Angled tonneau cover questions

[gone9]

no drilling in the cab for me, but I think I can make flap that bridges the gap between the angled tonneau cover with the conveyor belt and some aluminum strips/brackets. That way its rubber and won't damage the window its resting on but re-enforced with some aluminum tabs and arms to keep from flapping up/down with heavy winds.


SORRY for the paint picture lol.... but hope it gets the point across lol.

[BamZipPow]

Yer gonna want something in between the glass and the rubber so it doesn't scratch or break the glass. Maybe also make the rubber strip much longer and bend it down at the glass so it can flex accordingly?

[freebeard]

So my tonneau cover is on Order. Wife heard me yammering about tonneau covers and mpg’s. Long story short an Arrocap/Shell is out of the question for me

no drilling in the cab for me,

I don't see much of a way around your [wife's] prejudices.

If you came to us before the fact, we could talk about half-tonneaus, boxed cavities and perforated base plates. Those discussions are now moot.

All we have to work with is a picture of someone else's tonneau cover and a misguided assumption that a 3D flow field can be reduced to a simple 12° angle. By all means go ahead and [just] do it. That would be classed as wake filling. Base pressure is exerted against the rear face irrespective of it's angle, you'll just spread it over a larger area.

Here's is what I would do:



This is half-way between a half-tonneau and a spoiler. The line from the back of the cab to the top of that 3rd 4th taillight is...

wait for it...

12°.

[gone9]

The tonneau was 50/50 I need something to cover the bed and keep stuff mostly dry during trips. Worst case for long drives without needing the bed I can cab up a half cover for the bed and a custom headache each with a fin for the rear cab spoiler.

But the 83 f250 getting a solid 2mpg from his fabbed angled tonneau, I figured worst case I’ll gain something. I know the pdf and computer simulated tunnel is conjecture but tonneaus half or full seemed to help pickups on freeways above 45mph at least. I don’t think I’m up for a rear spoiler though. Looks like “not your average pizza delivery lol”


To my wife’s defense, if I wanted to build and aerocap and drill holes she would help me do it. But I’m not that dedicated to ecomoddong my truck yet. But if I can mod the truck to just be better, and not loose to much useability I’m
Game. She is surprisingly supportive of anything I do as long as I actually research and do some planning etc.

[freebeard]

Pardon my presupposition.

The tonneau was 50/50 I need something to cover the bed and keep stuff mostly dry during trips. Worst case for long drives without needing the bed I can cab up a half cover for the bed and a custom headache each with a fin for the rear cab spoiler.

It folds in half? Here's a golden oldie:



edit:
Camping World Cup trucks use a simple spoiler that follows the 12° rule.


http://www.rantsports.com/nascar/wp-content/slideshow/2012/11/top-five-future-sprint-cup-series-drivers-from-the-camping-world-truck-series/medium/ty-dillon2.jpg

No reason why the spoiler couldn't be clear plastic, and/or retractable. It doesn't need to be a rectangle, a half-octagon or curved arc would have less frontal area, and conform to the vortexes that stream off the back of the cab.

[gone9]

with the picture of the white pickup, from the front of the bed(essentially the bottom of the rear of the cab, they just built a flat cover that goes up at a 12 degree angle to the top of the 4rth tail light so kind of a reverse angled tonneau cover?


So the tonneau cover folds onto it self with three equal pieces. and a small strap to keep it unfolding while driving/ for storage.

heres the link: I can always remove the soft material and lay down plastic, or aluminum or something more solid etc.

http://www.autoanything.com/tonneau-...-tonneau-cover


Im not gonna lie I'll have to research the perforated base plates and spoiler thing for the truck. I am still really new and have some reading to do but would it be a fair assumption for the following?

Truck got 19.5 on highway stock, after level kit and 2in taller, 1 in wider tires down to best of 17.7.

first mod: Adjusting driving style-I already drive the speed limit +/-2mph and CA drivers hate it lol. Im OCD with maintencs for fluids, filters, tire pressures, etc..

second mod-
part A- Full tonneau cover-only expecting it to really help on long trips for 1mpg boost to be honest?

part B-Angled Tonneau-copying the orange diesel truck-1-2mpg up at best for highway speeds?

Part C partial tonneau cover- I'll start with 50% of read portion covered, then move to a rear wing on a DIY cab level headache rack? something sturdy to fill the gap.

third mod - Air dam- Big Dave and others discovered it doesn't have to go to the ground as much as it needs to cover the tires. he got .75mpg boost at best but I have the material so only my time is needed.


Do you have some links to the perforated base plate and spoiler? Im curious since I haven't seen it come up on my research for improving economy with a pickup etc.

Again sorry, im new to this and I kind of settled for what I could do practically and without going to crazy on the truck etc.

[freebeard]

I was mapping the outer limits of possibility, I don't know that these concepts have been applied to pickup trucks.

researchgate.net:The Effect of Base Bleed and Rear Cavities on the Drag of an SUV

See also Morelli, et al.

I don't think anyone has taken my suggestion for a truck wheel spat:

[gone9]

No biggy. Always appreciate someone’s experience to help me out. The tonneau cover arrives Friday and I’ll drive a few tanks without to get something to base post cover economy off of.

I’ve been driving a lot of city mies and that drops me into the 14s pretty much always.

[elhigh]

Originally Posted by justinooo9

Air dam seemed .76mpg max! not a lot but for my truck its the least invasive. so theres 19mpg

Somebody getting 40mpg or more might sneer at 0.76mpg improvement (generally nobody on this site, of course - we regard a win as a win no matter how small), or just disregard it as a small enough improvement that it might just be within the margin of error. But when your baseline results are in the teens, it's pretty big.

[teoman]

Originally Posted by elhigh

The Lund spoiler isn't what you want, the tapering lip that extends and lowers the trailing edge of the Toyota's cab is more suited to what you're trying to accomplish.

As to making partial gains with a box cavity cab wall extension, dunno. I don't think I've seen anything on that, but it sounds like it's at least worth exploring.

Visit the solar roadways!