To start off with i have a custom backdoor intercooler setup good for 400whp but im wan to retune my sleeved ls vtec on high boost and shoot for 580-650whp Whats the dangers if i keep my intercooler? or will it just be flat out to restrcitive and kill my power?

 

If you like Supercharger IAT's and a higher chance of Detonation then run the small intercooler, they have HP ratings for a reason.

 

You wont know that until you start getting up there in boost/power. DATALOG!!!

 

x2

 

If you have already invested all that money into the motor why not spend the couple of extra hundred for a quality intercooler. Otherwise your constantly risking detonation.

 

Yea most of the time a core is under rated but not by 250 hp. I would def upgrade and avoid problems of detonation. I doubt you'll be able to reach those 600+ with that intercooler and no meth or such. IAT's are gonna be pass any tuners/engines like imo.