A little help with wheel skirts?
 

I have a couple pics of the backside and rear driver's side corner of Cara, was wondering if someone could remove the bumper cover and replace it with a rollpan which is integrated with wheel skirts.

I suck at PhotoChop. Please?

http://ecomodder.com/forum/member-ch...0818091501.jpg
http://ecomodder.com/forum/member-ch...0818091502.jpg
http://ecomodder.com/forum/member-ch...818091502a.jpg

I want full wheel skirts that match the body, but wrap around the rear as a rollpan, deleting the rear bumper.

Oo.. a Kammback would be sweet, too.

Bumpers are there for safety... but if you don't care about it, you can easily just drill into it to hold anything else in place. And yes, a kammback would be sweet!

My original inspiration was a MS Paint file I made out of sheer boredom earlier today... it's crappy, but gets the general idea.

http://ecomodder.com/forum/member-ch...0818091501.jpg

I know what the bumper is there for... but I never said anything about removing the bumper.

wah wah... I guess I misread... you can still drill into a bumper cover to attach, and see if you get the benefits you are looking for before you go about building something potentially more expensive and elaborate.

I'm not sure how a piece of sheet metal replacing the bumper cover is going to be expensive or elaborate... you know what a roll-pan is? I want to get rid of the huge protrusion from the rear of Cara... she's got a big enough ass in those jeans as it is.

I'm thinking square off the columns, maybe, to encourage separation (I don't really know this aero stuff)? Oh, and ob skirts

Gimp is your friend :)

http://ecomodder.com/forum/attachmen...1&d=1250657517

I had gimp... but I didn't really do to well with it either.

I really want to see those skirts worked in with a roll pan though. And the door handles deleted, along with the plastic trim line along the side... I actually want to get rid of just about everything that's plastic on the outside.

Did you know in PA, I can legally delete both outside mirrors? I'm not going to, but I can, if I really wanted to. I drive to NY state alot, though, so I'd have to look around and find out if it's legal up there.

The skirt looks better than I thought it would, I'll admit that.

I don't think I'm going to do any major body modifications, perse, like squaring the trailing edges, but I do want to check out a kammback extension. Since it would be so high, length wouldn't really be an issue at all.

It will work great in Photoshop or whatever, but in real life the wheel and tire extend too far outside of plane of the body panels, especially as the panel curves inward at the bottom.

I'm not sure if that's b/c the van is sitting on an angle right now or not... the suspension in the rear is a solid axle with shocks/leaf springs, so it articulates quite a bit to compensate for angles, which makes the tires stick out from the sides.

But even if I have to compensate by bowing out the panel, that will be fine. It's called "custom fabrication" for a reason, right?

http://ecomodder.com/forum/member-ch...shaved-ass.jpg

I managed to shave Cara's ass... but even that took a long time. I'm just not up on the Gimp/PhotoChop techniques. Still can't make the rear bumper cover here look like a roll pan and keep the body lines.

Looks like you are getting the idea :thumbup:, gimp just takes time/practice. I cut and paste a lot then use the smudge tool to blend all the little polygons edges. Still havent got the hang of iwarp yet though.

FYI, for the square corner, I just drew a white line (holding the shift key and clicking when the next line segment looked in the right place) where I thought the crease should go then smudged it a bit (the finger looking thing).

Have to admit I don't know what a roll pan is.

http://www.customtacos.com/gallery/p.../tacoma071.jpg

See the spot where the bumper should be under the tail gate? It was replaced with a roll pan, then shaved (seams welded to make it smooth).

I want to do that with Cara, although primarily for aesthetics, It'll get rid of the parachute effect that the rear bumper has.

I'd like to do it so that I can permanently attach the wheel skirts to it, so it makes a single bolt-on unit, which I believe will be cleaner looking. As it seems, though, I'll probably just make some quick sheet metal covers and then modify it again later.

I'm not so sure it'll be that easy to do a roll pan on a caravan. I'm pretty sure there's bumper structure under that cover that might interfere with a completely smooth/rounded roll pan. You could pop the bumper cover off and have a look, and even if it wasn't fully rounded a shorter cover with less parachute (or maybe a shallow-angle diffuser up to the rear axle?) could wrap-around into wheel/side skirt. I'm thinking vertical to slight rearward taper like behind the Prius' rear wheels.

Really chopping the underhang off the rear bumper to eliminate the parachute and maybe lowering it in the rear could reduce wake size. It would make a shallow diffuser easier and more effective as well. I'm almost certain there are airbag leveling kits for this era van that would retain load-carrying ability even with a 2" or so rear drop.

also worth noting that a round trailing edge is usually worse drag wise than sharp corners afaik

Also not sure why squaring up the rear columns with some bondo and white paint would be "major", but this isnt :)

I'm not 'bagging the van... not even close to an option, because of the price/output equation. (They're too expensive for what you get/end up with.)

As far as the rear bumper structure, according to Dodge, the van is actually a FWD truck... which means that it doesn't technically need a rear bumper - that notwithstanding, there's still a hidden hitch that goes behind the roll pan, which will allow me to make it smooth and still retain some measure of impact safety in the rear.

yah, but the discussion has kinda left the realm of efficiency.

It wasn't really an efficiency discussion to begin with, I guess... it was more like me asking someone to help with a photochop.

As far as squaring up the rear columns, you just don't use bondo for that type of work. If you have to build it, bondo is not the correct material for the job. More likely would be to make a shaping section of foam, then fiberglass over it, and best option would be to actually bump hammer the whole section of sheet metal into the form that you need, then refine it with a peening hammer and dolly, then use some filler to "straighten" the lines. That's what I call major body work.

EDIT: None of this would be necessary, were I installing a Kamm extension. I still may, since I can make one quite simply, and it won't be anything wasted if the project takes a turn elsewhere.

What I'm actually considering doing here is not even close to any of that - it's cutting a few pieces of metal and riveting them together so that they match the original body lines.

The major body work doesn't come into play until I figure out if the final product will actually even have those rear pillars. It would be kind of pointless to play with them if they weren't going to be there, eh?

idea
 

Christ,that would be a good cleanup to the rear and get you in better position for more daring mods later.Also,have you considered integrating fairings for the rear tires into your valance? Those would clean things up even more.--------------------- And another thought looking at your photo.The rear windshield is blacked out on both sides and you have no vision there.If you made flat panels which mated to the contour of the hatch,which projected straight back a couple feet,with a top which sloped down like the Kamm roofline,and a bottom which came up like a diffuser,you could capture a big chunk of wake,and the surrounding air would skid off the attached vortices formed inside the voids outside the panels,and off the top and bottom panels.----------- It wouldn't be as good as a very complex and difficult to build formal boat tail,but you'd see a benefit at the pump.---------------- Continuum Dynamics has already proven the concept under a DARPA grant from NASA for an 18-wheeler.You could build it over a weekend probably.

I'm actually thinking about removing all the rear glass and replacing it with metal, a'la Caravan Cargo models. This may or may not include the sliding glass, and most likely would include the rear glass in the hatch as well.

I'm not sure I can quite visualize exactly what you're saying about the back window, though.. do you have a link or something to show?

For the rear tire fairings, I hadn't honestly thought about it, but I did think about full side skirts after I've established my ride height and weight requirements (after she comes off the road for project time.)

I also figured that while I'm under there for the transmission swap, I might as well figure out my mounting points for a belly pan, or at least an engine compartment bottom cover.

I don't have a representative pic, but after my dad buys me a new bumper cover (he hit mine... backed into it) I'm going to make a permanent upper grille block to fit in the space of the removable grille, and probably start with removable plugs for the lower grille areas.

I'm still not wholly sure what's actually going to happen with the rear of the van yet... I'm keeping that thought 007 for now.:D

Hey I live in Buffalo, N.Y. And the law here is the driver's mirror is mandatory and you must have at least one of the other 2. So you could at least take of your passenger mirror.

rear glass
 

With respect to the rear glass,it looks as though Chrysler has blacked-out the outer edges of the glass with paint.My thought was that since this area was already "blind",streamlining panels could be attached behind this area,extending straight back to create the 90-degree rotated Kamm "steps" on each side.The panels could be attached to a bicycle rack so to speak.---------- You wouldn't lose any visibility to speak of,as this area is already covered.

im not very good with ps but heres my 5 min ms paint rendition

I think I understand what you're saying...

You're suggesting that I make the sides of a Kamm extension to keep the side airflow attached past the rounded edge of the rear pillar, right?

This is a great idea, however, If I'm getting what you're saying correctly, would I also not want to make the upper portion of the Kamm? I'm not too worried about losing visibility, I'm used to driving trucks which don't have rear windows, and relying on the side mirrors to judge my driving.

Once I get my wife's car finished, and I get some more garage time, I'll probably pull the van in and measure it up for a Kamm extension... gotta find some decent metal that's affordable, though. I'll probably cut it from the CRX in my dad's yard. I think the roof will make a decent size piece of thin steel from which to make a kamm that follows the shape of the roof as an extension.

A question about the Kamm though - is it better to follow the natural taper of the sheet metal in the extension, or to make the extension follow a prerequisite angle?

(That spoiler thing isn't removable on my hatch - it's stamped into the sheet metal. It looks like a great mounting point, does it not?)