MR2 Owners Club

So my car is having a full rev 3 turbo rear clip conversion done.....at last.

I have everything I need including all the aftermarket bits and pieces to run a bit of extra power but I am confused with the ECU that came with the rear clip.

You will see on the plate of the ECU itself there is a sticker saying “Black Ten Racing Constructor” and I’ll get to that in a minute.

Now there is also the Jap writing as to be expected but there is also a SPEC and DATE part with numbers and letters written by hand next to this. They are far from clear so that’s the first possible issue.

Now if you look at the bottom of the ECU you will see a multicolored electrical ribbon coming out which attaches directly to the second pic which is of a black box that I can only presume is some sort of piggy back ECU of sorts? On the back of this black plastic box there are the remnants of double sided sticky pads so it’s been stuck in somewhere.

This black plastic box has no branding or real coding of any sort, just some Jap lettering with some hand written writing next to it. I did think that “Black Ten” must be the maker and it tuner of this supposed piggy back ECU but so far I’ve drawn complete blanks.

Any ideas or suggestions greatfully appreciates indeed.

On the black box:

SW20 - should be obvious.
DA1 - their model number for whatever is in there.
96.3.6 - date the ECU was modified.

The text on the ECU essentially a warning stating the ECU is not designed for road use, and they are not responsible for any engine damage that occurs while using the ECU, and gives a return period if it doesn't work well with the car.

Should you use it? Well, that's up to you. Presumably it was working OK with the engine before, but you don't know what fuelling, timing or boost targets it is running. You have no way of tuning it. Considering it was done in 1996, you cannot even be sure that it's running the same parts as it was tuned for.

Mystery ECU modification... hmmm, that sounds like a tough call.

I'd start by opening up the ECU and seeing what's inside. Might help make a call on it

Running a mystery ECU with mods added is always going to be a gamble. You might get lucky and it works fine with your set-up but most likely it will be more trouble than its worth. I'd investigate getting either a stock ECU or going aftermarket. Both may require additional wiring to remove previous loom mods.

The EMS cost has decreased and functionality has increased 10 fold in the past few years. Even a basic PNP will get you up and running with full capacity to tune your engine. In addition, you will be able to eliminate some proposed equipment like boost control or fuel cut as it can be handled by a full EMS with further capacity to expand as the need increases.

jim