tt-01 hop up

[owsey]

hi, could anyone tell me what this hop up does/what its for :TT-01 FRONT ONE WAY UNIT HOP UP.

[DJTheo]

Use the forum search on "one way", its function and characteristics have been covered several times.

Cheers

[peejay]

A one-way unit is a replacement for the front differential, and it affects the cornering characteristics of the car.  With a one-way there is no braking effort on the front wheels when slowing down for a corner.

Maybe someone who races will offer a better description of what a one-way unit does.

 

 

[DeeMiller]

A one way diff allows the car to hold traction while cornering.

The wheel which rotates the slowest gets all the power while the outer wheel rotates freely (when cornering, the inner wheel is doing a smaller circle than the outer wheel).

When both wheels rotate the same, all the power goes back to both wheels.

Also, coming out of a corner you have traction on at least one wheel (the one that rotates the slowest).

So when you put on the throttle, the inner wheel may slip (likely because of the roll in cornering -> weigth moves to the outer wheels) so that this wheel wants to rotate faster than the outer wheel: power moves to outer wheel until both wheels rotate the same speed -> traction on both wheels again.

It works almost as a (ball)diff, the only difference is that the amount of slip is provided by the wheels itself, not by the diff. 

 

Grtz Dee

[DJTheo]

For the XY time:

A one way transmits power to its connected axle only when its input (usually the other axle) rotates faster then it,  like pedals of a biccyle, they only have mechancial connection to the wheel when you try to accelerate. Since one ways are usually connected to the front axle, when accelerating power is transmitted also to the front axle only when the rear wheels start spinning, When braking like on the bicycle no power is transmitted, i.e. the front axle is rolling free and does not brake, thus having more cababilities of lateral grip. This is an advantage in fast and/or grippy tracks, while the significant longer braking distance makes it a disadvantage on slower, curvy tracks. In general its a very specific hop-up for very specific conditions and advanced drivers and usually not recommened for normal driving or drivers.

There are several types of one ways: http://www.rccaraction.com/articles/oneways.asp

Cheers

[peejay]

...

There are several types of one ways: http://www.rccaraction.com/articles/oneways.asp

Cheers

An excellent article.  Thanks for the url []

 

[DeeMiller]

when accelerating power is transmitted also to the front axle only when the rear wheels start spinning,

I don't know if I understand your words correctly but if the rear wheels start spinning under power, the front wheels do the same, right? (because there is no diff between the front and rear axles, right?).

 

Dee

[DJTheo]

No, as said the one way can act as a kind of 3rd diff by not always transfering power to the front, power is only transmitted to front when front wheels rotate slower then rears.

Cheers

[mr_pushrod]

As Theo has said, the one way allows the front wheels to freewheel under deceleration and braking. Under power it acts like a spool with no diff action at all.

[DeeMiller]

As Theo has said, the one way allows the front wheels to freewheel under deceleration and braking. Under power it acts like a spool with no diff action at all.

Yes, correct but that was what I had said earlier.

Theo mentioned "under acceleration".

No, as said the one way can act as a kind of 3rd diff by not always transfering power to the front, power is only transmitted to front when front wheels rotate slower then rears.

Cheers

No offence but that's incorrect, sorry.

The third diff would be the tires.

Both the diffs rotate the same, when the rear wheels are spinning, at least one the front ones does too.

I know it sounds strange but try it on your TT01:

-Both slipping: turn both the rear wheels and notice the fronts rotates the same amount (one or both slipping the same way).

-Both traction: hold down one side (front and rear wheel) and turn the other side's rear wheel, it's locked, isn't it?

If you try the last, watch closely if the propellor shaft is turning because that's where the power source is coming from otherwise my "experiment" is not valid.

Now that I think of it, if you use a normal diff on the front, both front and rear wheel would turn if you hold down one side, right?

So here we have the major difference between the one-way and the normal diff.

Also, when using a one-way, you don't need 3(ball)diffs (one in the drive shaft, one in front, one in rear), clever thinking, isn't it?

If this doesn't convince you, it'll be me then, no problem.[][][]

 

Grtz Dee.

 

[DJTheo]

"No offence but that's incorrect, sorry."

What exactly is wrong?

"The third diff would be the tires."

???

"Both the diffs rotate the same, when the rear wheels are spinning, at least one the front ones does too."

Yes, as I said when the rear wheels are spinning, the one way transmits power to the front like as if it wouldn't have it. But the front diff/spool can rotate faster with a one way as it allows it.

"-Both slipping: turn both the rear wheels and notice the fronts rotates the same amount (one or both slipping the same way)."

Yes, as I said as soon as the rear tries to rotate faster then the front, one way transmits power to the front too, think of it as a diode.

"-Both traction: hold down one side (front and rear wheel) and turn the other side's rear wheel, it's locked, isn't it?"

Yes, as a front one way is a spool (thus no front diff action) and when you try to rotate the rear the one way tries to rotate both front wheels but cant (as you hold one)

Hope its clear now?

Cheers

[DeeMiller]

"No offence but that's incorrect, sorry."

What exactly is wrong?

Never mind, I guess it is the way you put it, nothing personal.[]

As I said, it'll be me then.[:$]

"The third diff would be the tires."

???

I meant that if there's a difference between rear and front tires, the tires would slip (the third diff).

The way you put it it looks like the diff prevents that, it doesn't.

Anyway, to avoid getting this into an endless debate I would suggest to leaving it as it is.

We both know how diffs work but our perspective and explanation may vary.

Hope its clear now?

Cheers

Yes, it is.

Please relax man, as it is not a matter of life or death, I'm working on my replies (at least to find the correct words), don't worry.[]

I'm sorry that I offended you but I'm glad I got three yes-s.

Still, have a nice day (I hope I didn't ruin it...[:$]).

 

Grtz Dee.

[DJTheo]

I am relaxed and no offense taken, why would I, just like technical stuff and to understand what other people try to say []

Cheers