VW MkIV Aerodynamic Mods (Jetta, Golf)

[TeachMeToMPG]

I saw his post and pictures. It looks great and I plan on copying his covering. But looking at all the pictures of how he boxed in the front and rear and mounted the belly pan, it looks like he took self tapping metal roofing screws and went straight into the floor of his car. Im worried about doing that and nipping a wire or poking through my floor board.

[freebeard]

I went back to look. OP actaully cites a half-dozen other users, who had results that vary in quality.

deejaaa's box cavity is the low end. I thought trebuchet03 was the most interesting:



Airdams need a minimum a notch in the center. This goes to the extreme where is more of a wheel spat.

As concerns attaching Coroplast, it's an Okay material for prototyping but you'll never get to OEM let alone show quality with it. I propose Polymetal (Alumapanel, MaxMetal, etc.). It's a plastic sheet with alumninum skins and baked enamel finish. It's good for simple curves but not compund curves. I did some experiments with scrap.



Sheared, braked and rolled on bench-mounted hand tool (18" lever), Seam across the curve has an H-channel join, the brake shows it needs to be scored on the inside to prevent rupture.

The important thing is it's prefinished. Compare with sanding down fiberglass. Here's how you'd get compund curves.



Insofar as sheet metal screw, they have double-sided tape used to mount automotive trim pieces.

[COcyclist]

Originally Posted by TeachMeToMPG

I tried covering the lower driver side and center grill and majority of the upper. The car got to around 207F in stop and go traffic and I got to worried.

I found a dragging caliper when I did the brakes. The caliper, smarter driving and half moon hub caps im up to 51.87mpg.

I am very interested in your under car smoothing. Your images look like you use self tapping screws straight to the floor. Can you elaborate more on how you installed the Coloplast?

Thanks a ton. Im trying to copy yalls lead.

https://ecomodder.com/forum/member-c...0-img-0142.jpg

If you look at the photo where the piece of aluminum is attached to the screw, you can see the type of fastener I used into the factory rubber grommets in the floor. Make sure you get the front edge up tight onto the floor. My version 1.0 sucked itself straight down and was left laying on the deserted road when I hit 50 mph. The current version has been in place for years and only required an extra piece of reinforcement just ahead of the rear axle. It has been high sided on snowbanks and has held up pretty well with the cooler running diesel engine.

Coroplast would be only for testing on the top where it would be exposed to the sun but on my garaged car it only sagged a little from exhaust heat. You may find you need to drop a few screws and hose out the dust every so often.

[freebeard]

Make sure you get the front edge up tight onto the floor.

Underlap it.