A go kart torque converter is what differentiates an automatic transmission from a manual transmission. The torque converter allows the engine to do its own thing even while the go kart is at a standstill.
Manual transmissions use a clutch for this purpose, automatic transmissions use a torque converter because they have nothing that disconnects the main engine from the transmission. This is how it works in your everyday car, and it won't be much different in your go kart engine. Having to worry about shifting gears in a manual transmission on a go kart can be a hassle and tricky, thus a torque converter is the preferable way to go.
Building Your Own
Building a go kart torque converter can be a lengthy and complicated process, though it is quite doable with the proper equipment and know-how. An important question to consider before you do this is how much does it cost in comparison to going out and buying one that is already made?
To begin with, you are going to need tools to put the torque converter together. These tools will include items such as wrenches, pliers, sockets, screwdrivers, allen wrenches, safety glasses and work gloves. If you do not already have these tools at home, some of them can be a little costly.
A go-kart torque converter uses a centrifugal clutch. The faster the engine goes, the more a clutch will grip and this delivers more torque to the driven gear. As this is not something that is easily built, it is best if this is bought already assembled. The average cost for a centrifugal clutch runs between $40 to $200 depending on quality and brand.
You will also need strong plates for mounting it all together. A strong plate will cost individually around $10.
Finally, you will need either a belt or a chain. The chain runs from $12 to $20 whilst the belt runs from $20 to $30. Belts have the potential to run longer and better than chains as they're lighter in weight and aren't thrown off as much by centrifugal force, however belts can and do stretch or tear with time and need to be replaced.
To assemble your own go kart torque converter, not including any tools you may have to buy, you are looking at upward to $200 depending on the quality of the clutch you buy, and whether you decide to go the chain or belt route.
Consider the length of time spent and any complications you may encounter when putting it together, it is common for people who are building their own go karts to opt to simply buy a torque converter that is already assembled.
This could actually cost around the same price that you would spend on buying the materials to build your own, though it could also run up to $400 depending on the brand and where you buy it. It all depends on which option you feel is best for you.