Originally Posted by welderz

I won't say it's impossible but it's highly unlikely. The vq37vhr is putting out almost 90 horsepower per liter stock. LS motors don't come anywhere near that from the factory therefore they have more room to easily add horsepower. This is the biggest limiting factor in modifying the 370z for n/a. The vq35 is hard to even get to 300rwhp with full boltons and cams. The vq37hr has a definite advantage with vvel but no one knows yet what it's capable of I'm very optomistic about it. I don't know yet but I think 340rwhp is the limit with full boltons and a tune. High compression pistons won't give too much of a return considering your starting at 11-1 compression ratio and you will need race gas and engine longevity will be drastically cut. The heads already flow extremely well so a port and polish will help but results won't be drastic. If your shooting for 400rwhp n/a it's going to be very expensive and your engine won't last the life of the vehicle. I know you want to go n/a but FI is the better way to go. Many 350z's have been running for several years with superchargers and turbochargers putting down 400rwhp on the stock block. And the vq37vhr has been torn down and inspected by several shops and it has a proven stronger bottom end so I think it might even last the life of the vehicle at 400rwhp on the stock block. The cosworth engine is a bad benchmark to go by that's a race engine that would cost a lot to reproduce. Just so you know I'm a member over at my 350z so I have some background in the vq motors.

Originally Posted by KingDavid

Click the link. ~350whp.

Final Dyno Numbers - MY350Z.COM Forums

If they can make ~350whp (mustang dyno, low reading) on an Intake, header and full exhaust and a COBB AP tune on a vq37vhr(the motor in the 370Z/G37)...I think it's possible to hit ~400 with some nitrous...