Knock Question

[topher_]

Picked my car up from ben at racepace yesterday after getting a tune done. Took it for a drive tonight and twice under load at mid-high rpm the car sounded like it was missing (didn't sound like detonation.) Had a look at my power fc and the first time the knock was at 34 and second time 46. Are they dangerously high levels?

[R31Nismoid]

Not really, no.

If your car has developed a miss, that could possibly be it also. Dyno doesnt simulate everything, so just note down what RPM, how much throttle and what gear, nice easy fix

[STATUS]

probably just plugs or coil packs.....

Edited June 14, 2009 by URAS

[errno]

I've just put a powerfc in, still waiting to put in new mods before I take it to the dyno though, glad to see that around 30-40 knock isnt really worth worrying about, the highest i've seen under load was around 13 on the basic out of the box default

[Adriano]

Im surprised, usually with the stock default map they detonate out of th ebox. I wouldnt lean on it too hard without a tune. Remember a stock setup detonating can crack a piston easier than a 350rwkw well tuned setup.

[errno]

Im surprised, usually with the stock default map they detonate out of th ebox. I wouldnt lean on it too hard without a tune. Remember a stock setup detonating can crack a piston easier than a 350rwkw well tuned setup.

im suprised too, it runs so much smoother than the stock computer just plugging it straight in.

i dont want to spend 500+ on a tune, then in 2 months time upgrade the turbo etc which im planning to do and then have to spend the same again to get it tuned again

[Johnny]

im suprised too, it runs so much smoother than the stock computer just plugging it straight in.

i dont want to spend 500+ on a tune, then in 2 months time upgrade the turbo etc which im planning to do and then have to spend the same again to get it tuned again

I read an article on stock pfc maps for an s15 and they were very aggressive; i would assume that would be the same for most jdm imports too. You would feel more power but its probably running lean, a little too lean.

in regards to knock, I see 14 on cold nights at higher throttle but can see 34 or so on a hot day.........want to add, was cruising on a rough road at 80km/h, pushed the clutch in and let the car coast while i reset the handcontroller and monitored the knocks and it still registered about 25 so it would be plausible to assume that roadnoise can influence knock to some degree.