Thank you for those in this forum that helped me.

I took more or less 1 hour to change my ECU with much patience and care.
I was a little afraid about having some problem, but everything went fine.
For LHD Evolution 7 the Sport ECU (export version) part number is RA578511P1. It is 100% plug and play.
Started the car, everything was as before. Took for a ride and felt an improvement in low end torque, not much but is there. The car revs faster and easier with light throttle pressure. Mid range is A LOT smoother and faster, high end power I guess is the same as I'm with my stock exhaust yet.
The only thing I didn't like is that the fan operate much more time and in a short period of time to keep the engine cooler. For this reason I suspect that the Ralliart low temp thermostat is a must with this ECU.

I recommend this mod

More comments after this weekend...

 

wouldnt that ecu only really change fuel maps? unless it was cheap I don't see how that ecu would be any better than getting a flash?

 

I suspect that this isn't plug and play for the US Evo 8. I believe that you need to get the keys coded back in by the dealer. After that, it might work for us. Anyone else have any input?

Glad that it is working great for you k270.

 

I guess Ralliart didn't make any ECU for EVo 8 yet and be carefull because there are differences between EVO 8 JDM and US models. Maybe in the near future they make one special for US model, I hope so.
This ECU changes the air/fuel ratio, timming, waste gate operation, fan operation, raise the rev limiter and allow you to use 1.55bar withou fuel cut. It alone gives you 20hp and 14lbs of torque. I think the HKS and Ralliart are similar: http://www.kansaiss.co.jp/parts/kcm10.htm