Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

'84 Mustang Smog Pump


ellersk's Avatar
Member

Join Date: Aug 2001
Posts: 130

12-06-04, 07:01 PM   #1  
'84 Mustang Smog Pump

I have an '84 Mustang, 5.0 L with 5 speed and approx. 84,000 miles. Car runs fine. I was given a part called an "Air Pump Idler Bracket" to eliminate the smog pump and keep the same serpentine belt. I was told it will significantly increase HP.

Is it true I will increase performance? Will gas mileage be compromised? What does the smog pump actually do? And if it will work, how should the exhaust hoses to the pump be routed?

Thanks for your help.

 
Sponsored Links
pt_fixer's Avatar
Member

Join Date: Apr 2004
Posts: 106

12-06-04, 08:00 PM   #2  
Dont count on it to "significantly increase HP". You wont even notice the difference when you drive.

 
ellersk's Avatar
Member

Join Date: Aug 2001
Posts: 130

12-07-04, 09:36 AM   #3  
Thanks for your reply. What does a smog pump actually do?

 
davo's Avatar
Member

Join Date: Apr 2002
Posts: 2,417

12-07-04, 03:09 PM   #4  
It aids the catalytic convertor in functioning properly.If you have an emission program in your state removing the pump will cause you to fail the test.If you are trying to lower your et removing an air injection reaction pump will be a waste of time and money for the adaptor you would need.Those pumps use a very small amount of horsepower but will make your exhaust system last much longer.

 
slickshift's Avatar
Member

Join Date: Aug 2003
Posts: 4,320

12-07-04, 05:26 PM   #5  
Posted By: ellersk What does a smog pump actually do?
It's called a thermactor system
It injects fresh air into the (hot) exhaust
When fresh air is mixed with the hot exhaust it increases oxidation, reducing the concentration of CO & HC and converting them to CO2 & H2O

It it a mad desire of many hot rodders to rip out anything emissions because it must be robbing HP "If it's good for the evironment, it must be bad for power"
Many wives (racers) tales have sprung up around this
This is one
The amount of HP you will gain on your (stock?) 302 would likely be less than 3
And I do mean 3hp, not 3%

If you were to do this in conjuction with removing your AC, converting to an electric fan, and switching to underdrive pulleys, you might bump it up to 10
But then you'll need a new belt anyways

 
davo's Avatar
Member

Join Date: Apr 2002
Posts: 2,417

12-07-04, 06:08 PM   #6  
[QUOTE=slickshift]It's called a thermactor system
It injects fresh air into the (hot) exhaust
When fresh air is mixed with the hot exhaust it increases oxidation, reducing the concentration of CO & HC and converting them to CO2 & H2O[QUOTE]
Well actually the oxidation part is true that is what I said it makes the catalyst work.If the convertor is not there the result is much less effective.A Thermactor as you called it is a thermal air cleaner from the carburator days and helped reduce emissions during a cold start by introducing air heated by the exhaust manifold into the air cleaner to help with combustion thus lowering exhaust emissions of co and to a lesser degree hc.Heat risers were also employed to heat the intake manifold to lower cold start emissions and promote drivability.Fast forward to the fuel injection age and air injection reaction systems are meant to lower cold start emissions for about 30 seconds or less while the O2 sensor heater fires up the O2 sensor to better control emissions.Most vehicles today don't have air injection reaction systems but a few do.The new kid on the block is wide band O2 sensors and I'm not going there today.

 
slickshift's Avatar
Member

Join Date: Aug 2003
Posts: 4,320

12-07-04, 06:34 PM   #7  
Not Correcting

I wasn't correcting, just adding
Ford calls it a "thermactor exhaust emissions control system"
Maybe I'm spelling it wrong
Maybe Ford still calls it by an old term and it's kind of a misnomer
I'm trying to de-bug one on an '86 Mustang right now
It's got an upstream/downstream/bypass switch that's not working right
It's SEFI so no heat riser
ellersk has 1 or 2 heat risers
And a ther...smog pump

 
ellersk's Avatar
Member

Join Date: Aug 2001
Posts: 130

12-07-04, 08:01 PM   #8  
I think Slickshift just answered this, but it sounds like springing for a $100 underdrive pulley kit will just look nice and not really do much for performance. Sounds like I can spend my money in other places to get more bang for the buck.
Thanks.

 
slickshift's Avatar
Member

Join Date: Aug 2003
Posts: 4,320

12-07-04, 08:30 PM   #9  
A set of pullies could be 7-13 on their own, at the rear wheels
It depends on your set up and how much your particular accessories are taking from the engine

I'd actually recomend underdrives on a 5.0
Keeping in mind that some with high electric needs ('lectric fan, big stereo) have run into charging problems
If you get a choice between race and street go with street
I put them on the '86 and have no charging problems, but try not to let it idle under 2K for long

A good bang for the buck

 
ellersk's Avatar
Member

Join Date: Aug 2001
Posts: 130

12-08-04, 07:18 AM   #10  
Thanks and last question - from what I have read, when changing to underdrive pulleys on an '84 Mustang, the serpentine belt must also be changed. Is there a belt length difference I should look for or is it just trail and error?

 
slickshift's Avatar
Member

Join Date: Aug 2003
Posts: 4,320

12-08-04, 07:59 AM   #11  
On this project the pully co. and a ref. book gave me a size
Neither worked
I'll shoot you a PM with a specific resource for 79-86 Mustang/Capris
I'll bet someone there has done your combo

 
ellersk's Avatar
Member

Join Date: Aug 2001
Posts: 130

12-10-04, 02:45 PM   #12  
Thanks for the help and anything you can forward to me would be great.

 
slickshift's Avatar
Member

Join Date: Aug 2003
Posts: 4,320

12-10-04, 02:56 PM   #13  
PM sent
Check your Private Messages

 
aaronr121's Avatar
Visiting Guest

Posts: n/a

12-10-04, 09:35 PM   #14  
aaronr121
I put underdrive pulleys on my 84 5.0 many years ago. While the belt needed was a tad bit smaller, the stock size belt did the job untill I got another one and it has also served as a good replacement. I did notice a bit of difference in power too.
It doesn't have a problem charging, but like Slick said, you don't want to let it sit at idle for awhile, you just don't turn enough RPMs to get a charge.
It did help it run cooler tho. I think it's just because you are turn the water pump slower so the coolant has a longer time in the radiator to cool down. That's my theory anyways.

 
Search this Thread