There is a company that does rear mounted turbo setups that are really nice. They had one on a GTO that they ran in a top speed shootout that made over 600whp. With a small/midsized turbo on a large displacement V8 there is very very little lag. But the benefits are generally a charge temp about 50 -100 degrees cooler by the time it reaches the motor. The temperature drop far outweighs the losses from the remote mount. If I had a late model V8 and was looking at making some big power I would definately be running a remote mount setup.