Getting *high* Knock On Gear Changes

[privatealpha]

Rb25 (stock)

Apexi Power FC

Got the car running to pull pretty strong, 18 psi.

Do a run in third gear and get knock readings of around 35.

Pretty happy with that.

Do a run from first gear to third and it gets knock readings of about 70, only in the brief moment when you are changing gears.

Cant seem to tune this out, if i change gears slowly its fine (but where is the fun?)

HKS gt2535 turbo, got about 12 degrees of timing at full throttle 5000rpm+

Is it too much timing?

[GTSBoy]

At what point in the gear change? Just before unloading the engine? As the revs are dropping with the clutch in? As you load it back up again?

[Moodles2]

Tuning knock via the PFC readout... who needs proper knock reading equipment anyway...

[wolverine]

Does it occur to you that maybe changing gears is making a noise that the knock sensor is picking up?

[SiR_RB]

Noisy twin plate clutch that rattles when shifting??

[Lithium]

This can definitely happen with cars which don't knock under steady load - this is why ECUs such as the G4 Link have the ability to set up transient retard

[privatealpha]

I understand the knock sensor isnt the most accurate of devices but its something you can compare.

Well took it to the drag strip to do a bit of fine tuning.

Looks like its knocking under power, will have to reduce the timing a bit.

On the road, i did power runs in 2nd gear, maybe that didnt load up the car long enough.

Went to drag strip and i can load it up nice in 3rd and 4th gear, got some nice amounts of knock readings. Would help if i had a quieter exhausts to listen for it.

[WMDC35]

You dont want to be hearing it!, No dyno or tuner available?

[paulr33]

dont reduce the timing if its knocking

reduce the boost

reducing the timing will make it flat and doughey

reducing the boost will make it detonate less and keep it crisp with the timing the same

[DVS JEZ]

dont reduce the timing if its knocking

reduce the boost

reducing the timing will make it flat and doughey

reducing the boost will make it detonate less and keep it crisp with the timing the same

Depends if it has too much timing for the current boost tho. Or afr's arent safe

[privatealpha]

Got it all fixed, too much timing in 2 cells.

Boost momentarily spikes high on gear changes and goes into a few cells i didnt see.

Gotta work out this boost controller now...shouldn't be too much trouble, much easier then figuring out timing issues anyway.

[DVS JEZ]

Good u got it sorted. Normally something simple