Transmisison drive questoin

[mazda121BP]

Hahaha ok, I just go for high power. Fuels not that expensive... You probably get it cheaper then I do!!

[TominMO]

May I ask the reason for all the mpg issues on here? I've seen many topics about trying to improve your mpg? Just wondering why

Fixed it for ya.

Improving our MPG is just another aspect of what you can do with these cars, and it's just fun to explore. What I want, for instance, is two different cars: a high-HP sporty car (Festy) and a high-MPG "luxury" car (Aspire).

[mazda121BP]

May I ask the reason for all the mpg issues on here? I've seen many topics about trying to reduce your mpg? Just wondering why

[TominMO]

true, but i wonder, Tom, why the experiment? as in: is this for your own enlightenment, or is there an alterior motive behind this?

Yes.

a. just curious
b. was wondering if it was possible to use just one really large tire on front instead of two, to improve MPG. But that's probably not real practical anyway; two significantly different tires on front might lead to unpleasant handling characteristics.

[FestYboy]

true, but i wonder, Tom, why the experiment? as in: is this for your own enlightenment, or is there an alterior motive behind this?

[TominMO]

Talked to John about all this. We are going to run an experiment in a couple of weeks using his GPS to ascertain true speed. I have a tach in my Aspire to check RPM. We will drive in a straight line on the hwy at 60 MPH, with these front tire combinations:
Two small tires
Two tall tires
Left small and right tall
Left tall and right small.

That should nail this down for sure.

[FestYboy]

Movin, it' can't be the average... that would put BOTH in a slip situation (the big tire would slip forward and spin, the small one would drag and skip).

Tom the smaller tire will affect the engine RPM and the larger will freewheel to keep up (like you were making a turn all the time)

[TominMO]

sum of the total divided by two....Meaning neither it would be the middle between the two.

That's kinda what I was thinking. Arty, will you confirm this is true?

[Movin]

sum of the total divided by two....Meaning neither it would be the middle between the two.

[mazda121BP]

The diff would spin faster for the little tyre is it had most traction I would think so effectively if could throw out actual speed compared to speedo. But only if the space saver tyre had more traction.. One side if your open diff would spin faster for the space saver....

[TominMO]

Another kweschun: if you have two different-sized tires on the front, such as a space-saver tire and another tire which is significantly taller, which one effects engine RPM?

[TominMO]

OK Arty and Movin, thanks for the explanations. That makes it more clear for me.

[Movin]

Right spins, left doesn't

Do the E-series trannies only drive the right wheel, in all cases? Or does drive transfer to the left wheel if the right wheel loses traction? I ask beause every time I step on the gas going around a right turn, I get wheel hop on the right side; but never when making left turns, when weight transfers to the right wheel.

The power will go to the tire with the least traction unless restricted. In stock form the power will leave the transmission with equal opportunity for either side to spin. The right axle is roughly twice as long as the left axle.

Given equal lean in corners the left axle has nearly double the cv angle. This adds considerable resistance between the transmission and the hub making it almost equal torque to the tires in a left turn.

If you are familiar with torque steer, that is the same thing.

Equal length axles will cause equal opportunity tire spin.

A limited slip or locking diff fixes all the above. Except steering feedback!!

Except wheel hop as Arty explained, the right axle would need to be twice as stiff ( roughly ) so that torsional windup would be equal.

[FestYboy]

Tom, in that instance, the length of the right CV allows it to act like a torsion bar (read: spring). so, you apply power to the transmission and it sends it to the wheels, but that right side axle loads up and then releases all that energy to the wheel which can't cope with the excessive torque. now the wheel breaks loose, unloading the axle and since the load drops, the wheel can slow down and gain grip again, but the cycle starts to repeat all over. you are now experiancing wheel hop.

[mazda121BP]

Wheel "hop" is really bad for your transmission, as Is 1 wheel burnouts