Twin Throttle Bodies

[Freakazoid]

The Quad Turbo VH has got me thinking about my project. Not so much the Turbo's but the 2 independent intakes with throttle bodies on each. My project is to put the VH in a 4x4 very much like Darinz' Patrol. I am looking for a smooth torque curve and lots of low down torque as well. Not so much all out power at the top. I know one single TB flows more than 2 small ones, but will the control over the flow not be better. Going from closed to say half throttle on 2 smaller bodies must be better control than doing the same on one big TB?

Will the 2 separate intakes also have a smoother torque and better low down torque than one big plenum? Or alternatively the 2 plenum's but with a balance tube between them?

[Mettler]

The factory spider manifold is designed to boost torque throughout the rev range, and is one of the reasons the VH45 produces around 90% of its peak torque by 2000rpm.

I would be very hesitant to replace the standard manifold unless I'd done some serious mathematics to match my prospective new manifold's specs to whatever exhaust and cam configuration I had.

If you're concerned about throttle response... trust me, there's nothing to be worried about. The VH is very responsive!

[Freakazoid]

I know there is very little I can do to make it better than it already is, I am not going to mess with the intake if I can't find a good reason. I have a need to control rpm relatively accurately. Saying that, I could mess with my gear ratios and probably get a similar effect but thought I would ask the question anyway. I am more looking at the control over rpm I have in the lower rpm ranges. Would the 2 smaller throttle bodies be better than one big one. I suppose you could take it further and say would ITB's give you better throttle control than one single throttle body?

[Guishnu]

Im replacing the spider with twin inlet manifolds and twin throttlebodies, but that's for a twin turbo race application. The spiders were never designed for forced induction.

Unless you have a really good reason for doing it, i wouldn't mess with multi billion yen Nissan R&D

[ultrapulse]

. The spiders were never designed for forced induction.

True, but what works for NA works with turbos also.

[WizardBlack]

True, but what works for NA works with turbos also.

Yep.

If you want to control rpm's better, look at the factory throttle pulley and consider making an accelerated pulley so more pedal range equates to the first ~40% throttle to help with control. Stiffen the springs, too.