Kenworth Truck--air dam

[JasonG]

Its going to be tough with a drop deck.
I agree, be careful with the tool boxes hanging up, skirting would be safer.
You are getting good mileage as it is, I'm impressed.
I wonder if you could mount a Kamm to your headache rack to get the airflow started down for the shorter loads. Perhaps it would hinge up and act as an air wedge/ramp for taller loads?

[winkosmosis]

That truck already looks very aerodynamic.

How is it that the motor oil lasts 40,000 miles??

[thecheese429]

Originally Posted by winkosmosis

How is it that the motor oil lasts 40,000 miles??

I'm no expert, but I remember reading that it has something to do with the huge amount of motor oil there is in one of those engines. There's just a lot to be used up

[slowmover]

Hi Myron, used to be a flatbedder so nearly everything you write about sounds familiar. I'm impressed by the 8.5 mpg overall, and I know that tractor is a whole lot better to own/drive than the Freightshakers I had to drive. 3.55's on the rear? I always figured the "perfect" truck was a midroof with good aero, 500HP of Cummins with 13-speed & 3.55's. Sorry I don't know about your specific questions, but hope the rest of this may be of help or at least entertaining.

I'm impressed by the genny/inverter set-up, didn't realize that dash air was such a drag . . frankly, though, I'd keep it over an alternative source 'cause when it's needed it's really needed. So why not curtain off the sleeper entirely (only way to stay cool in Texas some days). A larger evaporator coil on the current system is one approach (with relay-driven fan control), plus a better condensor (not tube & fin) to up efficiency and lengthen compressor cycle time interval. Moving the interior air temp sensor may also be of help.

Don't know how the budget is, but PITTSBURGH POWER is always good for some tips: custom-made low restriction muffler, etc:

W900 Style 5 in 5 out muffler - Pittsburgh Power - High performance diesel engine systems

• View topic - October 2009: The $20,000 muffler!

• View forum - Power and Fuel mileage


Bruce Mallinsons site is worth the time to go through for the tidbits. I'd consider some of the less expensive items short of a power box.

Here's a series on a truck build for economy (notice the excellent record keeping):

Stories

Stories

Stories

Stories

Over on http://www.bobistheoilguy.com you should search out the posts and excellent informed commentary on big truck operation by DOUG HILARY an Australian fleet owner & international consultant in re fluids, etc. Take your time to go through all his posts on this subject (he also posts on cars); another very bright guy for all other subjects over there is MOLAKULE.

http://www.bobistheoilguy.com/forums...&Number=528355

I have taken my oil analysis business to Terry Dyson of Dyson ANALYSIS some years back. It's an art, not just a science and he's great to deal with (my personal vehicles).

Finally, a favorite from the RV world: an airspeed indicator to check "winds aloft". I've re-routed myself more than once with an overdimensional load and ******* head & crosswinds after trip-planning weather study.

http://www.aircraftspruce.com/catalo...nasi160m-3.php

Good luck

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[KamperBob]

Originally Posted by slowmover

Finally, a favorite from the RV world: an airspeed indicator to check "winds aloft". I've re-routed myself more than once with an overdimensional load and ******* head & crosswinds after trip-planning weather study.

FALCON AIRSPEED INDICATOR 0-160 MPH $126

Please share pix showing how the airspeed "sensor" was mounted. The concept is clear enough but I wonder about proximity to the vehicle that disturbs the wind field it plows through. For planes close to the body may be fine but for road warriors with keen interest in crosswind sensitivity is a mast involved for example.

Thanks
KB

[slowmover]

Could be mounted forward of radiator grille. Or, on side of hood. I know I'd experiment with locations prior to permanent installation.

http://www.evansaviationproducts.com...20Products.htm

[KamperBob]

Originally Posted by slowmover

Could be mounted forward of radiator grille. Or, on side of hood. I know I'd experiment with locations prior to permanent installation.

Other Products for the homebuilder. Pitot tubes, Static Port Kits

I thought maybe you had one on your truck.

I wonder if, to be accurate, the flow field needs to be sampled feet not inches from the vehicle surface. Otherwise, wouldn't pressure front of the vehicle bias the vector? Just thinking out loud...

Cheers
KB

[slowmover]

It is essentially a pressurized air source driving several instruments (altimeter, air speed, etc). Here's an old-fashioned one, venturi-type:

http://www.eaa.org/experimenter/images/0906_venturi.jpg

As to accuracy, well, winds are not really ever constant, are subject to shifting, and -- as one travels -- the road itself is not straight, so one is not ever likely to see a constant speed read depending on geography, climate & weather (Texas is windy, Georgia ain't). My understanding is that the instrument is going to change indications fairly regularly (but not a constant wobble, either). This assumes a windy day. On a not so windy day the reading is stable. Thus I don't think the mount is critical beyond stable readings on a day of ordinary breezes.

For RV'ers the eye-opener is the change in wind speed when being passed in the same direction as two semi's flying past (or, worse, the other direction) as the wind speed indicator is all over the place from truck bow waves.

No, I don't have one yet . . but it is high on the list. If I find the readings greatlyincreasing as one approaches the warmest part of the day, maybe it's time for lunch. A long one. Or, a different route if it makes winds more favorable. Or get's me away from heavy truck traffic. Etc.

It's all in trade-offs of time versus distance and the schedule to be kept: How far OOR can I go to offset the wind penalty? I might in fact choose to burn more fuel (distance) in order to avoid fighting the steering all day (one reason I used to like driving flatbed). Watching a 53' dry van lift the tandems in the air on one side -- and the driver not be able to feel it (by radio report) -- was an eye-opener.

Note the trailer (RV park model) "snaking" prior to roll over:

http://www.rvvideos.com/search?q=trailer+flips
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