AeroJeep (remote cousin of aerocivic)

[usergone]

What about making the profile end in a line, and not a point? IE, making a cover that has that profile in every cross section, with corners starting at the top sides of the cab all the way to the end. So, the top view would look square in the rear.

[usergone]

After driving my truck around today, I found just how un-permanent plastic sheeting is when not taped down profusely. The side skirts started to flap in the wind (45 MPH) so I plan to take them off.

I've been thinking that coroplast would work great (hmm, maybe that is why you guys use it...) to replace the plastic and look less... ghetto. Where would I find coroplast? Where do you guys get it?

There is one good thing about having a truck covered in tattered wrinkly plastic sheeting: Anti theft.

[euromodder]

Originally Posted by thecheese429

There is one good thing about having a truck covered in tattered wrinkly plastic sheeting: Anti theft.

It'd be easier to get a Prius, they don't get stolen very often either

[steve0]

You're more daring than I am -- I've been lightly modifying a 2002 Jeep Wrangler. The underbody seems to be the quickest fix, with a lot of running gear cluttering up the air stream. The big wheel wells look like major offenders, so I lined them with coroplast, reducing their volume, in hopes of spilling trapped air faster, with less turbulence. This change isn't obvious to the casual viewer. There is still enough vertical wheel travel for bad roads. I probably should have radiused the trailing edges out at the fender skirts, but that's for later.

The TJ has no front bumper skirt like the new Wranglers, so I made one that extends down to axle level. There's plenty of ground clearance.

Added some tire spats fore and aft. It may seem silly, as they ride so high on the front fenders, but I figure that any air that doesn't make it into the wheel well is that much the better.

Black spray paint hides the changes nicely, until the moment when the guys at the repair shop see all this stuff. They still aren't too sure about the Airtabs on the roof, I think.

No highway test yet.

[steve0]

You asked about coroplast. Home Depot (and Lowe's?) carry it. In our local store, it's in the 'Doors and Windows' section, toward the very back. Look where they have their lexan sheet stock. Their coroplast is about 24"x36". It's $5 plus per sheet.

I've tried to buy it from a couple of sign makers, but they wouldn't part with it, even when I asked "How about if I just buy a sign with no lettering?" If you need big pieces, maybe your local sign guys will be more accommodating.

Anybody know a cheaper source?

[SvdM]

Originally Posted by thecheese429

The coastdown tests did not show improvement, oddly enough. I lost 9 mph in the first 10 seconds instead of the 6 from last night. I did not record the temperatures yesterday/tonight, so I am sure that is the problem. Or not. Whatcha think?

How low is the front air dam? If I understand 'this all' correctly it only needs to be slightly lower than the lowest protruding part underneath your truck.

What could've probably happened with the side-skirts added, was that the pressure under the truck became much lower than pre side-skirts when air could leak in again from the side even though you had the front air-dam.

With just he front skirt, it helped clean up what happens at the front but still allowed for the lower pressure to be re-filled. Thus the low pressure at the back of the truck that will occur normally at speed was just about the same as normal.

With the side-skirts added however, you might actually have helped create a much lower pressure [and bigger vacuum area] at the back than it would normally be and this actually put you back to square one [kind of]. I could be wrong about the cause, BUT I also agree that air temp will definitely affect the readings.

I will add that you must remember not to add to the total frontal area and hence increase the air you need to displace. I think the problem with [some] pick-ups are that many times all the blocking and smoothing and covering that needs to happen underneath to get it car-like might be good for Cd, but bad for Frontal Area and finding the balance for what happens under the truck becomes much harder than for a car with an underbelly that's almost flush already.

-like I said, if I understand this all correctly.

[BamZipPow]

Originally Posted by steve0

You asked about coroplast. Home Depot (and Lowe's?) carry it. In our local store, it's in the 'Doors and Windows' section, toward the very back. Look where they have their lexan sheet stock. Their coroplast is about 24"x36". It's $5 plus per sheet.

I've tried to buy it from a couple of sign makers, but they wouldn't part with it, even when I asked "How about if I just buy a sign with no lettering?" If you need big pieces, maybe your local sign guys will be more accommodating.

Anybody know a cheaper source?

You can see if yer local recycling place has any they can give to you.

I'm surprised the sign shops wouldn't sell you a sheet. Give Regal Plastics a call fer prices and availability. They have a location there in Austin TX.

[steve0]

Originally Posted by BamZipPow

You can see if yer local recycling place has any they can give to you.

I'm surprised the sign shops wouldn't sell you a sheet. Give... Regal Plastics a call fer prices and availability. They have a location there in Austin TX.

Thanks, BamZipPow: I get the 'duh' award for not mentioning the recycling center. The days after an election day should be coroplast heaven, too. I'll give Regal Plastics a call when the plastic fit is upon me again.

How are things in League City? Is your cold spell over yet?

[euromodder]

Originally Posted by SvdM

With the side-skirts added however, you might actually have helped create a much lower pressure [and bigger vacuum area] at the back than it would normally be and this actually put you back to square one [kind of].

From reading here and elsewhere, there is a sideways flow coming out from under the car - and wheel boattails or deflectors should be shaped accordingly.

The sideskirts may be preventing that sideways flow from happening when they're too low, forcing all the air under the dirty rear underside

[usergone]

I started on the actual boat tail today. I decided to go with steel tubing because I have a lot of it laying around and it worked well for the airdam and side skirt rails.

I only got as far as the top surface, for lack of a cutting wheel for my grinder (where did I put them?!), but this is what I have:


It may not appear to have a very nice "parabolic" curve to it now, but it will as I get the actual frame put together. I will use 2 runs of angle iron running along the bed walls to clamp it down with the clamps for the camper shell.