prwatts

Ever heard of this trick to speed up the factory ECU's ignition timing learning process?

Background: There is something called "Ignition Advance Multiplier". It represents, by some complicated algorithm, the average learned positive knock correction applied to the ignition maps. It's represented in 1/8th degrees increments. 1 being the lowest and 16 being the highest (1/8 to 2 degrees in absolute terms).

The "happier" (knock free) the car is, the higher the number will be. Conversely, the lower it is, the more knock prone it is. This number, after ECU reset ore ECU swap defaults to 8 and usually creeps up to 16 (if well mapped) through normal driving. Depending on driving characteristics, this can happen within a few hours or a few weeks.
Well, here's a way to make it happen in about 5 seconds

First: With the car fully warmed up, reset the ECU. This can be done by killing power the ECU or by simply pulling off the neg. battery terminal and pressing the brake pedal for a couple of seconds.

Second: Drive to a nice open road without traffic. Don't go on boost until you get there. Put the car into gear (3rd gear works the best) bring the revs up to 2600rpm. Push the go pedal down slightly so boost stays right around 2-4psi. You will need to MAINTAIN 2500rpm and 2-5psi for approx 5 seconds. You can do this by left-foot braking gently as to prevent acceleration. During these few seconds, the advance multiplier (which you can't see so you'll have to trust me) will go from 8, to 12 and then to 16.

I am told it works like a charm and have done it before on my previous Bugeye

Note, while this artificially speeds up the learning process, it is only a good thing if the re-mapped ECU is mapped properly. If there are trouble-spots where knock is present, this will make it even more present.

Courtesy NAISOC

joz8968

iTrader: (13)

Yeah, read that on, I think, Scoobypedia too.