Forum » Off Topic Discussion » Rb25 forward facing plenum issues?

Rb25 forward facing plenum issues?

Off Topic Discussion

If it's not really about tuning or wiring. Then it belongs in here.

Page 1

There seems to be conflicting opinions on Forward facing plenums for RB25 , in particular an original Greddy plenum vs a stock Neo manifold cut and shut ? Anyone out there with some facts on the pros and cons?



I've never had the opportunity to do a direct back to back test with only that change, however I've tuned plenty of RB25s with stock and Greddy plenums and I've never had an issue with the Greddy plenum. I think the improved packaging of the Greddy plenum is probably its biggest advantage rather than an improvement in flow. There's also plenty of chinese knock off plenums which may or may not work as well as the genuine article so it can be a bit of a mine field.

Yeah thanks Andre, indeed a mine field - loads of conflicting advice , my research has unveiled that the NEO runners were changed by Nissan from the earlier 25 manifolds , I guess my driving factor for cut and shut or FFP(Greddy original) is twofold - shorting the intake piping to the intercooler and giving then engine a cleaner look, but am concerned that cut and shut manifold could cause leaning issues -has this been discussed on of your forums with success? - I appreciate that a lot also depends on what other upgrades one does overall , but just trying to get some realistic overview. I guess the only proof would be for me to a comparison on the dyno between the 2 , however not sure that a dyno would reveal leaning issues on any of the cylinders between the 2 options ? Thoughts?

Attached Files