Knock Knock

[Don Dada]

ok guys has anyone ever tested the voltage on the knock sensors?

The R33 Gtr service manual says 0.4 - 2.0v with a circuit tester

I am not getting any reading off mine????

[battery]

you wont get a voltage checking like that.

Its only gonna register at the point in time when it is actually sensing knock.

basically theres a crystal in there and when it is compressed it will output a voltage, between 0.4-2v depending on the severity of the knock.

I guess you could try tapping the sensor or the engine while hooked up to a multimeter.

Edited March 13, 2011 by battery

[Don Dada]

Figured that much...

Only when it actually picks up noise then it would output a voltage

Another glitch in the manual i suppose as the R32 gtr manual doesn't mention using a circuit tester, just an oscilloscope

I guess the sensors are working though because they are registering an increase in knk from off to on load

So what do you guys recommend? tune for a max knk of 15 ish? I would really like to see a similar log of a stock 26 tuned on 98

I have a next set of sensors that i could swap but i really dont think that will make a difference

[battery]

Personally I don't think PFC knock is reliable I would get it tuned by someone with a standalone knock detection device

[Don Dada]

Not in Aus....

Dont have that here

Dyno here dont have afr or boost plot either

[DVS JEZ]

Pm sent

[scotty nm35]

Buy a knock box, then you could start your own tuning workshop.

[SiR_RB]

my nistune software doesnt show any knock (0) dunno why?

does anyone know which cable on the ecu harness is for the knock sensor?

[Guilt-Toy]

its not supported in Nistune yet... Matt has been working on it for years

every engine has different noise, you dont just have a level that you should try and stay below, i have seen engines register 150 knock and when listening to it I cannot hear a thing!!

What you should be on the lookout is for major spikes, if the engine makes contstant noise but then spikes from 40 to 140 then you might be onto something...

can you sent the car to the states ? there might be some decent tuners there?

my nistune software doesnt show any knock (0) dunno why?

does anyone know which cable on the ecu harness is for the knock sensor?

[SiR_RB]

Well that's good to know, I was abit worried that my knock sensors mAy have been disconnected .

Why would nistune have the knock feature in the software but not have it supported yet? It's a pretty dam important feature

[SiR_RB]

Also, can you buy knock sensor kits or something along those lines to have permanently connected, which then shows you on a display your knock?

[femno]

My 32 GTR knock sensors never worked either. Dont know why. Tried new sensors, loom continuity, all good. The factory knock sensors should never be relied on anyway.

To tune it on the road you need a knock box. Theres no other way. Either that or you need a proper dyno tune by someone who knows what theyre doing.

[SargeRX8]

I'm noticing something in my car I wasn't before. I had a PFC with base tune and that thing used to register about 40 - 50 knock sometimes up to 100 knock. I got one now tuned for a stock R33 GTST with 10psi. I see about 4 on average on the knock sensor, very rarely shoots up to 10 - 30.

Now, originally I had the standard dump on the car and it was leaking coz of a crack and you could hear the look coming onto boost. I changed it out for a screamer split dump while my other one got fixed. Now I fit the other one back on and I get a weird tick tick tick sound which only seems to happen between 5000 - 6000rpm. It picked up my attention straight away. Ive never heard the sound before but it only happened when I got the old dump put back on after it was fixed. People say pinging sounds like the word, like a ping on metal. This sound I hear is more like a "chick" kind of sound, like a match getting striked on a match box.

Knock sensor on my PFC still wont show anything above 15.

And to OP, the Power FC will detect knock as its heard from your knock sensor. Your car is designed to detect knock but it does not display anything to you. The PFC just reads what the knock sensor says and displays it for you. You need an independant knock sensor. But that said, if you're still picking up some form of knock, your sensor probably is working. Like others have said, if its a ping so loud you can hear it, there is no reason your knock sensor wont.

[DVS JEZ]

sarge if its on a pfc even though the knock is reading 15 if you can hear the chick sound, try going to ign trim and back the timing down 5 degrees to see if the noise stops. dont keep booting it till you figure out if its pinging or not.

[Don Dada]

Buy a knock box, then you could start your own tuning workshop.

Dont have time for that.....

I just like my car and want it working up to scratch

My 32 GTR knock sensors never worked either. Dont know why. Tried new sensors, loom continuity, all good. The factory knock sensors should never be relied on anyway.

To tune it on the road you need a knock box. Theres no other way. Either that or you need a proper dyno tune by someone who knows what theyre doing.

That statement is so funny you wouldnt believe...

I realise you guys have a lot of dodgey tuners up there so imagine for a tiny island like mine.

[Don Dada]

Well time for a little update......

I have secured all sorts of loose shit under the center console/dash and under the car and tuned the timing around 24* which is what the oem ecu would normally run and i'm not hearing any vibration/rattle again and the values on the pfc is 10-12 max and very low on the safc2 as well and i have that set really sensitive

So i believe that the noise wasnt actually detonation but i have taken out a few degrees here and there so the safc would not show any high values like i was seeing before.....so i guess now its dyno time to compare ign advance to torque gain to see where shes happy

Man....talk about paranoid!!! every fu$king thing sounds like detonation!

Any tricks to listen for knk on the dyno??? With your bare ear i mean.....i just dont have any other devices available to pick up knk

[Rolls]

There are no tuners here with knk sensing devices and they are really bogus in my book thats why i bought the pfc in the first place to have some sort of detection

95 is the best we have here too and i'm running 11.0 afr from 4k up

imo the standard knock sensors are more likely to be bogus than proper knock ears, I would certainly get some on there to tell if it is your knock sensors playing up or it is just some mechanical noise.

think of an engine as a woman. there are many ways to get her to bed, once you get experienced enough you work out the fastest and best way

But dont expect a guy to tell you his secret, he dont want you taking all his women... took me a while to understand why experienced tuners keep their knowledge to themself's like they do.... but i would have it no other way now.

I don't really get this, in a lot of circles everyone shares info and works as a team, (eg forums) I guess when money comes into it it is different though.

[KiwiRS4T]

I don't know how to fix your tune but can you get 200L drums of toluene or methanol and add a few litre to each tank full to up the quality a bit?

[zebra]

imo the standard knock sensors are more likely to be bogus than proper knock ears, I would certainly get some on there to tell if it is your knock sensors playing up or it is just some mechanical noise.

I don't really get this, in a lot of circles everyone shares info and works as a team, (eg forums) I guess when money comes into it it is different though.

SAU is good for info like that, go ask a V8 builder about their Jet specs for a carburettor, you would be lucky if they didnt back hand you, same goes for cams/port work, the good guys wont tell you nothing, I know heaps of guys with Big power race V8s who dont even know what the specs are because the builder wont tell the owner.

It makes perfecet business sence, because the good guys earn good money becuase they are good, if they gave away their secrects then every wannabe pro-engine builder would copy them.

Imports are easy because everyone is lazy and leave the heads stock or near stock and just add boost, and its easy to look for the plate that says "GT3037S" etc and build the same engine.

[Rolls]

good points