WLRC Gearing advice???

[Mike145]

I know gearing can be one of those closely guarded secrets of the trade but its causing me something of a headache. I'm going to be racing a tc5 (don't laugh, got it for a good price and thought it would be a start) at wlrc this season. It's come with a 25t pinion on a 83t spur. Which according to the manual will give somewhere around 6.7 final drive ratio. Would that be ok for wlrc because I'm obviously going to have to buy extra gears if not. Any advice would be great, cheers.

[cjm_2008]

I know gearing can be one of those closely guarded secrets of the trade but its causing me something of a headache. I'm going to be racing a tc5 (don't laugh, got it for a good price and thought it would be a start) at wlrc this season. It's come with a 25t pinion on a 83t spur. Which according to the manual will give somewhere around 6.7 final drive ratio. Would that be ok for wlrc because I'm obviously going to have to buy extra gears if not. Any advice would be great, cheers.

The tc5 is pretty decent from what I recall.

I'd consult the manufacturers' recommendations for the motor you're running, and use that as a start point.

[Mike145]

I've fitted it with a speedpassion competition 3.0 17.5 turn motor. For blinky class. I'll dig out the manual and see what it says.

[beale]

The V3 is a good motor or was, it will give a good service but you will find most at WL will be using newer motors that withstand higher temps and therefore can gear them much lower for high straight line speed. You will need a selection of pinions and spurs to get down to a 4 ish FDR. Fit a good fan next to your motor and give it a few laps then stop and grab your motor ASAP, if you can hold it without thinking its burning you then you can go lower on the gearing, (temp gun makes it easier if you have 1 or ask someone that has)

[jimjav]

last year i was running 17.5 blinky and was using between 3.3 and 3.5 with a Team Powers motor. You should push timming as far as you can with the speed passion and play with ratio and always use a fan, always.
As beale has told you, 2 minutes run and check temps, if you have a temp gun after 2 minutes over 70 it might be an issue at the end of 5 minutes. After a 5 minutes run check always temp until you stop changing things, if it goes near 80 you are on limit.

Best regards
Javier

[Mike145]

Any clues to what pinion/spur combination to best use to achieve these ratios? Only because they can be achieved using different combinations.:confused:

[beale]

Some info on here
http://www.rctech.net/forum/electric-road/262199-gearing-17-5-brushless-tc5.html

To get from 64 to 48dp it's (no teeth/2)*1.5
For 48 to 64dp it's (no teeth /1.5)*2

In my X-rays I run 100 spur 47 pinion with an internal ratio of 1.9 to get 4.0FDR and 35* EBT on small indoor tracks, would drop to 96 spur on a big track with more EBT, always checking temps

[jimjav]

Try that the sum of tooth between pinion and spurs is between 114 & 105. And with that meausre try to get the smaller spur you can get and that gives you the desired ratio.
final ratio = [(spur/pinion)*(diff pulley / spur pulley)]
I do not know your internal ratio, depending of the TC5 version it will be one or another.

best regards

[Mike145]

It's got an internal ratio of 2.0:1. Downloaded an app for gear ratios. From what I can fathom from it, I'm gonna need between a 31-33 pinion against a 61-64 spur using 48dp which is what's on the car. Does that sound right or rightish? Really appreciate the help guys.