Page 1 of 3

For all the "Flat Nosers"

PostPosted: Mon Sep 17, 2018 6:22 pm
by McDave
I have been looking at this for a couple of years at the local junkyard. I'm wondering if the nose cone could be any help for MPG? Maybe along with some sort of tail piece to break the drag on the tailgate/ramp?

156207156206

Thoughts, ridicule etc. ...

McDave

Re: For all the "Flat Nosers"

PostPosted: Mon Sep 17, 2018 6:31 pm
by hankaye
McD, Howdy;

:thinking:

hank

Re: For all the "Flat Nosers"

PostPosted: Mon Sep 17, 2018 8:55 pm
by flboy
I am seriously thinking of putting vortex generators on the back of my CTC to maybe squeeze another mpg..

Not a crazy idea at all.

Sent from my SM-G935P using Tapatalk

Re: For all the "Flat Nosers"

PostPosted: Mon Sep 17, 2018 9:54 pm
by aggie79
Looks similar in shape to this commercial version: https://www.nosecone.com/cargo-trailer-models.html


Sent from my iPhone using Tapatalk

Re: For all the "Flat Nosers"

PostPosted: Mon Sep 17, 2018 9:59 pm
by aggie79
flboy wrote:I am seriously thinking of putting vortex generators on the back of my CTC to maybe squeeze another mpg..

Not a crazy idea at all.

Sent from my SM-G935P using Tapatalk


I can’t find it now but somewhere I saw an aluminum angle extrusion with v-notches intended to be used like a wickerbill or Gurney flap. The angle of the aluminum was ~135 degrees or so. It was intended to be used horizontally but I would guess it could be used vertically. As I recall those plastic vortex generators cost a small fortune but the aluminum was much cheaper.


Sent from my iPhone using Tapatalk

Re: For all the "Flat Nosers"

PostPosted: Mon Sep 17, 2018 11:12 pm
by GrantRobertson
McDave wrote:I'm wondering if the nose cone could be any help for MPG?


I'm thinking you would have to have that thing pretty close up to the back of your car or it would be a sail instead of a nose-cone.

Re: For all the "Flat Nosers"

PostPosted: Tue Sep 18, 2018 7:20 am
by flboy
I am thinking of putting these properly spaced (4 inches apart on center) along the rear sides and rear top of the CTC. It may help some with MPG, but also that "sucking" action that occurs when a large truck or bus approaches from behind at highway speeds.

If nothing else... they will look high tech. :-) not too expensive (about $198 for 66 pieces at 3 pieces per foot), so worth a try.

At current gas prices and assuming 10mpg I get now towing, it would take over 12,000 miles to breakeven given 5% improvement if true. So economics isn't the only motivation for investing in Vortex Generators unless you are a commercial driver and put on tons of miles each year. I can see doing about 6,000 a year or more when I hit the road next year however. 2 yr. payback is decent in that case.

I already have the V-nose , but that is questionable if it helps much at all. Many schools of thought on that... mostly anecdotal.



Image




https://www.raneystruckparts.com/vortex ... 7wQAvD_BwE

Sent from my SM-G935P using Tapatalk

Re: For all the "Flat Nosers"

PostPosted: Tue Sep 18, 2018 8:22 am
by aggie79
Don,

They have come way down in price since I last checked into them about 3-4 years ago. At that price, it would not be worth the time and expense to fabricate something on your own.

While I don't own a CT trailer (yet) I have pulled many trailers. I am not concerned so much with mileage as I am with stability in crosswinds and from passing, large vehicle, traffic. I think there may some minimal mileage gains with a v-nose, but the real benefit to me is the "parting" of the air and reducing buffeting from the v-nose. A nose cone on a flat front trailer accomplishes this same objective.

Likewise, I think the vortex generators could help somewhat in mileage, but more so in stability. At that small cost, it would be worth it to me if they provided some stability benefits.

Take care,
Tom

Re: For all the "Flat Nosers"

PostPosted: Tue Sep 18, 2018 9:11 am
by McDave
All good stuff here this AM.
I had forgotten about the commercial nose cones and haven't seen one for a long time. But the wind tunnel test was enlightening.
I failed to mention that my tow vehicle is a GMC G2500 3/4 ton van. So the proximity of the nose cone to the TV roof would be fairly close, 1-2 ft. and the height of the van roof appears to be close to the height of the lower part of the nose cone. I think I will run over there this AM with a tape measure and see what we are really looking at.
The vortice generators are expensive for our application, but I feel like some genius here can come up with a cheap hack made from beer cans or some other cheap material that would make it possible for everybody to DIY while sitting around the campfire. In my case, I would think I need (2) sets, one for the trailer and one for the van as it also has the flat vertical surface prone to the suction forces of drag. I have also seen where a tail extension from the roof of vans and trailers can prevent the suction on the rear doors.
The trick here is to make these mods affordable. But, at 10mpg or less it doesn't take much to make sense.
Thanks for all the input. If I stumble upon a 10-20% increase in MPG I will gladly share it here.
Maybe a homemade wind tunnel and some models would be a good place to start....
:thinking:
McDave

Re: For all the "Flat Nosers"

PostPosted: Tue Sep 18, 2018 11:42 am
by robctc
So I don't have a ton of experience towing and haven't started my CTC build yet, but I am the kind of person that researches for literal days, and as a result bought a flat nose trailer after reading many forum posts and other internet commentary from old curmudgeons with decades of road experience.

So heres what I found, summarized (hopefully) with simple explanations.

- Those air tabs DO make a difference, but the worth is more in preventing trailer sway and feeling more stable by breaking the suction at the back. Don't expect more than 1 MPG difference, do expect to stop feeling the sway when a semi passes.

- V-noses don't actually help aerodynamics, though many swear they do. If your vehicle was pushing the V-nose, it would help, but the air is already broken by the front of your vehicle. What happens instead is that there's more surface area on a V-nose for wind to hit both those sides, and add to sway. However, this is a difference you could see in a wind tunnel. The average person could pull both and probably not notice. If there is a MPG difference between the two it couldn't be more than 1-1.5 MPG.

- Those nose cones DO help, but you're probably better off with a DIY solution. 1-2 MPG difference but commercially they're around $700, so the math doesn't work out well.

Other things to consider doing:
- Insulate the underside of your trailer to the bottom of the supports. Air moves down there too, so the less pockets for air the better.

- Get the top of your vehicle level with the trailer. Personally, I'm going to add a rooftop carrier to my SUV because right now the trailer sits a good foot higher, and thats a big sail.

- Distribute the weight inside evenly. Thats just trailer 101.

So if you do all the things I wouldn't expect more than a 3-4 MPG increase, and that will vary per driver and vehicle. Doing all those WILL do a lot for trailer sway and safety, which arguable is worth way more than an extra stop at the pump.

Hope this helps, but take it all with a grain of salt because its just research.

Re: For all the "Flat Nosers"

PostPosted: Tue Sep 18, 2018 1:46 pm
by McDave
That is all good info there robctc. And, that is what I have found as well. Now if I can get that nosecone cheap and it would fit reasonably well it might be worth a try. If I could gain 2 mpg that would be at least 20% or 7.6gal/tank or approx. $23.00 per tank. I burn at least 3 tanks to go to just about any rally I attend. So let's just call it 75.00 per trip. 5 rallies per year = 375.00. That's a nice dinner and couple tee shirts at Sturgis. Maybe a whiskey or two as well. Seems like it might be worth the try.

McDave

Re: For all the "Flat Nosers"

PostPosted: Tue Sep 18, 2018 2:14 pm
by hankaye
McD, Howdy;

McDave wrote:That is all good info there robctc. And, that is what I have found as well. Now if I can get that nosecone cheap and it would fit reasonably well it might be worth a try. If I could gain 2 mpg that would be at least 20% or 7.6gal/tank or approx. $23.00 per tank. I burn at least 3 tanks to go to just about any rally I attend. So let's just call it 75.00 per trip. 5 rallies per year = 375.00. That's a nice dinner and couple tee shirts at Sturgis. Maybe a whiskey or two as well. Seems like it might be worth the try.

McDave


Not to sure what you're yippin' about, Fueled up in Las Cruces last Wed. drove back to Arrey,
couplea trips back-n-forth to TorC and just went to El Paso for a VA appointment. topped off
the tank on my way outta EP, took 25.271 gal of diesel @ $2.849/gal. (Texas remember?), that
was for 389.3 miles of driving in that time. It's 111.2 miles from home to the VA in EP. Tank
holds 42 gal. so I was just under 1/2 a tank when I topped it off. Price of diesel in TorC is $3.349.

hank

Re: For all the "Flat Nosers"

PostPosted: Tue Sep 18, 2018 2:49 pm
by robctc
McDave wrote:That is all good info there robctc. And, that is what I have found as well. Now if I can get that nosecone cheap and it would fit reasonably well it might be worth a try. If I could gain 2 mpg that would be at least 20% or 7.6gal/tank or approx. $23.00 per tank. I burn at least 3 tanks to go to just about any rally I attend. So let's just call it 75.00 per trip. 5 rallies per year = 375.00. That's a nice dinner and couple tee shirts at Sturgis. Maybe a whiskey or two as well. Seems like it might be worth the try.

McDave


Eventually I'll start a build thread once I get to work and hope to chronicle my efforts trying to DIY a nosecone. I know it won't have a computer engineered shape, but I imagine just eyeballing a similar shape is going to help more than nothing. I'm thinking a frame of PVC or some kind of easily bendable tubing covered in this forums very own poor mans fiberglass.

Re: For all the "Flat Nosers"

PostPosted: Tue Sep 18, 2018 7:12 pm
by flboy
I decided to quit talking/thinking about it and just do it. I bought these tonight and will have them on next week. I will be able to report the difference on my trip to South Carolina for Thanksgiving. I have good records on gas mileage and will know if these make a difference that is noticeable. Also, will be on the interstate, so will test the handling with trucks sucking the trailer over. Pics to come next week. Will update on my build thread as I am painting the roof white after cleaning and inspecting the Dicor lap seals along the edges and the holes I cut for AC, Antenna, and etc.. Never done with the build!


EcoFins.JPG
EcoFins.JPG (33.07 KiB) Viewed 10025 times

Re: For all the "Flat Nosers"

PostPosted: Wed Sep 19, 2018 7:43 am
by jmanscotch
In two years of owning my Tacoma, the best MPGs I ever recorded (and I record 100% of my tanks) was 19 MPG, and that was a highway trip from Colorado to Albuquerque, NM.

Since hitching up my CTC and hauling it on a couple road trips, my highest recorded MPG, which was while hauling, has shot up to 24 MPG.

So, I don't get what you fellas are going on about. I saw a huge improvement while towing mine and all I did was cut 8" out of the height of the roof on the trailer.

(as a disclaimer, I'm fairly certain my improvements are because my truck doesn't have tow/haul mode to keep it out of overdrive so I manually shift my automatic while towing).