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Apexi Engine Knock
Hi, my 97wrx (shell v power) runs normal on 10-12 knock but full blast/boost can reach 50s. would you think it's a mapping issue or mechanical? is it best to go mechanical side first rather than looking at remap etc.... cheers
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Has it ever been remapped? Have you made any mods to it?
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it was remapped in 08 by previous owner mods are
HKS Mushroom Induction Kit, HKS intake piping Full Stainless Steel Exhaust System IHI V5 Ball Bearing Turbo (VF22) HKS Electronic Variable on board boost controller Uprated MAF Sensor fitted at PowerStation Silicon Turbo Intake Pipe Believe it runs 310bhp |
At what rpm do you get the knock? If at very high rpm it could be other noise fooling the sensor. Best way to go about it is to get someone to listen with det cans and go from there
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When it gets to 6-7rpm i get a max reading on hand controller of 50-52
normal running is around 10-12 knock. |
Above 60 is something to worry about.
:) |
what would be main worry about high knock?
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Whats an acceptable knock level then? I take it the better its mapped the lower the knock levels will be?
Cheers Hutch |
pretty sure it's original sensor are they supposed to be crude ie could be inaccurate readings coming from it?
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The knock on the Apexi AFAIK is calibrated by the mapper so what may be ok and safe at 50 on one engine may not be on another. As said at high RPM it may be detecting other background noise, but over the course of the 3+ years since mapping other parameters on the car may have changed affecting the running such as sensor outputs etc where the Apexi cant adapt to sensor variations in the same way as the OE ECU (thats not suggesting there is a fault, just that over time the sensor output voltages can change slightly)
As above get the car to somewhere and run it with det cans then see if the map needs tweeked. |
on the commander, watch boost/revs and knock on the graph setting. if the knock line peeks sharp to 50 odd, then i would guess that it is knock. if it goes up smooth, then i would guess it is engine noist
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Great advice, i will get it checked with det cans and see what happens. is there any rule for remaps ie every 3 years etc.... or does it depend on how car drives problems?
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i had my car tweaked yesterday and was talking to the mapper about what was acceptable knock on the apexi, he did say the earlier the car the higher the knock readings, but tbh 50 does sound high to me, i would get it checked over by a mapper if i was you.
ive got a 98 and it doesnt go above 30 even when i`m giving it some beans, usually stays below 20, put it this way the mapper set the cel light warning at 35 |
Originally Posted by sandyRS16i
(Post 10476646)
The knock on the Apexi AFAIK is calibrated by the mapper so what may be ok and safe at 50 on one engine may not be on another. As said at high RPM it may be detecting other background noise, but over the course of the 3+ years since mapping other parameters on the car may have changed affecting the running such as sensor outputs etc where the Apexi cant adapt to sensor variations in the same way as the OE ECU (thats not suggesting there is a fault, just that over time the sensor output voltages can change slightly)
As above get the car to somewhere and run it with det cans then see if the map needs tweeked. |
Drove home with knock + rpm on map mode and no real spiking occurred. the knock followed rpm up through gears and did reach 50 knock at 6.7rpm but once i was in gear 5th on bypass with boost it was 10ish knock with no spiking. does this sound correct? seemed to get to max knock 50 when changing gear at high revs but then settled down.
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prob the best advice i could give, is drive is steady and off boost and get a good mapper to check things over. it would prob cost around £150 but it is a hell of alot cheaper than a new engine.
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Quick question, why the need to go to 6700rpm ?
Even on a cold day I don't see more than 27 and that's 1.37 bar full wot through all gears. :) |
alot of things could cause funny knock readings
bad fuel/wrong fuel mods changed faulty sensors map played with boost played with leak somewhere etc etc |
i will drive it steady and arrange for a mapper to take a look asap. i went to high revs to see what spiking would occur as a test, only briefly as not normal driving range for me. cheers for advice will let you know how it goes.
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too high.. I would expect 30 something on that year of car..
needs checking imho Simon |
Originally Posted by 53
(Post 10477619)
Quick question, why the need to go to 6700rpm ?
Even on a cold day I don't see more than 27 and that's 1.37 bar full wot through all gears. :) Normal running mine doesn't see over 15. :) |
My 98 type r reads 1 when i start it up, bout 10 on normal driving and no more than 15 on full boost 1.4 bar
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Quick update got car checked with det cans and sounds like a problem with pistons/shims getting it looked at so hopefully sort problem out. Did hear 97 cars were louder anyway but hopefully get it checked and result will be a lower knock from sensor.
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50 is too high specially around that RPM. My V3 STi with PFC mapped by JGM never went over 17 & thats with some good abuse. Average was between 7-12.
Get the map checked. |
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