AirFlow BulletTruck Project (aerodynamic, modified Class 8 transport doubles MPG)

[rossbro]

This thread is the best I have read regarding mileage improvements on any vehicle. Kudos to 777 for the foresight and gumption to fabricate the parts and assemble this beautiful truck body. Thank You

[radioranger]

should market a model of that baby

[Galane]

Since nobody else has, I'll mention the 1988-1993 Peterbilt 372. 10+ MPG cab over! It managed that with a flat, though V'd, windshield, a full size, flat grille that was slightly recessed and a big honkin' sun visor.

A truck ahead of its time, when fuel (diesel trucks burn *fuel*, not gas) was cheap. Hidebound traditionalists just didn't like the looks of the thing, even though it would've saved a lot of money. (About half of them hate the looks of that retro styled International Lonestar.)

The 372 is the Geo Metro of semi tractors. The companies boast of 29~30 MPG today. Pshaw! Yonder rusty Metro 20 years ago got FORTY-FIVE with an auto and FIFTY with a manual! New truck gets 7.8 MPG with the moon in Saggitarius and a tailwind? 372 did TEN. So often when it comes to many technological things, a real innovation gets tossed out, then when something comes along years later that achieves even half what was done before, it's touted as "revolutionary".

Makes me wonder why some smart shipping company hasn't snapped up and refurbished every 372 they can lay hands on. Would be cheaper than a fleet of new, less efficient trucks. Combined with the current aero treatments on the trailers I bet they'd easily do 12 MPG.

Get hold of a 372, fix up the grille to be sleeker, replace the 4 piece flat windshield with a curved one and delete the visor. Apply the rest of today's state of the aero art and you have a more conventional looking truck with no approach angle issues, and 14+ MPG.

Here's my idea on how to do a curved attachment to the front of ordinary semi trailers. Make it detachable, with a system on the back of the cab to pick it off and hold it. Fixtures to attach it to the trailers would have to be relatively inexpensive, standardized, and not interfere with cargo handling of removable box trailers*. Want to be a bit slicker when deadheading? Have an inflatable liner in the trailer cap that extends outward, making the back of the cab curved to help smooth the airflow.

*Not all trailers are that type. Ever seen those special railroad cars designed specifically for hauling semi trailers? They have a central beam with platforms for the wheels and trailer jacks to rest. The trailers have to be put on and taken off with a crane.

[Shepherd777]

Originally Posted by hardhatz

Just my humble opinion....

Congratulations on some very nice work!
It is particularly impressive that someone who doesn't care to drive them would put all this effort into such a huge undertaking.

Some thoughts:

1. Big rig fuel mileage strategies that rely too much on hypermiling tactics are only entirely relevant when time stands still and the world is flat. In real life in the business of trucking, there are many aggravating factors. For example, one MPH less speed adds an hour to a coast-to-coast run. So, if you arrive at the other coast on Friday night after the receiver closes for the weekend, you have just shot yourself in the foot. If-by driving 65-you arrive Friday morning, and reload back out the same day, you could be 2000 revenue-earning miles away by Monday morning. This is not an isolated example. I drive, it happens all the time.
Focus on the technology. Getting 14 MPG under ideal and atypical conditions is interesting, but there would be a lot more credibility if you also included real-world numbers.

2. Congratulations on running a 13-speed! The industry has really drank the Kool-aid on the Big 9 & 10-speed Lie. It's a hard cold fact that the lowest BSFC on an engine is only about 150-200 RPM wide.
However, most 13-speeds are RTO. (I'm assuming yours is as well) RTOxxx13's are overdriven in 13th, and trucks are usually geared to cruise there. 13th gear loads torque onto six gears, 2 countershafts, and several bearings. Only in 12th does the torque path run from input to drive yoke uninterrupted. RTOs should be geared to cruise in 12th. Don't feel bad, about 99% of rigs were built wrong, and the average new-truck sales guy is a blithering idiot.

3. The electric drive idea will not be efficient. The driven motor is most efficient only at a certain RPM. Locomotives are built with different gear ratios, based on expected use. They are significantly disadvantaged anywhere outside that ideal speed. To be more specific, the Diesel/generator must be operated at full capacity even though the driven motor may be turning at a small fraction of its efficient RPM. So, your engine-to-wheel RPM ratio goes completely screwy, and you are under full power. Once again, if the world was flat.....
If you are in love with electricity, use it to replace the hydraulic in the power-steering.

4. Consider radical redesign of suspension, as all vertical motion/vibration caused by road irregularities devours forward energy. Independent maybe, with bus-type IFS, and DeDion-type rear?...

5. How about an air-bagged front end to regulate front body-to-road gap?

6. Axle stub-mounted non-rotational front wheel fairings.

7. Charm the rolling-stock folks into building a "1 1/2-plex" low-profile front tire/rim system. (halfway between a single and a duplex) About 8000 lb capacity.

8. Centrifugal engine oil filter to keep oil free of abrasive particles.

9. A single-screw with tag axle does not provide the integrity needed in any but ideal situations, and I consider it cheating. Keep it honest.

I'll answer your first 3 questions.

1. Big rig fuel mileage strategies that rely too much on hypermiling tactics are only entirely relevant when time stands still and the world is flat. Agreed In real life in the business of trucking, there are many aggravating factors. Agreed For example, one MPH less speed adds an hour to a coast-to-coast run. So, if you arrive at the other coast on Friday night after the receiver closes for the weekend, you have just shot yourself in the foot. If-by driving 65-you arrive Friday morning, and reload back out the same day, you could be 2000 revenue-earning miles away by Monday morning. This is not an isolated example. I drive, it happens all the time. Focus on the technology. Getting 14 MPG under ideal and atypical conditions is interesting, but there would be a lot more credibility if you also included real-world numbers.

I have driven Class 8 vehicles over 750,000 miles hauling freight, mostly at 55 mph, so I know how the industry works. While driving last year for 8 months part-time, we only drove 55 mph, except downhill, where the fuel was free. Every day, all day, the same truckers would pass me doing anywhere from 60-80 mph. One could pick out certain rigs during the day. A weird flatbed load, a unique trailer or cab, etc. They would pass me after breakfast. They would pass me after lunch. They would pass me twice in the afternoon, after dinner, and twice at night. And I would see those same trucks in the truck stop at night sleeping along side me. So your one MPH less speed argument is not valid to me. If they spent less time bullshipping at the truck stops, or trying to plug every waitress at every truck stop, then driving 60-80 mph to make-up for lost time, they would be a lot more efficient. And the world would be better off. We never missed a delivery or a pick-up time appointment driving 55 mph during that 8003 mile trip. Or during any other trip last year. And I was the only one driving. My dog does have a license, but it is not a CDL.




Here are some real-world numbers. The 13.4 MPG we got last year was an average of exactly 8003 miles, hauling real freight. We loaded in Farmington, CT and delivered in Tracy, CA. The rest of the trip consisted of pickups and stops in Hillsboro, OR, Seattle, WA, Austin, TX, Memphis, TN, Southaven, MS, Louisville, KY, and then back to Cromwell, CT and home. We hauled automatic aluminum sliding doors, Halloween supplies, Ingersol-Rand air compressor parts, and furniture for a new Sunoco gas station. Real freight on all of these trips and had only a 3% deadhead (empty trailer) figure. I drove on every road every other truck drove on. I backed into every small ally, congested convoluted loading dock area, and stopped at every weigh station and DOT inspection that everyone else did. When Freightliner, Kenworth, of Volvo does long-distance fuel tests, they put weights or other such stuff in the trailer. They do not deliver and pick-up freight, unlike what we did. The BulletTruck would do 17.5-18 mpg and 10% engine load with a loaded trailer on level ground. Climbing up a mountain, we would get 2-3 mpg, like everyone else. So again, we averaged 13.4 mpg for that 8003 miles. Those are some real-world numbers for you.

2. Congratulations on running a 13-speed! The industry has really drank the Kool-aid on the Big 9 & 10-speed Lie. It's a hard cold fact that the lowest BSFC on an engine is only about 150-200 RPM wide.
However, most 13-speeds are RTO. (I'm assuming yours is as well) RTOxxx13's are overdriven in 13th, and trucks are usually geared to cruise there. 13th gear loads torque onto six gears, 2 countershafts, and several bearings. Only in 12th does the torque path run from input to drive yoke uninterrupted. RTOs should be geared to cruise in 12th. Don't feel bad, about 99% of rigs were built wrong, and the average new-truck sales guy is a blithering idiot.

Yes, I love the 13 speed for the very minimal rpm bandwidth spread. With that 13 speed, I was able to keep engine rpm between 1100-1250 rpm all day long. Again, except downhill.

3. The electric drive idea will not be efficient. The driven motor is most efficient only at a certain RPM. Locomotives are built with different gear ratios, based on expected use. They are significantly disadvantaged anywhere outside that ideal speed. To be more specific, the Diesel/generator must be operated at full capacity even though the driven motor may be turning at a small fraction of its efficient RPM. So, your engine-to-wheel RPM ratio goes completely screwy, and you are under full power. Once again, if the world was flat.....
If you are in love with electricity, use it to replace the hydraulic in the power-steering.

I disagree. Our Hybrid Electric drive system will be amazingly efficient. The diesel engine we will be using will have only 2 or 3 pre-set rpm modes. Idle, Peak Torque, and possibly a slightly higher energy storage charging rpm. We will be using batteries and/or super-capacitors for energy storage. So a lot of the time, the ICE won't even be running. I have just recently validated this design with one of the foremost diesel engine guru's in the world when he called me two days ago, and we spoke on the phone for an hour. I cannot say who this person is at this time. But he has verbally agreed to be on our development team. And yes, we will be using high-voltage electric power-steering, as well as air conditioning and compressed air, in the new truck.

[Shepherd777]

Originally Posted by radioranger

should market a model of that baby

Hi radioranger. Damn snow in Connecticut again today??? I'm getting sick of this stuff, how 'bout you?

Here you go. But if we sell models of the new trucks, I think we have to mass-produce them, as this Stratasys FDM 3-D printed model costs $6000.00.

[Shepherd777]

Originally Posted by Galane

Since nobody else has, I'll mention the 1988-1993 Peterbilt 372. 10+ MPG cab over! It managed that with a flat, though V'd, windshield, a full size, flat grille that was slightly recessed and a big honkin' sun visor.

A truck ahead of its time, when fuel (diesel trucks burn *fuel*, not gas) was cheap. Hidebound traditionalists just didn't like the looks of the thing, even though it would've saved a lot of money. (About half of them hate the looks of that retro styled International Lonestar.)

The 372 is the Geo Metro of semi tractors. The companies boast of 29~30 MPG today. Pshaw! Yonder rusty Metro 20 years ago got FORTY-FIVE with an auto and FIFTY with a manual! New truck gets 7.8 MPG with the moon in Saggitarius and a tailwind? 372 did TEN. So often when it comes to many technological things, a real innovation gets tossed out, then when something comes along years later that achieves even half what was done before, it's touted as "revolutionary".

Makes me wonder why some smart shipping company hasn't snapped up and refurbished every 372 they can lay hands on. Would be cheaper than a fleet of new, less efficient trucks. Combined with the current aero treatments on the trailers I bet they'd easily do 12 MPG.

Get hold of a 372, fix up the grille to be sleeker, replace the 4 piece flat windshield with a curved one and delete the visor. Apply the rest of today's state of the aero art and you have a more conventional looking truck with no approach angle issues, and 14+ MPG.

Here's my idea on how to do a curved attachment to the front of ordinary semi trailers. Make it detachable, with a system on the back of the cab to pick it off and hold it. Fixtures to attach it to the trailers would have to be relatively inexpensive, standardized, and not interfere with cargo handling of removable box trailers*. Want to be a bit slicker when deadheading? Have an inflatable liner in the trailer cap that extends outward, making the back of the cab curved to help smooth the airflow.

*Not all trailers are that type. Ever seen those special railroad cars designed specifically for hauling semi trailers? They have a central beam with platforms for the wheels and trailer jacks to rest. The trailers have to be put on and taken off with a crane.

I am intimately familiar with the Peterbilt 372, as they stole that design from me!

I built one of the first aerodynamic Class 8 trucks in the world in 1983 by retrofitting a Ford CL9000 COE tractor. That truck made the covers of both Heavy Duty Trucking magazine, and Land Line magazine, in 1984. And it was also in Autoweek magazine that year. Goodyear also issued some great press releases for us way back then.

Goodyear, who was a sponsor at the time, told me I could have spent tons of money enforcing any patents. And, the big companies like Paccar/Peterbilt would just steal the design anyway. Which they did.

So Paccar/Peterbilt stole my design and ideas, implemented them years later and then patented them.

Check out the similarities of the Peterbilt 372 to my original design. The only change Peterbilt did was to hinge the front end on the top, whereas I used a piano hinge at the bottom.

Again, I built mine in 1983. Paccar introduced theirs 5 years later.

[sheepdog 44]

Will you be able to grid charge the battery? It would be a lot cheaper to recharge battery reserves from a plug, than to convert it from diesel. Can you can charge overnight and at rest stops?

That would be funny to see a big rig parked at a car charging station!

I applaud your work! Raising the fuel economy of big rigs will have the single biggest impact of energy independence and fuel consumption in America. Not just the gas we buy from the pump, but every commodity that is shipped across country.

I've worked in both grocery and retail stores, and it was eye opening to see how much we are dependent on trucks! If the trucks stopped, people would starve and there would be no economy. We just just don't live in a locally sustainable world anymore.

[Shepherd777]

Originally Posted by sheepdog 44

Will you be able to grid charge the battery? It would be a lot cheaper to recharge battery reserves from a plug, than to convert it from diesel. Can you can charge overnight and at rest stops?

That would be funny to see a big rig parked at a car charging station!

You know sheepdog 44, that idea somehow eluded my mind, what with all the intricate details of the new truck, and all of those empty beer bottles and spider webs in there.

But I absolutely love your idea. And some truck stops are already electrified, providing the service of shore power and heat, A/C, internet directly into drivers cabs for a fee.

[hardhatz]

The truck designers of today would do well to copy that old CL9000 instrument panel right down to the last detail. I've never found one I like as well as my beloved old 78 double-wide CL. Or, as we used to call it, the "Two-Story Thunderbird".

[JRMichler]

That series hybrid will need one huge electric motor. Just to throw out some numbers:

Assume tires 40" diameter.
Assume 80,000 lbs gross vehicle weight.
Assume it needs to pull up a 10% grade at low speed.
Assume geared for 1260 RPM at 55 MPH, that would be a 2.5:1 rear axle ratio.

You would need 8000 lbs traction force plus another 1000 lbs for friction and whatnot.
That's 9000 X 20 / 12 = 15,000 foot-lbs torque at the drive wheels.
15,000 / 2.5 = 6,000 ft-lbs at the drive motor.

If the main engine is 450 hp, that would feed a 400 hp electric motor.
The electric motor would be rated for 6,000 ft-lbs up to 350 RPM (400 hp).
Above that, it would run in constant power mode.

I'm not aware of any off the shelf electric motors anywhere close to those specs. Which would explain why the big manufacturers did not develop series hybrids for Class 8 trucks. In order to get the motor frame size down to where it will fit in the truck, I think it will need liquid cooling.