|
No, but I'll chime in on a technical note regarding that second set of intake runners. There ain't any. Rather, VICS opens up a chamber which alters the resonance frequency of the intake manifold. The altered resonance facilitates induction at higher flow rates. This way the manifold has two tunings, for high and low rpm operation. :)
|
Originally Posted by JoshP5
(Post 388147)
No, but I'll chime in on a technical note regarding that second set of intake runners. There ain't any. Rather, VICS opens up a chamber which alters the resonance frequency of the intake manifold. The altered resonance facilitates induction at higher flow rates. This way the manifold has two tunings, for high and low rpm operation. :)
|
so says the bible:
Originally Posted by www.protegefaq.net
What some manufacturers (such as
Nissan and Mazda for example) have done is designed the intake manifold to have an isolated runner system (there are many types of intake manifolds) to offer the best flow characteristics. They didn't stop there. To squeeze as much power out of the engine, yet allowing the vehicle to be streetable and mass producable, they added a secondary set of intake runners into the manifold. With this dual runner system, there is the long runner system for low to mid level RPM operation, and the short runner system for high RPMs. On Mazda's dual runner intake systems (hereafter refered to as "VICS"), they designed the long runners to be narrow and oval in shape to help promote air velocity at the lower RPM ranges. As for the short runners, they are much larger and circular in shape to allow for maximum flow capability at high RPM. There are butterfly shutter valves fitted over the short runner and they are normally closed off. When engine speed is reached to a predetermined rate by the ECU, a solenoid valve is opened and vacuum opens the butterflies to allow for additional air flow into the engine. Hence the reason why the system is "variable". It allows for optimum drivabilty and performance at most RPM ranges. Note when this system is used with high boost forced induction systems, they hinder performance rather than aid it because of the runner sizes. For high boost applications, it is recommended that a large single (stage) isolated runner intake manifold be used. |
1 Attachment(s)
Yeah, I have Edwin's FAQs memorized, but I don't think he's right here. I had this same discussion with Nik and he showed me the figure at the top of 01-13b-10. You can clearly see it in the diagram. Also, next time you take your IM out and see the analog of the attached image, illuminate the "second runner" and you'll see.
|
It changes the length of the runner that the air travels through, no? I checked that diagram and that's exactly what I see there.
Thanks for the diagram though --it is different from how I thought the system worked. I thought that from the throttle body it went to 8 runners, 4 of which were direct and 4 of which were extended. That diagram does prove that it's not a whole lot different than VRIS.. no wonder it doesn't make the noise that the variable intake system on my mom's various nissans made. It was like you got a cold air intake all of a sudden at high RPMs.. a VTEC-ish noise but just from the intake the blast of power I get at 5500rpms is welcome though :) |
Originally Posted by _Kansei_
(Post 388109)
Anyone want to chime in on whether the Mazda 'hesitation fix' ECU reflash cures the flat spot of power msp03 and myself feel? From what I've read people say it leans out the mixture a bit which would definitely help things.
|
1 Attachment(s)
Originally Posted by _Kansei_
(Post 388165)
It changes the length of the runner that the air travels through, no? I checked that diagram and that's exactly what I see there.
|
| All times are GMT -5. The time now is 05:56 AM. |
© 2024 MH Sub I, LLC dba Internet Brands