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Inconsistent Knock Powerfc

Pattygtst

By Pattygtst,
in Engines & Forced Induction

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Pattygtst Veteran

Pattygtst

Posted
Posted

Hey guys

Ive got my car booked in to the workshop to try sort out why my car pings and basically their first solution is to put a custom oil catch can on there to stop possible blow by. Just before i go down that avenue of spending dosh on something that may or may not fix my issue i would like some feedback from the gurus. Basically the issue is the car will NOT knock over ~17 on dyno/road driven to red line. However everynow and then it will get one ping rangeing from 60-90. It always gets only one ping and my tuner said he could hear it through the ear phones. The thing is even when he took 2 degrees of timing now running 340rwhp it didnt make a difference. It still get inconsistent ping.

Brief list of mods

pfc

gt3076 iw 0.82

zaust - split dump, de cat

eboost 2 running 19psi

pod

fmic

bosch 044

z32 afm

And yes i only put in bp 98 octane. Ive attached a dyno so you can see air fuel ratio

Its a late friday arvo so if i forgotten crucial info let me know. :cool:

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R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Why is the intake temp 50 degrees?

Anyway... do you have a blowby problem?

Is it the same spot the ping occurs? Same/similar rpm and/or load perhaps? (could be a slightly off cell in the tune).

Blocked fuel filter maybe, although doesnt sound like it

Pattygtst Veteran

Pattygtst

Posted
  • Author
Posted
Why is the intake temp 50 degrees?

Anyway... do you have a blowby problem?

Is it the same spot the ping occurs? Same/similar rpm and/or load perhaps? (could be a slightly off cell in the tune).

Blocked fuel filter maybe, although doesnt sound like it

I dont know about the intake temp or if it indeed does have a blowby problem. That was just brought up as a possible explaination.

Yeah it generally pings aroung 6200rpm and up but as i said it does that only rarely

Zardos Community Regular

Zardos

Posted
Posted
Why is the intake temp 50 degrees?

I have the same problem with my intake is always sitting around 50 degrees.

I'm thinking it must be my cooler.

It has the standard end tanks and a custom core. (was like this when i bought the car)

But my knock readings are not high at all

What do you think Nismoid

paulr33 Grand Master

paulr33

Posted
Posted

you will have one or two cells that are too high

when you drive it on the road yourself you typically drive it different to how the operator plonks it on the dyno and does a WOT power run

my advice is take on the street with datalogit plugged in logging the map cells and knocking (knock map)

then youll find the 1 or 2 offending cells, you can take out 2deg in those specific cells and youll be fine

find someone local in perth with datalogit, drive around knock watch and youll see it

or get your tuner to do this for you - but he will charge you

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
I dont know about the intake temp or if it indeed does have a blowby problem. That was just brought up as a possible explaination.

Yeah it generally pings aroung 6200rpm and up but as i said it does that only rarely

Well if it is around the same spot - then that can only be the tune really. Or similar issue with a coil pack dropping out or something similar triggering the knock.

I have the same problem with my intake is always sitting around 50 degrees.

I'm thinking it must be my cooler.

It has the standard end tanks and a custom core. (was like this when i bought the car)

But my knock readings are not high at all

What do you think Nismoid

stock GTR temp sensor?

its taking heat from the plenum, they all do it so it reads high, but isn't.

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

should post up your timing map, most tuners only adjust the traced cells and ignore the rest because they cbf the rest, on a dyno it may not load into those cells but on the road wham you might load up cell N15, P16 and pow, knock... because it's got some silly value against it.

JonnoHR31 Grand Master

JonnoHR31

Posted
Posted

unless he was having a bad day i doubt it. i've had my car tuned at hyperdrive a few times and andy usually does a good job of smoothing out the map. altho looking at your dyno graph he hasnt added as much fuel around peak torque as usual

i had the exact same thing when i got my car tuned last, made 360 on one run but he thought it was a bit too unsafe so knocked some timing out and back down to 330

like i said, i can do a knock log for you with datalogit and find where its pinging

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