What car makers *should* be doing!

[mfor4x4]

CVT transmissions are great on SnowMachine like SkiDoo's but the car I drove was a Dodge product and it was cool to drive but I was not impressed with it. I drovei t on a single lane highway and when I passed the engine revved up to 5000RPM, I honestly can't see the engines lasting that long revving that high and the FE can't be that good either.

Has anyone heard anything more about camless engines?

[Frank Lee]

Originally Posted by lunarhighway

basically a two gearbox system where one gearbox is in series with the other
if you'd place a two speed gearbox in line with a 3 speed you could have 3 low and 3 high gears.

More gears... especially more gearboxes = more drivetrain losses, right?

In fact that gives me an ideer: pull 2nd and 4th gearsets outta my tranny. Hardly use em anyway.

[lunarhighway]

More gears... especially more gearboxes = more drivetrain losses, right?

a little but you'd have more gear for less weight... the whole idea is based on the thought more gears is a good thing.

In fact that gives me an ideer: pull 2nd and 4th gearsets outta my tranny. Hardly use em anyway.

i tend to skip gears all the time but at the end of the day i think i've used most of them... but if you can live without them and thing that'll contribute to a better milage... i'm interested to see the outcome.

CVT ?

that's pretty much what i had in mind appart from mechanical difficulties wich apparently seem to have been mastered, most of the other "downsides" listed seem to come from people's expectation of the device to replicate the negatives of the transmission it could replace. personally the lack of moise and jerkyness hardly seems a bad thing.

as for that dodge revving so high... i'm not sure how the system was set up but there's no eason why cars should revv any higher as they do today of the ratios can be vried enough, and in theory they can by useing multiple belts chould one belts ratio variation be to small.

[Frank Lee]

"a little but you'd have more gear for less weight... the whole idea is based on the thought more gears is a good thing."

If a drivetrain with a stick trans loses about 15% efficiency, adding another trans will surely lose more than a percent or two in addition to that.

We should examine this thought about more gears being a good thing. Perhaps it isn't?

[modmonster]

the CVT transmission is really good i don't know why they never caught on. i saw a diesel with CVT on a motor show called top gear and they nitroed it to beat a sports car in a drag race!

[Frank Lee]

drag racing and street driving are two different things. well... they should be anyway.

[lunarhighway]

We should examine this thought about more gears being a good thing. Perhaps it isn't?

i suppose that mainly comes down on how flexible the engine is... if it's got a wide RMP range of good torque AND efficiency that you don't need that much gears. that's why electric vehicles don't really need a transmission. an ICE on the other hand should ideally be ran at a constant rmp, so that's where a CVT could work wonders...

also the point where an engine is most efficient is not always where it provides the most power.... but than sometimes you just don't need all that power you basically have to run the engine in an rmp area where it's not all that efficient, but still uses less fuel overall
perhaps we don't need more gears but just the right gears for our speciffic driving....

what's best would be the setup where the gains cancel out the loses... but what that is... i don't know

[NeilBlanchard]

Here's two additional items to add to the list:

* Regenerative shock absorbers: MIT has a method of using hydraulics to drive a generator, eliminating the need for a mechanically driven alternator; or, to charge the electric drive batteries. These can also be used to lift and level the vehicle, to improve aerodynamics under different loads.

* Use a composite wheel/tire that has low weight, very low rolling resistance (by being strong enough to stay round), and low aerodynamic drag, no worries about inflation -- and re-tune the suspension to work with said wheel/tire. (see item above)

[NeilBlanchard]

Hiya,

Some more items for the list:

* When using a composite wheel/tire -- tune the (regenerative) suspension to work with said wheel/tire. This could gain even more energy, since very little would be damped by the tires.

* Multiple car door latches could be used to increase strength & safety of the chassis -- helps to further reduce weight, increase strength & rigidity, without requiring an unusual entry method.

The Loremo and the VW 1L car both use unusual entry doors (basically the roof opens up), and having multiple latches would let you keep more conventional doors, but not give up the overall strength of the chassis, and/or save weight.

[gtkid2002]

Anyone suggested putting solar panels on any flat/large body panels to make less of a strain on the alternator?