First I want to get this out of the way. I do not want to attempt to make my 89 5.0 F150 a speed machine. I have something else for that. With that said, are there any gains to be had from the removal of the smog pump, egr, and cats. This is something that can be done easily and relatively cheap. I am going to change mufflers but that will be mostly for sound with performance a side benefit. I would really be more concerned with MPG that HP. But if there are gains at there to be had on the cheap, I'll do it.

BTW there are no emissions testing here.

 

Out of what you listed, the only thing that will help is tacking off the cats, assuming they are clogged, and assuming that it is legal where you are.

That being said, there is really no point in having the smog pump if you dont have cats. It really doesnt steal any useable power by being there, but you CAN take it off. If you decide to go that route, get a idler pulley, not just a shorter belt. Doing it that way puts alot of extra tension on the alternator pulley.

And just for the record, that idler pulley costs about twice as much as just replacing the pump with a new one.

 

how 'bout underdrive pulleys? I haven't tried them, but some guys swear by them.

 

I guess the smog pump doesn't have that big of a drag on the crank? I'm not sure that the cats are clogged but they do have over 200,000 miles on them, so I am going to assume so. Yeah I had read that the idler pulley was the way to go, but if there are no mpg gains from freeing up that drag, then I'm not really interested.

 

Not so much. You never want the alt. turning any slower than it has to in these trucks, especialy if you have the stock 75-80 amp and any electrical upgrades.
I would get some high flow cats. While you are at it do a single 3" exhaust. Headers, Bassani Y-pipe, high flow cat, muffler of choice and then the single 3" pipe.

Some people take the pump off when it either locks up or starts making so much noise it is rediculous. If yours is ok I would leave it on though.

 

If you leave the smog pump on and remove or gut the cats, you will get a lot of popping and crackling in the exhaust, especially if you go to a low restriction muffler. I'd leave the EGR alone if it's working.

 

How do you figure? I have my smog pump on and working, with a gutted cat. No odd noises or poping...

I agree with leaving the EGR alone though.

 

For the gain I don't think it's really even worth it to mess with the EGR or the smog pump. The smog pumps turn easily and can't rob much power. If you do decide to rid yourself of converters it may as well go, but it probably helps as much in weight savings as it does in power gain.

Most stock mufflers are crap. From what I've seen the muffler is usually the worst restriction in the system, so anything else will help.

Underdrive pulleys are cheap and an easy way to free up parasitic losses. If you run major stereo and/or lights of power using accessories you might want to use caution on the pulleys if you make a lot of short trips or lots of city stop and go driving at night.

Intake mods can be done really cheap on these trucks, and help a decent amount.

I got some good gains with an aftermarket ignition box and hotter coil, but I've now killed two boxes. As a side benefit though the power gains alone wouldn't have been a good bang for the buck, it helped the MPG of the truck, and with gas prices what they are would have been worth it for that alone over time.

 

Aftermarket intakes will only be worth the money on the 351. The 302 flows as good or better than any aftermarket intake stock.

 

I'm smellin what yer cookin. I hadn't gone with them because I use e-fans. However, I mentioned them as food for thought, because some guys here have used them with good results.

 

An electric fan may free up some HP & add a little mileage

 

True. A stock Taurus fan is a popular upgrade.

 

ok so my cats are cut off, my smog pump is disconnected. your saying I should just leave the pulley for it there unless it seizes up? rather that a shorter belt? i guess the shorter belt would mean more revolutions for the alternator...right. which would maybe create too much electricity for my battery...?

 

Wrong. You aren't changing pulley sizes.

 

With reference to the EGR: A properly working EGR system improves mileage and costs exactly zero performance since the EGR is disabled at WOT. Leave the EGR alone if it's working and fix it if it isn't.