maf/turbo question
 

A friend of mine is selling a gt45 turbo for pretty cheap, and for now I still plan on using the MAF. My question is: Would changing the diameter of the intake pipe after the MAF effect anything? because the turbo inlet is like 4 inches.

No, it won't damage the AFM (MAF is generally associated with a completely different type of air flow meter), but if the turbo flows much more air than stock you're going to hit fuel cut much sooner on the stock AFM and stock injectors... keep that in mind. If the turbo wasn't already used in a Supra you may also want to do the math and see if it's going to have a lot of lag or if it's going to choke on the top end.