6 port... wha???
Hunting Skylines
Joined: Apr 2001
Posts: 3,431
Likes: 4
From: Brisbane, Queensland, Australia.
Firstly, a 4-port engine has 4 intake ports... a primary and secondary for each rotor.
A 6-port engine has an auxiliary intake port above each of the secondaries which only opens under increased load. This is done to try and give the engine better performance over a wider rpm range. SE's came with a 6-port.
A 6-port engine has an auxiliary intake port above each of the secondaries which only opens under increased load. This is done to try and give the engine better performance over a wider rpm range. SE's came with a 6-port.
Thread Starter
Joined: Jul 2002
Posts: 3,219
Likes: 8
From: Washington State
Know of any pics where i could see this on the housing? I thought it was the single wedge shaped intake port, and the round exhaust port... (now i feel reel dumb hehe)
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From: Saskatoon, SK & Montreal, PQ
It's not really a port in the housing, it's in the Dynamic Effect Chamber in the intake manifold.
Primary air is inducted through it's own tuned passage and is split between front and reat rotors - this air is tuned for low RPM. Secondary air enters in through two additional ports, one for the front rotor, one for the rear, when it's required at high RPM. These are opened by exhaust back pressure.
This is considered three stage porting, with the additional intake ports positioned before the final induction. So even though the housing still has just the intake and exhaust ports, it's a 6 port engine.
Primary air is inducted through it's own tuned passage and is split between front and reat rotors - this air is tuned for low RPM. Secondary air enters in through two additional ports, one for the front rotor, one for the rear, when it's required at high RPM. These are opened by exhaust back pressure.
This is considered three stage porting, with the additional intake ports positioned before the final induction. So even though the housing still has just the intake and exhaust ports, it's a 6 port engine.
Rotary Enthusiast
Joined: Mar 2001
Posts: 815
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From: Vancouver, BC, Canada
ok here are some pictures,
This first one is the 6port manifold, As you can see the intake ports on the both sides each have two holes:
Now this next one is a 4port manifold. Now the side ports are one huge port instead of two smaller ones.
This is identical on engine as well.
All the 13B's prior to GSL-SE are 4-port.
All the 12A'a are 4-port as well (well I know the RX-7's are).
GSL-SE and all the 2nd gen 13B N/A's are 6-port.
All the 13BT and 13B-REW are 4-ports as well.
This first one is the 6port manifold, As you can see the intake ports on the both sides each have two holes:
Now this next one is a 4port manifold. Now the side ports are one huge port instead of two smaller ones.
This is identical on engine as well.
All the 13B's prior to GSL-SE are 4-port.
All the 12A'a are 4-port as well (well I know the RX-7's are).
GSL-SE and all the 2nd gen 13B N/A's are 6-port.
All the 13BT and 13B-REW are 4-ports as well.
Hunting Skylines
Joined: Apr 2001
Posts: 3,431
Likes: 4
From: Brisbane, Queensland, Australia.
Originally posted by Manntis
It's not really a port in the housing, it's in the Dynamic Effect Chamber in the intake manifold.
Primary air is inducted through it's own tuned passage and is split between front and reat rotors - this air is tuned for low RPM. Secondary air enters in through two additional ports, one for the front rotor, one for the rear, when it's required at high RPM. These are opened by exhaust back pressure.
This is considered three stage porting, with the additional intake ports positioned before the final induction. So even though the housing still has just the intake and exhaust ports, it's a 6 port engine.
It's not really a port in the housing, it's in the Dynamic Effect Chamber in the intake manifold.
Primary air is inducted through it's own tuned passage and is split between front and reat rotors - this air is tuned for low RPM. Secondary air enters in through two additional ports, one for the front rotor, one for the rear, when it's required at high RPM. These are opened by exhaust back pressure.
This is considered three stage porting, with the additional intake ports positioned before the final induction. So even though the housing still has just the intake and exhaust ports, it's a 6 port engine.
Here you can see the auxiliary port above the secondary port as clear as day.
Last edited by REVHED; Sep 3, 2002 at 04:40 PM.
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A 6-port engine has an auxiliary intake port above each of the secondaries which only opens under increased load. This is done to try and give the engine better performance over a wider rpm range. SE's came with a 6-port.
.~T.J.
Junior Member
Joined: Sep 2002
Posts: 48
Likes: 0
From: Quebec, Canada
I was just reading this thread about the auxiliary ports on the GSL-SE 13B and thought I would ask a question since I recently purchased one and am just getting familiar with it.
I noticed that the backpressure hose from the exhaust is not connected to the tube on the auxiliary port actuator valve. The small hose from the valve is blocked with a screw. I guess whoever replaced the exhaust must have not attached it.
Does this mean my auxiliary ports are not opening? The car seems to have great power but maybe the top end isn't what it should be. I don't know because I never drove it with the hose attached.
I plan on putting low pressure into this hose tomorrow to test the actuator valves to see that they work.
The funny thing is I did notice a place on the exhaust just after the rear catalytic converter to attach a sensor or something. It was just open so I plugged it with a cover. I guess I should get the proper attachment for this to connect the hose to the auxiliary port actuator valve?
I plan on ordering a replacement pipe to fo where all the cats are from Racing Beat. They say they have a place to attach this hose on their pipe. I also plan on getting the power pulse main muffler from the. What do you guys think?
Thanks Again for any input.
Greg
Montreal, Quebec
1985 GSL-SE no mods ..... yet!
I noticed that the backpressure hose from the exhaust is not connected to the tube on the auxiliary port actuator valve. The small hose from the valve is blocked with a screw. I guess whoever replaced the exhaust must have not attached it.
Does this mean my auxiliary ports are not opening? The car seems to have great power but maybe the top end isn't what it should be. I don't know because I never drove it with the hose attached.
I plan on putting low pressure into this hose tomorrow to test the actuator valves to see that they work.
The funny thing is I did notice a place on the exhaust just after the rear catalytic converter to attach a sensor or something. It was just open so I plugged it with a cover. I guess I should get the proper attachment for this to connect the hose to the auxiliary port actuator valve?
I plan on ordering a replacement pipe to fo where all the cats are from Racing Beat. They say they have a place to attach this hose on their pipe. I also plan on getting the power pulse main muffler from the. What do you guys think?
Thanks Again for any input.
Greg
Montreal, Quebec
1985 GSL-SE no mods ..... yet!
Junior Member
Joined: Feb 2001
Posts: 39
Likes: 0
From: Coffs Harbour, NSW, Australia
My 12A's farked
Should I get a 4 port or 6 port 13B? I just want a simple upgrade. Is one easier to install than the other? Is the 6 port more economical and powerful? hmmmmz
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Joined: Jun 2002
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From: Saskatoon, SK & Montreal, PQ
The 6 port 13B is the one that actually came in the GSL-SE RX-7. You can get a parts car and swap over much of the engine bay contents.
The 4 ports came in other cars, so might require more custom fabrication to mount into your vehicle (I'm talking engine mounts, auxillary systems, etc.)
The 4 ports came in other cars, so might require more custom fabrication to mount into your vehicle (I'm talking engine mounts, auxillary systems, etc.)
Open up! Search Warrant!
Joined: May 2002
Posts: 3,838
Likes: 3
From: Kicking down doors in a neighborhood near you
Originally posted by Manntis
Alright, I was incorrect. I was paraphrasing from something written by Csaba Csere about the 13B.
Alright, I was incorrect. I was paraphrasing from something written by Csaba Csere about the 13B.
'nough said.
Junior Member
Joined: Feb 2001
Posts: 39
Likes: 0
From: Coffs Harbour, NSW, Australia
Originally posted by Manntis
The 6 port 13B is the one that actually came in the GSL-SE RX-7. You can get a parts car and swap over much of the engine bay contents.
The 4 ports came in other cars, so might require more custom fabrication to mount into your vehicle (I'm talking engine mounts, auxillary systems, etc.)
The 6 port 13B is the one that actually came in the GSL-SE RX-7. You can get a parts car and swap over much of the engine bay contents.
The 4 ports came in other cars, so might require more custom fabrication to mount into your vehicle (I'm talking engine mounts, auxillary systems, etc.)
Hunting Skylines
Joined: Apr 2001
Posts: 3,431
Likes: 4
From: Brisbane, Queensland, Australia.
Originally posted by Manntis
CAn't argue with that. The Canadian GSL-SE comes with snazzy headlight washers though...
CAn't argue with that. The Canadian GSL-SE comes with snazzy headlight washers though...
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