Originally Posted by SlowCar

Hi Dave, i myself am trying to find the limits of timing too. I had a chance to chat with Dynoflash-Al while he was in phx and was told that the stock ecu will not allow/start pulling timing >11 degrees(i'm on stock ecu w/ ecutek flash). I've seen another person on stock ecu + ecutek with 12 - 14 degrees.
I will get retuned in a few days time. My plan is to set boost @26psi, AFR = 12.5, and start cranking up timing till i see it either plateau/knock then back it off 1%. I'm at 11 degrees now@23psi boost.
No one could give me a definite answer and every car having a different knock threshold, i just have to experiment and see how it goes.

Originally Posted by strikethree

At what point does timing reduction get stupid?

Using totally unrealistic numbers (divisible by ten):

Let's say that through extensive experimentation on a load bearing dyno that I discover my engine makes max power without boost at 100 degrees advanced timing.

Let's say that my turbo will provide 100 PSI max.

When the turbo starts pushing 70 PSI, the engine starts knocking and I pull back timing to compensate. At 80 PSI, I pull back 50 degrees of timing to stop the knock. at 90 PSI, I have to pull back 100 degrees of timing (which leaves me at 0). At the full 100 PSI, I have to go negative 50 degrees of timing to prevent knock.

At what point (percentage) was the timing absurd? Please fill in more appropriate numbers if it helps. I was merely trying to work it out as percentages with easy to use numbers.

strike (Dave)

Originally Posted by MR

newbie question...

how do u know how much advanced timing u need for your car? ixit realistic to keep advancing til you hear pinging/detonation than reduce it..taking into consideration of a fixed efficient boost level...