Hydradrives - why the sudden increase in interest
 

I guess the question is in the title but I'd like to know the advantages from those who have tried them. I seem to remember them going out of fashion post Kinwald's Worlds 97 win as they never were fitted on the XXX series (although I understand you can). Now they seem to be cropping up all over the place. Is this a brushless thing, a mid motor thing or just a 90s throwback?

Cheers

Graeme

Back when they came out you really had to fight to make the batteries last 5 minutes with them on because they increased rotating mass by so much.
With lipo and brushles we now have insane amounts of power, speed and duration, so that hydras have become viable to use again. They really do smooth out a cars throttle response and make bump handling so much better, especially on slippy surfaces. Schumacher used to make a visco-drive back in the day as well, which worked similarly.

they where awesome and yes we need them now for bumpy tracks as power and endurance not a problem so someone make some money:thumbsup:

I found a mint one in my attic when searching through my old racing gear :p

I've got four of the little devils :p

And selling one of them too? :)

I think someone just ran out of double slipper spurs, xD.
Dual pads slippers were faster on 4x2, maybe we should give a try to the Hydra on a 4WD. Anyway, i think i have one somewhere, but don´t know how to try it on a B4.

I've got about 8 hydra drives in my garage.

Couldn't believe a gearbox and hydra drive for a XX went for £55+ the other night.

Funny people mention it as I've been looking at fitting the hydra drive to my XXCR which will be running brushless again this year.

I prefered the Viscous Drive from Schumacher, no need for weird oils, just shock oil, and it was adjustable.

I've got a few rebuild kits, so I may have to get one up and running.

What 3rd party oil do people use with them?

I only ran the standard slipper on my XXCR last summer and I'm not running the XXCR at the moment. During the summer it's a high grip bumpy track.

if I remember there were different thickness of oils, which oils did people run with modified motors?

Exactly what I was going to ask. You'd need and oil with good shear properties. A heavy silicone oil would be worth trying - don't know what weight or viscosity though.

Maybe this 1000 centistoke diff oil would be worth testing?

http://www.losipartshouse.com/servle...-1000CS/Detail

If memory serves correctly, the "buggy" version came with the middle weight oil (medium), trucks came with the heaviest and there was an optional 'light' oil aimed at buggies rather than truck.

Bugger as I have heavy and light :(

may be heavey is the way to go mike??now we have brushless and lipo

from what i could find, the hyrda drive costs about £80 to build up from parts. I cant find any new, so to see them go on ebay for £55 isnt really suprising to be honest.

Indeeed, I did think this as I was running a 7.5 last year with trakpower 3600s

Not Silicone oil then.....

G

Silicone oil has relatively good shear break-down properties.

Not when you get to high viscosities.....

G

Any recommendations on oils and viscosities to try?