At ~21:1, small injectors, and no intercooler the boost one can run is fairly limited anyway.
I've seen a max of 10-12 pounds on a factory turbo, but that's pushing it, after 10 the factory turbo doesn't do jacksh_t. The GM8 on my truck is set at 8 pounds with my manual wastegate; I've got an HX35 to swap in.
Allegedly you can run 15 pounds without lifting a head with an HX. I'd like to do an LB7 intercooler and head stud with an HX35/40 hybrid it to see how much I can get out of it then.
I question for you diesel guys out there, I am working on a 94 Sierra with 6.5 Diesel. Thinking of putting an upgraded turbo and an aftermarket wastegate, is this doable or do I have to stick with the original set up ? (that adjustable spring setup )
Please let me know,
TIA
Quadstar Tuning
Leroy Diesel
These two share a lot of the same products, but they do have individual components that only they carry. Zombie Solutions offers a Holset turbo conversion kit as well, that can be found on Ebay.
Most of your aftermarket wastegates are all going to be a spring and bolt type deal.
Without a tune you'll go into limp mode over 10 pounds, your truck being a 94 means you'd be able to get a muti-position tuner from Quadstar, a tune and a turbo swap will wake these trucks up immensely