I bought a STS kit a while back ago and it came with a Garrett 60-1 then I upgraded to a GT-70 then finally to a GT-76. That is what STS calls them but Garrett has a different naming system for there turbos. I have measured it and it looks like a 76 with a P-trim. The measurements were Compressor wheel inducer/exducer(76.47/102.29) and turbine wheel inducer/exducer(74.32/64.69).

I have a Silverado with a 408 and want to make at least 600rwhp. I now have a Trick low-front mount but want to use the turbo I already have. When trying to find out what turbo I had I posted pics and info on LS1 and they said the turbo was too small. I wanted to get your opinion since this is a truck forum and many have similar turbos.

Is this turbo to small to make 600-700rwhp? If so, what would you recommend?

 

That turbo should make that kinda power. Biggest restriction would be that P-trim turbine. What a/r is the hot side?

 

It is currently a .81 A/R but a buddy of mine has a 1.0x that is willing to swap or sell.

 

What do you think the hp limit is with it? Should I just upgrade to something bigger before I put it on?

 

I would put that bigger housing on it and put it on the truck and see how you like it before throwing down cash on a new turbo. You can make a lot of power with a 76mm turbo.

 

Mine made 620whp/640 tq, and I still need to get the tuning finished up. It's pretty low on timing, and I think I can turn it up a psi or two.

 

x2, I would bet you make it over the 600 mark fairly easy with that turbo on a 408, even if it could be a little bigger.

 

I just took the turbo off the Hemi and it too has the same turbo but with a .96 A/R on the hot side. The Hemi is rear mounted though so would that make any difference?

If it doesn't work I am thinking of just using both turbos on the Silverado and getting a new/bigger(88mm) turbo for the Hemi.

The guys on tech said this turbo would choke my engine because the turbine side is too small which will create to much back pressure. But STS rated them at up to 1000 crank hp.