Does anyone know why the 3.6L was chosen for the GT3 and not the 3.8L?

 

I'm not sure I completely understand your question (or which engines you are referring to) but the GT3 engine is derived from the GT1 racecar and share's the shame block with the Turbo and GT2. The engine has pretty much nothing in common with the base carrera engines (3.4, 3.6 and 3.8)...

 

Yea, they couldn't get their act together on the 3.8L.(not the same 3.8L used in the "S") That's what is currently used in the Cup cars but they were having problems with it. This from a Cup racer guy. The P spin is that the 3.6L revs higher

 

Because the 3.8L in the C2S/C4S is not a dry sump motor.
The 3.6L in the GT3 is. Basicaly a wet sump motor will eventually blow itself apart on a track - b/c the g forces will starve the motor of oil at race speeds.

 

Thanks, I also found some further info here: http://www.caranddriver.com/shortroa...nfo-page2.html