Ok, here's the deal. I'm either going with one of the stock twin hitachi turbochargers from an rx7 or the stock garrett from and older 300zx. I don't have the specs of either turbo but here is what I do know:
The hitachi has a larger compressor wheel than the garrett t3 but the garrett has a larger compressor housing. The garrett has a very slightly larger turbine and turbine housing than the hitachi. I mean VERY slightly larger wheel.
When you have the CHRA's side by side they look quite close in size. Do the larger housings on the garrett really outweigh the larger compressor wheel on the hitachi? I assume the hitachi would spool more quickly due to the smaller housings. Wouldn't a smaller compressor wheel in a larger housing be less efficient?
So what should it be?
A. Smaller housings with a larger compressor wheel
B. Larger housings with a VERY slightly larger turbine wheel.
The car is an 88 prelude with a b20a and I plan on boosting around 8psi. Help me out fellas!

 

The hitachi turbo has a 51mm turbine & 57mm compressor. Not sure about the garrett from the 300zx.

 

Anyone?

 

wtf, that sounds like a word problem in math :P

get the t3 off the z, i believe they were .63/.60

 

Well then someone needs to help me solve for BOOST!

 

solve what??

 

Solve for the best choice for street use running 8psi. I want to use the more efficient of the two turbos.

 

find the compressor maps of the 2 trubos then

 

both of them will be plenty effecient at 8 psi, that's not exactly an *** load of boost

 

I've been searching for them with no luck. I was hoping someone could supply info.