aero help

[Joenavy85]

Originally Posted by trooper Tdiesel

if you have on board air and tools in the truck taking the wheels/tires off the jeep "after its on the trailer" would lower the air drag "for the long drive". the jeep would drop nearly 9"/12"

And have your Wrangler facing readwards on the trailer when you take the wheels of.

[Frank Lee]

Don't take the wheels off.

[skyl4rk]

That is a very interesting project, I have always wanted to convert a truck to an RV. I have been looking at stepvans and box trucks with a pass through.

You have already done the most important thing, which was to get the rpms to about 2k at 60mph.

The biggest impact you will have on fuel efficiency will be finding a route where you can drive 45mph all day. Slow speeds in your highest gear will make a huge impact of fuel efficiency.

As far as aero mods, if your trailer was a box trailer instead of a flatbed, that would be better. With the flatbed, will you be carrying any other loads on the trailer? I am just thinking about how to distribute the loads to affect air flow. You might look at the bottom of the truck and cover any large open spaces (parachutes).

[kach22i]

Originally Posted by mekanic

I am thinking about a air dam

There is a simple chin spoiler in my link, you may have to stack them.

I'm not sure what the crowd here has to say about those Vortex generators on the rear box trailing edge, are they all hype? I saw these on a Transvan once, don't know if they work.

Aerodynamic Fuel Economy Savers for Road Vehicles




Automobile pictures by kach22i - Photobucket

[chris_kraft3]

^Add skirts to that picture.

[mekanic]

Originally Posted by kach22i

There is a simple chin spoiler in my link, you may have to stack them.
Automobile pictures by kach22i - Photobucket

I do like the looks of the air tabs. I'will check into them.
I havent driven this truck more than 200 miles since I bought it.
The MPG is largly unknown.
I almost took these things off the truck.


I was told not to touch them as they are supposed to help greatly in the transistional air flow from cab to box.
I will get air dam done before my big trip. maybe I can fix that gap between the bumper and front end. I'm thinking of sticking lights in the larger bumper holes. the upper holes are for the tow hooks.
Side Skirts will get done but it will be after I get back from this years trip.
I am planning skirts that also have a floor. I seen these done like that over at truckconversion.net and they look very nice.
I got my shorter rear tires installed yesterday and I must say the gearing is exactly like I wanted it to be.
Now to get the truck level I have to drop the front 2.5 or 3 inches. I'll have this done in the next week.

Something I am thinking about is making the air dam and then installing it at my first fuel stop which I think will be somewhere close to St. Louis.
The way i am going to make it is to have it bolted on to the lower part of the radiator support. which is like 6 inches behind the bumper.

[mekanic]

Well since that first pic was taken it now has shorter rear tire and the 2 in blocks were removed from under the front springs.
Well Today I went and did my baseline MPG test run and came out MUCH better than I thought I would.
I did a round trip from Mid town kroger fuel stop in ashland to grayson and back.
I did not try to drive for max MPG Ii ran 65-68on flat ground and held to floor on the hills. It only dropped 4 MPH on any of the hills.
I made sure to use the same pump and fill to same point (lower lip of filler pipe)
The result was 49.4 miles and 4.2 gallons of fuel used for 11.7 MPG.
I had heard these 12V cummins got good milage, but I didn't know it was this good. I think this is good mileage considering the over 13K empty weight, and the bluntness of the box.

Mods will be limmited because of the 3 weeks i have before my trip.
I will of course continue as time premits.

[mekanic]

I made it here out to Ouray, Colorado. truck did fine in the moutains. With the trailer/Jeep combo taggin along it got 10.5 on the flat land and right at 10 flat in the moutains with the fan en-gauged. (That fan is so loud that you can't hear the turbo whine). The gross weight of truck and towed weight is somewhere around 18-19K so that is ok so far. I didn't get to do much of anything done as far as a air dam, skirts, or anything else as I was too busy installing my entry door and building steps and such.
I did tape up the holes in the front bumper with (chrome) duct tape.
I'll get to modding it in my home time when I get back.
I am going to experiment slightly on the way back. I'm gonna point the jeep the other way on the traler to see if there is a difference.
Anyway I just though I'd tell you all how it did. Now i'm gonne get to doing some jeepin on Black Bear Pass to telluride.

[CFECO]

Ouray is beautiful, I'm going up that way next month, I like what you're doing with a non Eco vehicle.