marcinband

iTrader: (2)

Hey all. Just removed my airpump to get to the lower radiator hose, and when i went to put it on, found that i lost a few parts.

Does the airpump serve any other purpose besides emissions? If i left it off would it be harmful? I've had the belt off of it since last summer. I am just being lazy here because it is getting dark and i need to put the rest of the car together.

sTaLa

It depends if you have a turbo or a NA, an S4 or an S5. On the NAs, the airpump is used to open the auxiliary ports.

If I remember well, 1- on the S4s, the airpump pushes air into the cat, gives you more backpressure, wich is used to open the aux ports; 2- on the S5s, I think the airpump is directly used to open the aux ports (you can bypass it with an rpm switch).

But no airpump can clog your cat, and don't count on passing emissions without it.

I told you what I remember. This subject has been covered plenty of times, so you can search to be sure what I just said is really true.

Ravingecu21

it opens ur 5th and 6th ports

marcinband

iTrader: (2)

i have an 86' gxl (non turbo)

so this is a nessesary item?

ps..i'll search

thanks

VT_Rx7

I don't think it does anything to any S4 expect emissions.

sTaLa

Not directly but you may not have enough backpressure in your exhaust to open you 5th and 6th ports if you remove the airpump.

chano

what does the backpressure that goes to the aux ports actuators from the cat have to do with the airpump ??

marcinband

iTrader: (2)

i must add that i have had the belt off of the airpump for almost a year, without any related problems...just overheat. it moves a bit sometimes on it's own though.

sTaLa

Maybe I'm wrong; but if I remember well, there's a pipe that connects the airpump to the cat. I'd have to look under the car.

I'm quite confused: if the airpump is connected to the cat, how do the aux ports take their backpressure?

chano

well in my s5 the air from the airpump goes through the acv to the auxports/ vdi and from The ACV there is a tube that goes to the cat, i believe the airpump pumps clean air into the cat for emissions purposes.

But in the s4 im pretty sure the backpressure goes from the cat to the ACV to the aux ports. so the airpump is there for the emissions purposes only.

sTaLa

I was not wrong... neither was I totally right. This is a scheme from as 1987 NA, if you don't understand this...

Icemark

You are sort of correct.

The same line for feeding the main cat air, is used to pressurize the aux ports.

Its the timing that you are off on... when the RPMs and load is high enough, the aux ports will open regardless of if the air pump is feeding the cat. Infact at above 3850 the majority of the air from the air pump is shunted down the relief line anyway.

And back pressure is a bad thing...You never want back pressure.

You want exhaust volocity pressure to open the aux ports.

staticguitar313

iTrader: (2)

airpump . . .
alright lets break down that word . . . air pump

basically its part of a system to pump air into your AC

yeah . . . ac

Boostmaniac

Ok, I'll try to make this quick and simple.

The rotary, because of it's design, has very dirty emissions and has trouble passing smog tests. Mazda knew this and put multiple catalytic converters on the car. The catalytic converter the air pump is attatched to is normally referred to as the main cat just to clear up any questions. The purpose of the catalytic converter is to slow down the exhaust in it and to create a "hot spot" in the exhaust path. This hot spot helps burn off extra hydrocarbons that weren't consumed in the power stroke cycle. This works on regular piston engine cars quite well, but since our motors produce even higher levels of emissions, they needed to make the "hot spot" even hotter to burn off our excessive hydrocarbons. The air pump does just that. It pumps a large volume of clean oxygen into the catalytic converter to increase temperature and provide the oxygen neccesary to burn off our extra emissions. Removing this reduces the effectiveness of the catalytic converter and causes our cars to fail smog because it can no longer consume the hydrocarbons.

Most people at this level of tuning realize that they can't pass smog anyway and go ahead and remove the catalytic converters to free up a nice chunk of horsepower. This added power is usefull in trying to outrun the greenpeace van that will probably try to chase you once they get a whiff of your eye watering exhaust... so do what you want.

Also, some higher performance piston motors sometimes come with an air pump also to help clear the new smog laws. I think some LS1's came with an electric air pump, but that may be faulty information.

As far as the fifth and sixth ports are concerned, Icemark is, like always, correct.

I hope this helps.

P.S. the air pump is really only usefull at lower rpm's when there is light to no load on the motor. This is why the FD airpump is designed with a magnetic clutch to disengage at a certain rpm because it is really no longer needed and frees up some power. Ours just stays on the entire time.

slpin

iTrader: (9)

air pump is there to COOL down the cat
that is the biggest mess of mis information ever!!

and, no, air pump barely take up any power, if any.

Boostmaniac

ummm....
no.

Next time you want to flame a post, read first.

http://www.innerauto.com/Automotive_...stem/Air_Pump/

http://www.carcare.org/Emission_Control/air_pump.shtml

Just in case you missed chemistry, by speeding up the combustion of the emissions, it increases the temperature in the catalytic converter. But you probably didn't read those links so i won't go any more in depth.

But you are right about the minimal power gain by the removal of the air pump, so don't feel too bad.

riverzendz

marcinband

iTrader: (2)

Informative. Thank you all for the debate on this. I am going to leave it off and drive it, except on earth day; )

slpin

iTrader: (9)

uhh, yes...

straight from your OWN link

a non-working, non-existent air pump makes your cat run even hotter and overheat.

the air pump is there to cool the cat


next time you want to sound smart....

Turbonut

iTrader: (1)

Sorry, but it's not to cool the converter:
Essentially the air injection system supplies air to the exhaust stream to promote additional burning of exhaust gases such as hydrocarbons (abbreviated as HC) and carbon monoxide (abbreviated as CO). The air tube to the catalytic converter helps to further reduce HC, CO and oxides of nitrogen (NOx), a major contributor to photochemical "smog."

Aaron Cake

iTrader: (1)

What he said.

Now closing this orgy of misinformation and stupidity.