Full-boat-tail trailer with gap-fillers for Toyota T-100 pickup

[TheEnemy]

Were you passing through New Mexico about a weekish ago? If not we saw someone with a very similar setup on I-25 south.

[aerohead]

Originally Posted by TheEnemy

Were you passing through New Mexico about a weekish ago? If not we saw someone with a very similar setup on I-25 south.

I came over Raton Pass around Oct.1,made a beeline down I-25.Stopped at Socorro,then on to Dona Ana,north of Las Cruces and back up to Radium Springs.
Leaving town,I went south to University Drive,then back to I-25,up to 70,where I peeled off towards White Sands.
So,you might have seen me anywhere along that route.

[TheEnemy]

We live in Socorro, you were going south through the construction zone, we were down on the frontage road.

[jime57]

A question Phil,

Do you think it is worthwhile to use silicon, cut level and to shape, to fill the front end gaps around the headlights, bumper, etc. ? I don't recall finding anything in Hucho on the subject.

[aerohead]

Originally Posted by jimepting

A question Phil,

Do you think it is worthwhile to use silicon, cut level and to shape, to fill the front end gaps around the headlights, bumper, etc. ? I don't recall finding anything in Hucho on the subject.

Jim,I think Hucho dodges this one 'cause he seems to dwell more with production than modding.
GM taped every gap,except the driver door on the EV-1 for their LSR runs at Ft.Stockton,so you can gather that they weren't leaving anything on the table.
Fiat taped all body seams on a Ritmo for a wind tunnel study in the 1980s and dropped the drag around 30% ( I'd have to dig out the article to say for certain).
I think its fruit we can pluck.Any perturbation of the airfield around the car is absorbing energy from the engine so the small details make sense to go after.
I think Mike has addressed this some with respect to his AeroCivic.
If I can ever get to Bonneville on time I'll be sweating out all these details myself!
The guys (and gals ) use '200-mph tape' on everything out there.

[aerohead]

Here are some comparisons from the logbook:
Denton-Albuquerque,2010--------------------------------------- 29.872 mpg
ditto---------------, 2011--------------------------------------- 28.753 mpg
3.7% penalty
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Albuquerque-Lakeside,2010-------------------------------------- 31.367 mpg
ditto----------------,2011-------------------------------------- 31.474 mpg
0.3% benefit
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Lakeside-Salt Flats,2010---------------------------------------- 28.910 mpg
ditto-------------, 2011---------------------------------------- 29.583 mpg
2.3% benefit
----------------------------------------------------------------------------
Lakeside-Carson-Lakeside,2010--------------------------------- 28.885 mpg
ditto--------------------,2011--------------------------------- 31.102 mpg
7.6% benefit
--------------------------------------------------------------------------
Lakeside-Green River,2010-------------------------------------- 36.036mpg
ditto--------------- ,2011-------------------------------------- 31.282mpg
13.1% penalty
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Dona Ana-Denton,2010----------------------------------------- 33.187mpg
ditto------------,2011----------------------------------------- 33.171mpg
0.4% penalty
--------------------------------------------------------------------------
Cloudcroft-Denton,2009---------------------------------------- 32.812mpg
ditto-------------,2010---------------------------------------- 34.264mpg
ditto-------------,2011---------------------------------------- 33.882mpg
2010/2011= 2.8% penalty
2009/2011= 3.2% benefit
--------------------------------------------------------------------------
Artesia-Denton,2009------------------------------------------- 31.813mpg
ditto----------,2010------------------------------------------- 34.264mpg
ditto----------,2011------------------------------------------- 33.918mpg
2010/2011=1% penalty
2009/2011=6.6% benefit
--------------------------------------------------------------------------
Remarks:
Road-testing is problematic.Variables are
*aerodynamic drag (wind spectra )
*rolling resistance
*climbing/grade resistance
*acceleration/inertia resistance
*load/rpm BSFC
*curve resistance (NCHRP Report 111(Washington,D.C.:Highway Research Board,1971)
*yields,stops,traffic lights,road repair delays,overnight stays
*rain
*temperature
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If one 'could' keep track of all the variables in real-time,solving for unknowns,simultaneously for each mile puts this sort of thing into the realm of astro-physics.
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The 'captain' driver would need a 1st-officer riding shotgun with a 4-G hot-spot,laptop/tablet/smart-phone and on-board weather data acquisition hardware,airspeed indicator,wind direction,GPS elevation tracking.
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If your obsessive about data collection,you might be able to learn something quantitative about your vehicle.
Wind tunnels look better all the time!
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Considerations:
So far,it appears that on grades,the weight addition of the trailer is a liability.At 720-lbs now,with the nearly complete gap-filler mechanism,Viking represents the 'production' version of the tadpole,with a Nissan Leaf battery pack on-board.
For flat-landers,a holiday trip to Grandma's,pulling the trailer would probably incur no penalty.
Throw in some mountains and the equation changes!
Perhaps one day I can do the trailer without the prototypes weight penalty.
I'll keep chipping away at it.

[aerohead]

Al is home with intense allergies today so I don't have an opportunity to post any photos of the rig.I'll try for next Saturday.Sorry!

[aerohead]

I never had an opportunity to do a plan-view photograph of the rig before I had to detach and disassemble it.
And I was more concerned with how the gap-fillers would hug the trailer that I virtually ignored the rig when turning.
The following is a plan-view after the aluminum extensions were added to both the top and bellypan.The side panels had to operate between these two surfaces.
The second photo is a static shot of one of the side panels and top panel pulled out to demonstrate the articulation these undergo during pitch or turns.
Sorry,this is all I have for now.It will be many months before I even look at it again.
With nearly four months of building and testing,and everything else sliding,I have a lot of things to do to catch up.

[aerohead]

No great news or anything.
I continue to data mine the logbook entries,internet, and rats nest for comparative data.
I have little confidence that with all the variables associated with actual on-road testing I'll ever be able to actually 'nail' any hard numbers to the trailer.
I have re-discovered some articles and SAE papers and will continue to digest everything.
Day by day I have a growing appreciation for the efficiency of a full-scale wind tunnel and modern CFD.
I will do the higher speed wheel-bearing temperature testing before the year's out.
If I can get the confidence that I won't be spin-welding the Timkens,I'll drag Viking down the highway at speeds for which I have a larger database.
Now where did I lay that pyrometer......................................... ...............

[aerohead]

The weather was perfect yesterday.I needed to work,but the T-100 is due for inspection next month and this time of year you don't take the weather for granted,so I did routine maintenance with a little time left for mischief.
Air temp was 71F(21.6C) which is almost the SAE 'cold' temp for tires.
I pulled Viking out of the shop,'topped-off' the tire pressure at 90-psi(621kPa),hooked 'er up,and headed out.
I drove north on I-35,accelerating to 70 mph (112.6 km/h) north of Sanger and went the 16-miles to Gainesville,Texas.
Road temp was 72F (22.2C),Tires ran at 94F (34.4C),and bearing hub at 89F (31.6C).It was a non-event!
Purvis Bearing Co. had recommended a 200F (93.3C) temperature limit to prevent liquifaction of the bearing grease,then failure.
So,it looks like I've got 111F (61.7C) of wiggle room left on the table for bearing life.
Of course,when spring comes and temps start to climb I'll want to monitor things,but for now it seems safe to contemplate elevated speed trailer pulling.
I have quite a bit of higher speed mpg data for the T-100 for later comparison if I do trailer tests at these speeds.
I'll refine the gap-filler hardware,get everything as airtight as possible,then at some point re-create Run #1 out to Odessa,then on to Monahans where the speed limit switches to 80 mph ( 128 km/h). There I can bracket speed runs at 75 (120.6 km/h) and faster,depending on what the pyrometer indicates.
The fear of bearing failure has been the big bugaboo so far on this exercise.
Looks like there's some tasty chapters ahead with this science fixin' story.