Belly Pan and Side Skirts for CR-V

[Bill in Houston]

I'm thinking about putting a belly pan/side skirts on my CR-V. It doesn't look like a good candidate for an airdam, based on the shape of the existing front end.

Anyway, in the front, the suspension components are the lowest thing, and then in the back, the rear suspension components are the lowest thing. In between the front and rear, there is a lot of ground clearance under the car, with the notable exceptions of the exhaust system and the fuel tank. The car is not 4wd.


If you look at this photo, you can see how the exhaust hangs down, and then toward the rear, behind the shiny muffler, you can see the black gas tank hanging down.


Here is what I am thinking of doing.

I am planning to use the bolt holes along the side body seams (originally intended for side step attachment) to attach a rectangular plastic gutter downspout, extending from the front jack point to the rear jack point. I hope to find downspout material about 3 or 4 inches in the larger dimension of the rectangle.

Then I would attach a coroplast belly pan. In the front it would attach to the stabilizer bar. Along the sides it would attach to the gutter downspout side rails. And in the back, it would attach to the rear stabilizer bar or the leading edge of the rear suspension. It would also be attached to the fuel tank protector bar, since it is easy to access and would provide a lot of stability.

I would cut holes in the coroplast to keep it from bumping the exhaust system pieces that poke downward. Not sure how much distance I need between the exhaust and the coroplast to prevent melting. Anyone have an idea? I am not in the mood to use flashing in that area and enclose the whole exhaust for fear of something overheating.

Eventually I will also add a front undertray to smooth out that section.

In the rear the slope up from the rear suspension to the rear bumper is steep enough to install a diffuser and get some downforce, but that's not what I want. So I need to think of a way that cleans that up without making it worse than the original. That is the lowest priority.

My hope is that after this mod I could regularly see 30mpg on the highway.

If anyone has any wisdom or experience that they would like to share, or any questions to ask, I would certainly appreciate it.

Bill

[euromodder]

Originally Posted by Bill in Houston

In the rear the slope up from the rear suspension to the rear bumper is steep enough to install a diffuser and get some downforce, but that's not what I want. So I need to think of a way that cleans that up without making it worse than the original.

With a squarish shaped rear like that, you don't want a diffuser as it adds drag.
Keep the rear belly pan horizontal.
Give it sharp rear edges for the air to detach easily.

[aerohead]

Originally Posted by Bill in Houston

I'm thinking about putting a belly pan/side skirts on my CR-V. It doesn't look like a good candidate for an airdam, based on the shape of the existing front end.

Anyway, in the front, the suspension components are the lowest thing, and then in the back, the rear suspension components are the lowest thing. In between the front and rear, there is a lot of ground clearance under the car, with the notable exceptions of the exhaust system and the fuel tank. The car is not 4wd.


If you look at this photo, you can see how the exhaust hangs down, and then toward the rear, behind the shiny muffler, you can see the black gas tank hanging down.


Here is what I am thinking of doing.

I am planning to use the bolt holes along the side body seams (originally intended for side step attachment) to attach a rectangular plastic gutter downspout, extending from the front jack point to the rear jack point. I hope to find downspout material about 3 or 4 inches in the larger dimension of the rectangle.

Then I would attach a coroplast belly pan. In the front it would attach to the stabilizer bar. Along the sides it would attach to the gutter downspout side rails. And in the back, it would attach to the rear stabilizer bar or the leading edge of the rear suspension. It would also be attached to the fuel tank protector bar, since it is easy to access and would provide a lot of stability.

I would cut holes in the coroplast to keep it from bumping the exhaust system pieces that poke downward. Not sure how much distance I need between the exhaust and the coroplast to prevent melting. Anyone have an idea? I am not in the mood to use flashing in that area and enclose the whole exhaust for fear of something overheating.

Eventually I will also add a front undertray to smooth out that section.

In the rear the slope up from the rear suspension to the rear bumper is steep enough to install a diffuser and get some downforce, but that's not what I want. So I need to think of a way that cleans that up without making it worse than the original. That is the lowest priority.

My hope is that after this mod I could regularly see 30mpg on the highway.

If anyone has any wisdom or experience that they would like to share, or any questions to ask, I would certainly appreciate it.

Bill

Bill,looking at your photos,these would be my thoughts:
* consider blocking off the entire upper grille opening
* fashion a complete wrap-around airdam which originates at the license plate mount,curving all the way around to the front of the front wheel arch,which is as deep as the lowest suspension member under the car.( take a look at the new 53-mpg Lexus 200 hybrid nose ).
* put a front license plate below your lower opening ( DPS or TROOPERS will stop you without it ).
* fashion your side skirts as low as the new airdam and as close to the outside of the tires as you can.
* run your front wheels through their entire range of motion ( tire-flop ) and close off as much gap as you can around the front wheels.
* close off as much gap as you can around the rear wheel arches,or consider wheels skirts.
* skip the bellypan and diffuser for the time being.
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I have seen RAV-4 Toyotas return 28 mpg on the highway.I think 30 mpg for the CR-V is very doable.
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If you entertain even higher mpg,consider a receiver-hitch mounted cargo platform-based shorty boat-tail extension ( maybe 4-mpg by itself ).

[Bill in Houston]

Thanks, everyone, for the input.

[COcyclist]

Originally Posted by Bill in Houston

Eventually I will also add a front undertray to smooth out that section.

I would try to follow Aerohead's suggestions. If you do the belly pan eventually, I would sure do the front undertray before working your way toward the back. You don't want to scoop a lot of air up between your belly pan and chassis. If air coming from the front of the car is turbulent it will negate most of the gains of a smooth bellypan farther back.

[Bill in Houston]

I have been looking up there in the front and I think I have figured out my attachment points, and how to easily remove it for maintenance. Based on the input, I will probably tackle that one first. Thanks again.

[alaska45]

Bill, did you ever figure this out? I have a 2001 crv automatic and can't get past 23 to 24 mpg. I have experimented a little bit with putting the car into neutral at stop lights, on hills, but have not yet tried the push and glide. I need to read more about how that effects the transmission before I try it. What techniques have you used?

[Bill in Houston]

No, sorry, I never did anything. There wasn't any coroplast around, and I had found a new addiction by the time elections came again.

If I had the guts to enclose the exhaust system inside the pan, it would be really easy to put on a full front undertray and belly pan.

I am not the primary driver of the car, so I can't vouch for any particular techniques. I do have an Element with over 90k miles on the first set of brake pads, and very few of my miles are highway miles. So that probably tells you something about my techniques in that car.

Drain and fill your transmission fluid three times in the next couple of months if you haven't done that already. I don't really have any other tips for you specific to the CR-V.

[BamZipPow]

Bill...we could meet up so you can see my T-100 in person. Which part of Houston are you at?

[Bill in Houston]

Your T100 was a source of lots of great ideas, and your well-illustrated threads showed me how to implement the ideas. I am just not working on the vehicle now. It is my son's, and goes over 45mph maybe once a week. Thank you for the offer, though. If I ever do work on it, I'll be in touch.