Knock Level Reading 240 ?

[greyshoes]

I had my R33 series II couple of weeks ago, car in good condition and good power with a few mod like:

Apexi power FC

Bosch 040 fuel pump

NGK spark plugs

Manual boost controller 12 psi (dun know whether stock turbo or mod one)

Front mount intercooler.

Apexi turbo back exhaust 3.5" with 4" tip

Excedy heavy duty clutch

One day I drove a bit agressive and power FC read 240 on knocking level. I know it is something really bad cause the seller told me that this car now have been tune for economic drive to safe fuel and dont drive hard unless get it tuned properly (which will worn out my pocket for fuel). I'm a nope in performance car and dun know wat I should do now. My mate told me to bring it to dyno tune to check up wats wrong with it and tune it back to normal. Can u guy give me any suggestion of wat may go wrong with the car and how can I solve it. I appreciate that.

[R31Nismoid]

The car just needs a tune adjustment.

So book the car into a PFC Tuner, get the car tuned.

And thats that. Knock of 240 just means there is a bit of work to be done on the tune to clean it up.

[LatinR33]

Man 240 knock is pretty bad, if you just bought it you should of taken it to the dyno first thing to get it tuned. Take it now to get it checked out and I hope everything works out well. Get a compression test done aswell while your there.

[tridentt150v]

Avoid working the motor - making it knock - until you get it tuned. And get it tuned soon, summer heat is just around the corner and it will lean the motor out even more.

[aphid]

actually it'll do the opposite, make the air less dense actually richening it, however because the combustion mixture is hotter it will reach it's flash point sooner and therefore knock easier

get the car tuned asap, or if that's not financially viable do a little home tuning on the ignition map.. do a map trace to find out what cells the car is knocking in then retard the ignition in those sections.. Pauls PowerFC FAQ will tell you everything you need to know

  tridentt150v said:

Avoid working the motor - making it knock - until you get it tuned. And get it tuned soon, summer heat is just around the corner and it will lean the motor out even more.

Edited September 24, 2007 by aphid

[QWK32]

i've seen stupid knock readings like 280 on a car that had a stuffed engine mount. the vibration of the metal to metal contact was enough to give a false reading. any noise, vibration, hit can give a knock reading. tapping the side of you engine with a hammer is enough to get a reading. also check to see if anything is touching(bumping) agianst the engine.

i myself have had readings of like 160ish from when i had the safcII and i hit rev limiter. don't know if the safcII runs the same knock system though.

another option is that the knock sensor has stuffed.

[Ryan.R34]

I had a knock reading of 158, took it for a dyno and knock would max out at to 29 for about 3 weeks, now its back up to 145. Have no idea whats going on. So yeah, don't get on the gas until you sort it out bud.

[wolverine]

around 4800 there seems to be a noise on Neo's which i believe is the VCT. knock sensors seems to read around 140'ish at this level. no signs of knock above or below, just at this point. ryan, is this where you are getting the higher knock readings.

Edited September 24, 2007 by wolverine

[WogsRus]

RB25DET does it to, once the solonoid deactivates, you geta knock spike, really common. Especially if you do some data loging and look at the knock VS rpm

[greyshoes]

Thank for reply guys. I dun really know wats happening with it. I drove today, 3rd gear at 2800rpm, go up hill and the nock just jump from 15 to 57, any reason why suppose that car hace been drove for an hour. I tried to drive it soft but the retard sensor keep giving me a freaking number that really making me shock. I'm about to bring it to dyno tune next week and quote the price for $450 for a full tune or $250 for standard one maybe, any idea about the price ? reasonable ? Cheers.

[R31Nismoid]

Whats happening is a poor tune.

If you dont want knock, then dont drive it until its tuned.

Nothing more you can do, nothing more we can offer. $450 is reasonable

[paulr33]

hi,

have a read of http://paulr33.skylinesaustralia.com/docs/...powerfc-faq.htm and pay attention to;

Tuning Information

53). I always have knocking, is it true, is it lies or is something wrong?

54). How do I debug knocking, how can I make it go away?

you can sort it out yourself if you like or learn more about it, to better understand the issue

[Ryan.R34]

  wolverine said:

around 4800 there seems to be a noise on Neo's which i believe is the VCT. knock sensors seems to read around 140'ish at this level. no signs of knock above or below, just at this point. ryan, is this where you are getting the higher knock readings.

Yep that would be about right, always in 3rd gear too, under load light starts flashing i look across and see the reading on the handle controller.

[Ryan.R34]

  paulr33 said:

hi,

have a read of http://paulr33.skylinesaustralia.com/docs/...powerfc-faq.htm and pay attention to;

Tuning Information

53). I always have knocking, is it true, is it lies or is something wrong?

54). How do I debug knocking, how can I make it go away?

you can sort it out yourself if you like or learn more about it, to better understand the issue

Nice work mate

[DECIM8]

What fuel r u using?

Go get it retuned .. id spend the extra dosh n ask for a full workover of the map, make it for performance .. Its more fun anyway.

Not to clued up on pfc but cant you install more than one map?

Anyway good luck.. Id avoid driving it in high temps as well, check your cooler and pod/air filter that they are clear to just make sure the engine is gettin all it needs.

[my33gtr]

Get it tuned asap, back the timing off a few degrees if you can this may help temporarily but get it checked out asap.

[greyshoes]

when I had a the knock I used 95, but change to 98 now and I also change a igntime back to 1 deg and it works well.I just wonder if I keep driving like this will it be a lot of effect to the engine and also sone one had told me about the workshop can "clean up" the knock when I bring car to do dyno tune, what they acttually do to "clean up" the knock and what is the acttual dammage knock cause to the engine, for exp engine crack, blown, freeze.. etc.

Coz i'm only do daily drive so I'm still consider about the running cost, for sure get the car tune up to a proper performance can be cossy in long term drive. And fact that the previous owner had tuned it back from the performance just be cause the fuel economic.

Cheers,