I need to replace the Comet Torque Converter on one of my Karts. It currenlty has a 7" driven pulley, but for what I need I am only able to get a 6" driven pulley. Below is the info as to how much it affects the gear ratios. I just don't know how much it will change the kart's performance, I think it is possible to figure out with some math, but I am lost at this point. The kart is a Yerf with the Tecumseh 6.5 hp engine. It is all stock (tires, sprockets, and such). Anybody done this before or know what I should expect??? I am guessing that the smaller driven pulley will give a little more lower end power, but will loose a little off the top speed. Just don't know if that is right or how drastic going from a high speed ratio of 1.12 to .90 will be??? Also curious how much of a difference there is in going from 3.13 low speed ratio to a 2.68, which leads me to beleive it would be torquier at low speed, perhaps at take-off to mid speed?? Any advice or info is appreciated.


30 Series Reduction Ratios
6" Driven Verses the 7" Driven:

6" Driven / 7" Driven
High Speed .90 / High Speed 1.12
Low Speed 2.68 / Low Speed 3.13
Overall Speed Ratio 2.98 / Overall Speed Ratio 2.79

I posted this before, but it looks like I put it in the wrong place, so here it is in hopefully the right place.

I believe the bigger driven the more torque less speed.

Check this site out. You may be able to get your 7" driven here

Mark

http://www.hoffcocomet.com/comet/afterm ... erters.asp

The bigger the driven pulley, the wider the range you will also have. A 7" will give you more torque than a 6".