Rb25 Neo Twin Turbo Manifold

[lcxu105]

Hi everyone. Was wondering if you can get twin turbo manifold for rb 25 neo engine and if so where from. Was thinking about putting twins on my neo to run smaller turbos to get boost on earlier and be able to have cooler intake charge as a result. Thinking of twin 32 factory turbos running 12 psi each. Will this give me 12psi boost or 24 psi. Not fully undersanding how it works. Correct me if I'm wrong? Thanks

[niZmO_Man]

2x 12psi = 24psi

You'll have to go custom manifolds to get what you want.

Or you can save a heap of money and go for a stock sized turbo, exhaust and tune for the same/better result.

[Ben C34]

Seriously not worth the effort.

[34GeeTeeTee]

Look up previous results on here from Dori34 etc.... Lots of pipes, lots of work, lots of monies and lots of lagz

[GTSBoy]

There is no reason to put twin turbos on an in-line engine shorter than 12 cylinders in the modern world.

[34GeeTeeTee]

There is no reason to put twin turbos on an in-line engine shorter than 12 cylinders in the modern world.

So what you are saying is the OP needs a twin engine manifold?

[zebra]

Hi everyone. Was wondering if you can get twin turbo manifold for rb 25 neo engine and if so where from. Was thinking about putting twins on my neo to run smaller turbos to get boost on earlier and be able to have cooler intake charge as a result. Thinking of twin 32 factory turbos running 12 psi each. Will this give me 12psi boost or 24 psi. Not fully undersanding how it works. Correct me if I'm wrong? Thanks

12psi is 12 psi

doesnt matter if you had 135 turbos running 12 psi

its still 12 psi

[lcxu105]

So what you are saying is I'm better off with a hi mount manifold exturnal gate and say a 3076 or 30 82. Want to have more down low and limit to 6500rpm gear change. Engine is in a lc torana that weighs in at 1000kgs and runs 336.1 diff gears. Current set up full boost is at 3800rpm. Want to bribg it down to around 28-3000rpm. With the exturnal gate I can keep the current 20psi boost and eliminate the current inturnal gate drop off back to 15 psi.

[Ben C34]

Rb2530

[scotty nm35]

^^ or smaller (stock sized) turbo.

[XRATED]

If you can buy the whole hot side off a later model rb26 cheap, then have at it.... shure why not? if you modify the stock manifolds everything else will bolt up nearly factory (a couple of minor mods for oil and water lines).

Or you could save yourself alot of time and money and get a hypergear highflow/stock replacmnent turbo.

[Simon-S14]

just change the diff gear ratio, problem solved

and why limit it to 6500?

[bigmikespec]

2x 12psi = 24psi

I hope to Christ there is a carcastic undertone to that...

[KiwiRS4T]

I didn't see anyone say you should get a high mount manifold. What's your power goal? Are you sure its the IG that's causing the boost drop or maybe its just your turbo running out of puff.

[Dose Pipe Sutututu]

why not just save the cash and do a proper twin scroll setup? that would be a smarter solution

[GTSBoy]

The OP has full boost by 3800 rpm. This is equivalent to Hypergear OP6 highflow response. That (and 20 psi) is good for about 300 or more rwkW. If this turbo is not an HG OP6 highflow, then he would get more power with a one. If it is an HG highflow, then he would get more response with a 21U highflow (about 300 rpm) and a bit less power.

Or, he could consider speaking to Stao about a concept for an OP6 or 21U highflow that will allow 20ish psi of boost but come on strong with full boost by 3000rpm. ie, something that will trade 500 rpm of response for a bit less power. I'm sure Stao could find other buyers for a ~250rwkW RB25 turbo with very fast response. So far all his work has been towards retaining approximately the same response and moving the power upwards.

[lcxu105]

Looking for around 350kw@wheels. The hi mount manifold will help spool up and current turbo is an op6 hi flow with steel wheel from Stao. So it shouldn't be running out of puff I would think. Exhaust system is 3 inch from turbo to diff 100 cel cat and straight through muffler.

[scotty nm35]

350wkw on by 2800? You need a 3.3L stroker by the sounds of it.

[scotty nm35]

The hi mount manifold will help spool up

How?

External gate can help though.

[GTSBoy]

Yup, I'm with him ^. You're not going to get the power you're after AND the response you're after, even with twins. You already have close to the most responsive sort of turbo you can get and it would actually be pushing it to make it to your power target anyway.

Twins actually aren't that much of an advantage for response - most of it was marketing back in the 80s when the GTR and the Supras/Soarers were being readied for sale. Twins make sense on V engines to cut down on plumbing. They make the plumbing awful on in-line 6s.

If you do not mind a lot of work, a lot of nasty plumbing and a crowded engine bay, then what you really need to realise your goals is a twincharger setup. That would amount to a decent little supercharger blowing into the inlet of a turbo. The turbo needs to be special - a small compressor but a large turbine section. The two compressors multiply the boost you get. So if the blower is set to give 8 psi at its outlet and the turbo is inherently able to make about 8 psi, then the multiplying effect will give you about 20 psi after the turbo (instead of just adding 8 + 8 and getting 16). It is dead easy to make big arse boost, big arse power and near instant boost response this way. Well, easy except for the work and the plumbing.

Edited June 6, 2014 by GTSBoy