R32 GTR intake manifold upgrade,worth it on a stock-ish engine?
running a mostly stock rb26dett with aftermarket turbos (garrett 2860s), fmic, and a haltech ecu. currently making about 350kw at the hubs. thinking about an aftermarket intake manifold (plazmaman or hypertune) but theyre $2500+. is the factory intake manifold actually a restriction at this power level or should i spend the money elsewhere?
at 350kw the factory manifold is starting to be a restriction but its not the biggest one. the factory fuel rail and injectors are more of a bottleneck. if youre already on bigger injectors and fuel rail then yes the manifold is the next step. the plazmaman 6-into-1 design flows significantly better than the factory plenum. but if youre still on factory fuel system, spend the $2500 on injectors and fuel rail first.
Dyno results I've seen from the GT-R community show about 15-20kw gain from a Plazmaman manifold at the 350kw level. That's a lot of money per kilowatt. But the throttle response improvement is significant and hard to quantify on a dyno. If the car feels flat on tip-in the manifold helps with that regardless of peak power numbers.