So many factors involved here first that comes to my mind engine size and desired power or planed boost level Also what do the heads flow? First red flag I see is large frame smaller flange, I would bump to T6, but what is the inlet pipe size. I would also assume non twin scroll?
You could always log it. Nothing more then another bung on the pipe. Even EGT help see how the turbo is handling things.
I blew out my flex joint with a smaller turbo. But we made the most power so far with it. It would spool right up like a champ.

 

I am not one to give you an absolute black and white expert opinion, but I can say with a high degree of confidence that changing the diameter of the wheel will have a much larger impact on drive pressure at this point than the a/r of the housing.

Your turbine exducer is only 74mm and the outer diameter of the wheel is 83mm. Increasing the size of the turbine wheel is kind of like going to a stroker or busting out the breaker bar. You need less input to get things to move. On the flip side I have heard that they are less happy at extreme RPM.

I think as a general rule it has been shown that the LS motors that run relatively low boost (even the "high boost" guys arent really "high boost" in the world of boost) are capable of a TON more power with a larger turbine.

I'd couple that 80mm compressor with a 92 or 96mm turbine wheel depending on how you intend to use it.

 

If you like the math I really like this guys books and especially this one:

 

Aint that the truth. Imagine our heads with the 58-65lbs the 2JZ guys use? Drool worthy. Not sure they make a sub $20k transmission that would survive that

 

Thank you guys for all the replys. I think ill buy the book and work some math. Other than than, I am curious about extending turbine capability with some head porting (katech's work looks well designed for my 317's) and minimizing backpressure after turbo (Kyle is building me 4in dp). Seems like fun to run a rear suburban evap core in a water tank to Keep Iat's down......Now I want to know parasitic loss on A/C compressor. Losing my mind......

 

I don't know if you mean parasitic loss as far as reducing mpg, or as far as power output goes. Don't forget, the compressor shuts off at some larger throttle opening, I forgot the %. If the reservoir is big enough, the cold water (glycol mix) will be enough during a WOT pull. I hope you do it.

 

The "killer chiller" setup has been done a lot. It works well, just have to give it time to cool the water tank down. The AC compressor is not parasitic loss, it is a work consuming device, generally < 1hp.

Honestly the turbo and engine size dominate every aspect of the system, so unless you are looking for every last bit of something I wouldnt bother with head work. Large the DP the better, and also the shorter the better.

 

 

Best to have the DP same size(min) larger(best) also as stated short. Fender exit and no muffler. However I will say watch your O2 mount location as it may read open air of throttle. Worry more about WG location and size as well as bov. The big boy have speed sensors on there turbos.

What heads and what size motor? there are super cheap LS head available.