My porting on 6 port plates
Thread Starter
Joined: Nov 2001
Posts: 2,239
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From: Watertown, NY
My porting on 6 port plates
Hey guys how is going? Just got a question more like a opinion, i usually use ethier mazdatrix or pineapple plates on my motors but i had this though of porting the 6 port to port the primary port as close i can to the secondary port. I did a test on a crack plate so don't mind the opps by the secondary ports and just want your opinion if anyone done this before. I'm always careful porting 6 port because i heard alot of bad stories of broken side seals and joining both ports will actually loose alot of low end torque. Maybe you guys that done this before can throw some ideas. Btw is not going on a n/a car. I'm planning to do this for a 6 port turbo setup. Thanks
Eddie
yes. i've ported 6 port engines like that. you're definitely better off leaving it as 6 ports and NOT making the monster siamesed 4-port out of it. regardless of the wonderful memory i have of my friend's Rx-7 with one of those "siamesed" ports, the older me that has knowledge now and understands these things can confidently say it's probably not a good idea - even with a turbo. 
of course, now i have to ask: why turbo the 6 port though?
also, i know you said it's a junk housing, but i try to make a habit of using duct tape to tape off the areas around the scribe. it works.

of course, now i have to ask: why turbo the 6 port though?
also, i know you said it's a junk housing, but i try to make a habit of using duct tape to tape off the areas around the scribe. it works.
Thread Starter
Joined: Nov 2001
Posts: 2,239
Likes: 1
From: Watertown, NY
yes. i've ported 6 port engines like that. you're definitely better off leaving it as 6 ports and NOT making the monster siamesed 4-port out of it. regardless of the wonderful memory i have of my friend's Rx-7 with one of those "siamesed" ports, the older me that has knowledge now and understands these things can confidently say it's probably not a good idea - even with a turbo. 
of course, now i have to ask: why turbo the 6 port though?
also, i know you said it's a junk housing, but i try to make a habit of using duct tape to tape off the areas around the scribe. it works.

of course, now i have to ask: why turbo the 6 port though?
also, i know you said it's a junk housing, but i try to make a habit of using duct tape to tape off the areas around the scribe. it works.

Thread Starter
Joined: Nov 2001
Posts: 2,239
Likes: 1
From: Watertown, NY
I had my share but not a every day builder for sure. Budget and the fact that i live in the middle of nowhere is always a factor. Always looking for ideas and opinion. I always listen to the people that done it before. Thanks for the input. Always welcome
oh man, i can relate to this so much! although i think i would still trade places with you in a heartbeat ... i know. i know. mind blown!
Always looking for ideas and opinion.
1. what safeguards will you be running with this in terms of boost limits?
2. are you removing the exhaust diffusers?
3. which intake manifold will you be using? again, just a curiosity-thing. i had a friend that patched up his T2 with a 6-port a while back, and he used the T2 manifold on it.
Thread Starter
Joined: Nov 2001
Posts: 2,239
Likes: 1
From: Watertown, NY
oh man, i can relate to this so much! although i think i would still trade places with you in a heartbeat ... i know. i know. mind blown!i know what you mean with this, too. as far as your project is concerned, you already know what you're in for in terms of results though. it sounds like you'll be running your Turbo rotors, so that issue is dealt with (though there's nothing wrong with the 9.4s). so the only thing left is the port timing issues and there isn't a whole lot you can do about that in a practical sense.
1. what safeguards will you be running with this in terms of boost limits?
2. are you removing the exhaust diffusers?
3. which intake manifold will you be using? again, just a curiosity-thing. i had a friend that patched up his T2 with a 6-port a while back, and he used the T2 manifold on it.
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i know of a guy who did a full bridge 6 port turbo, and it did 631hp at like 20 psi of boost.
they used a Greddy T88 (it was a long time ago), S5 T2 intake manifolds big intercooler.
they used a Greddy T88 (it was a long time ago), S5 T2 intake manifolds big intercooler.
Thread Starter
Joined: Nov 2001
Posts: 2,239
Likes: 1
From: Watertown, NY
I couldn't imagine starting with FC parts. i have a GSL-SE based 6 port with stock port timing and it feels like peak torque happens around 8000-9000rpm. It pulls harder the higher you rev it, which is not conducive to performance unless you have engine internals and a transmission that can handle 14,000rpm shift points.
In short, anything 6 port will have intake closing points far too late, and the FC 6 ports close the latest,
In short, anything 6 port will have intake closing points far too late, and the FC 6 ports close the latest,
Last edited by peejay; Jun 11, 2019 at 04:30 AM.
Thread Starter
Joined: Nov 2001
Posts: 2,239
Likes: 1
From: Watertown, NY
I couldn't imagine starting with FC parts. i have a GSL-SE based 6 port with stock port timing and it feels like peak torque happens around 8000-9000rpm. It pulls harder the higher you rev it, which is not conducive to performance unless you have engine internals and a transmission that can handle 14,000rpm shift points.
In short, anything 6 port will have intake closing points far too late, and the FC 6 ports close the latest,
In short, anything 6 port will have intake closing points far too late, and the FC 6 ports close the latest,
I never feel a peak, the butt dyno says it keeps pulling harder the higher it revs. This is also probably largely due to the fact that the midrange torque sucks.
Very naturally aspirated. It's the "something completely different" engine. Holley 750 as the throttle body (I also milled off the choke horn and removed the boosters), some kind of intake manifold that is an inch taller than the Racing Beat 4-port manifold on my old engine (had to notch the hood for clearance). Haven't been to a dyno because there is just no time for that. I'm sure the numbers will suck in part because my duty cycle peak is a lot lower than the bridge port did, and I have a Ford 9" now and those rears are power hogs.
It actually reminds me of a 6 port based engine that Dave Lemon was describing here, where they never did find a torque peak except for late in the development cycle.
Very naturally aspirated. It's the "something completely different" engine. Holley 750 as the throttle body (I also milled off the choke horn and removed the boosters), some kind of intake manifold that is an inch taller than the Racing Beat 4-port manifold on my old engine (had to notch the hood for clearance). Haven't been to a dyno because there is just no time for that. I'm sure the numbers will suck in part because my duty cycle peak is a lot lower than the bridge port did, and I have a Ford 9" now and those rears are power hogs.
It actually reminds me of a 6 port based engine that Dave Lemon was describing here, where they never did find a torque peak except for late in the development cycle.
Last edited by peejay; Jun 11, 2019 at 08:45 PM.
Thread Starter
Joined: Nov 2001
Posts: 2,239
Likes: 1
From: Watertown, NY
I never feel a peak, the butt dyno says it keeps pulling harder the higher it revs. This is also probably largely due to the fact that the midrange torque sucks.
Very naturally aspirated. It's the "something completely different" engine. Holley 750 as the throttle body (I also milled off the choke horn and removed the boosters), some kind of intake manifold that is an inch taller than the Racing Beat 4-port manifold on my old engine (had to notch the hood for clearance). Haven't been to a dyno because there is just no time for that. I'm sure the numbers will suck in part because my duty cycle peak is a lot lower than the bridge port did, and I have a Ford 9" now and those rears are power hogs.
It actually reminds me of a 6 port based engine that Dave Lemon was describing here, where they never did find a torque peak except for late in the development cycle.
Very naturally aspirated. It's the "something completely different" engine. Holley 750 as the throttle body (I also milled off the choke horn and removed the boosters), some kind of intake manifold that is an inch taller than the Racing Beat 4-port manifold on my old engine (had to notch the hood for clearance). Haven't been to a dyno because there is just no time for that. I'm sure the numbers will suck in part because my duty cycle peak is a lot lower than the bridge port did, and I have a Ford 9" now and those rears are power hogs.
It actually reminds me of a 6 port based engine that Dave Lemon was describing here, where they never did find a torque peak except for late in the development cycle.
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