Rb26 Low-mount Manifolds

[R31Nismoid]

After peoples thoughts on RB26 Low-Mount manifolds. Im looking at using something as opposed to 100% stock items.

Im sure there is gains to be had there in conjunction with a various head work inclu:

Mild porting, Trust split dumps, cam gears (at this stage not going to use cams)

All the little things are going to add up hopefully to something a little better than expected

I'll be using GT-SS turbos so around the 300-330rwkw mark.

Have people tried extru honed stock manifolds?

Ive got a little info already about UAS ones with the bench/flow testing done there, which seems to yield a gain on the bench, but how much as tested on a car... im not sure.

Alternatively, have people tried Aftermarket ones... ie the Tomei ones as an example.

They look the goods going from thier larger dimensions, but for a positivbe or negative effect?

The aim is to bring boost on as early as possible and make the new setup as responsive it can be

I'm just trying to work out which is better justified $$$ wise.

Stockers honed - $600

Tomei (or otherwise) - $1100

Any thoughts or products that havent lasted the distance that one should be wary of?

-ash

[kwazza11]

just my 2c about the tomei or larger diameter low mounts, if you want the best response then keep the runner diameter small in order to keep the gas vilocity high. faster the gas travels the harder it hits the turbine. but then you loose out on flow at the top end... sort of a catch 22.

[SLY33]

very true kwazza.. how much larger diameter are we talking?

how about the HKS stainless ones? im thinking of going an HKS stainless balance pipe type. Not cheap tho! could always go the UAS ones and weld my own pipe between them?

so whats the gist of the aftermarket stainless mani's? is it top end power more than response? or are they meant to have good response too?

[m&m]

HPI make some great low mount manifolds.I have used their SR20 manifold on my S15 and it made 20rwkw over stock at 4000rpm,7rwkw up top.I will be upgrading to the HPI units as soon as I can get Gerald to fit them cheaply lol

[R31Nismoid]

Yeah, it seems to be a grey area not really dabbled in "hugely"

but having it larger, would that allow more to flow, decreasing backpressure and making it more responsive?

Hmm.. seems a fine line. Not a lot of info about A/M ones unfortunately

[StageZilla]

i had hks low mount manifolds on mine with the highflow stock turbos, but unfortunately i did a few mods and changes so i couldnt tell the difference (turbos were stockies originally) in power/response. but i cant see any big differences in the different aftermarket brands, its a simple 3 into 1, which is str8 as, not like single turbo spagetti manifolds that can be good design or total shit.

the hks ones looked heaps better flow and smoothness internally than the stock ones thats for sure

i got em cheap second hand though, so i dont think id rush out and spend the $1500 or whatever they are worth new in a hurry B)

sorry it wasnt much help....

Brad

[R31Nismoid]

mm.. $1500 i cant justify.

$1100 i could...

Some places have what probably are china ones for $600-$700.

risky depending on the materials and grade/thickness of the stainless.

Hmmm... need to do more readings i do. Also i think the stocker (or non stainless) would keep temps down a tad also