Below is a little trick I found on a Subaru forum that has been shown to accelerate the factory ECU’s ignition timing learning process. This procedure is commonly known as the Vishnu Reset after the company, Vishnu Performance, that wrote this on a Subaru forum (it works!).

Background

There is something called Ignition Advance Multiplier (IAM) as part of the OEM ECU software. 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 an ECU reset or ECU swap defaults to 8 and usually creeps up to 16 (if well mapped, over a week to re-learn) 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 ….

Fast learning procedure (GC8 WRX)

1. With the car fully warmed up, reset the ECU.
2. 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.
3. Push the accelerator pedal down slightly so boost stays around 2–4psi (~0.2 bar). 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. Works like a charm. And on your reset ECU, it is worth an immediate 10–20 BHP.


**The information above has been pulled from another Subaru site, but it works quite nicely and may add the pep back to your stock ECU if it's been feeling flat to drive**

__________________
[CENTER][SIGPIC][/SIGPIC][/CENTER]
[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]

Nice find Rossco! So you actually saw the IAM increase using your PowerFC hand controller?? Very interesting...

I found that my GC8 would run like shit for a while after getting a bad batch of fuel. Not sure if it was this particular issue but I figured that it was connected with the slow ECU relearning.

__________________
MY99 WRX (Sold)
MY06 WRX 241hp 430nm atw (Sold)
MY09 BMW 135i 247kw atw (Current)

No...This only works on the factory gc8 & 16 bit Liberty RS ecu's, it has nothing to do with Apexi ecu's.

It can be watched with open ecu software and a tactrix cable.

__________________
[CENTER][SIGPIC][/SIGPIC][/CENTER]
[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]

I thought the Vishnu reset was for the GD cars, as Vishnu is an american company and they only got the WRX from 02?

__________________
MY93 Impreza GX 1.8L, 0hp, 0nm

It does work on GD onwards aswell, but I'm not sure of the reset procedure or how to set the ecu into it's "fast learn" ready mode on the later models.

I know it works on GC's because I could log the timing before & after using the Greddy scan tool I had (that Damo has now) and see the base timing come up by 3 -4 degrees across the board.

If someone knows the GD method feel free to post it up!

To quote MRT:
"NOTE: This is only applicable to MY93-00 (GCA) models. The later model MY01 (GDA) onwards require the use of a product such as the DeltaDash or similar to reset the ECU. Please see www.ecutek.com.au/delta-dash.htm for
more information."

__________________
[CENTER][SIGPIC][/SIGPIC][/CENTER]
[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]

lol my bad. It was late
I was trying to figure out how you'd see the IAM change.

__________________
MY99 WRX (Sold)
MY06 WRX 241hp 430nm atw (Sold)
MY09 BMW 135i 247kw atw (Current)

Cool, only reason I ask is because all i've read about it on nasioc and scooybnet has been for the GD models, found this link which is verbatim what you posted for the "newage" WRX (GD)

http://www.scoobypedia.co.uk/index.p...tLearningTrick

Should give it a go on shannons car and see if we can get it to drop a skid

__________________
MY93 Impreza GX 1.8L, 0hp, 0nm

or lunch a gearbox.....

Yeah the fast learn method is posted all over the net but not here on P-wrx...

I just thought I'd add it here so anyone looking for it can find it easily.

__________________
[CENTER][SIGPIC][/SIGPIC][/CENTER]
[CENTER][COLOR=#ff0000]Built Ej207: Semi-closed RA Cases - Wiseco Forgies - Manley rods - BC 272 cams - GDA Heads - billet f/whl - Vi-pec - WbO2 - 800cc Yellow tops - TD05-20G - 409Hp ath @ 1.75bar on E85[/COLOR][/CENTER]