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What is the gear ratio on the 6 gear tranny?
Posted: Sat Feb 16, 2008 8:25 pm
by 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
Re: What is the gear ratio on the 6 gear tranny?
Posted: Sat Feb 16, 2008 8:45 pm
by 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?
Re: What is the gear ratio on the 6 gear tranny?
Posted: Sat Feb 16, 2008 8:58 pm
by tbfoto
aconsola wrote: 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
Re: What is the gear ratio on the 6 gear tranny?
Posted: Sat Feb 16, 2008 10:07 pm
by 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.
Re: What is the gear ratio on the 6 gear tranny?
Posted: Sun Feb 17, 2008 11:17 am
by 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.