. The stock rears have been pretty well proven in the A4 cars. They'll take quite a bit of abuse! I've watched a '99 SS A4 cut 1.43 60' times on the STOCK 10-bolt with 3.23's! <img src="images/icons/shocked.gif" border="0"> He never so much as cracked the cover off. You might know him as KECHME on the board. He was running a dual stage NX kit to push the car to a 10.30 @ 130 MPH. I've seen many 1.5x 60' times in A4's with very little problems. I don't have any plans for a 12-bolt at this time, but you never know when that is subject to change. <img src="images/icons/smile.gif" border="0"> I'm planning on running points next year at TX Motorplex, 10-bolt and all. <img src="images/icons/cool.gif" border="0">
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11-13-2001, 04:39 PM
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Re: knock retard... thanks guys...i took the reading right after I put in the ends...i've had them in a week now i'll take some new numbers and double check my timing... I also have a MAFT laying around...if i richen it up a little do you think it would get rid of the knock so i could keep the ends??
