[ChrisH]

Just to confuse you, why Porsche uses turbo and not supercharge then? ;-)

Good question, someone with an engineering background might be able to answer. I suspect it has something to do with size? Wouldn't a turbo add-on be smaller? Although with all the extra piping and intercooler, maybe not.

Porsche also uses the boxer type engine with horizontally opposed cylinders, perhaps that has something to do with it.

 

[ChrisH]

With the improvements in turbo technology (see BMW twin turbo, Porsche variable turbine geometry etc.) turbo lag and temp issues have been virtually eliminated.

Maybe Porsche has worked out the temp issues, but BMW still has some work to do in that department.

I don't see much room for a turbo or supercharger and I think adjusting the engine management and changing the electric motor-controlled intake and hydraulically adjusted exhaust valve timing seems a tall order for tuners

Agreed, there isn't a lot of room. Might need to put a large bump in the hood for the supercharger, or maybe just cut a hole and open it up to the outside for all to see and hear...