ECU chip need info

[CanadianSVX]

i just bought my svx did the crush mod on it and found i have a chip

its got a serial number on it and was wondering if anyone could tell me whats on it or whats it does thx

i can type out the code if you can't read

[Conn SVX]

What chip is it what company? I have ECU tune 1.5V..mine does not look like that . yours i think is a factory one . my install instructions says to rermove it to add the ECUtune . The factory chip they show is 22677AA040 F23AVH06

[CanadianSVX]

oh alright just wondering, didn't now if it was anything special or not

thx

[Conn SVX]

I am trying to check it out . Some of the earlier SVX did not have it , there was an empty socket. It is used to up grade things in the engine management . What I don't know

[Earthworm]

I had a chip in mine as well. Is your SVX originally from Canada like mine?

[Conn SVX]

I guess you can't buy them from Subaru so a guy made one .It is 3 times the size( memory ) and it is mapped / programed on a dyno. A little better than the stock one and a lot better than without a chip. . You are lucky you have one

[longassname]

That is a factory ROM. I ordered one 5 or so years ago as it was the easiest way to get SVX ECU firmware at the time. Of course now you can use the ECUtuner interface to download the firmware off of any OBD1 Subaru.

That firmware is the basecode the ECUtune modifications are added to. It in itself doesn't offer any real performance enhancement--the ECUtune Stage1Av1 of course does.

[Conn SVX]

Do u know what the difference is between the 1.0V and the 1.5V? must be a lot better if the PO paid extra for it .

[longassname]

I'm not %100 sure what you are asking but I'm thinking you are asking the difference between the ECUtune Stage1Av1 and the ECUtune Stage1v5 although really bastardizing their names.

There is no 1.0 and no 1.5. There is the Stage 1 line of ECUtune products which aims to improve the performance of the SVX without requiring any other changes to the engine management system. The Stage 1 line started with the original Stage 1 which was quickly superceded in quick succession with new versions during development until we settled into Stage1v4 which was the stable product release for a good while.

A couple years later Stage1v4 was replaced with Stage1v5 which had further tweeked fuel and timing maps and the major addition of filling in the timing maps below 2500 RPMs to improve functioning with manual transmision swaps which were becoming popular.

Around that same time we were finding that some SVXs were performing a lot better than other SVXs. In particular very dramatic differences were being seen between cars running forced induction. Cars with the same hardware and same tuning were performing radically different. It took about a year but I did eventually figure out what was going on and solve the problem. The solution was what we now call the "Agressive" tuning. The SVX ECU uses two timing maps simultaneously which we call the primary and revision ignition timing maps respectively. The ECU starts with the primary timing map and then successively learns in additional timing according to knock sensor readings up to a maximum revision specified in the revision table. The primary table specifies a hearty amount of timing under no and light load but barely has enough timing to run under load. It is up to the learning function to learn in enough timing for the car to perform well. For reasons not fully known, some SVXs do this better than others.

The aggressive tuning we've switched to now pretty much forgoes the learning function. We put full performance timing in the primary ignition table and in most of tuning, the Stage1Av1 for instance, the revision table is pretty much empty. This change results in all cars running significantly more timing netting a performance increase and a mpg increase. The first version of the Stage 1 aggressive tuning has been in full release for about a year and in trials for about a year before that. It is v1 because it is the first version of the Stage 1 Aggressive tuning.

Other aggressive tunings for cars with futher engine management modifications have been in trial for about a year now. There's a Stage2Av1 for use with a z32 air flow meter and 370cc injectors. There's a Stage2Av1F for use with E85. There's a Stage2Av1Idle with modifications for big camshafts. There's a Stage3Av1 for use with dual intakes with twin SVX air flow meters and STI yellow top injectors. There's a UK-Stage1Av1.