360 rally clip

Post by **clitti** » 24 Apr 2007 11:52 pm

I know its only 10 seconds long but you can imagine the fun we had that day

http://www.youtube.com/watch?v=_7PaFrod0Ds

Post by **foggyjames** » 29 Apr 2007 02:11 pm

Hehe, that looks like a lot of fun

cheers

James

Post by **clitti** » 29 Apr 2007 09:27 pm

Got some more clips from other events,i'm just trying to work out how to transfer it to my computer.(Old man ,new technology)!!!!!!!!!!

Post by **meintag** » 30 Apr 2007 01:07 am

I see a welded diff or it's my impression ?!

Regards !!

Post by **Frits** » 30 Apr 2007 10:42 pm

On dirt is it easy that both wheels spin.

Post by **clitti** » 30 Apr 2007 11:07 pm

No welded diff.Just a diff full to the top of super thick chainsaw oil.!!!!!!!!

Post by **foggyjames** » 01 May 2007 07:23 pm

Haha, I like your style

Post by **A M R** » 01 May 2007 08:11 pm

hmm now thats an idea

Post by MJ » 01 May 2007 10:40 pm

Would using very thick oil cause wear issues though? Certainly a good cheap way to create a LSD

Post by **Roop** » 01 May 2007 10:45 pm

I don't understand. How does adding thick oil to an open diff cause it to act like a viscous? Surely it won't work without fins on the drive gears?

Post by **A M R** » 02 May 2007 12:29 am

it wont make it act like a viscous. well it sort of will. it will just make it harder to move the gears as theres more resistance and a bigger coefficient of friction.

its like if you put your hand in a swimming pool and moved it around, and then if you did the same thing and the swimming pool was filled with golden syrup (no i dont know why i picked golden syrup). chances are you would have a harder job of moving your hand around in the syrup.

MJ: i doubt there would be any wear issues. but theres only one way to find out

Post by **Roop** » 02 May 2007 01:28 am

Good explaination!

I'm with you now. In that case, I presume it's only effective on dirt or in the wet when neither driven wheel has much grip, or am I still confused?

In practical terms, I imagine an open diff using standard oil would "open up" and spin up one wheel more quickly than an indentical diff using thicker oil under indentical conditions. Am I getting the right end of the stick yet?

EDIT: I'd be very interested to hear anybody's experiences with this in practice!

Post by **foggyjames** » 02 May 2007 02:04 am

I do believe A M R has come up with a good point

Long may it continue

Yes, in theory that would work. You'll also be adding to the drag on the ring/pinion. Whether either actually has any effect is another question, but I'm fascinated by the theory. It'd have to be pretty seriously thick oil...although it's worth noting that the standard stuff is pretty damn gloopy to start with.

cheers

James

Post by **Chris_C** » 02 May 2007 09:50 am

Only problem as I see it (and I havn't given this much thought yet...) is that the co-ef of friction has increased, on both the pinion and the ring of the FD, and whatever magic gears are on the diff (I've never been inside a 300 diff casing, so I'm just going on how I expect it to be/the equiv is in Lego

)

Because the co-ef is equally raised on all gears, the only difference is the moment of those gears, i.e. all dependant on the dimension from the center of the gear too the teeth, which is where most friction gain will be made. This would mean that 2 gears of equal size are not affected, but a big gear would be affected more than a little one, which as far as I can think of it at the mo, is the opposite of what you'd want. Let me go and have a look at some exploded diagrams!

Post by **Chris_C** » 02 May 2007 09:54 am

Right, VADIS is useless for a diagram of the diff... I'll carry on looking