Question: Nismo 'VQ' (VQHR) Engines
 

Are the Nismo engines any different from the base or sport model Z engines?

I understand the tunes are different to extract a bit more power. But, is this only because the Nismo has an improved exhaust that's less restrictive?

Are the cams any different? Valves any lighter?

Is any part of the VQ (VQHR) engine forged? Crank?

Thanks

Same engine. Different tune. Different exhaust. These give you about 17 additional hp. Nismo also has some extra suspension bits (dampers and such).

Same engine. The horse power gains are from the CBE. The difference with the tune with the stock is negligible.