Jeep Cherokee Aeromods - Page 8 - Fuel Economy, Hypermiling, EcoModding News and Forum

FastPlastic · 08-13-2008, 04:28 PM

The latest addition to the aero mods of the Jeep. Skid plate wings!

I didn't have enough time to finish two. Plus I wanted to make sure my mounting design would hold up (Didn't drill in to the plastic bumper). But It should help keep the air lower near the wheels. Maybe even cover a little of the wheel itself.

Memorytwo · 08-20-2008, 02:36 AM

hi, ive been checking this out. will you be making a full belly pan? ive been checking out my grand cherokee and i dont think i could make one. I dont know if i should make "segments" of pan since the axles need to articulate.

justpassntime · 08-20-2008, 04:06 AM

Impressive! Great work, gotta like sheet metal. Looks like in the first pic that you are scooping air by another belly pan behind the front differential. Is this an illusion?

FastPlastic · 08-20-2008, 11:37 AM

So far I haven't made it past the front differential. I think what you see in the pic is a cross brace about halfway down the Jeep. I do plan on making a scoop for the cross brace just haven't gotten that far yet.

The project I'm working on now is a small lip I'm going to attach to the front axle. According to the Flow Illustrator it should help to keep the smooth jet of air flowing farther down the Jeep.

I'm designing everything with the idea that smooth connected air flow under an SUV is almost impossible. So instead the goal is a jet stream that passes under everything with as little obstruction as possible.

Smoove · 08-20-2008, 11:46 AM

Stupid question time: Is an air dam better for highway and full undertray better for around town?

I ask because I do 90+% highway driving (albeit in NYC that isn't always above 30mph) and planned on doing a lower front valence in addition to an undertray from the LCA mounts back.

FastPlastic · 08-20-2008, 11:59 AM

You will see the biggest improvement for both at highway speeds (aerodynamic drag increases dramatically past about 35-40mph). Slight improvement will happen at city speeds. Most people suggest using both if you have the time/cash.

aerohead · 08-20-2008, 02:29 PM

Quote:

Originally Posted by Smoove

Stupid question time: Is an air dam better for highway and full undertray better for around town?

I ask because I do 90+% highway driving (albeit in NYC that isn't always above 30mph) and planned on doing a lower front valence in addition to an undertray from the LCA mounts back.

Smoove,there is no such thing as a stupid question.And we're all probably suffering because so many were afraid to ask.------------ The deep chassis design of the Jeep may be one of the best candidates for the pan.It's a big project,but paves the way for even better things to come.Do it if you have the stomach for it,if not,a optimized airdam will get you part way there.

Smoove · 08-20-2008, 04:25 PM

I felt it was a stupid question because even after doing the required research, I still felt the answer was unclear - especially for the type of driving I do. I also feel like a bit of a snake in the grass, since my end goal has nothing to do with mpg's, but to achieve a more stable and pleasant to drive jeep with the added bonus of better mpg's. But thanks to both of you for the replies.

The cost of this build is irrelevant, as I can get many of the supplies for free (you would be amazed at what people throw away here). Time is an issue, but finding a safe place to work is more of a problem. My parking garage does not allow any work to be done to a vehicle (as per the HOA) so that means I have to do it on the street. On 1st ave, usually during rush hour, and my block is a thoroughfare to the Queens-Midtown tunnel. This is not an easy task.

Alas I bit the bullet and circled the block about two dozen times until a parking spot big enough to do the task was found and I got to work with the lawn edging air dam. 90 minutes later (those damn plastic pop-rivets are worthless!) and I have a satisfactory looking air damn, only satisfactory because getting the final curve on either side was not easy nor consistent. I will be driving double my 80 miles per week trek, so hopefully I can get some numbers soon.

Thanks for the help, advice and pics, and apologies for hijacking your thread.

Memorytwo · 08-20-2008, 05:38 PM

ah excellent, im looking forward to your progress

FastPlastic · 08-23-2008, 09:07 PM

So the latest installment in the mods. I finished the second wing for the skid plate.

Also I ran a few tests with the flow illustrator which pointed to placing a small lip on the back side of the the front axle, as seen below.

Which resulted in this.

Haven't had time to take it out on the highway to see what the difference may be. But I feel like it coasts a little bit farther in town then it use too.