crx coroplast belly pan finished!
 

Just finished belly pan using 3 sheets of 1/4" 'natural' color coroplast. Hubcaps too.
Pics @ http://www.paulstoys.blogspot.com

Nice job! It's looking good so far.

Nice work! :thumbup:

Your car stands are frightening though :eek:

Excellent work. Where do you get your coroplast? I haven't been able to find it around here. Have you had a chance to put a lot of miles on the setup? I would be a bit concerned about its proximity to the exhaust and catalytic converter.

Looks good. Have you driven far/long with it installed yet?

Very nice work.

I'm in the seattle area. Laard plastics sells 4x8x1/4" sheets for about $12 per.
I shook the crap out of the car and chucked the wheels before going underneath. I'm nota fool, just cheap. Besides my 25 mile commute today, with about 10 minutes of stop and go, outside temp in the mid 50's, the temp guage didn't move. Fan is probably working overtime I'm guessing. Will work on installing radiator vent with cable adjust from inside next.

Paul... That/Your blog = awesome!

It's a collection of so many things I'm into... 'bents, small motorized vehicles, micro boats...

The Wheel! In freaking sane! My roommate is looking at me funny because I'm getting excited over a concept centuries old :p

That, might be a weekend project for me :D Plus, I like your name - it's just something I grew up with :p

The wheel...build it, you will have fun, damb it.

So, where does the engine and exhaust heat go? Is it sucked out through the gap between front and back sections of Coroplast, or past gaps around exhaust pipes/mufflers?

Couple of thoughts:

Near heat sources you may suffer some Coroplast melting. Time will tell, but you could add edging to the Coroplast in the form of aluminum foil tape. This would seal the edge, keeping moisture and crud out, and be a good way to dissipate heat from any hotspots, aluminum foil being a superb heat conductor.

If you need to stiffen the Coroplast, insert thin dowel rods from a lumber yard. Alternatively, use L bracket or extruded aluminum, orienting it to act as flow fences to shunt the under-car airflow gently out to the sides. Google for Ferrari aerodynamics.

What has this done for fuel economy so far?

What about noise level in the car, at freeway speed?

I can comment on the noise level being reduced when I briefly had a full belly pan on my Firefly. I recall krousdb saying the same thing - he's added full pans to 3 of his cars so far.

Nice work on the REX!

Otto ~Welcome to the community.

Very nice. How much would you charge to do my Prius?

How much quieter did it get?

Smoother flow and greater aero efficiency would make less wind noise under the car, less engine noise since less throttle is needed for propulsion, and the coroplast acting as an insulator/reflector of noise away from the car body. In theory.

Can you hazard a guess as to decibel reduction?

How durable and fireproof has the coroplast proven to be? In other words, what shape is it in after a couple of years of driving? Or, am I gonna have to shinny under the car constantly to mess with this stuff?

Hmmm, need a cheap source of coroplast locally. Somehow, I think Sam's Club would get upset if I stole the big sheets from their shopping cart garages...

I have the added challenge of trying to smooth the bottom of a Jeep with a shovel for a transmission skidplate.

Otto - can't hazard a guess on decibel reduction. Though all your points are valid. The belly pan was only on my car temporarily. For safety, I used a mix of aluminum flashing (near the exhaust) and coroplast.

My coroplast underpanelling has been in place since May 2006 with no deteriation problems. Since its made of thin polyethylene, it should last well in locations like the underside that don't get a lot of direct sun, but will get brittle after a few years exposure to direct sun. I've replaced all of the coroplast on the top and sides of my car with aluminum sheet, but left the underpanel, side skirts, and front wheel spoiler in coroplast for its flexibility when hitting road debris.

Props on the Coroplast! I am going to experiment with it until I achieve a final shape. That will be my pattern for thin sheet aluminum.

With all of those projects of yours, a good set of ramps and a 2-ton engine hoist might be a wise $200 investment. Much cheaper that the ER.

I saw the 3-wheel motorcycle on your website. Great idea! Is it a 2-seater? What front suspension did you use?

THX,
Cowspots

That is exactly what i wanna do to mine.

What mpg change did you get?

Any issues with it so far?

Thanks!

88CRX, I did an A-B comparison with a full undertray on my car and measured a 2.2% increase in MPG @ 90 km/h (55 mph).

The comparison won't directly apply to your case, since the CRX has a much lower ride height for one thing. But I bet it's in the ball park.

If you haven't got the coroplast yet... what i did was go to Lowe's, they didn't know what it was, so i pointed at a large box made of it. They gave me 3 boxes for free, more than enough to do my car.

I guess if your nice enough, you can get it free.

Thanks for the information, i'm gonna do it when i get the chance.

I like it!

Love all the toys too

:thumbup:

That was then, This is now
 

I'm sorry I havn't been visiting this site in a spell. Figured you needed an update seeing the coroplast bellypan went thru a rough year. First, I removed it, mostly because last winters snow fall was 2 feet, and I was scraping the pan on more than several occations in order to get by.
The coro Hubcasps became quite brittle too, plus spinning my tires in deap snow didn't help much. I removed them several months ago.
I first removed the rear pan section soon after installing. I discovering it rode too low at the rear axles which was creating drag. I drove around for many months before winter with just the front section on and yes, I do remember it being a little quieter inside, and I'm sure there was some mpg gain.
After fiddling with interior mirror options in an effort to eliminate side mirror drag, I opted to re-install my drivers side mirror and this works for me. (The 4 section interior mirror was inches from my head!)
With the onset of summer I removed my plex air vent to keep things cool. My tires are practically bald after running them @ 45 psi, and the ride is rough, I did feel I was getting my best gain in mpg from running them that high, but by doing that I wonder if I hastened there life expectancy.
I'm back to my old habits now, driving fast as usual and not keeping up with the expensive oils etc. But I still chech my mileage and I'm happy averaging 45 mpg.
Not too many cars can do that, with one battery :)

Elkinstein images
 

Gee Paul,are you ever going to have some ideas? Of course I'm kidding! Loved your photo archive.I would be far further down my learning curve had you been a neighbor.Your motorcycle reverse-trike is something I'm making slow progress on.I'm including your idea for the aero shell from the bicycle.No telling when she'll see road duty,but when I see stuff like your's,it surely keeps my interest picqued! Thanks for sharing all that.CRX belllypan looks good!

COROPLAST 4MM which I have plenty of I DO NOT LIKE for the following applications

Belly pan,underbody, and wheel covers. 4MM coroplast is (for me) to thick to cut for wheel covers and making the wheel covers seems to be to much of a hassle with 4mm. Nobody local stocks 2MM coroplast and cost is $35 USA dollars 4 x 8 sheet. Any suggestion

I used these pallet liners for Turtle's belly pan, which I got for 2 bucks a sheet. The guy I get them from has enough of those to cover a stadium. They're really thin and strong and are holding up great.

https://lakeland.craigslist.org/for/4990053699.html

Wow. This thread was posted back in 2009 !

TexasCotton, you asked for suggestions. Here are mine :
Some recycling centers will have coroplast signage. I know the one in Houston did a few years back when I lived there.
They will give you as much as you can haul home.
Also, election signs are great, but you have to wait for the right timing, and unfortunately, you can't just go take one off of a fence once the elections are done.

Lastly, I work at bLowes. I had several large sheets of coroplast - some as large as 2' x 6' that were going in the dumpster. Resets happen quite often, and also, several of the boxes that products come in in the outside garden deptment are made of coroplast. To get it though, you have to have good timing and follow up on it.
When you go to a store, ask to speak to a PSA. These are the guys that do the resets.
Say that your wife wants it for the garden, and that it makes an excellent choice for use in the flower beds because it stays rigid. ( or something like that )
Ask when the resets might happen, and follow up with them regularly. They don't give a crap, and any inconvenience on them, results in them throwing it away, so you have to check back with them regularly.
Also, explain that the sign won't be displayed in public, since they will be reluctant to give the signage to you for legal reasons.
If you dont have any luck at one store, try another till you get what you need.

Good luck !