difference between GM X-series turbos

[kapnklug]

Does anyone know the difference between the various (i guess series 1 thru 8 GM turbochargers? I have a series 3 from a 1993 6.5L, which I believe is the last year where the wastegate is mechanically controlled. But T_F_E seems to have made his own mechanical wastegate for his series 4 turbo. Is this possible with any of the turbos thru series 8, and if so are the newer units more efficient?

 

[T_F_E]

Yes, its easy to make a wastegate just weld a piece of all thread on to the actuator and use a spring. The gm-8 is the most efficient. gm-6 was used in vans and hummers and is center mount.

 

[kapnklug]

How do you choose which spring to use? Or perhaps a better question, what are the specs of the spring you're using?

 

[T_F_E]

Just pick a heavy, compression spring that you cant compress with your fingers