you have to remember that the WRX and Sti, even though the engine is horizontal, the banks for the engine has to go to ONE turbo. thats the reason why they have a single exhaust. I also think that it would have clearance issues under the chassis because its not designed for duals. If they made it into twin turbos then that would be something but it would have to use puny turbos.

 

Exactly. This pretty much sums it all up!

 

You never know, if they weren't turbo'd they might benefit. Just look at Porsche's.