Help with knock (graph inside)
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TECH Resident
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From: England UK
Help with knock (graph inside) I was doing a run on the freeway, at a constant speed, AFR was 12.18 okay a little rich, but if it was lean it would explain it. Spark advance is 26 deg @ 3500rpm. The knock appears then goes away and returns to 26 deg.
Can anyone explain?
Can anyone explain?
Thread Starter
TECH Resident
Joined: Aug 2003
Posts: 970
Likes: 4
From: England UK
I guess its nothing worry about. I got the WB on the drivers side, I guess the passenger side my have had lack of fuel at the point or something. Who knows.... This knock rarely comes up.... so I guess its nothing major, probably false knock.
Originally Posted by RedWS6 00
I was doing a run on the freeway, at a constant speed, AFR was 12.18 okay a little rich
did I see that right? 152MPH? LOL Good gawd man LOL Your obviously doing a "run". 152mph, IAT @ 199*, spark at 24*, RPM 3500ish...I'd go with real knock if those #'s are correct. IAT at 199* and those enviroments, it's not hard to believe your mixture is pre-igniting. What octane gas?
Thread Starter
TECH Resident
Joined: Aug 2003
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From: England UK
Originally Posted by SSpdDmon
Just curious...how could you be at 3500rpm and maintain a constant speed with 100% throttle? You could try setting the timing at 25* there and see if it helps any.
Originally Posted by dewmanshu
did I see that right? 152MPH? LOL Good gawd man LOL Your obviously doing a "run". 152mph, IAT @ 199*, spark at 24*, RPM 3500ish...I'd go with real knock if those #'s are correct. IAT at 199* and those enviroments, it's not hard to believe your mixture is pre-igniting. What octane gas?
Thanks for all your replies.
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Originally Posted by RedWS6 00
It was wind resistance slowing me down, the speed is gradually dropping off, was going 156mph in 5th, popped it into 6th and the speed gradually went to 150mph over about 20seconds even at 100% throttle
That was IAC on the log was tuning for idle some time ago. I did log IAT(not shown on graph) I'll find it out and post it. The gas used is Shell V-Power, so I guess its 93 octaine or a little higher.
Thanks for all your replies.
That was IAC on the log was tuning for idle some time ago. I did log IAT(not shown on graph) I'll find it out and post it. The gas used is Shell V-Power, so I guess its 93 octaine or a little higher.
Thanks for all your replies.
IAC, IAT...boy what a mistake there
. Not used to seeing IAC being logged on a 150+mph run LOL. Got me good. Well then, carrying on, it's common to hear people complain of kr in the "lugging" area, obviosuly at that speed not much "lugging" happening. High MAP low RPM. Even with good afr, spark and every thing. What was the g/cyl? Thread Starter
TECH Resident
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From: England UK
I'm unsure of the 'Dynamic g/cyl', but did have the 'Calculated g/cyl' enabled in HP tuners, so attached is a pic of 'calculated g/cyl'. At the point of knock 0.68g/cyl and its fluctuating just like the MAF, it seems to do this when 100%tps, when not under so much load the MAF reading is smoother. I do have a de-screened MAF so this could be the culprut of that.
I have a little bit of knock in 5th too, justbefore I changed to 5th, all other signals look resonable stable before/duriung and after the knock in 5th.
I will do some like of Dynamic g/cyl and Calculated g/cyl and see if they are different. If they are different what could that mean? I was going to recalibrate the MAF some time back but I have +4 and -4 adjuments near each other, which kinda let me know to leave it and it would average out about the same. My maf is stock but with anodised MAF ends and no screen.
Perhaps its just a random knock. I wouldn't mind learning more on the g/cyl, I beleive the calulated g/cyl is (MAF g/s * 120) / 8 / RPM, but where does Dynamic G/cyl come from?
I have a little bit of knock in 5th too, justbefore I changed to 5th, all other signals look resonable stable before/duriung and after the knock in 5th.
I will do some like of Dynamic g/cyl and Calculated g/cyl and see if they are different. If they are different what could that mean? I was going to recalibrate the MAF some time back but I have +4 and -4 adjuments near each other, which kinda let me know to leave it and it would average out about the same. My maf is stock but with anodised MAF ends and no screen.
Perhaps its just a random knock. I wouldn't mind learning more on the g/cyl, I beleive the calulated g/cyl is (MAF g/s * 120) / 8 / RPM, but where does Dynamic G/cyl come from?
