Under Engine Body Pan
I have a 95 Acura Integra which I have fully converted to EV. My question applies to just about any front engine (motor) car. What material can I buy and install that will close off the bottom of the engine compartment? It would seem that some form of plastic (or maybe aluminum) about 1/8" thickness and maybe about 4X6 feet in size would be a good starting point. The objective is to improve aerodynamic drag, reduce the chance of water intrusion, and generally keep things cleaner than having a typical open engine bay. Also, what kind of fasteners would work well? It would probably be a rare event that I would have to remove the pan for servicing, repairs, measurements, etc, but it should be relatively easy to remove and reinstall later, so pop rivets are out as is gluing or some other semi permanent attachment technique. Must be a pretty common situation so I'm hoping lots other enthusiasts will gain from comments from those of you who have already solved this problem.
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I put a belly pan on my car and I love it. Keeps water and dirt out and looks clean. I haven't verified any aerodynamic improvement, but it must do something at freeway speeds.
I used .025" aluminum sheet. The front panel extends to the back of the front wheels and is just screwed into the frame rails. I used washers with rubber gromets but I don't think that was absolutely necessary. The front is supported mainly by the plastic clips that hold the bumper cover.
I put a few .25x.5" Al stringers to dampen and support the sheet, as well as a piece of angle Al on a larger span to support the part in front of the wheels where there aren't fasteners. They are all taped on with Scotch outdoor mounting tape. The tape is more than sufficient and I think it helps with the damping.
It doesn't rattle at speed, total cost was about $100, finished weight is 5-10lbs for the front panel.
I used .025" aluminum sheet. The front panel extends to the back of the front wheels and is just screwed into the frame rails. I used washers with rubber gromets but I don't think that was absolutely necessary. The front is supported mainly by the plastic clips that hold the bumper cover.
I put a few .25x.5" Al stringers to dampen and support the sheet, as well as a piece of angle Al on a larger span to support the part in front of the wheels where there aren't fasteners. They are all taped on with Scotch outdoor mounting tape. The tape is more than sufficient and I think it helps with the damping.
It doesn't rattle at speed, total cost was about $100, finished weight is 5-10lbs for the front panel.
Check http://ecomodder.com/forum/aerodynamics.html
They do a lot of this. You might want to consider extending the belly pan to the rear bumper.
They do a lot of this. You might want to consider extending the belly pan to the rear bumper.
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After election night, I drove around and harvested old campaign signs. The corroplast is perfect, and the price was right. We attached them with zip ties, so it's not a big deal to snip off the zip ties when you need to remove it.
If you seal off your grill and the underside that's good for aerodynamics, but if it is sealed too well you might recycle hotter and hotter air into your motor -- in that case you might need a fresh air intake and/or hot air exhaust for your motor.
If you seal off your grill and the underside that's good for aerodynamics, but if it is sealed too well you might recycle hotter and hotter air into your motor -- in that case you might need a fresh air intake and/or hot air exhaust for your motor.
Maybe I'm looking in the wrong places, but the best price I can find for coroplast is around $30 for a 4X8 sheet. That would be fine but shipping is around $75! Geesh! I tried a local sign shop and they said "Sure, we'll sell you a blank 4X8 sheet of the stuff for 'only' $138". Would you willing to share where the quick search brought you to $20 a sheet pieces of coroplast?
Thanks.
Thanks.
Hmm I didn't look close enough. You can get it for under 20 a sheet, but you have to buy it in packs of 15 sheets.... Sorry about that.
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1/8" black ABS sheets are available in 4'x8'. you might find at local plastics shop, or consider delivery of SEVERAL sheets in a group buy to cut shipping costs. I got a sheet of 1/4" polypro for battery boxes, and 1/8" ABS for bellypan.
the ABS is easy to work with, glueable, heat bendable, and pretty tough. get some 'j' nuts at local hardware store, go into bottom of bumper, and some U bolts on front sway bar..... etc.
I've got some pix of what I did in my gallery (link in sig)
the ABS is easy to work with, glueable, heat bendable, and pretty tough. get some 'j' nuts at local hardware store, go into bottom of bumper, and some U bolts on front sway bar..... etc.
I've got some pix of what I did in my gallery (link in sig)
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DTBAker, you are to be congratulated on your handiwork! Your battery box came out really nice looking and I LOVE your belly pan. Wish I had your fabrication skills. My latest iteration on finding the right material for the belly pan was to go to a friend's sign store a few miles from home. After begging and pleading, he said he would be willing to sell brand new 4X8 sheet of corraplat for $27.95 right out of his inventory. I thought that was pretty decent of him. I plan to purchase a sheet shortly and begin the (probably) tedious process of cutting it to fit properly. Doubt that my finished project will look anywhere near as smooth and professional as your ABS plastic belly pan. Thanks for the ideas. And thanks to the others who replied to my initial post. It's really a great service to all to be able to share ideas and brag on accomplishments.
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if only my girlfriend was so appreciative of my belly pan!
seriously, the 1/8" ABS is not any more expensive than coroplast I don't think, and is very easy to cut w/ sabre saw. It was an 'iterative' fit that took 3 or four test installs and trims.
the bottom of bumper had existing holes, so I just got some j-clips from local hw store and bolted up the front. The rear I used u-clamps to the sway bar as you can see from the gallery pix.
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