I've spent hours reading this forum since I bought a 1986 F250, 6.9L, standard cab. I've visited dozens of websites looking for intake and exhaust mods which fit this truck, and keep coming up against the same thing...it's all for newer trucks.

I'm not a mechanic, so I'm looking for better-than-stock air intake systems and exhaust systems I can buy and take to my wrench for installation.

I'm not interested in stacks, turbo or anything which will drastically alter the look of the truck. I just want it to inhale and exhale a bit better.

Any suggestions of sources for these mods would be greatly appreciated.

 

Dynomax makes a relatively inexpensive 4-inch exhaust system for the NA trucks (part # 19429). From there, a free flow intake with a ducted cool air intake (you'll have to build that, Banks took their NA Stinger kit off the market) and turning up the pump just a skosh will add a bit of power. Take the time to carefully search this forum and you will find a bevy of good advice and inspiration.

To be honest, anything less than a turbo kit is a waste of money. Nothing will give you more in one big lump than a turbo... at least in a form you can live with day to day. MPG will also tend to bump up. Remember the old adage...

"There's no excuse for a naturally aspirated diesel!"

Start saving now!

 

Jim..thanks for that Dynomax part#. I found it at Walker for $339.

Are you saying this kit won't do the truck any good, that the stock exhaust system is just as good?

I'm not necessarily interested in more power. So far, it seems to have plenty. I'm looking to preserve an engine which only has 42k miles.

 

No, I'm just saying the amount of power you get is small. I haven't dydo tested this system against a stock system, but typically, a setup like this will give you UP TO about 10 hp and 15 lbs-ft. In my experience most are less with no other changes to the engine. You can multiply those numbers with other enhancements but $330/10= $33/hp, $330/15= $22/lbs-ft (compare that to the below numbers) if you are lucky enough to get the maximum. The cost effective way to approch it is when your exhaust system is ready for replacement, then get the better system and take the gains as gravy. EGTs will drop when towing or working, too.

As for the turbo, when you bolt it on, you go from 175 flywheel hp and 360 lbs-ft to 230hp and 500 lbs-ft (sort of an average of ATS and Banks) and you can pretty much count on those numbers if your pump and injectors are in good shape. That's $40/hp, $16/lbs-ft on a $2200 kit with mondo amounts of both. Prices run from about $2000-2800 for a full kit, last I checked. A lot of money, but a lot of payback.

I didn't drive my truck all that long as an NA, but I recall about a 1 mpg increase with the Banks kit installed driving it in my "normal" way. Eventually, especially if you keep the truck as long as I have, it will pay for itself.

 

It's interesting to see a mpg increase with such serious power increases.

As I said, however, it's not more oomph I'm looking for right now. 90% of the time, the truck will be driven with no load to light loads, and I doubt I'll ever tow with it.

I found another exhaust system, in addition to the Dynomax Catback you mentioned. It's a Hypermax 3.5" system for $225. They also have a cowl intake which apparantly takes air from the area at the bottom of the windshield.

Anyone have experience with either these exhaust kits, or the cowl intake?

 

Cowl intakes worry me.
The piston to head clearance is almost non existant, around 35 or 40 thousandths.

Any amount of water that makes it into a cylinder can spell disaster on the compression stroke.

Hydro locked engine since water does not compress.

Possible damage to the head bolts, piston, connecting rod or crank shaft.

If the intake is not open on the top and lower than the intake manifold you do not have to worry about a leaf stopping up a drain hole and filling the engine with water.

Just my opinion though.