Rotary Manifold
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Joined: Dec 2002
Posts: 4,107
From: fredneck MD
Originally Posted by Leetheslacker' date='Oct 1 2003, 02:47 PM
[quote name='Dysfnctnl85' date='Oct 1 2003, 02:21 PM'] [quote name='Baldy' date='Oct 1 2003, 01:38 PM'] 2 runners for each rotor
each rotor has 2 of it's own intake ports, which are situated on either side of the rotor. 1 runner for each intake port.
If I'm wrong, someone please clarify.
each rotor has 2 of it's own intake ports, which are situated on either side of the rotor. 1 runner for each intake port.
If I'm wrong, someone please clarify.
Thats only on 6-port NAs i think. [/quote]
You think correctly. They have a secondary port that comes online at high rpms.
hey, its like rotary VtECH!!
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Joined: Nov 2002
Posts: 2,286
From: Cincinnati, Oh hi hoe!
Originally Posted by rfreeman27' date='Oct 1 2003, 04:52 PM
[quote name='Leetheslacker' date='Oct 1 2003, 02:47 PM'] [quote name='Dysfnctnl85' date='Oct 1 2003, 02:21 PM'] [quote name='Baldy' date='Oct 1 2003, 01:38 PM'] 2 runners for each rotor
each rotor has 2 of it's own intake ports, which are situated on either side of the rotor. 1 runner for each intake port.
If I'm wrong, someone please clarify.
each rotor has 2 of it's own intake ports, which are situated on either side of the rotor. 1 runner for each intake port.
If I'm wrong, someone please clarify.
Thats only on 6-port NAs i think. [/quote]
You think correctly. They have a secondary port that comes online at high rpms.
hey, its like rotary VtECH!! [/quote]
I was pretty sure it was 6port only, but i was kinda half asleep.
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Joined: Apr 2002
Posts: 2,930
From: IL
The 6 port NA's have 3 stages, the primary intake ports (intermediate housing on the engine) secondary intake ports (at the fornt and rear end plates, the lower port), and tertiary (AKA 6PI / Aux ports, these are situated above the secondary ports in the front and rear end plates)
The staging between the primary and secondary ports is handled by the throttle body, this is why there are 3 bores in it. The primary throttle (the lower singular bore) opens first, then the secondary throttle plates open (the upper pair), these secondary bores are associated with both the secondary and tertiary ports on the engine, since they share the same runners leading to the secondary throttle plates.
Opening at higher RPM, there are sleeves which act as valves in the tertiary / aux ports, these sleeves are literally inside the port on the end housings and are rotated to open / close the port leading to the combustion chamber. The rotation is done via whats known as an "aux port actuator", S4's use exhaust backpressure to drive the actuators, and S5's use air pump pressure.
I'm pretty sure the 4 port engines (turbo) still utilize the primary/secondary staging of the intake, the way this is done is by having the linkage connecting the primary throttle lever to the secondary throttle lever loosely coupled. So when you start opening the primary throttle it has some slack to take up before the secondary throttle starts opening.
Back on NA's though, there is another feature of the intake known as the "dynamic chamber", this chamber is used to link the front and rear rotors' runners, while keeping the secondary and primary intake tracts seperate up to the throttle body. The result of this is a ping-pong effect due to the rotors being 180 degrees out of phase, there's a slight supercharging effect via the plenum improving performance within the rpm range it was tuned for (the length of the runners affects the timing of the pings and pongs, so it is tunable at what rpm this effect is, well, effective). In the S5 NA's they took this a step further and added something called VDI, variable dynamic-effect intake if my memory serves me correctly. This basically an extension to the dynamic chamber concept, adding another valve for selecting between different length runners, in an attempt to broaden the rpm range the ping-pong effect is useful in. (it works too, on stock motors at least, S5's have significantly more top end after the VDI makes itself known)
most of my experience is with FC's, primarily NA's. So what I believe is true and stated above may not be quite so accurate for other generations. Hope it helps.
The staging between the primary and secondary ports is handled by the throttle body, this is why there are 3 bores in it. The primary throttle (the lower singular bore) opens first, then the secondary throttle plates open (the upper pair), these secondary bores are associated with both the secondary and tertiary ports on the engine, since they share the same runners leading to the secondary throttle plates.
Opening at higher RPM, there are sleeves which act as valves in the tertiary / aux ports, these sleeves are literally inside the port on the end housings and are rotated to open / close the port leading to the combustion chamber. The rotation is done via whats known as an "aux port actuator", S4's use exhaust backpressure to drive the actuators, and S5's use air pump pressure.
I'm pretty sure the 4 port engines (turbo) still utilize the primary/secondary staging of the intake, the way this is done is by having the linkage connecting the primary throttle lever to the secondary throttle lever loosely coupled. So when you start opening the primary throttle it has some slack to take up before the secondary throttle starts opening.
Back on NA's though, there is another feature of the intake known as the "dynamic chamber", this chamber is used to link the front and rear rotors' runners, while keeping the secondary and primary intake tracts seperate up to the throttle body. The result of this is a ping-pong effect due to the rotors being 180 degrees out of phase, there's a slight supercharging effect via the plenum improving performance within the rpm range it was tuned for (the length of the runners affects the timing of the pings and pongs, so it is tunable at what rpm this effect is, well, effective). In the S5 NA's they took this a step further and added something called VDI, variable dynamic-effect intake if my memory serves me correctly. This basically an extension to the dynamic chamber concept, adding another valve for selecting between different length runners, in an attempt to broaden the rpm range the ping-pong effect is useful in. (it works too, on stock motors at least, S5's have significantly more top end after the VDI makes itself known)
most of my experience is with FC's, primarily NA's. So what I believe is true and stated above may not be quite so accurate for other generations. Hope it helps.
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Joined: Jul 2002
Posts: 2,483
From: Fayetteville, Georgia
Originally Posted by pengaru' date='Oct 2 2003, 01:52 AM
The 6 port NA's have 3 stages, the primary intake ports (intermediate housing on the engine) secondary intake ports (at the fornt and rear end plates, the lower port), and tertiary (AKA 6PI / Aux ports, these are situated above the secondary ports in the front and rear end plates)
The staging between the primary and secondary ports is handled by the throttle body, this is why there are 3 bores in it. The primary throttle (the lower singular bore) opens first, then the secondary throttle plates open (the upper pair), these secondary bores are associated with both the secondary and tertiary ports on the engine, since they share the same runners leading to the secondary throttle plates.
Opening at higher RPM, there are sleeves which act as valves in the tertiary / aux ports, these sleeves are literally inside the port on the end housings and are rotated to open / close the port leading to the combustion chamber. The rotation is done via whats known as an "aux port actuator", S4's use exhaust backpressure to drive the actuators, and S5's use air pump pressure.
I'm pretty sure the 4 port engines (turbo) still utilize the primary/secondary staging of the intake, the way this is done is by having the linkage connecting the primary throttle lever to the secondary throttle lever loosely coupled. So when you start opening the primary throttle it has some slack to take up before the secondary throttle starts opening.
Back on NA's though, there is another feature of the intake known as the "dynamic chamber", this chamber is used to link the front and rear rotors' runners, while keeping the secondary and primary intake tracts seperate up to the throttle body. The result of this is a ping-pong effect due to the rotors being 180 degrees out of phase, there's a slight supercharging effect via the plenum improving performance within the rpm range it was tuned for (the length of the runners affects the timing of the pings and pongs, so it is tunable at what rpm this effect is, well, effective). In the S5 NA's they took this a step further and added something called VDI, variable dynamic-effect intake if my memory serves me correctly. This basically an extension to the dynamic chamber concept, adding another valve for selecting between different length runners, in an attempt to broaden the rpm range the ping-pong effect is useful in. (it works too, on stock motors at least, S5's have significantly more top end after the VDI makes itself known)
most of my experience is with FC's, primarily NA's. So what I believe is true and stated above may not be quite so accurate for other generations. Hope it helps.
The staging between the primary and secondary ports is handled by the throttle body, this is why there are 3 bores in it. The primary throttle (the lower singular bore) opens first, then the secondary throttle plates open (the upper pair), these secondary bores are associated with both the secondary and tertiary ports on the engine, since they share the same runners leading to the secondary throttle plates.
Opening at higher RPM, there are sleeves which act as valves in the tertiary / aux ports, these sleeves are literally inside the port on the end housings and are rotated to open / close the port leading to the combustion chamber. The rotation is done via whats known as an "aux port actuator", S4's use exhaust backpressure to drive the actuators, and S5's use air pump pressure.
I'm pretty sure the 4 port engines (turbo) still utilize the primary/secondary staging of the intake, the way this is done is by having the linkage connecting the primary throttle lever to the secondary throttle lever loosely coupled. So when you start opening the primary throttle it has some slack to take up before the secondary throttle starts opening.
Back on NA's though, there is another feature of the intake known as the "dynamic chamber", this chamber is used to link the front and rear rotors' runners, while keeping the secondary and primary intake tracts seperate up to the throttle body. The result of this is a ping-pong effect due to the rotors being 180 degrees out of phase, there's a slight supercharging effect via the plenum improving performance within the rpm range it was tuned for (the length of the runners affects the timing of the pings and pongs, so it is tunable at what rpm this effect is, well, effective). In the S5 NA's they took this a step further and added something called VDI, variable dynamic-effect intake if my memory serves me correctly. This basically an extension to the dynamic chamber concept, adding another valve for selecting between different length runners, in an attempt to broaden the rpm range the ping-pong effect is useful in. (it works too, on stock motors at least, S5's have significantly more top end after the VDI makes itself known)
most of my experience is with FC's, primarily NA's. So what I believe is true and stated above may not be quite so accurate for other generations. Hope it helps.
Maybe soon when I can put my hands on a rotary I will know a fraction of what you know.
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Joined: Dec 2002
Posts: 204
From: Queens, New York
Very well stated guy's.
I just want to add that although their carried out in different way their is a definite similarity in the way the auxiliary ports on a rotary work and the v-tech systems found on some Honda motors. Both are able to generate more top end power without sacrificing low end acceleration. Which is the purpose of both systems, and in both cases this is accomplished through port timing activation.
PK797 NYC
I just want to add that although their carried out in different way their is a definite similarity in the way the auxiliary ports on a rotary work and the v-tech systems found on some Honda motors. Both are able to generate more top end power without sacrificing low end acceleration. Which is the purpose of both systems, and in both cases this is accomplished through port timing activation.
PK797 NYC
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