Smog Pump Needed?

[uber-charged]

Hey guys, I am little new to mustangs I just picked up a 1985 Mustang GT and just started doing maintenance on it ( new cap, rotor, plugs, oil change, etc.) and I noticed it has something called a "smog pump". Apparently it connects to the intake and the exhaust am I correct? Well I was thinking of what it could be used for or if its needed and all I found was this on another site. http://www.allfordmustangs.com/Detailed/660.shtml Seems like you could just bypass but I was thinking I could just remove the whole assembly and all of its hoses. My questions are.

What is the Purpose of a Smog Pump?

I am going to be putting on headers and a full exhaust, do I need it?

Can I just remove it or bypass it, and forget its existence?


oh and btw I live in a town where there is no DEQ

[JACook]

With the other changes you're making, the smog pump would make for a little
less exhaust stink, but it's main purpose is to provide supplemental air for the
catalysts.

Lotta guys think removing the smog pump will free up horsepower. It won't.
And it doesn't weigh much either. So removing it is pretty much just a looks
thing.

[uber-charged]

Thanks I was thinking about getting the BBK 2.5 inch High Flow Cat H Pipe. With that in mind, i dont believe the smog pump connect to it. am I right?

Ill probably just bypass it.

[embler]

you will need the smog pump for a catted pipe. without one, the cats might overheat and start to melt.

[uber-charged]

Oh so aftermarket cats need the smog pump?

[JACook]

Yes. The BBK cat pipe has the provision for the downstream air. You'll need
to change the '85 cat air tube with an '86-'93 tube. The cylinder head tube
is fine. You'll also need to change out the driver side shorty header with the
later version, or if you're going with aftermarket shorties, just use the later
ones. You can add short pieces of pipe to the later shorties if you're wanting
to keep the factory air cleaner heat tubes.

The later 'H' pipe will also require the double-hump transmission crossmember,
as well as the later exhaust hanger plate that goes between the transmission
mount and tail housing. Some guys just leave that plate out, but I don't. My
'85 sits pretty low, and I didn't want -any- exhaust system sagging.

[Curtis]

Yes. The BBK cat pipe has the provision for the downstream air. You'll need
to change the '85 cat air tube with an '86-'93 tube. The cylinder head tube
is fine. You'll also need to change out the driver side shorty header with the
later version, or if you're going with aftermarket shorties, just use the later
ones. You can add short pieces of pipe to the later shorties if you're wanting
to keep the factory air cleaner heat tubes.

The later 'H' pipe will also require the double-hump transmission crossmember,
as well as the later exhaust hanger plate that goes between the transmission
mount and tail housing. Some guys just leave that plate out, but I don't. My
'85 sits pretty low, and I didn't want -any- exhaust system sagging.

I installed a catted BBK H Pipe and didn't need to change the cat tube on my 85. If I remember I just cut a short section off of my original and used the short section of hose supplied with the H Pipe. I was worried about the rubber hose melting, but I called BBK and said it would be fine. No problems in 3 years with the rubber hose. I was also lucky that my drivers side header fit also, I just had to elongate one hole in the flange slightly. I did use the double hump cross member and the hanger plate. The H pipe was a bitch to get to fit on the hanger plate, I ended up having to uninstall the cross member, install the hanger on the h pipe then re-assemble everything. Cook is right, I think you could hang on the exhaust once the hanger plate is installed. I wouldn't install with out the plate.

[uber-charged]

Yes. The BBK cat pipe has the provision for the downstream air. You'll need
to change the '85 cat air tube with an '86-'93 tube. The cylinder head tube
is fine. You'll also need to change out the driver side shorty header with the
later version, or if you're going with aftermarket shorties, just use the later
ones. You can add short pieces of pipe to the later shorties if you're wanting
to keep the factory air cleaner heat tubes.

The later 'H' pipe will also require the double-hump transmission crossmember,
as well as the later exhaust hanger plate that goes between the transmission
mount and tail housing. Some guys just leave that plate out, but I don't. My
'85 sits pretty low, and I didn't want -any- exhaust system sagging.

Oh i wasnt going with the shorty header set up. I was going with long tube. Do i still need the double hump cross member with the long tube set up? and or everything else that has to do with the smog pump?

[JACook]

The cats will still need an air tube, but I can't say whether the factory air tube
will work, or which one. You might not need the double-hump crossmember,
but you'll be able to tuck the exhaust up for better ground clearance if you do
use one.

[uber-charged]

ok so cats need hose period, dang haha. Maybe ill go Catless where can i get a double hump cross member?

[86_Notch]

get a double hump cross member and do it right, i've never had any luck with the hanger ( maybe it's just me ? ) but i always bolt everything up finger tight only , then i put a floor jack under the H pipe and jack it up till it just hits the floorboard, then i tighten everything up and when the jack is removed the exhaust will drop just enough that it doesn't touch the floor without sagging, i have 3 inch exhaust from the headers back and they don't sag one bit ( i can't stand a car that has it's pipes hanging low ) as far as the smog pump , you don't [I]need[I]it. but if you delete it you need to plug the holes in the back of the heads with some bolts . i either pinch weld the tube shut ( on the h pipe ) or clamp a short piece of rubber hose with a bolt threaded and clamped in the end of it. btw my cars always pass emissions without the smog pump so i don't see the harm in deleting it, it cleans up the engine bay and eliminates weight which is always a good thing

[uber-charged]

So they wont melt and die? haha. What kinda Cats are you running?

[JACook]

Without supplemental air, the bigger problem is the cats can clog, which many
mistake for meltdown, since the initial symptoms are similar.

I don't really understand why people think the air pump is such a burden. Those
things weigh what, 5 lbs? And where the air pump system sits, how much are
you really cleaning up the engine bay?

[86_Notch]

the more stuff you have the more stuff to go wrong ( cracked hose going to the smog pump , pump seizing, extra wear on the serp belt, the more accessories you have to turn the worse your gas mileage will be ) and the uglier your engine compartment will look

[embler]

Without supplemental air, the bigger problem is the cats can clog, which many
mistake for meltdown, since the initial symptoms are similar.

I don't really understand why people think the air pump is such a burden. Those
things weigh what, 5 lbs? And where the air pump system sits, how much are
you really cleaning up the engine bay?

totally agree. I have went through the trouble of removing it and the hoses and such. other than it being easier to get to the spark plugs, I noticed no benefit from it. only a gassy smell (and no not just from myself )

the more stuff you have the more stuff to go wrong ( cracked hose going to the smog pump , pump seizing, extra wear on the serp belt, the more accessories you have to turn the worse your gas mileage will be ) and the uglier your engine compartment will look

a smog pump maybe takes 1/2 hp to turn, if that.ive never noticed any difference in gas mileage without having the pump.