XXX-4 diffs, butter?

[Alexi]

Right, I replaced the above pulley, and the exact same thing has happened. Why? Do I really have too much power (mamba on 10 cells)? I can't believe that, I've run the same setup in cheap Tamiyas with no problems

Is there any other possible cause? Belt too tight? I don't know, so any well educated suggestions would be welcomed.

Thanks in advance

[bigred5765]

seems to happen if you a fan off doing doughnuts (wheel spinning in circles)
and 10 cells and a mamba OMG it must be like a hotrod

[Alexi]

Originally Posted by bigred5765

seems to happen if you a fan off doing doughnuts (wheel spinning in circles)
and 10 cells and a mamba OMG it must be like a hotrod

Thanks for the quick reply, nearly as quick as the car was (when it was running )!

So is this a common problem? I didn't actually doughnut at all, but it span out a few times, and did a few burnouts Not many though...

[bigred5765]

we can do it on the xx4 in seconds if we start doing doughnuts

[Alexi]

Originally Posted by bigred5765

we can do it on the xx4 in seconds if we start doing doughnuts

That's really what I didn't want to hear!
So what I am experiencing is normal?

[Col]

oops, sorry.
post deleted (wrong thread!)

[Southwell]

I never broke one in my xxx4 or xx4 using up to 8 wind motors, i think it's just the power your putting through it.

[PaulRotheram]

just use 6 cells.. maybe even 7

[Alexi]

Originally Posted by PaulRotheram

just use 6 cells.. maybe even 7

I bought the XXX4 because I thought my Mad Bull couldn't take it (fixed gearing, so tbh it was more the motor that couldn't take it, the car didn't break once).

So spending money on a new car to find out I'm going to have to slow down is a no no

From what has been said by Southwell and others, the stock diff can't take it. So the solution is going to have to be 'make or find a diff that CAN take the power'...


Wish me luck

[Chris Doughty]

if you are not intetested in racing fit a spool front and spool rear. either that or CRANK up your diff mega tight.

it only melts from diffing out a lot and heating the balls up.

[Alexi]

Originally Posted by DoughtyUK.net

if you are not intetested in racing fit a spool front and spool rear. either that or CRANK up your diff mega tight.

it only melts from diffing out a lot and heating the balls up.

Well I had the rear very tight anyway, but not locked. I might give that a go, but I'm running out of pulleys

I've only seen front spools so far, will they fit in the rear? Thanks

[PaulRotheram]

yes as the front is the same as the rear. just make sure the number of teeth on the pulley are the same.

[Alexi]

Originally Posted by PaulRotheram

yes as the front is the same as the rear. just make sure the number of teeth on the pulley are the same.

I thought you could use different tooth pulleys for overdrive/underdrive. Though I'll stick to 41's for now.

[Alexi]

Right, I've decided to just rebuild the stock diff, but tighten it LOTS
If that doesn't work, I'll start finding an alternative solution.

Anyway, before I give it a go, can anyone tell me how many teeth the orange spur gear has, and how many the white one has? I'm currently running something like a 23t pinion, but I'll stick a 15t on and see how that goes.

Thanks in advance,
Alexi