New and seeking aero advice for my "brick"

[kach22i]

Originally Posted by euromodder

Bigger / wider & higher deflector on the roof of the cab.

Bigger radius on the corners of the box
(by adding a half-pipe - can be used to store long thin items)
or
turning vanes on the corners

I agree strongly with the wider & higher deflector on the roof comment that I highlighted in dark red (above).

On the second point of radius box corners that he already has, there are other areas much more deserving of attention, and that is probably the least of them.

Those European cab over engine air curtains are a fascination of mine as well, but here those giant rear view mirrors that he has are air flow interrupters and concept killers, that beautiful illustration will probably not work here.

A fine example of huge roof top fairing combined with curved leading edge box corners has already been posted, it helped me to look at it closer a second time. We need to get over that it's a Sprinter example, and focus on the details, these are details similar to the ones I sketched up early on and that we all seem to be in agreement on lately.

Originally Posted by freebeard

https://ecomodder.com/forum/showthre...uck-34674.html

EDIT-1:

Regarding the below comment, sounds expensive and heavy compared to gluing some foam wedges to the door and painting them black. Neither idea is bad, just that there is just so much more low lying fruit to pick and these would be the very last things one would do if at all.

Originally Posted by freebeard

If you find a derelict cab that uses the same door you could cut the door frames down into a pie-shaped piece and slip it inside the half-open door and weld 'er up.

[xx_ED_xx]

Good info I am trying to improve aero on this

[kach22i]

Originally Posted by xx_ED_xx

Good info I am trying to improve aero on this

That is a much cleaner starting point, although not 8-feet wide like that ambulance.

[freebeard]

Interesting.

Good fineness ratio and taper in elevation. You could panel in the sides and put pontoon fenders over the three axles.

[3304hl]

Having just read through the thread, I don't see that anyone has mentioned some of the obvious improvements; that being the underside of the truck.
As is, it seems to be slightly nose up, and this won't improve with a trailer in tow.
Depending on the needs demanded by usual roads, drop this down to no more than 6", give it a bit of forward rake, put on a front air dam, and try and smooth the underside as much as possible, then repeat MPG test.
cheers

[kach22i]

Originally Posted by 3304hl

.......... the underside of the truck..........

So many other things going on with that project, why not add a belly pan indeed.

That should cover his "to do list" for the life of the vehicle.

[kach22i]

Originally Posted by freebeard

Interesting.

Good fineness ratio and taper in elevation. You could panel in the sides and put pontoon fenders over the three axles.

I see that the trailer caught your attention, a work of art isn't it?

I assumed he was talking about the white van.

[ProDigit]

I would start, by changing air and fuel filters, and go to a lighter grade synthetic oil.
Aerodynamics will do very little below 55mph. It appears to me your engine is just horribly inefficient.
At that cc, your engine should be running at 1500rpm. If it's doing 2k or more, gearing is also to blame for it.

Perhaps time to change piston rings, as well as change the head gasket, and check the cylinder bores.

If the piston rings create blowby, your oil is very black every oil change, and new piston rings will do most of the mpg gains.
But if they're good, and air and fuel filters are good, I figure you probably can gain 2 to 5 mpg at best, by tuning.

It has an overly large engine, that produces the same amount of power (or less) rhan a 2.6 liter Ecoboost engine from Ford, which is half the size, and double the mpg.

[slowmover]

Sorry I missed this earlier.

The 53’ trailers I pull with an aero Class 8 tractor vary from no aero mods, to those with full skirts and tail. The difference is somewhat slight, but telling as to the extra work I’ll have to do that day. I’d always prefer full aero.

The biggest change would be to have a flat-front trailer hooked to a non aero tractor. It’s unreal how much force is necessary to pull that down the highway. I speak of how noticeable this is to the driver. How hard it is to show decent FE on the gauge.

Some cattle-haulers prefer this set-up as it’s literally an aid to braking (moving livestock a world of its own).

I see that ambulance and the first thing I think I’d do is to add (brand name) Nose Cone to the body. Get that problem out the way and the feel to the vehicle changes rapidly.

Steering slop and old shocks can’t be tolerated. Same for worn body bushings. Steering corrections per 100-miles is a measurable FE effect according to industry. Aero won’t help much until your steering degree of angle and duration x corrections is minimized.

Until you’ve minimized the flat front effect with some aero, and made steering AND handling brand-new, don’t expect aero band-aids to do much for you. That comes AFTER the driver can feel what’s happening thru the wheel. Sensitivity.

As to the rest, ORBYWAN modified a Class C motorhome on these pages a while back. Read all those threads. (Great stuff above in this thread).

For the vehicle rear, a custom trailer that followed the lines suggested by Aerohead to cause a passenger bus to be able to run 100-mph on the same fuel would be the right approach.

Or study the design of a (brand name) Trailer Tail.

Straight trucks (non-articulated) are terrible on the highway. It’s the wind that is not released by the body until passing AGAINST the air moving cross-ways underneath. I feel certain that an air dam and side skirts are a worthwhile investigation at a low cost and are easily removed. Will smooth the vehicle passage so that nose cone and trailer tail devices can more easily be evaluated.

1). Steering
2) Handling
3) Body to ground mods
4) Entry & Exit Mods

One has to have great feel at the wheel. Like locating the direction of a sound.

As to the RV as RV:

A motorhome is inefficient in all respects. It’s weight, complexity, and shape keep its initial cost and operating costs high and camping utility low. Only newbies love them.

If my 63’ combined rig RV can average 15-mpg (17,000-lbs), sleep six with far more storage, capacities and features, where is the advantage of a commercial truck-based RV?

As 13-mpg isn’t bad. If driving a few extra feet off-road is really worth it.

The formula for total cost is annual nights aboard into years of service. Answer that for relative cost and the balance falls into place. Value.

.

[slowmover]

From leaving the pavement to the camping spot. With that vehicle, it’s that distance that kills fuel economy.

Over a years time, what is that distance?

Over on Airstream Trailer & Motorhome Owners Community is contributor, “Moosetags”, with a diesel 4WD pickup plus camper pulling an Airstream. A big budget vehicle for most of us as it was new. This is the third generation as I recall. He and his wife travel for months. The travel trailer gets left behind as the truck ventures off-road.

That would be the “better” approach as to flexibility and fuel economy. The template. His FE not that exciting, but no off-pavement use vehicle will ever be so.

Dirt = Drag.