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knock sensor on s-afc2

nitemare5

By nitemare5,
in Engines & Forced Induction

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nitemare5 Rising Star

nitemare5

Posted
Posted

Just installed a S-AFC II on my r33 gts-t, everything was ok except for the knock sensor. I followed the instructions correctly as far as i know and everything seems to read ok except for the knock sensor, it always sits on 0. I've tried both knock sensors on the ECU and i get the same result. Could it be that my knock sensors are stuffed? or have i just installed it wrong. Any help on the matter would be greatly appreciated.

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https://www.sau.com.au/forums/topic/29719-knock-sensor-on-s-afc2/
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gtstii Collaborator

gtstii

Posted
Posted

what sort of knock readings do you get - and does anyone know what constitutes a knock?

I get 0 - 10 on a normal day and up to 20 on a hot day. I know the scale goes up to 200 on the safcII, so these can't be too bad. Would it be like to Power FC scale where above 60 means you are knocking?

Busky2k Veteran

Busky2k

Posted
Posted

Bad readings are when your talking 50+ over the IDLE figure. So if your getting say 20, and its a hot day, and you get 100 (via peak hold) after a WOT blast, then you have knocking. If the peak is only a lil more, then there is nothing to worry about.

Also dw about the idle figures as they rise with temp. NFI why tho. But the engine isnt knocking.

MJ Mentor

MJ

Posted
Posted

I just got mine installed today and i've just been for a drive and the knock goes upto about 10 which seems to be normal. But it takes quite a while for it to move though. I was driving a good 15mins before it moved off 0 on throttle.

However when i was at idle the knock would always read a higher value of 15-20.

strutto Grand Master

strutto

Posted
Posted

Mine was installed today too and so far the highest I've seen is 9 at idle... During a WOT blast it sits on zero?

I've done the knk set a few times but it makes no diff?

Out of curiousity, what are everyones raw knock levels in the knk set menu? (ie 1550, and 3650)

Thanks

MJ Mentor

MJ

Posted
Posted

My knock in the knk set was about 50-60 when i first started the car then after driving it for a while it was upto about 70-90 odd.

what do u mean a WOT blast? In the monitoring menu on acceleration mine sat on 0 for a little while then it started to read figures. But the whole time it was working when the car was idle. Im sure its setup right, perhaps the engine needs to be at operation temp before it gives figures?

Who thought a knock sensor could be so confusing :D

strutto Grand Master

strutto

Posted
Posted

WOT blast = Wide Open Throttle blast.

My knk set readings are pretty much identical: 50-60 to start with, 80-90 after a thrash.

At idle mines the same, between 4 and 10. But when flooring it, 0 all the way to redline? I was only driving for about 30 mins though... I will try it again tomorrow in the heat I guess...

At least I know it's not my crazy switch mod hey... :D

Busky2k Veteran

Busky2k

Posted
Posted

First of all, guys you shouldnt get huge numbers like 80 while idling. Otherwise your calibration is wrong. Go to www.apexi-usa.com to get the SAFC II manual! Btw u need the jap language pack, even tho there is no jap in the PDF? lol

Anyways, the higest ive seen is 20 at idle, but at cruising speeds, its zero which is most important. After a WOT blast i might get 25 or so, which indicates 25 - 20 = 5 knock counts during the WOT blast. Thats nothign to worry about. If its like 80 after the WOT blast, then pinging is at hand!

gtstii Collaborator

gtstii

Posted
Posted

yep - me the same.

- raw figures are 50 - 60.

- idling sits on 0 - 10 on a cool day and maybe 10 - 25 on a 35 degree day.

- when accelerating, car is breathing in cool air from outside the engine bay and comes down to 0 (maybe 10 on a hot day)

it would be good though to speak to apexi and ask for some guidance on what level a knock is (ie 50 or 100?)

I know that Access Auto's in Vic is Apexi's Australian distributor and they have technicians that you can talk to if you bought the product in Australia (ie not imported from japan).

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