Obviously your mods and the mods of the people I know who have done before and afters will differ. 80pounds isn't going to be every car, but it will be a lot. No you will not make 400WHP NA. The most I have seen on a dyno is 340ish with 320-330 being obtainable. (LTHs, Full 2.5"+dual exhaust, admin 3" intakes with Ported upper and lower from 370z, Light weight Wheels)

Yes the difference is VERY pronounced, You do give up a bit on the low end.

So From my understanding on what I have seen with dynos, is the HR manifold is tuned for a flat TQ band. so it gets great low end, but the sacrifice is while it's still making HP up to redline its losing TQ SUPER fast past 5800.

The VHR Mani has shorter runners so you lose the low end but gain HP on the top, On the 370z this is countered by the VVEL, we dont have VVEL so you will give up some low end, it's not much but around 20 FT pounds at 2k (it is noticeable), but the TQ curve for us stays flat from 3500-redline. I have not seen pulls past 7500 but every pull I have seen Peak HP was near redline and the TQ was holding.

I'm currently looking to buy this set up and try my own hand at porting. It would be interesting to see the gains with the VHR intake mani's but fully port matched from TBS to the heads.

 

Yes.

They're Tokyo Time Attack TE37s. 19x10.5 +22 (x4)
Front 255/35 , Rear 285/35

 

Clean Z.

 

 

Thank you, davidmrqz3!