Knock between 2800 and 3000
At what load are you switching from closed to open loop? Is the knock happening around the changeover point? How do your AFRs look right before the knock occurs?
I had a very similar issue to this and solved it by lowering the open loop changeover point so that the car would run richer than stoich earlier. I think my changeover point is around 80 load or so, whereas stock it is much higher.
I had a very similar issue to this and solved it by lowering the open loop changeover point so that the car would run richer than stoich earlier. I think my changeover point is around 80 load or so, whereas stock it is much higher.
I won't be back home until the 29th so I can't check my knock summary. If I recall correctly, my knock seemed to be at quite a range of loads from 80 to 120 or so, but I also didn't have the knock decay timer turned down to pinpoint the origin yet, so this may very well be part of the issue. I'll get some more logged info with some AFR's in there and check back in this weekend.
- Eric
Next, fill up (or maybe 1/2 tank or so) of 100 octane and go out and do the same logging. If you've got the exact same sort of problem, you can probably write it off as phantom knock.
If it phantom knock, go read up at this thread:
https://www.evolutionm.net/forums/ec...e-found-3.html
I had problems a bit worse than the OP had descirbed and small tweaks to the knock control tables got rid of the problems.
-Robert
Success!!!
We were able to turn down the overall sensitivity of the knock sensor. Thanks to all for the tips. I went from throwing a total of 10 - 20 occurrences of 1 - 4 counts of knock in a 15 minute period, to throwing 2 single counts of knock on a 2 hour highway drive with a few pulls!
In the end i turned up the knock load table up to 75 for the low rpm range, and bumped the knock sensitivity on the low and mid table by 1 point.
I am very happy with my car now, and we were able to get another 30 whp and 40 tq out of it with zero count of knock! I think there's still more left in it, but my wastegate needs some help... I creep to 28-29 psi of boost at 5000 down to 19 at 7500.
We were able to turn down the overall sensitivity of the knock sensor. Thanks to all for the tips. I went from throwing a total of 10 - 20 occurrences of 1 - 4 counts of knock in a 15 minute period, to throwing 2 single counts of knock on a 2 hour highway drive with a few pulls!
In the end i turned up the knock load table up to 75 for the low rpm range, and bumped the knock sensitivity on the low and mid table by 1 point.
I am very happy with my car now, and we were able to get another 30 whp and 40 tq out of it with zero count of knock! I think there's still more left in it, but my wastegate needs some help... I creep to 28-29 psi of boost at 5000 down to 19 at 7500.
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