I was wondering if I should be able to see the aux port actuators moving when I rev the engine by hand past 3,800 rpm, or do they only work when driving the car and under load?

Mike

 

They only work when the car is under load.

 

if you're talking about secondaries** if you have mechanical secondaries you can open them by hand, i never had vacuum secondaries long enough to see if you could open those by hand, i don't know if that's what you're talking about tho.

 

He has an SE so I'm pretty sure hes talking about the 6-port thingamajiggers. Sooo yea, the port things only open under load as stated by poster number 2.

 

Mike,

Is this with the S5 intake that you are installing? If so, he is running a lumbar pump running off an RPM switch. In that case, load does not matter. They should actuate on your RPM setpoint.

For stock, they operate under load. However, you can usually get them to open in the driveway if you rev quickly enough. It also depends on if your exhaust is stock or if you have some type of aftermarket exhaust.

 

S4 actuators work just fine with no-load.
In Europe

Yeay Butterfly Power

 

I tested my actuators with my compressor. Pump it up and regulate it to ~ 6 PSI and give a shot of air to each actuator. Mine snapped right open and led me to find my problem to be a leaking hose from the exhaust venturi.

 

Hey Kent,

I decided to not use the air pump/rpm switch for the aux ports. I'm using exhaust back pressure to operate the S5 aux actuators, since they take less pressure to work than the stock SE actuators. When I rev the engine they move a little, but I'll have to put some goop on the actuator cams to see if they are hitting the stop to make sure they are working while driving. I am still having LIM leak issues, so I might be loosing back pressure, which would explain why the aux port acts don't move much under no load.

FYI--I am using the lumbar pump and RPM switch for the VDI.

Hopefully I'll do some tests tomorrow and let you all know what I came up with.

Mike

 

Ok, from the posts here and from Pm's that were sent to me, it seems that half of you said that the aux ports work under load while the rest said they work under no load. I invite either RX-7doctor or GSL-SE Addict to verify who is right. Of course, I am asking that this check be done with an SE that has a racing exhaust or at least headers.

Thanks,

Mike

 

Just a curious question. Can the aux ports opening up be felt by the driver as a slight increase in power, or heard?

 

They operate on load. 100% sure. This is what happens:

- throttle plates open (going uphill or accelerating)
- more open plates means higher flowrate of air/fuel going into the engine at a given RPM
- what goes in, must come out the exhaust
- the pressure drop (backpressure) along the exhaust pipe depends on 2 things:
1. resistance of the exhaust design
2. exhaust flowrate

So your exhaust design is fixed. The measured psi at the 5/6 port pickup tube is then only a function of flow through the exhaust. At say 3psi to fully open, this can be achived by:

- restrictive exhaust at lower load (or RPM)
- less restrictive exhaust at a higher load (or RPM)

Say the exhaust design is fixed they actuate on:
- lower load, higher RPM
- higher load, lower RPM

So, it is primarily load driven with a fixed exhaust..but you can have the same flow (back pressure) at say 7000rpm under low load or say 4000 rpm under a higher load. They don't know the difference between the two. They just open when pressure is high enough.

Now on a stock exhaust, they can open in the driveway if you snap the throttle open fast enough. With an aftermarket exhaust, that may or may not happen. It depends on the design of the exhaust.

 

Thanks Kent.

 

Take a tiny zip tie and fasten it around the bottom of the rods. Go out for a drive making sure to take it to 5-6000 RPM a couple times. When you get back pop the hood and look at the actuator rods. The zip ties should have moved up to the top of the rod. Remove the ties for full travel afterward.