'03 Tacoma Prerunner

[trebuchet03]

That's a super small fill..... 33mpg is great, but wait for some better data on your next two complete fills

Mods look good though

[mobilerik]

That's a super small fill..... 33mpg is great, but wait for some better data on your next two complete fills

NOOOOOOOOOOOOOOOOOOO!!!! :-)


I'm cheering on my wheel mods, see. They just scored a touchdown, and whether the ref made a bad call... is completely beside the point. The scoreboard says 33mpg. GO WHEEL MODS!! Woooooooooo!

Besides, two fills is two or three mods away, so the science experiment is doomed from the start. Now it's just pure sport. Feel the adrenaline. I think I can beat 30 this week. Dig???

[mobilerik]

Last night my truck got a new bonnet to go with the skirts.




Hmm... I think I should restate that, b/c I think my truck is a dude.
"Last night my new truck got a new bandana to go with his kilts."


I don't love this design, but I thought it was a clever use of an extra 4x1 foot strip of coroplast.

Construction was easy. Using a template from a piece of poster board, I cut it and had it ready within 20 minutes.





Then I decided to get fancy and screwed it up, causing me to spend another hour fixing it with ugly tape.

Here's how it's applied. The tab attaches to the back of the truck.



I stuck it to the truck with double-sided duck tape. Good stuff.

Since I didn't bother to pre-bend the coroplast, it was tough to get the tab to hold, so I wound up layering a pile of aluminum tape.



The drive:

I got to my car this morning to find that the tab on one side had detached. Because it was cold and dewey, there was no way I was going to get it to stick, so I left it dangling. Otherwise it was solid, and it made the entire 34 mile drive.

My ScanGauge is calibrated a lot closer now, and marks are easier to hit. Not my old marks, mind you, but marks nonetheless. I think it's still calibrated low, but it's close enough not to be maddening. If it's not still really low, then I'm worried that my engine is starting to lose efficiency now that it's well out of its stock sweet-zone. I'm not sure that's a good diagnosis of my experience though... I'll have to meditate on that.

My nicest discovery ... I can Pulse-and-Glide now! Not everywhere, of course, but at least on some moderate downgrades where my previous choice was limited to DWL at 65mpg. And I was totally able to coast all the way down a few long hills. I noticed the same after the wheel mods yesterday, but now it's even better.

I don't like the look right now though, so I'll be in a hurry to upgrade to a full "fastback". I'll probably procrastinate today by folding paper designs of the folds and cutouts I'll need.

[mobilerik]

Originally Posted by MetroMPG

I'm betting the air tabs made no discernable difference.

Great mods!

Thanks! The DIY AirTabs... hard to say what if any difference they made. When I first installed them, there was a lot of noise, but no real difference in how the car handled. At least as far as I could differentiate from the belly screen that I was fiddling with at the same time. Now, I did see a consistent 1 mpg boost when I cut them down from 2.5 inches to .75 inches and better handling. But again, I was finishing and repairing the belly screen at the same time. You could say "I want to believe" that they should work on my truck. The vacuum suck when I shift to N downhill is hugely frustrating, and it would be great to minimize that. Maybe they need to see a wing. It's a fact that my short bed doesn't allow a shallow 12 degree angle -- it's more like 20. Soon I'm thinking I might experiment with a whale tail. But first I'll see if managing the angle of the roof and sides can accommodate the short 5-foot bed.

I'd definitely work on that coroplast taper to the roof & side of the cab. You can't go wrong with a 10 degree taper (sides & top) if you just want to slap something together.

Yeah, "slap" definitely describes this last mod. It's not even a bonnet -- more like a kerchief. Ideally, if I wanted to stick with this mod, I think I need to make it look like a manly backwards baseball cap.

I'm having trouble imagining how to apply the sides-taper to a fastback attachment, that I assume would affix to the bed rails, when my bed is wider than the cab. Is there a model somewhere for this? Or maybe the idea is a gradual taper as it rises towards the top...

[mobilerik]

Originally Posted by Sulfuric

33 mpg is simply amazing in pretty much any pickup, high five.
If you could pick a number in mpg, how much do you think you scangauge helps?

Well, yesterday it didn't help me the slightest bit, LOL. But generally I've been saying it's worth to me about 6mpg, or 20% of my mpg. Of course I could've learned a lot of it, and did learn a lot of it, without the ScanGauge. But I totally depend on DWL, and with the automatic, I often just have a hard time figuring out what gear I'm in, especially coming out of neutral coast. It's so much easier for me to watch the mpgs. If I'm cruising at 48 but eating fuel, I know I need to get my overdrive back. And knowing whether I'm trolling around town at 10mph getting 30mpg vs. 5mpg is priceless.

[mobilerik]

Originally Posted by taco

flat landers!!!!!


very nice 3rz ftw!

ROTFL!!

Dude, I'm from WV myself. Northern. And I'm so impressed you get 27mpg in a 4x4. Nice!

[mobilerik]

"Fastback"-style Cab Kamm: Check!


Here's what I "slapped on" last night:




The Build:

Funny thing is... I stopped at Lowe's after work to pick up some clear plastic and supplies to make the side fairings. But by the time I got home, I decided it was too complicated to bust it all out in one night, so I decided to put it off.

But I thought "Why don't I try this with some of the screen left over from the belly screen?" It took me all of 15 minutes to cut the screen and prep it. But when I got back to the car... too short. (Measure twice, cut once, stupid!) And that was the last of my screen.

The experience was good, though. When I realized how small those fairings really are (about 17x12", tapering to 5"), I noticed I had a couple small pieces of coroplast left over from the wheel project that were exactly the right size!

I quickly cut 'em to size, and cut a few smaller pieces to use as joints - to attach the fairings to the bed rail and to the top fairing. Again I used Double-Sided Duck Brand Tape. If you haven't tried it, I really recommend it. It not only sticks solidly to the car, but it also peels right back off. It's gummy, so I think it's helped by simple vacuum action.



Geometry:

It's hard to tell from the photos what kinds of angles are involved. Honestly, I didn't measure, but tried to eyeball a taper that would allow around an average of 10-12 degrees. The sides start at the bottom flush with the inside edge of the bed rail and twist to meet the top at around 15 degrees.

The top likes to bulge upwards in the middle, so the angle is near flat, but rapidly starts to curve downwards towards the sides approaching 20 degrees. Note that the tailgate of my short 5 ft. bed is about 20 degrees south of the top of the cab. I'd like to reinforce the middle of the top so that it bulges less and keeps a more consistent downward angle across the top that will keep it from "splitting" the air over the bed.

Visibility:

A short note -- I was very concerned that the visibility around my blind spot would disappear, and that's why I was prioritizing clear plastic or screen for the side fairings. But now that they're on -- not only are they not in the way... I can barely even see them, because they are hidden behind the C-pillars. How about that!

Questions, anyone? Comments from experts?
I'd really like to know if this "Fastback" style would be better converted to the downward "chopped" style Kamm-back, with the side fairings smaller at the bottom than the top. It's obvious to me that the V where the top and sides meet won't do, but beyond that, what shape should I be going for overall?

By the way, if anyone is counting, I believe this is my 5th ecomod this week.
1) Wheel covers, 2) Rear wheel skirts, 3) Passenger mirror foldback, 4) Top cab fairing, 5) Side Cab Fairing. With two more days to fillup, what's your bet on this week's numbers?

[FastPlastic]

That looks awesome!!! Who knew aero mods could look so beautiful (crying a little inside).

Can you still see the 3rd brake light?

[mobilerik]

Yeah, the brake light peeks under just fine. But that's a good reminder for when I try to lower the angle a little.

[MetroMPG]

Cool. I really like the way the mods are looking on your truck. Business like for sure.

My first comment: make it bigger!

As for shape to follow, look at Bondo's or Phil's truck and follow those lines. The fact that you're chopping yours off before the tailgate doesn't matter. If you can round the "shoulders" (the transition between the "sides" and "top" of the extension), it'll help.