Tweaking a 1966 F250 for better FE

[freebeard]

That would be the one. I don't remember the notch being that big though

[Eco1966F250]

Originally Posted by JRMichler

When I read your title, my first thought was LOWRIDER, but you beat me to it.

When you get it back on the road, look closely at the air flow over the hood. If there is a swirl in the middle of the hood, then reshape the leading edge of the hood to get smooth air flow over the hood.

Then look at how the windshield is installed in the cab and compare to modern vehicles. That mini visor at the top of the windshield is pure air drag.

I am sure plenty to gain by re~shaping body but simply don't want to change the basic shape. Its already 2.5 x improvement in MPG over stock.

Originally Posted by kach22i

Regarding your front chin spoiler;

1. I think perhaps a lot of air is being washed up into the engine bay - not so good of a thing.

2. I've had bad luck with plastic lawn edging, but it was not recessed and protected like yours. Other vehicles were parking by braille and damaging it on mine. Conveyor belt material is the superior choice but is many times more expensive.

3. My shortbox Ford van in the early 1980's I had installed a chin spoiler which did not quite cover the front wheels and stopped a little short like yours. As I recall I still enjoyed the majority of the benefits but there was some fruit left on the tree.

4. Regarding the cowl and chin spoiler, there may be a common aerodynamic treatment for both but I have not yet done it to my truck - see signature links below in my post.

I plan on installing plastic "Barrier Paver Edge" at the bottom of the chin spoiler as a "splitter" for down-force, and at the rear edge of the hood as a Gurney flap.

The Gurney flap just before the windshield wipers will according to an aerodynamicist I met with will kick the air up to meet the lower part of the windshield and not get messed up with the messy part of the wipers and such.................terrible description of what he said, but you get the idea, right?

Conclusion:

If you are getting 1 mpg more now with your chin spoiler, the best you can do is 1.5 mpg. Therefore you are leaving at most 1/2 mpg on the table.

Considering all of the other things you want to do to your truck, I say finish those things up, and by then the existing chin spoiler will require replacing by then anyway - based on my experiences with that material.

Barrier Paver Edge

I gained a full 2 mpg with airdam and fresh air intake. I will go back to track this coming friday to see how much change in MPH in a 1/4 mile. Expect to gain a little from the HP increase but hope to gain a bit of MPH because of AirDam. I do need to work on engine bay air movement also along with open areas inside of box, but one never knows maybe underside air is coming out of open area in box mixing with air going over truck. LOL

[Eco1966F250]

Originally Posted by aerohead

The conventional wisdom is to use a full-width,wraparound airdam,which cuts airflow off to under the vehicle,and brings it around on the sides as you see on late model pickups.
It's a torture chamber for air underneath







Consider leaving around 6-inches of ground clearance to prevent ripping your hard work off on driveway ramps 'n such.

Right now I have around 3 1/2" of clearance in front. About right as very seldom touch & thats only in steep driveways with a bit of rain gutter dip. Do not hit on speed bumps here in Arizona.

[Eco1966F250]

Originally Posted by freebeard

Consider 3 1/2" of ground clearance.

That should be a nice truck. It sounds like it's drivable now?*

I failed to find it but there was a hatchback car posted here that had a massive air dam with a notch in the center I wanted to use as an example. It was some theory like wheel spats and a jet of faster air down the middle to pull air out of the engine compartment or something. Also additional clearance so you don't high-center on gravel roads. Maybe aerohead has an example.

It looks like in your case, a bellmouth or plenum on the intercooler/trans cooler would be called for.

Have you thought about a varnished redwood 'barrelback' airocap?


https://www.google.com/search?q=chris+craft+barrel+back

Because I have.

Edit: *Okay, 13-second quarters. Got it.

Right now even in 120 deg heat I have no overheating issues. The opening in bumper and AirDam seems to give pretty good air movement. I can read and record the ambient air and also air temp as it enters the engine. Currently only a 5-11 deg diff depending on speed. Testimony to how well my cold air intake works in conjunction with the custom homemade Intercooler. LOL
Hoping for a 12 second 1/4 mile pass this coming Friday . . With the A/C on of course!


My YouTube:

https://www.youtube.com/watch?v=VDIEY1vU8RY

[Eco1966F250]

Current pic

[slowmover]

This discussion came up circa 2009-10. I walked an apartment complex parking lot in Texas with a steel tape -- no lack of pickups -- and found that regardless of brand the standard front air dam clearance was 10".

In looking at reports by those who've gone to great effort with pickup underbody enclosures, I decided that for my diesel one ton that a more pronounced airdam and side skirts from conveyor belting would suffice for my needs. See threads/posts by Big Dave and skyking in this.

Rear exit has been addressed somewhat (aerohead), but I don't remember thread topic or title. Probably on one of BamZipPow's threads.

Partial bed tonneau (plywood would suffice) extending from tailgate to barely past the midway point to cab is a cheap upgrade. Again, aerohead.

If you're a genuinely good guy, contact ChazInMT for how to take a profile photograph of that pickemup, and get him to draw the curve superimposed. Use it or not, but you'll better understand aero lid covers.

Aerohead has also talked about tapering the body exterior inwards from cab to tailgate. Doesn't look like you're afraid of much.

Take in the full array of what can work for aero. Subtle changes might work wonders.

And, Polymetal. (With Da Beard Free we're gonna find a way to make that Miracle Metal a holy sacrament for initiates. The old Hip Eye picked up on the vibrations of that stuff and damned if the waveform didn't finally hit Tejas).

.

[Eco1966F250]

Originally Posted by slowmover

This discussion came up circa 2009-10. I walked an apartment complex parking lot in Texas with a steel tape -- no lack of pickups -- and found that regardless of brand the standard front air dam clearance was 10".

In looking at reports by those who've gone to great effort with pickup underbody enclosures, I decided that for my diesel one ton that a more pronounced airdam and side skirts from conveyor belting would suffice for my needs. See threads/posts by Big Dave and skyking in this.

Rear exit has been addressed somewhat (aerohead), but I don't remember thread topic or title. Probably on one of BamZipPow's threads.

Partial bed tonneau (plywood would suffice) extending from tailgate to barely past the midway point to cab is a cheap upgrade. Again, aerohead.

If you're a genuinely good guy, contact ChazInMT for how to take a profile photograph of that pickemup, and get him to draw the curve superimposed. Use it or not, but you'll better understand aero lid covers.

Aerohead has also talked about tapering the body exterior inwards from cab to tailgate. Doesn't look like you're afraid of much.

Take in the full array of what can work for aero. Subtle changes might work wonders.

And, Polymetal. (With Da Beard Free we're gonna find a way to make that Miracle Metal a holy sacrament for initiates. The old Hip Eye picked up on the vibrations of that stuff and damned if the waveform didn't finally hit Tejas).

.

Thanks for the input!

This pic will better show the height. This is after driving up on ramp for my 4 post hoist around 6". I do plan on extending the airdam to better cover the tires. I really want to make my own out of metal with maybe a rubber or plastic lip so no damage will occur if a speed bump etc is too high.

Once I finish testing with the E30 fuel that is killing mileage I will switch back to 91 and then start tweaking more for MPG. I am planning on a trip to southern california at end of this month so hoping for more gains by then.

This truck is a 126" wheel base. (stock is 129")
Back to the 1/4 mi this weekend to see what if any MPH the tweaks add.

[freebeard]

I don't know how much you've lurked here, so I will repost a few things, again.



This is a wheel spat that consists of a metal strap and that other wonder material, conveyor belting. Two U-shapes connected on their long edges so the belting can flex if necessary. The belting would want to curve more than bend, so the sketch isn't too accurate. As many as one or two on all four wheels.

For the rear, a diffusser. They require a smooth underbody airflow. Here are two extreme example to show the features:



Outside fences that extend to the axle line, to separate the wheelwell airflow from the underbody flow.



The inside fences exist because the outside channels are more turbulent. Three or four channels are more typical. Note that the outer fences flare outward. The slope of the diverter floor and the angle of the outer fences make a divergent duct.

Here's a picture of Bombshell Betty as a bonus:

[aardvarcus]

I built a conveyor belt air dam for my Tacoma, have a metal bracket where the frame is to hold its shape and the conveyor belt hangs down. I use my truck off-road plenty and you can drag the air dam all day long, doesn't phase it a bit. I did the air dam as low as the lowest point of the underside, and then just a little lower close to the wheels.

http://ecomodder.com/forum/showthrea...tml#post454423