Wastegate mounting on hybrid turbo
A lot of people are considering running a hybrid T3/T4 turbo and that always brings up the question- How do you control the boost?
As you can see in the first picture the factory wastegate canister is attached to the front of the compressor housing.
No such provision here!
There are three ways around the problem-
1) Weld bosses on the front of new housing. Two problems with that, one is that the hybrid housings are larger and the angle will be wrong and difficult but not impossible to make work. Two, if you need to rotate the housing in the future you will have to relocate the bosses again!
2) External wastage (I.E. Deltagate) expensive and your manifold or header has to be configured for this provision of course.
3) Take a 84-87 Turbo I wastegate can, remove the "can" by drilling out the spot welds, attach the bracket (modify if need be to get correct angle) to the back of the compressor housing. Drill two holes in the bracket to mount Turbonetics "large can" wastegate can (PN 30314) or something similar and your all set. Minor alterations of the bracket may be needed. I set the arm tension so that 9 psi is needed to just get the wastegate to start opening, stock 89 TII or S-60 is 6 psi.
This affects Minimum Obtainable Boost of course, in my case that's 22 psi!
See pictures below.
Here you can see the modified bracket and the single bolt holding onto the compressor cover.
Front view
Another view
For my application this is attached to the motor using a Carb/TBI exhaust manifold with a turbo mounting flange welded to it. The turbo is very close to the firewall and turbo exhaust outlet clearance is tight. Also notice the 90 degree bends needed to get the compressor discharge going in the needed direction.
If your planning on running a hybrid with the stock exhaust manifold I'm told you will have to clearence the head for the larger compressor housing.