Why drive a manual?


#101

Stranger things have happened. Who’d have thought that watching folks play video games would turn into a multi-million (billion?) dollar world-wide business?


#102

Well just imagine the spectacle of hot air balloon racing over the track filled with robot cars racing. That should make for a real money maker.


#103

When you take the drivers out of the cars, the cars can be much much smaller and therefore cheaper to race and the track itself can be scaled down to the size of a basketball court, putting car racing within reach of multi-hundredaires.


#104

I used to do the RC car and truck races. Had a lot of fun and made a few friends.


#105

As a kid racing slot cars at a commercial track was fun. Watching other kids race? Not so much…


#106

I guess I’m just not a big race car fan. The only racing I’ve done is with the Cub Scouts Pinewood Derby. Of course they were driver-less so I guess I was ahead of my time.


#107

I assumed you meant efficiency loss.

One way to minimize parasitic oil pumping losses is to use a variable displacement pump that automatically reduces piston stroke in response to the pressure coming up to specs instead of a pop off valve that just dumps excess oil pumpage to regulate pressure. This type of oil pump is already used in large hydraulic systems that have a constant high pressure. The pump responds to different flow demands by changing the angle of the swash plate that moves the pistons. This type of pump is also used in Hydrostatic continuously variable transmissions used on tractors. You control ground speed by changing swash plate tilt in the pump and the pump changes the oil delivery to the hydraulic motors that drive the wheels while the engine stays at full rpm to power the mower.
It could also be used as the engine’s oil pump and eliminate the pop off valve that regulates the engine’s oil pressure. A half horsepower here and a half horsepower there and it adds up you know.

Whenever I change my motorcycle’s oil and filter, I start up the engine and wait for the oil light to go out. There is a noticeable drop in idle speed when that light goes out due to the oil pump having to pump against pressure.


#108

Automatics are now equal to manuals in efficiency.


#109

And zero emissions gravity powered.


#110

Gravity doesn’t power anything. Something or somebody had to lift that pinebox derby car to the top.
Shut off the power to the chair lift and see how much skiing is done on the slopes.


#111

I was joking with Bing.


#112

He was thinking about the orange crate races we’d make as kids and those you had to haul to the top of the hill in order to race them down. The pinewood cars are just 6" blocks of wood and you put them on the track by hand. Not much energy expended at all.


#113

Even though not much energy is expended, the energy still comes from you lifting the car back to the top. Potential energy becomes kinetic energy as the car goes down the track and ultimately becomes heat, increasing the entropy of the universe.


#114

Fortunately at the age of 8 thru 10 all I worried about was gravity favoring my Pinewood Derby car a bit more than my competitors. That rarely worked. I guess that’s why I never raced Soapbox Derby.


#115

Even variable displacement pump draws power. And I haven’t mention the seals that keeps oil pressure within various shafts for clutch activation. Speaking of clutches, wet clutches are bathed in oil that creates viscous drag between plates when the clutch is disengaged- that’s why zf uses two dog clutches in their nine speed automatic.

AMT in trucks and manual require zero horsepower to stay in gear. To those who say that a modern auto is more efficient than a manual, that is because new auto has more gears to keep the engine in its optimal operating range. Install a manual with the same gear count and ratio as the auto in the same car and see what happens


#116

When the pressure relief valve opens on an oil pump I imagine that the energy needed to turn the pump doesn’t increase as RPMs increase further.


#117

Yes it does. The pop off valve keeps the pressure (head) constant but the gallons per minute of oil pumped against that head increases proportional to rpm. The torque needed to drive the pump is constant but the power needed to drive the pump increases with rpm. This is for the positive displacement pumps used as oil pumps in car engines and transmissions.
Centrifugal pumps are different, stopping the flow actually unloads the motor that drives the pump. You can see this for yourself by stopping the air flow into a vacuum cleaner and observing the increase in motor speed.

If you stop the flow of a positive displacement pump, the pump shaft locks. I have seen the distributor/oil pump drive gear on an Olds 442 engine totally trashed because the mechanic that overhauled the engine didn’t put the hollow banjo nut in the right place on the oil pump/ totally blocking the flow.


#118

The thing about both manual and automatic transmissions is that when you add more gears, the transmission itself becomes less efficient. The gears that aren’t being used are still meshed and turning, they are just freewheeling on their shafts, but they are adding friction losses from oil being constantly stirred and squished out from between the gear teeth.

The two speed Model T transmission was extremely efficient in high gear. It was just a locked up clutch directly driving the output shaft and non of the planetary gears were rolling. There may have been some low and reverse band drag if they weren’t adjusted right.
The most efficient transmission in the whole world is the bicycle derailleur system. Roller chains are very efficient and the unused sprockets are just spinning in air. However, you have the added friction of the idler sprockets that keep the chain tensioned so it’s not quite as efficient as the one speed bicycle or the direct drive penny farthing bicycle.


#119

I live in the land of hydroelectric generated electricity. Water gains momentum while falling from behind dams and turns huge turbines generating electricity. Weights on grandfather clocks provide their power. Gravity operates our universe. Without it our moon would be gone. Energy far beyond our feeble imagination.


#120

What lifted that water up into the lake behind the hydroelectric dam in the first place? Heat from the sun?
What lifted the weights of a grandfather clock so that it could drive the clockwork? A person who’s energy came from food that grew because of sunlight?
Gravity stores energy, it’s not a source of energy, unless we can figure out how to build highways that go downhill in both directions.