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

[Shepherd777]

Originally Posted by sheepdog 44

I'm curious what your thoughts are on running trucks on CNG, or making a CNG electromotive truck? Everybody keeps saying that that all trucks should run off CNG, but do you find this realistic or is it cost prohibitive to have giant CNG tanks. Range issues and filling stations?

I just don't think CNG is gonna take off. They are supposedly building the infrastructure for the filling stations. And a 20+ mpg truck would not need tons of fuel.

One thing I do know is if it does take off, the price will go up to where it matches or surpasses diesel fuel.

[Big Dave]

At this time, penetration of CNG into either the gasoline or diesel market is poisoned by the steep price of new or converted CNG engines.

The equipment is not expensive. Its that super-expensive EPA permit that lets manufacturers or converters install CNG. Chevy makes a CNG pickup. It sells at a $11,000 premium over the gasoline engines.

Thank you, EPA.

[UFO]

Originally Posted by Shepherd777

We will have an air bladder that inflates at 35 mph and deflates very quickly below that speed. It will seal up that gap tighter than a bulls rear-end in fly season.

LOL! There's an image I will never erase...

Originally Posted by Big Dave

At this time, penetration of CNG into either the gasoline or diesel market is poisoned by the steep price of new or converted CNG engines.

The equipment is not expensive. Its that super-expensive EPA permit that lets manufacturers or converters install CNG. Chevy makes a CNG pickup. It sells at a $11,000 premium over the gasoline engines.

Thank you, EPA.

I'm ok with that. In the zeal for natural gas drilling we are squandering our fresh water supplies, and I like water better than cheap gas.

[DieselCAR]

It would allow the diesel to run at a constant speed, except when going down hill, where it would idle.

The VW TDI turbo diesels cut injection quantities to next to nothing when in gear going down hill - (with your foot off the accelerator). Even more efficient than coasting out of gear with the engine idling.
It seems that there should be some way to use this same technique in your truck when there is no demand on the engine.

[pete c]

I think the best option is for the engine to go immediately to off when no power is needed. Kicking it over is a breeze seeing as it is connected directly to a giant starter motor (the generator).

I also think that even with today's battery technology, it makes sense to have a half way decent sized battery bank. You could get some regen out of it and use it for your electric needs when parked. I would think that maybe a dozen or so golf cart batteries could do this. Don't know if the extra cost of Nimh or Li batteries would be worth it. Good old lead acid is cheap and the weight sitting right over the drive axles may actually be beneficial.

[UFO]

Originally Posted by DieselCAR

The VW TDI turbo diesels cut injection quantities to next to nothing when in gear going down hill - (with your foot off the accelerator). Even more efficient than coasting out of gear with the engine idling.
It seems that there should be some way to use this same technique in your truck when there is no demand on the engine.

Actually it's not more efficient than coasting with the engine on, there is significant engine braking that costs momentum when the fuel is cut.

[NeilBlanchard]

If you want to coast and carry as much speed as possible, then coast with the engine idling, or turn it off and bump start when you need to.

If you need to slow down, then downshift and use the engine for part of the braking. This completely shuts off the fuel in any electronic fuel injected engine.

[Otto]

1. Scraping at the front end: Cut and hinge the lower fairing like the visor on a motorcycle helmet. Retraction string at nose. Pull the string and it lifts up for driveways and slopes, release the string and it drops down low for highway driving. A fancy system would have automatic retraction at, say, 35 mph to protect it from idiot drivers.

2., Shape: You've done magnificently with the Class 8 cards you were dealt. If able to start with a clean piece of paper, just go to the Air Force boneyard at Davis-Monthan AFB near Tucson and see if they'll give access to the nose/cockpit section of a mothballed C-141. Make female fiberglass molds off that, then duplicate the aero shape for the truck nose and cabin, add tractor/trailer joint fairing, and you're done. Trailer mods per your work already proven.

3. Wheel hub motors: See my comments on the other thread about MTSU add-on motors to a car. Hub is the worst and heaviest place to apply drive torque, rim the best, compromise only as needed practically.

[JethroBodine]

Originally Posted by NeilBlanchard

This completely shuts off the fuel in any electronic fuel injected engine.

..., sometimes. I've never seen my Nissan Pathfinder go to zero gph, no matter how hard I decelerate, even down the 10% grade in front of my house. The Jetta would, sometimes, but I could never predict it.

Sheppard, I like the way you think and look forward to your build/results

[sheepdog 44]

Better acceleration, or well more even acceleration? When your behind a tractor trailer getting moving at a light, it like yeah he accelerating pretty fast, wait, shift. and your braking into him.

A small battery bank would be beneficial for engine autostop. Autostop at lights, going downhill.

If you wanted an EV mode for slow highway traffic jams, thats another thing. Imagine the wieght and volume of the batteries to be able to move a tractor trailer! Maybe a hydraulic or pneumatic compressed tank to store braking energy would be cheaper. Powered by an electric pump/generator. But this is just me thinking out loud...