Knock like a Mofo
05-12-2007, 09:14 PM
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Knock like a **** I just datalogged the car at the track for the first time. Turns out I have some severe knock I saw it reaches 10 degrees at some points. Usually around the time the car is about to shift (A4) is when all the knock comes into play. Im guessing I might have had this problem forever and It may be false knock. However, I need some help in trying to find out whats causing this problem. Anybody have any ideas i dont want to blow my motor and I know once I get this issue fixed I'll be well into the twelves.
I have the datamaster datlog if anybody wants to see it.
I have the datamaster datlog if anybody wants to see it.
05-12-2007, 09:20 PM
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Run some high octane gas. If the knock goes away, it is true knock. If it does not, it may be false knock. Sounds like yours may be true knock, if it is higher in the rpm range.
05-12-2007, 11:16 PM
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Knock = Predetonation. Higher octane helps prevent that. If you're running all the stuff in your sig and haven't had a your computer tuned yet, it's no wonder. Those 42# injectors are only running probably 30 at most, just from force. If it HAS been tuned, then you might want to think about a dyno tune.
05-13-2007, 05:44 AM
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Get a LT4 Knock Module. Replace your knock sensor. It might be REAL knock, as in clacking lifters (since you have RRs), I don't see it but I assume you have LTs, they could be banging against something.
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05-13-2007, 12:12 PM
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yeah i think i will go and get an LT4 KM. I'm going to have to go over the entire car real carefully to make sure that there is nothing that could be banging or pinging. now i have one suspect 1/4 inch bolt head that could possibly be touching the exhaust tubing that i will have to fix. and then i will keep checking for stuff. i hope this doesn't turn out to be one huge struggle. funny how it only happes at and right before the shift points.
05-13-2007, 03:16 PM
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The motor isn't torquing as much up in the high RPMs. So when it settles back down, that could be just the right position for it to clack against something. *shrug*
05-13-2007, 03:28 PM
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With RR's and a stock KM you are bound to see that amount of KR. I have a good amount of valvetrain noise to I used the LT4 KM and I wrapped teflon around my knock sensor for the earmuff effect
05-13-2007, 04:19 PM
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Originally Posted by 396D1SS
With RR's and a stock KM you are bound to see that amount of KR. I have a good amount of valvetrain noise to I used the LT4 KM and I wrapped teflon around my knock sensor for the earmuff effect
how much of a help was that. I did some research and saw that sometimes the LT4 KM isnt enough and the max retard vs. rpm table has to be adjusted.
05-13-2007, 04:32 PM
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Originally Posted by C_Rules
how much of a help was that. I did some research and saw that sometimes the LT4 KM isnt enough and the max retard vs. rpm table has to be adjusted.
It worked pretty good I really suggest you give it a try, My new setup is so radical it is showing 2-3 degreese of false knock full time (yes, I have verified it) So I deleted the knock sensor and I am no longer running one. I really have to watch my *** on the 300 shot now
many AF dyno runs and a wideband running rich should make it pretty safe. ALOT of cars do not even run a knock system
05-13-2007, 04:51 PM
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the knock sensor is killing me at the track and in general since i use the same tune all around. if the LT4 KM doesnt fix the problem I'm going to have to start messing with the tables. hopefully i dont end up messing anything up. i'm almost 95% positive its false knock.
05-13-2007, 07:52 PM
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I wouldn't be so sure that it's false. Make sure you try the race gas first to see if it goes away to verify what it is. I'm betting the knock you're seeing is real.
05-13-2007, 08:46 PM
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I put a lt4 km in mine after the cam swap and had it dyno tuned yesterday..with just the km there was not one bit of knock at all before we tuned it..through 9 pulls its never showed any knock..mine must be working for me
05-13-2007, 09:18 PM
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Originally Posted by Rowdy94
I wouldn't be so sure that it's false. Make sure you try the race gas first to see if it goes away to verify what it is. I'm betting the knock you're seeing is real.
05-18-2007, 11:16 PM
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so i finally got my LT4 KM and installed it then reprogrammed all my low octane tables in tunercats to 0. took the car for a test spin with the datalogger and it looks like the problem was almosr completely fixed. only saw knock retard twice at low rpms while just cruising around at low speeds. i got on the highway opened it up and absolutely no knock all the way to 6350 rpm.
ill keep logging the car to see how it responds and will take it to the track soon. it looks like my problem is 90% fixed.
ill keep logging the car to see how it responds and will take it to the track soon. it looks like my problem is 90% fixed.
05-20-2007, 04:08 PM
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unfortunately it was a totally different story today when datlogging the car. knock everywhere. looks like im going to have to inspect my whole exhaust and underside of the car followed by the race gas. this is starting to suck.