Aux. port actuators
 

I had one of these corrode through on my GSL-SE I was looking for replacements but had a suggestion to remove the actuator entirely. Has anyone done this? Does it work? Other than unbolting them is there any other modifications required?



Thanks
Jim

YOu should remove the sleeves that the actuators operate. You will have to remove the entire upper and lower manifolds to do so though.

There someone that hooked the actuators to some valve attached to the air pump to trigger them at 3500 rpm. Anybody remember how. But in reply to the question above you can wire them open if you want. Some guy here did it that way.

Is removing the better than putting new ones on to replace the old ones?

If I remove the actuators and port sleeves will the car have to be re-timed to account for the additional air/fuel coming in?

Regards
Jim:beer:

I'm having trouble with my actuators also. But I believe my problem is due to a old worn out cat and the tube that leads back up to the engine. As I understand it, removing the sleeves or wiring them open reduces some of the low-end torque, but you make up for it in mid to high rpm. Can't speak from experience, but my engine builder says it's the way to go.

Sratching my head under the Stetson,
Denny, from the corncrib...;)

I don't know much on the GSL-SE/13B/6 port thing, but I'm gonna go out on a limb here and say you're not gaining anything by taking the port actuators off.

Think about it. At low speed you loose torque because the timing is off. That's a given. What happens at high speed. If the actuators were there, they'd be open. With them gone, the ports are still open at high speed, so I'd assume it'd be the same at high speed, actuators or no actuators. You only loose out on low speed.

*shrug*

I wouldn't say I'm a 13B 'expert' but I'm with Pele. I don't see the benifit either.

Ah! Great, I get to sound smart now ;)

Ok, the aux port sleeves are basically little tubes with slots cut in the end so they act as rotary valves. The actuators turn a rod with a notch in the end, the notch turns a small pin that is in the end of the sleeves. ok, with me still? Good, the pin, and the rod that turns it (to open/close the port) sits RIGHT IN THE INCOMING AIR STREAM.

Wiring the ports open won't give you much, if any gains. REMOVING the sleeves, and the actuators will, however give you more top end because of the improved airflow into the aux openings, but will hurt low end torque.

Anyone still following? Those that did follow that get a cookie ;)

--matt

Nicely Done, Speckamp....

I see that you agree with my engine builder in the actual function. Wish someone had a picture, or better yet an exploded view drawing...
Thanx again, Speckamp.

Denny, from the corncrib... :D

Well from my experience, they were not opening up with my racing beat exhaust even thought they were supposed to. I know that the sleeves were not gunked up too. So I chucked them. Better top end lose a little low end.

I have done it multiple ways on my GSL-SE. If you have stock ports, keep the actuators. If you port the motor, lose them. They become the bottle neck when you port.

The low end torque loss is minimal. I wish I would of chucked
those acutuators in the garbage eariler. I also chucked the
air pump and all that other associated garbage. The car is still no speed deamon, but it feels fast compared to my 4.0 ranger.

If the actuators weren’t working how would one know? What would be the symptoms? Loss of low end torque, but what else do they do?

Just Curious.

Thanks,

Where's my cookie?!?
 

Ah I see. So the actuators do impede flow, even when fully open.

Yessir, they most certainly do. But some would argue that the low end grunt is worth it.

What's the symptoms? well you can't really tell unless you either check them with a pressure pump (give them a gentle 3-4psi and you should see the arms move), or you can do what I did and top out 4th gear. w/o the ports opening 4th topped out a good 15MPH less than before. I've got a link fer ya cowboys (as Denny would put it ;) ), it's a big .jpg, but it's an exploded view of the 6 port system from the shop manual that I got off the RX-7 list a while back when I had similar questions about the motor (what? a rotary with *gasp* VALVES? hehehe) so I hope this helps.

Yeah Denny, a clogged cat will hurt the 6ports as well as the overall performance of the motor, get those things outta there! heh.

here's the link. http://www.ub3rgeek.net/~mernisse/RX-7/6PI.jpg
(as you curious kids can see, the little pins that the actuators use to rotate the valves get in the way of quite a bit of airflow. be warned, this is a 130k .jpg)

playin smarty pants again ;)

--matt

Ok, I finally had a post that sparked some interest. I would like to try wiring them open first... When I get some time to take the intake off I'll remove the sleeves. to wire them open do the both turn the same direction? Clockwise or Counter Clockwise.

Thanks
Jim:beer:

Impressive!
 

Speckamp, really neat job...
Gonna have to promote you to Wrenchboss!
Sure glad you had that at your command, helps me a lot...

And rreader, I'm sure this won't be your only post to "generate interest." A swat on the back and a good 'ol "Atta-boy" for your great post!

A tip of the 'ol Stetson,
Denny, from the abandoned corncrib...:D

When I look at mine, the actuator rods are extended all the way out while they're at rest. so I'd say wire the rods IN to the actuators, and make sure to unhook the little rubber hose that goes from the aft actuator to the split air pipe that goes to the cat so you don't have the pressure fighting your wire.

If you do end up taking them out, you might want to try and fab, or have made a pair of blocking plates so that you can remove the actuators as well. (don't need a nasty vac. leak ;) ). The 2nd gen guys do this kinda thing, but usually not until they've done other trick stuff to the point where the actuators are hurting more than helping.

Heh, thanks Denny, glad I could help!

--matt

Thanks Matt, I going to wire the ports open this weekend great sketch by the way. Do you think I will need to adjust the timing? I may try it anyways. If this all works great I'll remove them.

Cheers
Jim:beer:

timing should be ok. if you're running stock timing and the advance stuff I don't see a problem, and to be honest I don't even see a problem if you've advanced the timing per paul yaw's specs, since when you set that you're supposed to hold the motor at 4krpm (the limit of the mech. advance) and then set the timing, so even with the sleeves removed and running paul yaw's specs you should be ok (the ports should be wide open by 4k anyway!)

Good luck, tell me how you like it, I'm wondering what to do about the aux. ports myself...tho I'm pretty close to deciding to go J-spec Turbo II motor...corksport's pretty hard to resist.

--matt