GTR Engine outputs

[mogg]

I've come across various power and torque outputs from GTR's. Is this simply down to what the initial buyer / builder wants, I've seen outputs from 375bhp to 537bhp.
Following on from this, if I had a 6.7L Chevvy producing 450bhp, how easy / expensive is it to increase to 540 bhp ?

Thanks

[kevinday]

The engine power is down to the initial car builder and what they specify. Most people opt for the Chevy small block engine, with power outputs from 350 to 680 bhp, depending on wallet etc. Others may opt for different engines such as BMW.

[steve_D]

mogg said:

I've come across various power and torque outputs from GTR's. Is this simply down to what the initial buyer / builder wants, I've seen outputs from 375bhp to 537bhp. Following on from this, if I had a 6.7L Chevvy producing 450bhp, how easy / expensive is it to increase to 540 bhp ? Thanks

Too many variables. How did the engine come to be a 407ci? Has it already got performance parts? When do you want the extra power? NOS will give you what you want but only in short bursts.

Steve

[jschwartz]

407ci is a production 400 ci small block chevy bored .030" oversize which is about 406.7 ci
We recently built one that made 477 hp with iron truck (vortec) heads. Bumping the engine we did to 525+ would require better heads like AFR210's and maybe a bit more camshaft.
Jeff S