the smaller it is, the faster it has to spin to create a certain amount of boost. the larger turbos dont have to spin as fast, and thus creat less heat.

 

one other thing you need to consider..
using a small turbo with a small turbine housing and wheel will create more backpressure so... boost will need to be higher to get the same horsepower
simple example, take a good old V8,add a super charger to it.. you end up with lets say 10 psi of boost and 500hp
now take the exact same car, put good headers on it and a good exhaust... woooo... what happened you only have 8 psi of boost now but your making 540hp

it's the reason why past some HP you don't have much choice to use larger turbine housing and wheel.. you do get more lag but end up with more power

 

so any answers to my fmu vs. fpr question? or estimates on how high i can safely boost with the turbo I have

I plan on 7 psi as of now, Im 99% positive thats safe, but for some reason I thought I had seen someone running 8 in the past with a similar setup.

 

bump?? someone has to have an answer fing02.gif