American Revolution

iTrader: (4)

whats up guys need some help on what size injectors i need for my build.well im running a forged 383 with 317 heads(for knaw),victor jr. with an aarons elbow and a edelbrock tb,epp blower cam,a gt4788 turbo with the racecover, and behind that is a 4l80e.so my question is what size injectors do you guys recommend me.would appreciate any help thanks.

ZL1Killa

iTrader: (17)

what is the cold side and hot side sizes on that turbo?

what compression? how much boost and what power do you expect to make?

I'm going to have to guess 90# + injectors... we kind of need to know a power level. the exact size of the turbo will help

American Revolution

iTrader: (4)

the turbo is gt4788 with .96ar.planning on doing around 16 to 18lbs of boost.my goal in power would be aroun 750+ whp.

ZL1Killa

iTrader: (17)

i made 650hp and 680tq at 71% duty cycle on 79.6LB/hr injectors on a 5.7 L. I would guess you would want somewhere around the 96# range.

I understand the turbo is a gt4788, but the cold and hot "turbines" have a particular size, and per that size and housing you have a certain airflow, its essentially a centrifugal blower, we have two huge ones that feed gas to our shaft furnace. that particular GT4788 i think according to a google search:
Turbine
-Wheel: 92.7mm w/ 82 trim
-Housing: 0.96, 1.08, 1.23, 1.39 A/R

Compressor
-Wheel: 117.6mm exd./88.0mm ind w/ 56 trim
-Housing: 0.69 A/R

are you building a front mount or rear mount? To make 750whp that is rather big..you will have plenty of room for 900hp range.

race car or street car or half and half? If you want a quick spooling setup, I would step a size down to say around a 80mm ~ 86mm. I would ask advice from other turbo people and look at different peoples builds on here...that honestly just seems overkill to me for the power you want to make