Knock during spool/load up
Evolving Member
Joined: Apr 2009
Posts: 131
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From: southern cali
these problems were here pre and post tune. it seems like the knock moved after the tune though. i used to only get this issue at higher rpms and it was random. i got the car tuned though, and there was no knock during the tune, but started again shortly after....like not even a day or so after the tune. then i found that i had a bad injector, so i replaced all four, and my tuner emailed me a new tune for the scaled injectors, but the problem didn't go away. i sent him all the logs, and my rom, and he didn't see that there was anything different from the original tune as far as i know. this was all within a few days of it being tuned.
there's another tuner coming out here this weekend, and i'm going to have him take a look at everything with a wideband.
i guess my question is, does this seem like a tuning issue, mechanical, or false knock?
i have been reading and some people are saying that the knock voltage should spike when there's knock. on my logs, even at 20-28 counts of knock, the knock voltage remains between 1-1.8, or lower, and the most it ever got was 2.1, and that wasn't even at the peak of the knock. so does that tell you anything about whether the knock is legit?
there's another tuner coming out here this weekend, and i'm going to have him take a look at everything with a wideband.
i guess my question is, does this seem like a tuning issue, mechanical, or false knock?
i have been reading and some people are saying that the knock voltage should spike when there's knock. on my logs, even at 20-28 counts of knock, the knock voltage remains between 1-1.8, or lower, and the most it ever got was 2.1, and that wasn't even at the peak of the knock. so does that tell you anything about whether the knock is legit?
EvoM Guru
iTrader: (50)
Joined: Mar 2006
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From: Tri-Cities, WA // Portland, OR
For the question in the first post, I had consistent knock on spool and at peak load for a very long time. Richer or leaner didn't help. Pulling timing in the areas corresponding to the knock didn't help either. Some advice from R/TErnie to pull a bit of timing in the load cells before the knock to make for a more gentle ramp down in timing from cruise conditions to high boost did the trick.
I agree w/ MRFred on pulling timing prior to the sensitive load areas. Knock is an event... you have to "anticipate" it to prevent it.
For the other question from TScomp... Im just referencing the voltage that we've seen when you see a knock count on EvoScan. Im personally on AEM so we tailor the knock threashold accordingly. That voltage range is actually pretty conservative and seems consistent.
EGR lines are usually culprits... Im guessing from the EGR ign adv tables.
Another wacky idea... a friend and I had a recent guy come in w/ an evo9 that would knock consistently at partial throttle. (high counts) The logger showed insane amount of ign timing adv at tip in regardless of what we had on the ign tables. In the end we wiped everything out and started over w/ a fresh rom and bam it fixed it. Still don't know till this day what exactly it was.
For the other question from TScomp... Im just referencing the voltage that we've seen when you see a knock count on EvoScan. Im personally on AEM so we tailor the knock threashold accordingly. That voltage range is actually pretty conservative and seems consistent.
EGR lines are usually culprits... Im guessing from the EGR ign adv tables.
Another wacky idea... a friend and I had a recent guy come in w/ an evo9 that would knock consistently at partial throttle. (high counts) The logger showed insane amount of ign timing adv at tip in regardless of what we had on the ign tables. In the end we wiped everything out and started over w/ a fresh rom and bam it fixed it. Still don't know till this day what exactly it was.
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