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OK, so the Losi 22 seems to be generating 10th scale mod buggy interest at the local track and I have enough parts to build a black tub RC-10 or refitting a built JRX-2 (5 link, original trans) with a new body.

It dawned on me that somewhere along the way I picked up enough parts to build a few hydradrives and I was wondering if the HD system would really like the new high RPM brushless / LiPo tech we have now. The hottest thing I have would be a 1st gen Novak 5800, which is a bit long in the tooth but probably more than enough for a 10th scale buggy.

Has anyone revisited the hydradrive lately? Any tuning tips with BL/LiPo?

Bob

I was thinking along similar lines a few months back when I started rebuilding my XX, but haven't tried it yet. Definitely worth revisiting IMO.

Yes! There's been alot of drivers using them on their CR2s & XXXs here in the UK & mainland Europe al least... this is partly why they seem to be fetching such decent money at the moment.

Back when they first came out - one of the biggest dissadvantages with the Hydra Drive was the shear amount of rotating mass created. However now with the torque & power available with brushless motors etc its not really an issue, also with the current trend for tracks to be laid on astro-turf with large ramps & features the Hydra Drive is supposed to make the car easier to drive as it is better at damping the transmission from shocks applied through it.

That said I never used my Hydra Drive back in the day as I could never get it to stop leaking

There was a recent follow up article recently in RC car action (January 2011) where Gil Losi Jr said the higher heat levels of the hydra drive due to the shift from 2000Mah to 3000maH batteries and 5 minute heats the hydra drive was working hotter than ever, so hot that any more it would need additional cooling. This would have been an expensive and complicated option that was not going to take off.

He also acknowledged the molds for the complex parts were getting old so who knows how much of each was a factor. It was ultimately cheaper to develop the dual disc slipper and the rest is history as they say

He also said the fluid was equivalent to 5000-10000wt diff fluid today.

I know that it may end up be more of a pain than anything, it helped out back in the day and like mentioned before you were not spinning / spooling the thing up to crazy RPM's (motors winds were not run that low back then). Now you have crazy brush-less and Lipo's, that possibly would do more harm than good with a Hydra Drive or Schumacher Viscous Drive (they weren't designed for this new power). And like mentioned before they can be a pain to keep from leaking - and now with more rpm ??? But you can always give it a try and see what goes / works / and doesn't. It's always worth a try.

X Factory has a brass flywheel you can buy to help "tame" today's power plants. I would think a properly built Hydra could do the job better.

Heat was the thing I was worrying about. Repeatedly heat cycling the internal plastic parts to the point of fatigue failure...

I'll probably give it a try though. Loading it up with heavy diff lube and running it very loose would be an interesting experiment if nothing else...

Bob