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Hi All -

Can anyone explain the purpose of the center slipper in the 870C, and under what circumstances you would tighten or loosen it?

I understand that in most modern cars there is a slipper on the main gear to protect the drivetrain and mitigate some of the motor's punch, but in the 870C it appears that the slipper reduces power sent to the front wheels only, having no effect on the rear wheels.

I loosened the slipper on mine just to see what would happen. The only effect I can see so far is that high-speed turning radius has increased significantly.

I have looked all over the Internets for this information but only can find numerous explanations of the modern slipper, not the 870C front slipper.

Thanks in advance.

Brian

That front slipper is designed to adjust the 4'wheeledness' of the yokomo chassis. On rough tracks it's meant to adjust front traction to tune between drag and grip.

Would a rough or loose track call for a tighter slipper?

When would you loosen the slipper all the way? High grip conditions? How loose might you go?

I just loosened it all the way, which I suppose is like a 2WD conversion, and the car is now noticeably faster!

Also seems more difficult to control.

It seems like, when adjusting the slipper, all of the action is just in the range where it goes from loose to tight, kind of like when adjusting a ball diff.

I have observed on my relatively high-grip surface (carpet):

When the slipper is tight, the car has trouble navigating turns at high speed, maybe due to the speed difference between the front and the rear wheels. Turning radius is enlarged and the front wheels stutter a lot. But the car moves in nice arcs.

When the slipper is fully loose (2WD mode), the front tires do not stutter, so the front end is more planted in turns. The car is really squirrely, though... Turning radius is much smaller, steering response is instantaneous, handling seems to be much better, but it requires throwing the rear end of the car around all the time.

I am now trying mode 3, in between, with some slip, say 50%. It seems to preserve the better handling of 2WD mode but perhaps makes the turns more smooth, with the rear end swinging left and right to a lesser degree than 2WD.

I thought it was a torque splitter, so you can adjust the amount of power to front wheels? oR something along those lines

fakiee wrote: ↑Fri Aug 25, 2017 5:53 am I thought it was a torque splitter, so you can adjust the amount of power to front wheels? oR something along those lines

Yes, I think that's right, and also per jwscab's reply.

I'm wondering about people's experiences and how they use it in practice.

On my high-grip surface it seems like I need lots of slip to prevent stuttering because the wheels aren't slipping on the surface (as they would on dirt, for example).

you might want to explore some of the YR4 manuals, especially the very first one. it is essentially the 870c with touring car arms. So there may be further tuning info in the manual, as I think(can't remember exactly) if they still kept that front slipper. but that would for sure deal with that chassis and high grip tracks.

jwscab wrote: ↑Fri Aug 25, 2017 12:53 pm you might want to explore some of the YR4 manuals, especially the very first one. it is essentially the 870c with touring car arms. So there may be further tuning info in the manual, as I think(can't remember exactly) if they still kept that front slipper. but that would for sure deal with that chassis and high grip tracks.

Good idea! Thank you, will do.