I'm a roots guy and this is my first turbo go. Been looking at 75, 78 , 80 compressors but didn't know if a 1.15 , 1.35 a/r is to big for twins on a 496 with a 88mm turbine ...
Looking at 15-20 psi boost . Please throw me some ball parks if you can . Thanks

 

How much power does the engine make NA, what is your overall power goal, Drag car?

 

850 HP n/a ......looking for 1500-1700 ....mud drags and it will be coming off on a trans brake

 

Not a great deal of difference between a 1.15 and 1.35 on the same turbine wheel, especially off a transbrake. What rpm range? What turbo?

 

Ok...as I said first turbo deal ..4500-8000 rpm range .
Looking at a pair of b/w s475 or a s480 with a 88/96 turbine with a 1.32ar

 

And that's on a divided t6

 

You'll be fine with either. With an 80 mm you'll have room to grow, you have plenty of load between the trans brake and the mud. 75mm is a few hundred cheaper.

 

The 75's will be pretty much maxed out compressor wise. If your 850 na hp is legit I'd go 480s with the 1.32's especially on a race only application.