I do not have one of those newfangled RX7's that the aux ports are opened by the air pump thru a solenoid. Some of the posts here got my curiosity up. Can you rev a 1990 model in the driveway and see the aux ports open? If they are just rpm activated I would think so, but from some of the posts on these newer models, you'd think that is not the case. I don't think there is access to a say 1990 model Factory Manual on the net, or I would look myself. Thank you.

 

On '86-'88 you can rev it up in the driveway, and see the rod move. I did this on my neighbors. The '89-'91 have to be under load so you can't really see them move unless you mount a spy camera down there.

 

You could use a series presure and vacuum gauges with Tee fittings to monitor line conditions. You could also manually make the actuators move by using a hand pump.

 

I have a 87 and 86. I know how they work. Back pressure from the exaust, originaly. I just got curious about the 90 models because of posts I read here. I know they are activated by the air pump and there is a solenoid valve b/t the air pump and aux actuators. I more or less know that the solenoid opens around 3800. I'm just curious if the trigger for the solenoid that opens them is just rpm activated or is there some other element. I never seem to read a post on 90 models where the person says *I reved the engine in the drive way and the actuators did not open as they usually do*. Just makes me wonder if there is some other thing besides the rpm involved.

 

I have a '90 NA and there is an ECU output for both the VDI and 6PI. I assume these signals open their respective solenoids. I recently monitored the ECU output signal and found my VDI opens at 5500 RPM and 6PI opens around 4400 RPM. I correllated my tach with DVM.

Accroding to my seat of the pants dyno, the VDI has a huge impact. I couldn't really feel the 6PI.

I don't know where the ECU gets the signal to switch these outputs. Is it from the pressure sensor or is it RPM activated? Does anyone know?

For those of us using an RB presilencer and header....

I've always been curious why you couldn't connect the presilencer air tube (forward facing) to this line and do away with the air pump. Most people thought I was nuts and several posts I put on this site didn't get any replies. Finally I got through to someone knowledgeable at Mazdatrix and he said it would work. Here is his quote....

"Yes, the tube will work, but the 6-ports, and the VDI will probably open a little early. The tube should produce about 4psi at 4000 rpm. (Approx.)"

When I get a chance I'm going to try this. You could always adjust the pressure with a bleed off. Why am I interested?....to make room in the engine compartment, reduce weight and take a little load off the pulley.

It's funny, I hear people always talking about the 6PI, but never about the VDI? That opens with the same air pressure. Do you guys just disconnect it or wire it open? I have huge power gains when the VDI switches in.

According to the '90 manual....
The VDI opens at 2.8 psi
The 6PI starts to open ay 0.85psi and is fully open at 1.4psi