losi hydradrive

[Rc1oGtMaN]

Hey all,
I race Associated, but have been looking into losi vehicles for about a month, and I saw a hydradrive option. What is it? What does it do? Thanks

[jeepinator]

It is essentialy a torque converter, if you are familiar with big cars.
It is a viscous coupling between the motor and the drive train. Unlike a regular friction slipper, the Hydradrive has a variable coupling coefficient. This means that the coupling will slip less (percentage wise) when the input torque is greater and slip more when the input torque is less.
Regular friction slippers slip MORE when more power is applied. This makes them linear. Hydradrives have an exponential rate at wich the motor is connected to the drive train.
This is all very hard to explain. I hope I did an OK job ;)

EDIT: The main advantage of this unit seems to be on rough tracks. You can set the slipper looser without losing acceleration. This helps when accelerating over bumpy areas.

[ 05-19-2001: Message edited by: jeepinator ]

[Railman]

Hydra Drives used to be very popular about 5 years ago. I never really messed with them much & never was into them...just seemed like they added too much rotational mass to make sense for stock motors. I think they used to make a lot more sense on older rc cars with lesser suspension and traction, especially with mod motors. They also helped run time by allowing the rpm to come up faster so as to reduce amp draw. The bottom line is they aren't needed anymore because: radios got better, speed controls got better, batteries got better, tires got a WHOLE LOT better, & suspensions got better. The net result is that cars NOW perform better without the Hydra. Just don't need them anymore! Just my $.02
:rolleyes:

[Rc1oGtMaN]

Thank you. That clears up a whole lot.

[gubbs3]

The dual disk slippers that losi now includes with all their kits is supposed to act like a hydradrive by being most consistent but it is lighter. I think the biggest thing for not being used anymore is you simply don't need them because nearly everything on our cars are better.

[rdockrey]

My son just started driving and we use the hydra-drive. It seems to soften the punch when coming out of a turn and when coming off the line. We will probably drop it when he gets to driving better, but for right now, it helps a bunch. :)

[Rc1oGtMaN]

It seems to soften the punch when coming out of a turn and when coming off the line. We will probably drop it when he gets to driving better, but for right now, it helps a bunch.

That interests me, rdockrey. Anyboby know if there was ever a hydradrive made for the old AE RC10? I'd like to drop one in there and turn it into a trainer for me.

[ 05-20-2001: Message edited by: Rc1oGtMaN ]

[WhoKnowsWho]

For the old old RC10? Um, stormer hobbies has some odds and ends. Search for "hydradrive" and you'll get some sort of stealth tranny conversion for the hydradrive. Search for "hydra drive" and you'll get some Losi spurs and some sort of adaptor...

[jeepinator]

I adapted a hydradrive for my RC10GT. That was cool. Not easy to do, but it worked quite well on our ultra bumpy track here.

Railman, I know I have been out of it a while. I agree with the rotational mass thing. I thought it was gimicky even from the beginning. They DO work, but the gains were only found on really rough tracks. The motor and tranny would keep a nice constant pull and all the harshness got soaked up by the hydradrive. Even after the hydradrive lost almost all of it's popularity we had Losi team dudes putting them on at the local track that hosted the regionals. This was due primarily to the roughness of the track surface.
Anyway, I was answering his question strictly, meaning I was answering, "What is it? What does it do?.
BTW, people STILL use them and at the very least feel they are doing them some benefit.

[bryceanator]

i have a hydra on my xx should i get rid of it and how would i get rid of it

[Gokou]

I had a hydradrive on my old RC-10 Team Car-- Losi made a whole conversion kit, at the time, around $50. I absolutely loved it when I ran mod and the track was loose and bumpy. It really helped keep the rear end planted, because you could run the slipper very loose-- the hydraulic coupling would spool up and drag the tranny along, so you could run the slipper very loose, which made the car very forgiving over rough areas of the track-- you could power over bumps them and the rear end wouldn't dart all over. I agree with Railman though-- with new suspension and tires, the Hydradrive isn't really needed. Also, the rotational mass of the tranny is greatly increased by the hydradrive-- my run times with comparable gearing (years ago) were on average 30 seconds shorter when I ran the Hydradrive compared to just a slipper. Still, when the track was rough and I was running mod, I turned the fastest lap times with the Hydradrive. Keep in mind though this was ~7 years ago and car and tire design have come a LONG way. However it is still a nifty item and a very novel and ingenious design, which is why I still have mine. It really was an overly complicated solution to the problem though.