It the garrett gt42 turbo too big for a 347ci motor? I'm looking to do a single set up on my car with 9.5-1 compression. Only looking to boost 10psi and want it to run on pump gas. If i have to I'll to a alky set up. Of course there is going to be a good front mount intercooler.

I'm just wondering if that turbo is too big for that low of boost.

 

i know i blew my head gaskets with 9.5 and 6 psi - probably the tune but with 10 psi and 9.5 you will be way over the effective comp ratio probably past way past the 14 to 1

 

With good gas you'll be fine with that much boost on 9.5:1. Maybe use some alcohol injection if you get really high EGT's from backing out the timing a lot. To be honest i'd be more worried about your block staying together from sheer power rather than detonation.

 

This is a ls1 motor, it should hold 1000hp. Only thing you have to change in the motor is pistons and rods for them to live.

 

I'm not really worried about the motor living, but rather if the gt42 turbo will be ok at 10psi with a 347???? Will i need to boost it higher in order to keep out of surge?

 

Gotchya. Go check out the compressor maps for the GT42 on the web, they can tell you if it will be surging or not.

 

http://www.inductionmotorsports.com/ hey this site has an excellent calculator to figure out what a good combo on pump gas would be