GEAR RATIOS FOR 12TH'S

[Wacker1]

Hi all,

I've recently bought a new 12th Pan Car after a 3year break, but I just wondered if anyone had an idea on what Gearing would be best for a new Orion 2008 Race Spec Vortex 10.5T Sintered Motor on brand new Jaco Prism Tyres?

When I Raced 12ths before, I had a full Gear Ratio/Tyre size Chart for the 19T Brushed Motors..........obviously, thats useless to me now, as everyones moved on to the Brushless technology..........does anyone know where I can get hold of a Gear Ratio/Tyre size Chart for Brushless Motors?

Cheers.

[jeroen206]

look over here http://www.gearmachine.net/

[SlowOne]

New Jacos are about 48mm out of the packet, and you will be looking for about 58mm/rev. You'll need an 88T Kimbrough spur gear, and to get that ratio a 34T pinion is about right. To cover that ratio as the tyres wear, and to allow you to fiddle with timing and ratio, you'll need pinions from around 28T to 34T. HTH

[terry.sc]

Rollout sheets available at http://www.carsrcracing.co.uk/?page_id=33 along with a few 1/12th specific technical articles that will be useful to you.

[Wacker1]

Thanks Guys for your advice...........I ran my 12th last Week on the Gearing you advised(88/34) & it performed great

I've now upgraded to the Modified Class & bought an Orion 2008 Race Spec Vortex 5.5T Motor, what would be the best Gearing to start off with on the same Jaco Prism Tyres?

Cheers.