I've read and researched much about Porsche G50 transaxles. Its my understanding the only difference between a 5 speed non turbo and a 5 speed turbo box is the size of the ring and pinion and the strength of the case. Generally speaking though the price of a turbo box is twice that of the non turbo. Ultima cars does not recommend using an expensive turbo box and in fact said they use a stock G50/03 for their record breaking 0-100-0 runs. I read a thread about how stout 930 4 speed turbo boxes are. Non turbo 5 speed Porsche G50's, How hard they can be run?