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Intake Manifold

The primary function of the intake manifold is to evenly distribute the intake air to each port in the cylinder head. Even distribution is important to optimize the efficiency and performance of the engine.


The stock intake manifold has been dyno proven to flow more stock vs. stock when compared with the Quad 4 HO intake manifold, however this greatly changes once forced induction is introduced. The stock intake manifold can handle moderate amounts of boost pressurization, but being that it is constructed from a plastic, it's integrity may be compromised. Some have had theirs break into pieces upon adding too much boost or having a wet nitrous system puddle in the manifold and ignite. If you're looking into adding much more power, the stock is not the intake manifold you want to use.


Porting the stock plastic manifold is generally considered a waste of time. It flows good enough as is, and there is not much material to port; attempting to widen the stock manifold is useless. Otherwise, you use a dremel or porting tools kit available online.

Quad 4 High Output

From past designs prior to the LD9 Twin Cam, this manifold accompanied the LGO HIGH OUTPUT Quad 4 engine.  It increases volumetric efficiency, yet for a stock LD9 one must opt out for the LO manifold from the LD2 "NON" High output engine.  Dynos have shown the stock LD9 may have the potential to loose power with the manifold.  However if the engine is boosted or running high compression with a well ported and polished head along with an acceptable exhaust the swap would be ideal.  Great for turbo applications. 
Lots of modifications must be handled to fully benefit from this swap.  The key and most essential modification would be the intake manfold's flange.  The LD9 Twin Cam and LGO Quad 4 engines each share distinctive cylinder head intake ports.  Thus one must modify the manifold for a perfect fit.  
    This can be accomplished with three options.
  • Swap the stock head with the 2.3L Quad 4 head.  Which in turn would fit the manifold ports perfect.
  • Get your hands on a rare and hard to find 2.4L Twin Cam intake flange, then get it welded on.
  • Install with a 2.3L gasket and a spacer which are found at along with lots of sealant.    


Intake manifolds are CNC machined with billet aluminum head flange and intake runner surface. Runners are CNC machined to reduce turbulence thus increasing the speed and volumetric efficiency of the intake manifold. The manifold accepts up to a 66 mm throttle body. Can be used on naturally aspirated orforced induction engines. Increases volumetric efficiency by 70% over the stock intake. Made from CNC billet 6061 T-6 aluminum. Available at TurboTechRacing.