Rotary_MD

Just bought a S5 NA - only have had S4s to this point. Is it possible to change the actuator function from air pump to exhaust ?

Going to put in a RB header system - can I get the one with a exhaust port and hook up to the actuators? That way I can remove the air pump /acv/split pipe etc.

RotaMan99

You can, but why? With open exhaust you wont have enough backpressure to open the aux and VDI. I don't know if you would have enough pressure if you went with only RB mufflers. Maybe someone else can chime in here.

The air pump doesn't take much engine power. Not enough to measure anyways.

Rotary_MD

Reason I want it gone is more room and simpler setup. The RB exhaust in the S4 is able to actuate the ports by back pressure.

RotaMan99

Thats if the exhaust is not a high flow exhaust. If its to free flowing there won't be enough pressure to open the ports. I havn't seen or heard any issue with running RB muffs and header with the aux ports though.

arghx

iTrader: (3)

easiest thing to do is keep the air pump. you can still remove the ACV and other emissions crap.

Black91n/a

You're forgetting about the VDI, you'd need to convert that to exhaust as well. The general consensus is that the airpump doesn't actually rob much power and is very reliable. All the other cobbled together means of actuating it all would probably be much less reliable.

Do a search for things like electric aux ports, there's a bunch of people who run electric pumps.

NZConvertible

This is a truly terrible idea and will result in a loss of performance. Stick with what you've got, it's far superior.

RotaryResurrection

iTrader: (8)

Running ports off the exhaust is/was a terrible idea on mazda's part. Just as with turbo cars it is well know, higher gears put more load on the engine, and more load = more airflow at the same point. NA's do this as well, just to less of an extent. So, the ports are set up so that X amount of airflow/pressure opens them. But, in the higher gears, X would be achieved sooner, and in the lower gears, X would be achieved later. So the ports will be opening and closing whenever they damn well feel like it, instead of at certain RPM/load points that the intake is tuned for.

This is where the s5 setup shines above the s4; the computer determines these points and activates the ports using dedicated vacuum solenoids so that they work reliably and exactly when they should.

IF you want to get rid of the airpump, then it can be done. Use an electric air pump to replace the smog pump, and have it turned on by a relay, using the 6 port solenoid wires as a trigger. here I am using a cheap tire compressor pump, you could also use a late model GM or rx-8 electric smog pump. You only have to keep the 2 vacuum solenoids, and you can hide them and clean up the few leftover wires/hoses however you see fit, this was just a quick and dirty.

Now, it seems my web guy kinda joined 2 writeups together and called it "89-91" here even though this is actually more geared for 86-88, so just ignore the parts about the MSD rpm switches etc. which would be necessary for this conversion in an 88 or earlier model. Air supply would go from the air pump, teed to both VDI/6PI solenoids, and then from each solenoid to their respective actuators.

http://www.rotaryresurrection.com/2n...elec6port.html