Looking for Transmission Gurus! Manual and Auto Front engine rear drive!

[Nutz4sand]

Playing with some new ideas as of late.

Looking for any and all input on inline car transmissions.

What I am seeking is any info you may have on small and lightweight manual AND Automatic trannies from cars with a front engine and a rear drive pig/punkin.

For instance:

I know a Mazda Miata is tiny and light and pretty quick. But I wonder what kind of power its tranny could handle? How much does its tranny weigh?

Now I KNOW there are a million factors including car weight and rear gear ratio and tire size and on and on.

So lets say roughly a 1000-1100 pound car with at least 1300 Padla tracs tires. A rear end near a 3.55 or possible deeper ratio maybe.

What I am looking at is making a miniature sand rocket type car. Instead of a honking V-8 up there (while fun they are HEAVY) I want to look at placing say a Hayabusa or ZX-14 engine sideways and feed it through a driveshaft back into a diff and out to the wheels.

Now thats easy enough. But looking for options on adding a inline car tranny to have multplie ranges and reverse. The manual is self explanitory. But I am also looking at the possabilites of feeding a big bike motor into a Chevy Powerglide then to the rear end. Having two ranges that could be shifted on the fly under load (and reverse) just might justify the 95 pounds of a Powerglide tranny.  Plus not to many (as in zero) electronics to mess with in a Powerglide. But still a newer tranny that had relatively simple electronics could be something I would still mess with.

So what have you seen over time that you might think might work in this application/abuse??

(side note: I am also thinking that a BIG newer four stroke sled engine with a reverse gearcase feeding into the driveshaft would be the best and lightest and not to bad on cost when you really add it up.)

But the bike motor with ranges does have its appeal.

So what do you think?

[fabr]

Mount that busa mid ship and you got a plan.

[Nutz4sand]

Define midship and why you think its important?

[fabr]

Midship to avoid the weight being way forward. In other words somewhere between passengers if 2 seater. BTW,anything you want to know PG specifically I can help. Done MANY of them. Strong as hell in a fairly light package. Problem is they are HP robbers even if much less than most automatics.

[Nutz4sand]

I do not think the forward weight issue is going to be near as much of a problem as most think. If the motors a lil farther forward and the people a lil farther back it will be close enough to a mid mounted buggy to not matter and may compliment a certain driving style.

I also am aware the automatics (heck even the manuals some) are gonna sap a lil power but what doesn't? Some do a lot and some fairly little. Your gonna pay for the weight. The parasitic drag. And the rotating mass.

A price I may be willing to pay. To be able to shift ranges. Especially with the auto on the go. Maybe better than downshifting or upshifting a gear on the bike motor in many conditions.

Reverse with it is a bonus.   

[fabr]

Not to argue with the rev bonus. +=+++++. I don't even dislike the idea that you are proposing. IMO no reason it won't work but just like my setup there will be a need for upping the power level IMO to be "competitive" with similar powerplants using an RPM/Jeffco/in a conventional 2 seater/bike power. I also really like the variable final drive ratio but I'm thinking when you go to calculating road speeds you will find the ratios unacceptable. I may be very wrong about that tho.

[fabr]

Unless you run the bike motor in 5th or 6th and I doubt the bike clutch will hold up to that usage. Again maybe wrong but,IMO, that's the case.

[Nutz4sand]

Yah gots yer gerz bakwerds... lol The clutch sees MORE load in the higher gears.   

But as for the loads I do not think it will be any harder than some ofthese guys making heavy buggies and flailing on them.

In fact if the bike motor was spinning a torque convertor it would have a hell of a "cush drive" right there.

I have seen a lot of different bike motors turned sideways in dwarf cars with but a shaft straight to the rearend. So the reduction ratios in the tranny would only benefit for more weight and hill climbing and bigger off road tires etc.

Other than the added weight and drag to me its win win win. Plus the cost is gonna blow an RPM or Jeffco out of the water.

I do also not like the loss of power in the 90 degree of the ring and pinion. But again any VW tranny is seeing this some. You do not loose THAT in an RPM or Jeffco but with this you will save a lot in cost.

We will call it a budget approach!

(EDIT: I should say any VW Bug or Beetle or Bus tranny from yesteryear. (Not the new front drive only setups) loose thru the ring and pinion at 90 degrees)

[fabr]

Yah gots yer gerz bakwerds... lol The clutch sees MORE load in the higher gears.   

But as for the loads I do not think it will be any harder than some ofthese guys making heavy buggies and flailing on them.

In fact if the bike motor was spinning a torque convertor it would have a hell of a "cush drive" right there.

I have seen a lot of different bike motors turned sideways in dwarf cars with but a shaft straight to the rearend. So the reduction ratios in the tranny would only benefit for more weight and hill climbing and bigger off road tires etc.

Other than the added weight and drag to me its win win win. Plus the cost is gonna blow an RPM or Jeffco out of the water.

I do also not like the loss of power in the 90 degree of the ring and pinion. But again any VW tranny is seeing this some. You do not loose THAT in an RPM or Jeffco but with this you will save a lot in cost.

We will call it a budget approach!

(EDIT: I should say any VW Bug or Beetle or Bus tranny from yesteryear. (Not the new front drive only setups) loose thru the ring and pinion at 90 degrees)

No,I don't. We agree on the loads and that's why I said it won't work to use the bike tranny in just 5th or 6th so the countershaft rpm's will be  similar to a standard car engine. Remember that all busa and zx's have an internal primary reduction that brings countershaft rpms down to usable levels before  the tranny input shaft. When you do your math though I think you will find what i found out. Way too much for me to type out but you will soon see what I'm saying when you go to the math.

[fabr]

As for a torque concerter I don't know but I'm thinking it is doable  and the bike clutch would have no issues but also I think the parasitic torque loss percentages would be huge. Most busas make what?less than 100 pounds tq?Badass turbo ones 175? Compare that to any decent car engine.

[Nutz4sand]

I have been toying with the ratios.

But I AM right about it being harder on the clutch in the higher gears.

The ratios bit is what got me to thinking about this with the manual tranny.

In high gear most manual trannies are one to one (unless overdriven) So a tiny STRONG lightweight manual would have only minor drag issues feeding power thru itself in high gear and low weight. Lower gears as needed (if wished) and the beloved reverse (but face it drag in reverse should not be an issue!)

The auto gear ratios would need to be looked at as I know there IS a slew of them but again with a taller rear gear ratio it could likely be easily dealt with.

[Nutz4sand]

As for a torque concerter I don't know but I'm thinking it is doable  and the bike clutch would have no issues but also I think the parasitic torque losses would be huge. Most busas make what?less than 100 pounds tq?Badass turbo ones 175? Compare that to any decent car engine.

Yah but is that crank or output shaft on the tranny??

[fabr]

I have been toying with the ratios.

But I AM right about it being harder on the clutch in the higher gears.

The ratios bit is what got me to thinking about this with the manual tranny.

In high gear most manual trannies are one to one (unless overdriven) So a tiny STRONG lightweight manual would have only minor drag issues feeding power thru itself in high gear and low weight. Lower gears as needed (if wished) and the beloved reverse (but face it drag in reverse should not be an issue!)

The auto gear ratios would need to be looked at as I know there IS a slew of them but again with a taller rear gear ratio it could likely be easily dealt with.

I SAID I agree with you/read WTF I said.

[fabr]

Yah but is that crank or output shaft on the tranny??

I'm NOT getting into that again.

[Nutz4sand]

No,I don't. We agree on the loads and that's why I said it won't work to use the bike tranny in just 5th or 6th so the countershaft rpm's will be  similar to a standard car engine. Remember that all busa and zx's have an internal primary reduction that brings countershaft rpms down to usable levels before  the tranny input shaft. When you do your math though I think you will find what i found out. Way too much for me to type out but you will soon see what I'm saying when you go to the math.

I read what you said but I also read this.

No,I don't.

From where you said:

Unless you run the bike motor in 5th or 6th and I doubt the bike clutch will hold up to that usage. Again maybe wrong but,IMO, that's the case.

In the lower gears the bikes clutch sees less load so its got it easier.