TexasGunRunner

One of my recently acquired GSL-SEs was being put into a 'race' configuration by a prior owner. Apparently, as part of this, they removed the auxiliary port actuators.

Yesterday, I found some in a salvage yard and bought them. Although I stupidly did not bother to take the intake further apart and get the auxiliary port valves (I haven't checked whether they were removed on mine - probably not), I have some questions about what I am about to do.

In talking to a tech at Mazdatrix briefly about another matter, he implied they might have removed them mistakenly thinking they were part of the emissions control and/or thought removing them would increase HP

I assume the idea is that ports 5 & 6 provide additional air into the engine at high load/revs, thereby improving upper band performance (letting it breathe more). Is that correct? The FSM does not explain the operation of the actuators - are they controlled via vacuum? Does the ECU cause the vacuum to be routed to the actuator?

If so, I have some additional questions:

1) why would somebody remove the actuators?

2) Wouldn't simply removing them have caused a leak in either the vacuum system and/or the intake system?

3) since they provide a known state (open or closed), wouldn't removing them lead to the possibility they were in different or wrong position (closed at high speed or open at low speed)?

4) I intend to put them back on, is this a good idea, or should I do something else? Is there something I can do here to improve performance beyond stock, or should I just replace them as stock?

5) They had gaskets, where can I get them, or would it be alright to use Permatex Ultra Blue or a similar silicon based gasket caulk?

Thanks,
Brian

Dom

The sleeves (valves) are probably still in the intake and they are most likely rigged up in the open position. This means that you are loosing in the lower end, not upper end.

Since the actuators run off the exhaust pressure they may have been discarded after headers were installed if the headers were not specific to that motor.

Regarding gaining or loosing horsepower or drivability issues I am not willing to step into that pile o' sh_t!

Forseti

They were drunk and bored or intending to open the 6-ports by another method.
Hmm possibly but I would think this would only be possible if they left the port runners open to the atmosphere and the sleeves were in the open position.

Well without them there the intake port will always be open. Check out
http://www.mazdatrix.com/faq/port6p.htm
to get a better understanding of the sleeves.

Pineapple racing sleeves. I'm not sure if they still sell the entire sleeve or just the insert. Essentially they are just tapered to provide more flow into the 5th and 6th ports...a pretty nice upgrade.

Gaskets? hmm I've pulled mine out entirely ...there are some grommets and washers around the actuator rods but I don't recall gaskets.

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TexasGunRunner

I read the Mazdatrix FAQ (I had read it before, but now I understand it better) and searched for the replacement valve insert. I couldn't find the insert, or a listing for any gasket for the actuators.

On my engine, the actuators were removed, but the lever coming out of the header is still there and it will rotate. How can I be sure the sleeves are still in there, short of removing the header?

I want to avoid removing the header because, 1) the engine runs great now, why break it or risk damaging it, 2) that is a lot of work and there are other higher priorities on the car.

So, why do I want to fix this? Because I think this is where the inspector claimed he heard an exhaust leak. I need to fix that to pass inspection.

Is there any way to, short of removing the whole intake, to test to see if the sleeves are in there and not bound?

Thanks,
BTC

TexasGunRunner

At lunch I started the car and moved the actuator levers...there was no change in RPM, or it was barely noticeable. Of course, that was at idle. There was some resistance in moving the levers...that is they were clearly attached to something causing friction, but I am still unsure. Would changing the valves at idle make a noticeable difference in sound or RPM?

If I remove the screws and flange that retain the lever, can the valve come out that way, or do I need to take off the whole manifold?

I am still looking for other ideas on how to verify the valves are functioning properly?

Thanks,
BTC

Forseti

BTC,

Your exhaust header has nothing to do with your intake ports.

The levers you are talking about are your actuator rods...i.e. someone pulled the actuators off and left the rods in place. If this is the case then the sleeves are staying closed.

THese rods pull straight out from the lower intake manifold...pliers or vice grips will pull them out and you can see what you are dealing with. Then the sleeves can be removed and cleaned.

Without your actuators there's nothing to turn the rods so your 5th and 6th ports are not operating properly. I would find used actuators off the forum or at a wreckers (I got both for less than 20 bux). And verify that your split air pipe is correctly hooked up.

Once you've done that just pull the throttle open when your car is idling and you'll see the actuators turning the rods at about 3800-4200rpm. By 6000rpm they should be fully turned (wide open).

It's worth it to look at this as it's like night and day for your top end.

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ZachstylezRX7

So the car just sitting there revving should open them up? i was told that there needs to be load... because i revved my engine up to 7k and nothign happened as far as the port actuators go.

Zachstylez

Forseti

Not load, exhaust backpressure. Once the actuators see 1.8psi from the split air pipe (or air pump if you're using that method) they will start to move. By 2.7 psi they should be fully open.

Check Page 50 of the 4B section of the FSM at

http://www.wankel.net/~krwright/cars/rx7/85_manual.html

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Forseti

I can rev my engine and see them open at about 4200rpm using either the air pump or the exhaust backpressure method.

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ZachstylezRX7

Would this also cause a delay in power between shifts?
FOr example... i am cruisin in second gear and i decide to floor it... i floor it and then i shift into third... when i shift into third there is this delay in power and i can't go faster than 110mph for some reason... i replaced the fuel pump and fuel filter and those didn't help...
Could it be that actuators just aren't opening?

Zachstylez

Forseti

It should not. You can run your car in 4-port mode without issue (aside from a loss in top end power). As for the top speed..mine topped out at about 124mph and that was with 5-ports working. It's possible that not being able to burn enough fuel will somewhat limit your top speed but it sounds like you have another issue.

Does your surging ever happen in the same gear? How is your clutch?

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LongDuck

In my view, there is a distinct gap between SE owners who swear by the '6'-port design, and those who wire theirs open... I'm of the belief that the Mazda engineers were ahead of their time when they released this system, and that, when it's working correctly, it works VERY well to broaden the powerband of an otherwise 'peaky' horsepower curve.

With that in mind, I offer up the following; your '6'-ports are an effective means to increase air column velocity at low engine RPM, which is conducive to producing torque - which the rotary engine lacks at low RPM. When the RPM goes up, the '6'-ports open, allowing more fuel and air into the chambers, thus producing more top end power. Both of these things acting in concert produce more power than wiring them open (which hurts low end torque), or leaving them inoperable (which hurts high end power).

If your '6'-ports are not working correctly, you will suffer from one or possibly both of these conditions. Either way, the 13B still produces more power than a 12A, which is why a lot of guys who 'move up' to 13B power just wire them open and are done with it.

If you've felt a good-running 13B w/'6'-ports, you'll never go back, because there is a definite 'push' at 3800-4500 rpm that is not present in a 12a engine - it's almost like a turbo coming into boost range, and once you learn to drive and shift within this range, nothing else will do. Now, onto your problem...

Now that you have the actuators, I would suggest that you work toward hooking them up correctly. The upper intake manifold houses the '6'-port actuators, turning rods, and the port sleeves are located inside the engine side housings (front and back). There are only 2 '6'-ports in the engine - center housings do not have sleeves. The header/manifold has nothing to do with port actuation, other than the single metal tube which leads back up from the catalytic converter (#3) and provides back pressure to actuate the port valves.

If you feel resistance when you rotate the rods by hand, your sleeves are most likely in place. I do not recommend removing the turning rods without also removing the upper intake manifold, as you may not be able to get the rod lined up with the sleeve correctly without knowing what it looks like and how it operates internally. Once you've had it apart, it's pretty easy to do, but for the first-timer, I'd just cut out some gaskets, hook up the actuators and verify function.

You cannot have any gas leaks from the actuating tubes or where they connect to the actuators. You'll notice that underneath the lower intake manifold is a shiny metal tube which connects the exhaust backpressure tube to both actuators. Any leak in getting this backpressure to either actuator, and neither will work correctly. We're only taking about between 2-6psi, so that is not a lot of pressure to be working with to get the ports to operate.

Test the actuators before installation by covering the holes at the bottom with your thumb and trying to push the actuator rod in with gentle pressure. It should not move if it's good. If the rod can be moved back and forth easily, the valve within the actuator is bad and will not work. Check both actuators to ensure that they're both moving freely.

Then, before you install the actuators, rotate the turning rods by hand to be sure that they rotate through their roughly 90 degree rotation smoothly and without undue force. If they catch or seem 'scritchy', then you'll need to remove the lower intake, remove the sleeves and clean everything out until they slide like glass.

Once you have this system sorted out, it is a vast improvement over having them set one way or the other. Mazda intended this for specific airflow management in concert with the Dynamic Chamber effect, and you're hobbling the car's ability to perform if you don't get this system running right. Good luck, and reply back if questions,

Forseti

Longduck, REALLY well written...I think this thread should be stickied..

After you've finished cleaning everything, you can hook up a hand pump to the backpressure tube and pump air until you see the actuators move and the rods turn.

To add to that...one of my sleeves even though I cleaned it out (rods, manifold, etc) would still stick; luckily I'm rebuilding the engine so it doesn't matter.

Mazda's still doing dynamic induction on the rx-8 so I would definitely stick with the 6-port design if you can.

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TexasGunRunner

LongDuck:

That is by far the most useful and thorough explanation of anything I have seen posted here yet. This one is worth printing.

Thank you very much for the detailed instructions and recommendations.

As per your instructions, I tested the actuators that I pulled off at a salvage yard and they seem to work very well. The levers on the engine seem to move smoothly.

I still need to test the backpressure, but I will do that when I remount the main cat to pass the safety inspection (next couple of days). Then I will clean the mounting faces off and mount the actuators.

I will report back on my progress professor.

On kind of a tangential point, in looking through the catalogs and posts, I've noticed they always reference "6 port non-turbo" or "turb"o in referring to the 13B. On this particular car I am not interested in doing a turbo, but I am curious, why is the 6 port design mutually exclusive with turbos? ...or is that just exclusivity with factory turbo manifolds?

Forseti

All stock 13b turbos (TIIs anyway) are 4-ports.

I'm sure you could turbo a 6-port but since the turbo would provide all the additional air you would need (just crank the boost) I'm sure it's much more simple to turbo a 4-port. I dunno I'd be interested to hear someone who's turbo'ed a 6-port and how well it worked.

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ZachstylezRX7

So if i top out at 110mph... and when i shift and quickly floor the car i experience a huge delayed response time (yes it does feel like teh clutch is slipping) could this be a clutch? Like i said, it only delays when i floor it.

Zachstylez

XLR8

iTrader: (52)

Would wired open 6ports produce the same airflow as removed sleeves? I am going carby with a full new manifold so the sleeves will have to go. Just wondering what to expect.

I wired my 6ports open due to a cusom exhaust.
My car has tons of torque!! I was impressed, it has the torque of a pissedon engine Every rotary friend that rides with me comments on the torque of my engine.......maybe because the SE rotors were the heaviest of any rotary? hhhhmmmmm...

spoolin

long duck is right on except where he said the 6 port actuators and rods are in the upper intake manifold......

The upper intake manifold houses the '6'-port actuators, turning rods, and the port sleeves are located inside the engine side housings (front and back).

they're in the lower mani

LongDuck

Yeah, that's right, and thanks for the correction regarding upper/lower intake manifolds. I was amazed at how grungy my '6'-port sleeves were when I pulled them out. I had to degrease, then polish them down to get 20 years of carbon off of them. I can only imagine what my rotors look like.

In regard to the original question about the car slipping at 110mph, even a slipping clutch should allow an SE to top that on level ground. If you think your clutch is going out, an easy test is to drive along a smooth, flat road at about 30mph, put the car in 3rd gear and floor it - if the RPM's go up first and then the car accelerates, then your clutch disk is slipping and will need to be replaced. HTH,

Forseti

I've always attributed this to the se's transmission ratios. I swapped in a 90 N/A tranny when my original went and it sucks

Either way I was surprised how much guts my car had for an 85 with lots of mileage.

F-

ZachstylezRX7

Hey thanks a lot longduck... when i get my car back from the paintshop i will definetely do that. When i got the car (end of June), it ran great and i easily went 125 no problem. Also, when i shifted and floored it... the car jerked my head back so hard i almost got whiplash... Now, it tops out at 110mph and when i shift, like i said, the rpms go way up and then it actually gets power about 2 seconds afterward.
This could all be from a bad clutch? Wow... i didn't realize. In that case i will do the test and if the rpms go up... i will definetely get a high performance clutch... and maybe while i am at it i can sneak an aluminum flywheel thanks a lot duck YOU DA MAN.

Zachstylez

kennedy

so what is the "air pump method" to open the 5 and 6 ports? is it covered in a faq somewhere?