^ And remove cats and air pump.

Or you could not pollute with your daily driver :\

$1000 FOR A S5T2 SWAP?? Girl, pounce on that like a tiger!!! If I wasn't already going 20B-REW in my S4, I'd grab that. If it has good compression, that's a steal.

www.rotaryresurrection.com has plenty of info on doing a S4 to S5 conversion. Also, you'll need a Mazdatrix T2-to-NA driveshaft if you're keeping the N/A rear end.

There are some minor wiring differences between S4 and S5 such as the ECU pinouts (in the shop manuals). But since you're getting the ECU and harness, it'd not be too difficult to repin the car's remaining ECU connector (S4 cars have 3, S5/FD has 4) to play nicely with the S5 ECU. Because the location is a PITA, what I'd personally do is get the connectors/pins and build an adapter patch harness. They're made by Tyco Electronics (www.te.com), whom will send you a free sample on request. If you're not too confident in wiring, send an email to Banzai Racing, as they make adapter harnesses to use an Apexi PowerFC in our cars. And last, this is gonna sound silly, but you should divorce the wipers from the rest of the engine harness when you pull it. Read my build thread "12 Days of Rotormas" for more info.

Ok, thanks guys.

Some specs on the engine. There is a little dent on the top of the ecu. Im not sure if its in good condition or not. The motor was ordered from an online engine importer. It has the 5speed still attached to it. It has a brand new clutch in the box still. The wiring harness looks cut in a couple spots. I looked at the ecu and I remember it having 4 slots i believe. So must be an S5.

Is the swap really that difficult to do? S4- S5? BTW, this motor has been in the rain of and on for a few months. Is that going to ruin the motor?

Any information you want to know about the swap is available on this forum. If the engine spins freely by hand and makes 6 even "sucks" and "hisses" it should run.