GN T3 or T3/T4 hybrid?

[66Sprint6]

Okedokee, lol
Ive decided to ditch the T04b turbo with .96A/R and look for a better turbo for my needs (daily driving seeing strip duty every week or two). Now I have a decision to make. Im probably going to go with a Grand National T3 because Dan (inportkiller) is using one very succesfully but I have seen some T3/T4 turbos going that look good. Which one sounds best?

Now for the dumb question...
Would or could you make more power at the same boost level, say 10psi with a bigger turbo or is 10psi the same no matter what? Thanks guys!
Matt

 

[StrangeRanger]

10 PSI is 10 PSI no matter how generated. But to get a tubro to generate 10 PSI on your specific engine and to spool up quickly enough to minimize throttle lag without spooling up so fast that it surges, that is the trick.

 

[66Sprint6]

Thats what I thought...but sometimes my thoughts arent whats true, lol. Thanks for clearing that up. Now another thing I want to learn is how to read compressor maps. Everyone talks about compressor maps but I have no idea what they mean. Anyone wanna help me out?
Matt

 

[Anonymous]

A flow map is nothing more than an X, Y chart. The lines in the flow map go around in an "abstract oval" shape and encompass levels of efficiency. Ideally, you want to try and be in the highest level of efficiency as your plot different flow and pressure rates.

First you have to calculate flow in cfm and convert it into lbs/min. This is the "x" variable. (cid x maximum RPM x .5 x Volumetric Efficiency %)/1728 for N/A flowrate in cfm. Now multiply your cfm figure by a density value of 0.069 and you will get your flow in lbs per hour.

Then figure your boost ratio. This is the "y" variable. Pressure ratio = (atmpheric pressure + Boost)/atm. Take 15 psi (the max you would probably ever run) Pressure ratio = (14.7+15)/14.7 = 2.02

15 psi of boost equates to a pressure ratio of 2.02 10 psi would be a 1.68 pressure ratio.

A good example: A log headed 200 with a 70% volumetric efficiency, a 5500 maximum rpm will flow about 30 lbs/min.

Now you can take your two vaiables (2.02 pressure ratio, and 30lbs/min flowrate) and start plotting them into different compressor maps and seeing what efficiency level you are landing in.

 

[66Sprint6]

Thanks alot inliner!!!
I believe I have found the turbo Im goin with, but I cant find any compressor maps for it. It is a GNX turbo, which I hear is different than a GN turbo but only in the material it is made. Anyone have any other info on this turbo? Thanks guys!!!
Matt