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Discussion Starter · #1 ·
First stages of the fairing for my roof rack are done. Was originally going to go with sheet metal but it would have to be strengthened to keep it from flexing. Then I thought thick plexiglass and remembered there was some at one of my schools thats been sitting in my boiler room forever.

The roof line cut isnt great but will be covered by some split fuel line. I originally had it farther out at the bottom and to the top of my lights but it looked like a freakin billboard. I think it will be ok the way it is now, just look a bit odd with half the lights poking out. The angle should force the air over the tire.





Now I have to figure out how I'm going to attach it. The plan right now is to get some 1" square tubing. The attachment to the rack will be done with some 1" flat T brackets top and bottom of the tube then held in place with some thumb screw hose clamps like these:



The idea is to make it easily removable since it will mainly just be for long highway drives. Not sure yet how I'm going to attach the tubes to the plexiglass. Maybe angle brackets top and bottom and bent to the proper angle. Then paint the whole thing black. Thought about leaving it clear but the UV rays here are brutal on plexiglass.
 

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Gizmo42 said:
First stages of the fairing for my roof rack are done. Was originally going to go with sheet metal but it would have to be strengthened to keep it from flexing. Then I thought thick plexiglass and remembered there was some at one of my schools thats been sitting in my boiler room forever.

The roof line cut isnt great but will be covered by some split fuel line. I originally had it farther out at the bottom and to the top of my lights but it looked like a freakin billboard. I think it will be ok the way it is now, just look a bit odd with half the lights poking out. The angle should force the air over the tire.





Now I have to figure out how I'm going to attach it. The plan right now is to get some 1" square tubing. The attachment to the rack will be done with some 1" flat T brackets top and bottom of the tube then held in place with some thumb screw hose clamps like these:



The idea is to make it easily removable since it will mainly just be for long highway drives. Not sure yet how I'm going to attach the tubes to the plexiglass. Maybe angle brackets top and bottom and bent to the proper angle. Then paint the whole thing black. Thought about leaving it clear but the UV rays here are brutal on plexiglass.
nice are you going to cut it in half?
 

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Looks like a good idea. Maybe make a couple of cutouts for the 2 lights?

:happy1:
 

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Discussion Starter · #4 ·
nice are you going to cut it in half?
Why would I cut it in half?

Maybe make a couple of cutouts for the 2 lights?
Thought about that with my original sheet metal design but decided not to do that. The idea is to angle the air over the entire roof rack with no straight parts. Will have a bit because of the top of the lights but cant have everything. Might eventually cut them out sometime down the road, dont know yet. Right now its more a proof of concept.

Its only meant to be temporary for highway use. The lights are for offroad only so doesnt really matter that half of them are blocked. Thats the reason for making it easily removable. Will just look a little weird with the lights poking over the top but I dont care about that.
 

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We've been doing this for years on the big rigs. Most efficient angle is 30 degrees from the roof line if you want to redirect the most air over the top.

I like your idea, but the plastic may tend to flex too much as the air passes over it at 60 mph. You might consider using aluminum angle brackets for mounts and for stiffeners. Its got to be well supported at both the top and bottom to keep the angle from flexing.
 

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That should keep the drag down and you can't beat the cost either.

The thing I hate about plexiglass is how unforgiving it is, one crack and it's over. The good thing about it, you can paint the back side whatever color you want and the bug impacts wont chip the paint.
 

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Nice, I'll try to get you some pics of how the fairings on my Thule + Yakima racks mount if you like. It's just 3 piece of aluminum flat stock in kind of an L shape. One side is flat aganst the fairing bottom to top. Then it bends parallel to the roof and goes over the bars and is attached with a small U bolt deal and wing nuts. I like the clear. your lights will work right through that. If it was me and I had some more material I would make it a tad wider and cut the shape of the sides to follow the angle of the truck sides viewed from the front. It will be a nice prifile and cover the rack mounts ect.

Here are is a pic that sorta shows the mount on one side.


This one kinda shows what I was talking about on the shape and width. Mine is the Thule brand one out of lexan. It is stock shape. They sure do make things quieter.
 

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Discussion Starter · #8 ·
I thought about doing wider and shaping it like yours, but thats like, geometry and stuff :lol: I had a hard enough time trying to freehand the bottom of it for the curve of the roof line.

Doesnt look like I'll be getting anything done on it today after work. Have a low pressure system moving through from Utah and its windy as hell out. Not going to try fighting that thing trying to blow away while working on it.
 

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Discussion Starter · #9 ·
Got everything done except painting tuesday evening. Ended up pulling it into our shop after work because of the wind. Havent gotten any pics till now because its been raining/snowing non stop since then.

Came out pretty good I think, probably way over engineered. All I have to do is loosen the 4 hose clamps and it slides off.






Been driving with it the last couple days. Not sure how it will do on the highway or if it will help mileage or power up the passes but I've been up to 55 mph and its much quieter and seems to do well. Finally I no longer have that horrible noise the rack developed in January. Sounded like a dry bearing getting ready to lock up if I went over 40 mph.
 

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nice work!!! i know the storm just got over there from utah... now is sunny and 70s now!!
 

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Discussion Starter · #11 ·
The fairing seems to have helped. Didnt struggle nearly as much up the passes as usual and going over 65 is no longer an issue. We stopped in Georgetown to top up since Jacks 4 runner wouldnt make it all the way to Grand Junction on a tank. Its only about 66 miles but I topped up too. Its mostly up hill and I got 24 mpg which is the best I've ever gotten. The run from there to Grand Junction I got 21 mpg which matches the best I ever got in that stretch (pre roof rack and larger tires) and would have gotten better if it wasnt for that long stretch of high head winds.

And it is SOOOO much quieter.
 

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Congrats! I think this was a great idea!
 

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Looks good Gizmo....so did you use clear plex or Lexan for it?
Lexan will hold up alot better than plex plus plex comes in different grades from FF to SG with SG being more durable (old sign guy stuff)....Looks Great 8) 8)
 

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Discussion Starter · #14 ·
AZneonguy said:
Looks good Gizmo....so did you use clear plex or Lexan for it?
Lexan will hold up alot better than plex plus plex comes in different grades from FF to SG with SG being more durable (old sign guy stuff)....Looks Great 8) 8)
its 1/4" plexi. its been sitting in one of my boiler rooms for years. since its free i went with it.
 

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Gizmo42 said:
AZneonguy said:
Looks good Gizmo....so did you use clear plex or Lexan for it?
Lexan will hold up alot better than plex plus plex comes in different grades from FF to SG with SG being more durable (old sign guy stuff)....Looks Great 8) 8)
its 1/4" plexi. its been sitting in one of my boiler rooms for years. since its free i went with it.
That is cool.... looking closer at the pictures it looks like you drilled through it to attach it to the rack....Just heads up if it is indeed plex keep an eye out on the drilled holes as it ages suns and cold it will expand and contract and with stress it will develop spider like cracks and eventually break even if it is !/4 plex. Nice job though just heads up to check it every once in a while.... 8) 8)
 
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