1998 turbo ecu swap
 

Hi all been a while since my last visit (no longer have the 1998 wagon, but going to look at a saloon tomorrow, also a 98)

had a little thought occur to me tonight while I was out for a random drive, I have read threads to the death that say the 1998 ecu is not mappable and needs replaced, but people are quoting about 700+vat for an aftermarket ecu, I was just wondering if it would be possible to take an ecu from eiter a pre or post 98 model ( 1 which is mappable) and drop that in the car.

and if it wouldn't work can someone please explain why not?

just a point of curiosity that I cant find an answer too in any threads iv searched lol

easiest way I can tell to check is if the coil pack is in the centre of the engine it's a MY98 and if the pack is off centre to the right then it's a MY99, other differences I have noticed is the steering wheel on the MY98 has the momo badge in plain black.also front bumper but people change these.

my car is registered 02/10/1998 and is a MY98 but can be a MY99 in 1998

MY98/97 can't be mapped and is a new ecu/daughter board job.

I might be selling my ecu which is also not mappable and needs programming at a cost of roughly £25? but is a pro drive ecu which is modified by prodrive, with a decat exhaust and panel filter I would estimate 240 - 260bhp and once programmed is plug and play no mapping needed.

I've an ecu for sale too.
It's had the ecutek licence paid on it so it will just need mapping to suit yr car

£130 delivered

Thanks but I'm not actually looking to buy a new ecu just now I dont even have a subaru just now. But does anyone know the answer to my question? Can you take a stock ecu from another year of impreza and put it in a 98? And if not can you explain why?

Nope you can not.
Most of the sensors are different, so a ECU from a different version can not understand the signals coming from those.Also for example the idle control uses a different system (with more wires) on 99-2000 models then is uses on 97-98 models.

The My99-2000 ECU has much more connecting pins then a My97-98, though they are both 3 plug ECU's one has about 60 pins in total, the other has in excess of 90.

So a swap will be far from straightforward, and will involve a lot of work.

For example the intak manifold has to be swapped (for the idle control valve), but that only fits with the heads of the same year, so those have to be swapped as well, causing problems with compression ratio and squish etc.

So the costs of making a later model (mappable) stock ECU work on a earlier model are far greater then buying a mappable plug & play ECU (ESL/Simtek/Alcatek/Syvecs etc) for the earlier model.

Thank you thats the sort of info I was looking for, very informative :)