pmr147

interested in purchasing the possum link on my 94 wrx need a few answers
does it replace the old ecu
what extra performance will i get
is it worth getting or go for a different ecu upgrade

pat

Howdy!

Yes it does replace the old ECU; you remove the old one from the car, remove it from the case and install the Possum in the same case, then refit to car, it's pretty much "invisible" in that sense.

Power depends on how brave you are But seriously, you will be able to get quite a bit more out of your engine; without upgrading the injectors I'de suggest you stick to about 300BHP, but in order to get that you will need to run somewhat more boost. This requires a replacement MAP sensor on your car; the older cars (mine included, OK ? ) had a MAP sensor that was only good to about 16 PSI. What you will need is a Weber-Marelli 250kPa sensor; the Link has calibrations for both the Subaru and the Weber sensor, so it's a case of swapping it over and changing one setting on the Possum, then you can resolve up to 1.5 bar (that's not to say running 1.5 bar is a good idea, but it IS a good idea that the ECU should know that you are running more than 16 PSI )

FWIW, with bigger injectors (I went for 480cc units, the standard ones of this era were 380cc which run out of puff at about 300BHP) I was able to get about 330BHP and 310lb/ft out of an STi II engine running about 1.35 bar (about 20PSI). This made the car very quick indeed

What you will need is a KnockLink and a LambdaLink so you can keep an eye on the engine when you're setting up the Link (or, if you don't want to do it yourself, I can thoroughly recommend BR Developments, they will supply, fit and map a Linkl or MoTeC for you). At any rate, if you do go for an after market ECU then it IS worth while having the KnockLink and LambdaLink anyway, even if you are not mapping....

Hope this helps (a bit)

Cheers,

Pat.