rearviewmirror

Does anyone have a link to a good article on the operation of the GSL-SE 6-port? I've searched but didn't find anything with good information. I'm planning my exhaust upgrade and I know that RB has an presilencer that will operate the 6 port. I also know there is an airpump mod to open them as well. (http://www.rotaryresurrection.com/2n...actuation.html)

First I really want to understand how it works, from there I can decide how to approach the exhaust. I'd also like to find a good article that explains how to test the 6-port operation and all the parts associated in its operations.

Thanks.

branca

iTrader: (1)

this works great on my SE

rearviewmirror

I've not seen that one. I've seen the RB pre-silencer that has a connection back to the valve, but not that one. What exactly does it do?

John64

I'm running the Racing Beat pre-silencer and it has no issues opening my actuators.

rearviewmirror

I know it's not a problem opening them, I want to have a better understanding of how it works.

TeamSMS

the 5th and 6th port's work off of backpressure....the header pictured above is IMO the best place to get it when removing the stock cat or doing a full custom exhaust. Tap in the header like the one above and that will supply enough backpressure to work the extra ports.

Keith13b

iTrader: (6)

The 5th and 6th ports on the GSL-SE are closed at low rpm to aid in low rpm power. Then, as exhaust gasses build pressure at higher rpm's the back pressure travels up the tube and pushes/activates the two actuators which rotate an internal sleeve in the 5th and 6th ports allowing them to "open" up. Thus providing a larger intake port and aiding in high rpm power. I'd recommend looking up a photo of a 6-port plate to see the extra 2 ports. This is a completely wrong analogy, but it will help the layman - imagine a bridgeport engine where you can open/close the "bridge" ports. Thats like what is happening (not really but visually it is) - the intake timing of the ports are all different.

The best bet is to just remove the damn sleeves and actuators. They aid in rpms below 3000 (If memory serves me right). How often do you need power at that rpm anyway? The sleeves stick closed frequently without you knowing and rob the engine of top end power. If you need to go - just rev to over 3K and dump the clutch. The idle remains the same - or at least mine does.

rearviewmirror

^ Interesting. So I guess someone would know if there was a problem. Are these ports all or nothing or do they sometimes get gunked up and only open partially? Is there any serviceable parts that should be cleaned at a regular interval? I'll try to dig through the FSM for this, but it's interesting. My car has 68k miles and pulls to redline fine, but I can't help to wonder if there isn't "more".

bugman1973

https://www.rx7club.com/1st-generation-specific-1979-1985-18/air-pump-operated-gsl-se-6th-ports-how-do-i-do-253169/page2/
thats how mine is hooked up. but when i get my headers I'm going to get these ones. Road Race Header* - with 6-port actuator pick-up tube
& oxygen sensor position - for 1986-88 RX-7 (with 13B 6-Port Engine)

Racing Beat's Road Racing Header is the first step in building a serious racing exhaust system. The engine-to-pipe flange is flame cut from 1/2-inch thick flat steel for superb exhaust gas sealing qualities. Like all of the headers we manufacture, the Road Racing Header is constructed with 2-inch O.D. mild steel tubing, .120-inch inch wall thickness, and mandrel-bends throughout. This header weighs approximately 15.5 lbs and is approximately 28” in length.

these will fit the 84-85 SE im going to take my air pump off then or you could get the S5 lower intake manifold and and run a RPM controller to actuate them when ever you want them to open

bugman1973

i would not do this unless building a turbo motor they dont open up till 4500 or more so anything under that would be like a brick wall till then. then it will take off like a rocket but under that it will be no fun at all trust me i had it like that for a little while

Hec's 79 gs

first make sure their moving freely,my were not so I removed them today and they were full of carbon. I'm cleaning them real good and while I'm at it replacing all vacum and fuel hoses.You do have to remove UI and LI to get this done.

Slammed_GSL

iTrader: (14)

Question: If you tap into the header or like the header pictured, what is the temp of the gases entering the actuators? Is the life expectancy shorter with hotter gas temp then getting it from the end of the header or the silencer?
I'm preping my -se 13b for a weber and cleaned the sleeves and ports out to make sure they are working smoothly, I just want to make sure if I do this mod on the header I'm not shortening the life of my acutators.
Also, what hose type would you run from the racing beat header? It has a barbed connector for a a hose and clamp, what hose can take that temp?
I would think a hard line would be best, didn't the stock ones have a 1way valve on it of some sort?
Thanks alot for this thread, it is right on with what I was wondering about.

bugman1973

where do you think the air for the system comes from in the first place. there is no one way valve. just straight exhaust gases. the one pictured is one of the better setups but it is not adjustable. the reason i changed mine is because my hose broke because the exhaust was old and the air pump mod worked really well

lastphaseofthis

iTrader: (8)

while correct, it's best to think of the extra ports as more timing, not volume.
and the timing of the aux ports at anything under 3.5k would give you shitty idle quailty.

MaX PoWeR

iTrader: (2)

http://www.rebuildingrotaryengines.c...6_Port_Inserts

Keith13b

iTrader: (6)

Don't forget to clean the actuators as well. They are notorious for not turning all the way. It took me a long time to realize this. Even only opening 80-90% causes massive turbulance in the port. My car felt fine and strong through the power band, but oh my F'n God did I see some nice top end improvement once I removed them. If you street port the engine, they basically have to go anyway.

The exhaust gasses should not affect the actuators. Remember the air acts as a liquid and is compressed at the header. Meaning gasses do no flow up to the actuators - they are blocked by the existing air in the line. The existing air is compressed, which pushes on the actuators.

I'd use a SS tube w/ flare fitting - thats what RB provides with their kit.

Slammed_GSL

iTrader: (14)

Very nice tip on the SS hose, thanks!

rearviewmirror

I'm going to try to seek out a write up on the whole system, cleaning the ports and actuators. I need swap my injectors out at some point so I'll take this once the UI/LI is removed.

Good information on the 6-port.. keep it coming!

Mazdahead

I am modding a car and plan on not using the sleeves at all. I am going to be using a megasquirt to supply fuel. Since this is going to act like a ported engine now, are there any megsquirt settings I should be aware of to make it run a little smoother?

rlr240sc

The two ports open at about 1-1.5 psi. The RB system works fine. Look at the last page of the dyno sticky I have dynos posted with 5th,6th ports wired open and working normaly. Hope this helps.

Rx-7Doctor

iTrader: (13)

Do this as a general observation to see if the 6 ports are opening properly.

Rev the engine up and watch the movement of the 6 port actuators, if you can see them opening up as you rev the engine then they are free and operating as they should be.

I recommend the installation of pineapple racing sleeves if you take apart the system for cleaning.

Rx-7Doctor

iTrader: (13)

If you have not read this thread it may be of interest to you also.

https://www.rx7club.com/1st-generation-specific-1979-1985-18/5-6-port-operation-13b-505956/

rlr240sc

Mine are nice and free but will not open while just reving the engine at a stop. But on the dyno they opened just as they should.