My dad is in the process of swapping the exhaust and engine accessories from his old GSLSE autox car unto his stock GSLSE. This includes deleting the air pump and installing a Racing Beat ACV block off plate. I know that the airpump allows the fifth and sixth ports to actuate, will the ACV blockoff plate still allow them to do this? We are really just trying to replicate what his old car had.

 

I see in your profile you list a GSL. If you haven't swapped in a 1984/1985 GSL-SE 13B, then your 12A does not have 5/6 port actuators.

 

Yeah, forgot to put my dad's GSLSE. My bad

 

You can add a copper line in the header to activate the ports.

 

The air pump has nothing to do with the dynamic effect intake system and the operation of the 5th and 6th ports. The 5th and 6th ports are opened by exhaust backpressure. There's a pressure tube called a split air pipe that bolts to the main catalytic converter and runs to the intake manifold. One the criteria is met for operation of the dynamic effect intake system, the 5th and 6th port actuators open and the air that is stored in the dynamic chamber is forced into the engine through the 5th and 6th ports for what Mazda called, "a supercharging effect". It works quite well and a fully functioned SE is pretty quick. If you are still running a catalytic converter it's best to leave the air pump in place and functioning. The air from the air pump does help to cool the cat and maintain temperature for efficiency. Removing it does nothing for power gains.

 

As previously stated above, the Series 3 SE cars used the exhaust acupressure from the Main Catalytic Converter to provide 4-6psi (*available only at high throttle, high load) which was backfed up the split-air pipe with a bleed which goes to the 5/6-Port Actuators on the Lower Intake Manifold. This split-air pipe has a one way valve from the Air Control Valve to the catalyst, thereby allowing the Air Pump to provide fresh air to the catalyst under all other conditions.

I have emissions testing in my area, so I leave my Air Pump installed but unbelted, the Air Control Valve installed and otherwise functioning, and run a Racing Beat SE exhaust which features a presilencer with a bung to match the stock split-air pipe to provide backpressure to the Port Actuators. It all works just fine without air pump pressure, as theres not catalytic converter to feed, anyway.

If your dad is trying to replicate the stock system, leaving the Air Control Valve in place has no I'll effects on the car and preserves 5/6-port operation, which is impressive when working correctly.

 

I prefer to leave the airpump on if possible, for positive water pump drive.
You can pull the end cover off and remove all of the vanes so it becomes nothing more than an idler pulley.
(You do need to put the cover back on, of course)

 

Dual Sheave alternator pulley solves this problem very cleanly, and underdrive models are available in the event the driver likes RPM. I went with this, and only revert to the Air Pump belt when I do emissions testing every other year. Air Pumps don't last forever, but when I need it to work, I'm glad it's only run when I need it.

 

Dual pulleys did nothing for mine. I know many that have had luck with no belt noise, but some like me, it was a fail.

 

If you run a dual belt, you need to run a pair of matched belts. Otherwise one will be slightly longer or wider than the other, which results in slippage and trashed belts because they will be running at slightly different speeds.
I used to run a minibelt for the water pump, and this actually caused my alternator belt life to go down. About 2000mi between belts. Switched to a single Continental brand belt and belt life increased dramatically.

 

Thanks everybody for their input. He has a full RB exhaust so it has the tube off the presilencer to activate the ports. He normally runs a dual pulley with two matching continental belts as without it he would eat up belts every 500 miles or so. It looks like he is going to install a blockoff plate for the ACV, put his dual belts back on and take off the airpump.