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Old 12-23-2008, 11:56 AM   #42 (permalink)
mobilerik's Avatar
Join Date: Nov 2008
Location: San Diego, CA
Posts: 108

rik's prerunner - '03 Toyota Tacoma Prerunner Double Cab TRD 4A
90 day: 29.68 mpg (US)
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Clear Kamm and Giant Spoiler

Clear Kamm and Giant Spoiler

"Man, that's one big-ass spoiler!"

This sturdy version of the "rear reattachment apparatus" turned out even cheaper to make than the original coroplast prototype. I used a double-layer of 1/8" hardboard, both layers cut from the same $7 panel, glued and screwed together. It's painted for waterproofing. It lasted fine through the rain yesterday. It's bracketed to the half tonneau, and there's some wood braces under the sides that hold it solid. The plexi board at the rear is a quick attempt to encourage the stationary vortex ("the bubble") to force the air over and around. This afternoon I'll add some tufts underneath to see what the air is doing under there.

Visibility unfortunately is decreased from the first prototype in my attempt to allow more surface area on top. It is also sitting a tad higher than I intended, and that is why it may appear that the angle is a little steeper than the roofline. Actually the angle of the "rear Kamm spoiler doohickey" is 10.5 degrees. But I didn't adequately take into account the rise that would be added when I double-layered, and adding the error at the bottom, it's about 1" too high. :doh!:

The "Clear Cab Kamm"

I made this from two sheets of Optix acrylic from Lowes: I think one was 28x32", and the other was 24x36". The sides are attached to the top with screws and joints made from the same plastic. This was my first attempt at acrylic, and I'll say that it's, well... a heck of a lot tougher than coroplast. After a lot of cracking with every jigsaw blade I could find, I found some success with a Dremel router setup. I wasn't patient enough to make a template, so my lines are pretty squiggly. Also bending was basically a blind affair, as I did the bending in the garage out of the rain and went out just to check if I was close. And since I don't know how to bend acrylic with consistency, the fairings are warped a bit, and in a few places are just mismatched and creating a lot of drag. But that's why it's called a "prototype" and that's why I'm happy to stick with the low-res cell phone pix.

Did they work??

Of course they worked! Why wouldn't they? But I can't give any definite evaluation for a number of reasons. Mostly the weather has been too inconsistent to even know what I should be getting right now, and I've been interrupting my commute in different places to Christmas-shop.

So I'll just say this: It definitely accelerates and coasts better. I was able to hit higher numbers at my TPS markers in certain locations. And the ScanGauge told me I hit 30.2 on my morning commute with what I believe is now a fairly close (though still work-in-progress) calibration. I expect the numbers to go up as I solve the height issue and plug the tunnel.

But in the whole context, the next must-do "mod" is to make my tire valves accessible again!!! I just haven't had time, so as it is, I haven't pumped my tires in a month. While I'm at it, I'm going to see if I can make those pizza pans shine.

Last edited by mobilerik; 02-02-2009 at 01:02 AM..
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