VICS manifold pics
‘95MSM @ www.mazda-speed.com forum was kind enough to take some photos of his 99-00 Miata VICS manifold that are going onto his 95 NA with a complete MSM engine/drivetrain swap etc.<div>These are said to be better than the later 01-05 VTCS manifolds that I was looking at in this post.</div><div>They look pretty similar from the outside with the runners visible in the upper part of the manifold.</div><div>
</div><div>On the inside they are very different:</div><div>
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</div><div>At first it could look like there are two sets of runners with different length that could be switched by activating the butterflies.</div><div>The “runners” with the butterflies are actually resonance chambers that will open at a certain RPM which makes it possible to optimize the manifold for a broader rpm range than a single static resonance chamber like the other NB manifolds.</div><div>
</div><div>This pic kind of explains the effect and inner workings…. in Japanese….</div><div>
</div><div>I believe the greyed out part on the two lower illustrations are the pressure pulse/resonance path and not the air flow. The torque graph shows an improvement after 5250.</div><div>
</div><div>The neck going from the TB to the plenum looks to have the same limitations as the VTCS manifold with angeled path into the plenum.</div><div>
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</div><div>Gary at trackdogracing.com has seen power gains at higher RPM by porting the VICS intake.</div><div>Here are some before and after pics from his website:</div><div>
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</div><div>A dyno comparison between all the NB manifolds tested on the same car/conditions would be very interesting, but i seriously doubt that will ever happen.</div><div>I know 949Racing is developing their own manifold partly based on the JDM manifold but that could take a while with all the other projects they are involved in.</div><div>
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