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whys that???

Because if you running a twin scroll turbo (and I'm not sure whether the 4088 is) you will have better pulse energing by keeping the ex gasses separate up to the ex wheel by having twin gates.

Otherwise a single gate will allow pulse energy to "crossover" from one collector to the other prior to the ex wheel. If you look at the full-race twin scroll mani's they all have twin gates for this reason. The original twin scroll sr mani's were previously twin gate tubes merging to a single gate but are now also available in twin gate.

Edited by juggernaut1
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Because if you running a twin scroll turbo (and I'm not sure whether the 4088 is) you will have better pulse energing by keeping the ex gasses separate up to the ex wheel by having twin gates.

Otherwise a single gate will allow pulse energy to "crossover" from one collector to the other prior to the ex wheel. If you look at the full-race twin scroll mani's they all have twin gates for this reason. The original twin scroll sr mani's were previously twin gate tubes merging to a single gate but are now also available in twin gate.

ok, i understand fully, yeah the 4088r is a twin scroll housing...

thanks for that..

Nice manifolds. Theres some really nice RB gear out of the states.

6Boost ones are great when you finally get one and once its made to fit the engine.

I wish I could afford an R31house Takoashi Project manifold and T04E Pro-T for my 31...But at $4,500+ for the bare manifold...nah.

DR30 FJ20ET kit..

ee6582.jpg

I heard the tuned length manifolds make no differrence due to all the bends they cause a restriction which makes them as good as any other and what makes those manifolds worth so much why not just get a six boost?

because they are works of art.

oh, the restriction is the turbine wheel :)

it would be very expencive to get each runner bent up perfectly to shape with no welding except for the turbo and head flange.

the dude that has the gibson r31 has priced up a replacment.... (same style as the fj one above) he told me $10,000 and had to be hydroformed.

the full race ones are expencive because of the materials they use and that the are welded by a robot. (very pricy tooling)

can i join the waste gate flanges 2gether and run my 60mm gate on my full race manifold ???

i understand the pulse energy yous were talkin about bieng greater by using the 2, would it make such a difference if i ran the single ????

i understand the theory with it, makes sense, but personally ive never had a problem at all controlling boost with my single 45mm trust gate on an ETM split pulse mani runnin split t04z. thats running 15psi right up to 30psi :-s

This is a response I received from Geoff at Full-Race in respect to my query on single gate vs twin gate during the development of the dual gate T4 twin scroll manifold for sr20's when I ordered my sr twin gate twin scroll manifold a little while back.

Ian --

glad you like it. We have done back to back testing of the dual gate vs single gate, and the difference is significant. In fact we have to add about 18-25% more fuel from 3000-4200 rpm due to how much more air is being moved since the turbo spools up so soon. i can pull the results off the dyno computer next week (ill be on the dyno then)

The comparison results were done on a T4 3582R and a T4 4088R.

The use of twin gates on T/S manifolds is not about boost control - I've no doubt a decent gate will ensure that...........as can be seen from the above response its about improving pulse energy to drive the ex wheel which in turn spools up the turbo sooner. A single gate will 'leak' between the collectors as you are unable to create a perfect seal between the gate tubes.

Cheers,

Yes if you quiz Geoff he'd tell you it's all about keeping the flow rate high and the pressure low . You want the pressure rise and fall ("pulse") to be sharp and quick and to be as good as it can be you need total isolation of the front and rear three cylinders (on an inline 6) all the way to the turbine nossles .

To have one ext gate means it has to be able to vent both sides and that means having a divider at the gates collector/mount . The divider can't touch the gates valve because it won't then seat and seal . The small gap necessary does allow some leakage and this affects the manifold pressures being high or low when they need to be , not as sharp or quick in the changover so some of the positive pulse energy is lost .

Still better than a single scroll housing but not the ultimate .

A .

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