Spoiler (Jeep XJ) - Page 2 - Fuel Economy, Hypermiling, EcoModding News and Forum

Taylor95 · 02-23-2019, 11:55 PM

Quote:

Originally Posted by kach22i

I almost bought a Jeep Cherokee 9-years ago but an ice storm hit so I had to wait and ended up with my S-10 Pickup truck.

I sometimes wonder what my path of modifications would have been.

I'm pretty sure it would have a box cavity of some kind, maybe in the form of adjustable flapper vanes - like tail rudders canted inward located along the trailing edges of the boxy body.

With the ground clearance of the Cherokee I may have even gotten into making a belly pan in lieu of my multiple chin spoiler projects.

There's a lot of low hanging fruit when it comes to the Cherokee. One guy was able to get his to 25 mpg highway on a modest parts budget!

https://www.jeepforum.com/forum/f11/...5-ats-1551782/

freebeard · 02-25-2019, 04:35 PM

Quote:

Yes, the looks are one reason I would get it. It is unique; none of the American XJs came with those.
....
I'll have to try that with the cardboard, although I'm not sure how I will measure the difference, or how I will attach it. Any suggestions?

It appears your hatch wraps to the point of aerodynamic separation. If your device has a rolled leading edge that you can pull over the edge of the hatch, then all you need is a detail that crimps it on.

http://www.vehicleclips.co.uk/fasten...ess-panel.html

You could box the three sides of the hatch and put a clear plastic fin on the taillight lens to fill down to the bumper. Voila! Boxed cavity.

Taylor95 · 02-25-2019, 11:46 PM

That's an idea! And yes, the hatch opens at just the right spot to be able to do that

Taylor95 · 01-15-2021, 12:40 AM

It has been a long time but I am more serious about buying this spoiler now. I will definitely modify it so it angles downward some.

I am thinking about adding small fins on the outside edges of the spoiler to guide the air. In addition to this, I may add a lip to the spoiler to help decrease lift. Thoughts on this?

JulianEdgar · 01-15-2021, 01:22 AM

Quote:

Originally Posted by Taylor95

It has been a long time but I am more serious about buying this spoiler now. I will definitely modify it so it angles downward some.

I am thinking about adding small fins on the outside edges of the spoiler to guide the air. In addition to this, I may add a lip to the spoiler to help decrease lift. Thoughts on this?

You probably don't need to try to reduce lift - squareback shapes with a roofline basically parallel to the ground don't develop a lot of lift.

As has already been suggested, I'd experiment with different configurations first.

This took a lot of tweaking but ended up working pretty well (as far as I could tell; I didn't know about throttle stop testing then):

aerohead · 01-15-2021, 01:09 PM

In addition to a any small drag benefit, for regions of the country which experience truly four-seasons weather patterns, that overhang might mean less snow and ice to clear off the rear glass.

Piotrsko · 01-16-2021, 09:32 AM

Was hoping the addition solved the boil up after the car. I have the same problem in my 13 golf..... ten minutes on a snowy or wet road and you can't see out the rear window for all the road grime from the rear. Vw's fix is to turn n on the wiper back there.

mattrod · 01-21-2021, 02:11 AM

Quote:

Originally Posted by Taylor95

It has been a long time but I am more serious about buying this spoiler now. I will definitely modify it so it angles downward some.

I am thinking about adding small fins on the outside edges of the spoiler to guide the air. In addition to this, I may add a lip to the spoiler to help decrease lift. Thoughts on this?

Keep us posted. I'm curious about your plan.

Taylor95 · 03-20-2021, 06:51 AM

The company that makes those spoilers wanted $75 for shipping on top of $225 for the spoiler, so I decided I did not want to pay that. I am currently thinking about how I can make my own spoiler. I have some plexiglass laying around, so that may be an option if I can figure out how to attach it.