Hydra drive on B4 ?

[stefke]

This seems an odd question, but can you put a Losi hydra drive or Schum viscodrive on the B4 ?

The reason I ask is because of a track we race on in the belgian/dutch nationals. After the first qualifying round, it becomes so bumpy and rutted that driving one lap without you bouncing into something (or someone ) becomes very difficult. And with modern power systems, you really have to have 110% control over your throttle finger.

Now I remember from my first serious race car, the Losi XX, that a hydra drive made a 2wd car more sedated and easier to drive on extremely bumpy tracks, this at the expense of a lot of inertia in the drivetrain. But the drivetrain inertia and extra losses can't be a problem anymore given the modern power systems, much like the phylosophy behind the reintroduction of the XX4.

[jimmy]

I would guess it can be fitted but im not sure, I sold mine with my xxx a few years ago.

I was going to try it at tiverton which got really loose and rutted but the big losi boys all reckoned it would be no good.

So, I can't say how much or even if it would be an advantage, but worth a try.

[stefke]

The reason I ask is that I see 2 problems :

1. The layshaft will propably have to be longer. AE (or was it Losi) used to make them for AE cars (B2/B3)
2. the gearbox cover won't fit anymore. MIP used to make hydra drive covers for the B2/B3

Considering the comment of the Losi team drivers : they can say that because of their superhuman throttle control, but I'm convinced that for mere mortals like us, a hydra drive can still be usefull on very rutted tracks.

[MattW]

It might fit. I think i'm right in saying that basically the xx/xxx and B4 slippers are the same - although possibly the Losi layshaft might be abit longer.

[DCM]

Out of the two, and I have used the two, the Schumacher variant was FAR better as it allowed you to use shock oil and then it had a vernier adjustment to fine tune it. But basicaly they were a glorified liquid slipper clutch and most ditched the Hydradrive on the XX for the slipper which was easier to use, set and adjust.

The Viscous drive, they may still have them and adaptors on Schumachers site.

[Chrislong]

I used both units and didn't get on with them at the time. The spinning weight on the layshaft was more noticeable than the improved throttle control, and so the cars felt aweful.

This will ofcause now be exagerated as we'll be spinning them faster.

Recently at the Tiverton national, I found 5 cells and a tight slipper best when slippery and then 6 cells and a approx 3ft slip of the slipper best when bumpy (i.e. not super loose but not spinning the wheels like crazy either).

[stefke]

Very good point there.

The theoretical cons are enough for me not to invest my precious time in trying it.

But back in the days of the XX, I liked the hydra a lot for some tracks.

[Chris Doughty]

I use the 6 puck slipper to replace the use of a hydra drive.

have a look at a xxx4 manual on the Losi site, get an old spur and make 6 holes so it is just like the xxx4 gear, and use the 6 pucks instead of the slipper.

works really well if you want a lot of slip, not so good when you want it to slip and then go.

[jimmy]

OOh! thats a bit interesting. never thought of that.