Hi guys, I have lurked here for a long time, and I am one of the original homemadeturbo.com members from back in 03/04 when the site was legit. A formal introduction will be posted in the noob section but I have an urgent question. I am building a forged y8, and today I bought a new precision
3431E aka sc34 57mm/57mm and I got it with the .63 A/R hotside. This is my first D build ( have done a few B motors) And i felt like the .63 A/R was the no brainer choice as I am shooting for HIGH 300's or hopefully 400+ whp (stock head btw) But after doing some reading around I'm a bit scared I should have gone .48 A/R because of lag time and streetability for a fun power band....Should I keep the .63 or switch a .48???? I litterally have like one day to change my mind before it gets shipped out....please help!

 

geez guys thanks for the insight.....I'm worried the .63 will drop out of boost when I shift with the y8 trans. but not sure if the .48 will get me to 400+ whp

 

If you're building the motor, why not go for larger displacement? 1.8, 1.9l?

then the larger hotside would be better.