Underdrive pulleys+smog pump delete= ??
 

I just finished installing underdrive pulleys and deleting all the smog. I am trying to make a 90.5" belt work, but I am not sure its going to happen.

Has anyone done this with success? Do the Mustang smog pump eliminators fit? I know I can gut the OEM pump but I don't want that thing back on my truck.

I am going to figure this out, just wondering if anyone else has traveled this road. Truck info in signature.:thumbup:

i just took the pum pulley off and bought a shorter belt

I want to do the same thing. How about posting the belt part number.

Thanks,

I did buy a shorter belt. However the way the tensioner works it leaves no room for error. I had to stretch a 90.5" on. I do mean stretch!:unsure:

ive also wondered what removing the smog stuff does to your fuel mileage? as far as not recirculating those gases?

I really don't care about fuel mileage, but I do know hot exhaust gasses are not good for an engine wanting cool/fresh air. My truck pulls really hard and drive ability has improved.:thumbsup:

why not get a 91.5 or a 92.5 belt...?

stretching one on the hard way is only going to make other things wear faster...the belt done give as much and the water pump will prolly go shortly....

perfect fit no ac on air pump 1992 to 96 f150 4.9 part number 790k6 duralast at autozone .. feels like 20 plus hp and torque low end and lot!!! more power at 3500 to 4000 . no check light so far, i removed the old air conditioning pump.. AIR pump left in place but not in service ....... highly recomended mod no ac or dummy pulley smog working is part number 930k6

update all is good no light ... this is wow big power change mod AAA someone needs to make underdrive Pulley Kits for the 300

I put the A/C delete pulley on mine from Summit. The Smog pump is still on but not being used hose cut- off in the back. I also thought about the stang pulley delete?? Not sure if it is in the same location- never really looked. As far as the A/C delete pulley I bought - I had to make spacers & get longer bolts to mount to the new bracket to the existing A/C bracket and to fit the normal stock belt as mine would not get tight enough- you would have thought the delete pulley would be the same distance???. It really just starts cleaning the engine bay up.:blush:

Well for those who do care about gas mileage, does a smog pump delete really help at all?

BUMP! I've been looking all over and couldn't find anything super useful. So i'm reviving this thread. For those of you who have done the smog pump delete, have you noticed a millage improvement?

Stang delete pulley works fine.

Have you noticed any gain in millage or performance with the delete?

The smog pump has very little drag. You're not going to see any horsepower or mileage gains.

Thanks Sean

What about the ac sean?

I only put a delete pulley on cause my smog pump seized up. Couldn't tell you either way. I added a lot more with it

The a/c is an idler when not engaged so no gains there either.

Sean is right on the money as usual. The AIR pump doesn't recirculate exhaust gas. It does what it says. It pumps fresh air to the cat to provide oxygen ( which is generally burned up in your engine) needed to convert polutants. It has less drag than your cooling fan and about as much as the alternator. Just try spinning it by hand. The EGR recirculates exhaust gas to reduce combustion temperature and increase flow. Removing it can cause a bunch of trouble. As for the A/C , when not in operation , it is just an idler pulley until the magnetic clutch is activated. Again just try spinning it. If someone found 20 HP from deleting these pulleys I've got some swamp land to sell.