The Amocat- 2005 Tacoma

[Sven7]

Originally Posted by Daox

Lots of OEMs put their dams back farther like you did though, so there still must be some benefit.

Sometimes they just want a good approach angle. The truck's up so high it probably wouldn't hurt to push it forward. Maybe scoot it a half inch at a time and see when it scrapes...

Anyway, the build quality looks pretty good and I'm interested to see how that aero cap comes along.

[aardvarcus]

Wdb,
The older information and older pictures of the Colorado from about six months ago (when I was seriously considering waiting for one) didn’t have the air dam on the Z71 models, just the base, work truck, and LT. Now it appears they have the air dam on all the models, probably for on road stability reasons. If you look on their website though you can still see some of the older photos up of the Z71s without them.

Sven7,
I looked long and hard about moving it to right under the front bumper cover. Since mine is rubber, it doesn't matter at all if the dam scrapes or drags, but since I actually offroad the truck a bit, I didn't want to risk dragging the aluminum subframe, since that could potentially damage the truck or puncture a tire if it came off. I could mount if more forward, but it would complicate the mounting significantly.

If I didn't offroad and want the clearance, the X-runner Tacoma has some interesting aerodynamic lower molding pieces on the front bumper, sides, and back that I would probably try to retrofit. Toyota has the 2WD Pre-Runner access cab at CD 0.394, but the 2WD X-Runner access cab at CD 0.357. So there are factory toyota bolt on fairings available that could reduce CD by 0.037. Nothing to sneeze at.

[aardvarcus]

Well, I only got part of my V1.2 list done, so I am labeling this as V1.1 for now. I was able to reshape the outer radii into a tighter arc, and trimmed about one inch off of each end. This should keep the air from drastically overshooting the tire, but I don’t know for sure that I didn’t overcorrect and bend it too far.

Looking again at how close my tow hook is to my aluminum air dam frame, I was unable to increase the slope in the two flatter parts of the middle towards the side, so that idea was a no go for now. Further examining Hucho’s book and the many charts it contains, I decided to cut out the center middle of the air dam, 1” tall by 28”sloping to 34” wide.

Inspecting other charts in the book that had heights of air dams and placements front to back, my far back placement of the air dam appears to have some but not overwhelming impact on the available reduction in drag coefficient, but clearly had implications on available reductions in front lift coefficients. Honestly it’s already better than stock, so I think I can live with that for now.

Examining the charts in the book further, a front lip on the air dam was shown in the book with positive results, so I began testing attaching some pieces of rubber fuel hose to a scrap of conveyor belt to act as a lip when I ran out of time to work. I quickly re-bolted the air dam on, a let than five minute job.

Anyway, here are some pictures of V1.1 as I reinstalled last night. Based on some “coast down hill” type tests this morning, V1.1 appears to have slightly lower drag than V1.0, but there are way too many variables to know for sure right now.

[freebeard]

Good improvements. The notch in the lower edge is good because unpaved roads tend to have a high center. I regularly re-grade my friends driveway.

[aardvarcus]

Insomnia struck again, so I got up early and put the tube lip on my airdam. I ended up drilling holes through the rubber tube, putting a rivet though the inside of the tube through the conveyor belt. I used a washer on the back side to expand the rivet into, so it wouldn't just pull through the conveyor belt. Made a pretty solid connection, and the fasteners semi-hidden from view.

I need to put something over the end of the tube to hide the gaping hole for cosmetic reasons. It is also getting about time to take it off and paint the aluminum. I am about ready to call this project "good enough for now" and start working on the bed cover.

Any thoughts, suggestions, or ideas are welcome though.

[BamZipPow]

Expanding foam would work to plug up the ends of the tubing...

[aardvarcus]

Well, I removed the air dam, got the aluminum painted flat black, let it dry to the touch, and got it reinstalled yesterday.

[Daox]

Looks good to me.

[Sven7]

What's the reason for the tube lip?

[BamZipPow]

Originally Posted by Sven7

What's the reason for the tube lip?

Probably fer reinforcement...