final drive Ratios for B4

[B4 Sloth]

Can anyone help..I am struggling to grasp the whole drive ratio malarky. I have just got a xcelerion Sensored 6.5T. In the instructions the FDR is 10.8 for a 2wd buggy. according to instructions this is calculated by divinding spur by pinion then multiliny by internal car ratio (2.6 on a b4. Working backwards an 81t spur equates to a 19t pinion.
Is this right?
How close to the instructions should i go- any scope for higher teeth pinions.
What are you guys running with your6.5T brushless?:eh?:

[Mike Hudson]

is the rotor in the motor bonded or sintered?
I run currently run a 5.5L sintered rotor in my X6 (conversion of a B4) with a 20t pinion/81t spur i'd play around with 20/21/22t pinion on a 81t spur with a 6.5 sensored motor, just check the temperature of the motor after each run and if you can't touch it with your finger for a fair few seconds without it burning you then it's geared too high so drop down a tooth or two if needed, hope this helps
Mike.

[MiCk B.]

Here's a b4 gear chart

http://www.rc10b4.com/images/driveRatiosMini.gif

So you'd want to be running 20 on a 81t spur to get close the recommended overall ratio.

MiCk B. :-)

[B4 Sloth]

makes sense now- cheers

[Wicked-Wayz]

Do spur times transmission ratio divided by the pinion. That is the way I have always done it.

Peace Aaron(W-W)

[ben]

[quote=Mike Hudson;131047]is the rotor in the motor bonded or sintered?
I run currently run a 5.5L sintered rotor in my X6 [quote]

Yes but the x6 has an extra idler gear compared to the B4 so im sure that will change the internal ratio?

[ashleyb4]

no ben you can add 600 iddler gears of any size and it wont effect the internal ratio.

A

[ben]

Can you explain to me why please ashley :confused:

[ashleyb4]

Only the gears on the layshaft and diff gear are used when calculating internal ration the idler gear i just for joining the gears together and determaning the way the wheels and motor spin. The idler gear with 90 teeth or 9 teeth wouldnt make a diffrence to the internal ration as the iddler gear just transferres the power. Its very difficult to exsplain.

A

[bigred5765]

OMG Ashley is right once again.??
the idler gear is just like a transfer gear Ben, and as its the same size as the first theres no reduction or increase it just turns the gear in another direction,

[ben]

owww ok thanks :D ahhh you learn something new every day:D