What is the gear ratio on the 6 gear tranny?

[tbfoto]

Just rebuilt my 6 gear tranny. I have a 54 tooth spur gear (64 pitch I think it is). What size pinion should I use for a stock motor? Also does anyone know what that Tranny gear ratio is?

tbfoto

[aconsola]

The 54T spur is most likely a 32pitch.
I was just wondering what the gearbox ratio is myself and was going to look it up.
To add to you question, How would a modern stock motor vs a vintage stocker change the starting point for gearing?

[tbfoto]

How would a modern stock motor vs a vintage stocker change the starting point for gearing?

Do you think it would change at all? I realize that modern day motors may be better made but I'm not so sure their output would be much better. Some of those older motors were pretty good!

tbfoto

[scr8p]

i was told many years ago that it's 1.83. but, i've also seen it labeled a 1.85, and even 1.87. so, take your pick.

[JK Racing]

I have always used 1.85 when figuring gear ratios out.

Your gearing is going to depend on the track your racing at, or if bashing, how much speed/runtime/heat your want or are getting.

54 @ 32 pitch = 81 @ 48 pitch (most all modern offroad cars are 48 pitch)

For stock racing (in my modern car), I run 78/20 * 2.6 = 10.14, for larger tracks, and down to an 18 on smaller tracks ( 11.27 final )

Even running a 10T pinion, with 54 spur, your looking at 9.99 (54/10*1.85).

To figure final ratio out...

Spur/Pinion*Tranny ratio = final drive.

Dont forget to take into account rear tire size, smaller tires can take a lower final drive number.

Hope that helps some.