Humans are obsessed with going fast. It makes us feel alive! And it is no different when it comes to Go-Karts. You can find People making Go-karts go at ridiculous speeds.
so, What exactly determines the top speed of a Go-Kart? In theory, there are only 3 things that determine the speed of your Go-Kart, they are, Engine’s RPM, Tire Size, and Gearing.
Let’s have a look at how to make some simple and cheap modifications to make your go-kart faster.
- Increase Engine’s Power
- Remove Governor
- Change Carburetor
- Engine Modification
- Upgrading Engine
- Using a different Fuel
- Higher Gearing
- Bigger Tires
- Using Lightweight Go-Karts
- Transmission system: Clutch vs Torque Converter
1. Increase Engine’s Power (Engine Mods)
The first factor in determining the speed of your Go-Kart is Engine’s RPM.
What is Engine RPM? It is defined as the number of rotations that your engine’s crankshaft makes in a minute.
What is the crankshaft? It is a shaft in the engine to which your clutch/torque converter is attached.
How does it all relate to speed? The higher the RPM, the faster your Go-Kart will be.
How to increase the RPM? By increasing the power that your engine produces. Power is directly related to rpm.
Horsepower = Torque x RPM / 5,252
As you can see, the more power your engine produces, the higher the RPM can be.
Important to note, it CAN be faster that is not to say that if you increase the power it will only increase rpm, Torque is also a factor.
If you want to go fast, you need an engine that produces a lot of power.
Here are a few things you can do to increase the power that your engine produces.
Almost every Go-Kart Engine comes with a governor that limits the RPM to 3600 rpm.
This is done because most of the applications involving small engines benefit from the rpm set to 3600.
If you want to go faster, your first step is to remove the governor. This will instantly increase your speed by a few mph.
Please note, some engines do not have a good enough interior to work without a governor and can fail at higher rpm.
We suggest you do your own research about your particular engine to know whether or not it is safe to remove the governor.
A carburetor is a device that takes in fuel from the fuel tank and air from the outside to mix them in proper proportion to then provide it to the engine for combustion to take place.
Generally, Go-Karts come with small carburetors which are perfect for Lawnmowers and normal Go-Karts but don’t supply the engine with enough fuel to be useful for faster Go-Karts.
Upgrading Engine Parts
If you’re an Engine Geek, making a go-kart faster will be one of your favorite projects!
There are so many performance parts available in the market and so much that can be done.
You can upgrade the air filter, exhaust, camshaft, connecting rod, and almost every other part of the engine to make it go faster.
It is impossible to cover every upgrade in this article, we have a different guide for mods on Predator 212 Engine that you can check out for more details.
Please note, modifications can get really expensive, and changing any internal parts of the engine will end the warranty provided by the manufacturers.
Get a New Engine
Doing upgrades on an existing engine isn’t something that everyone will enjoy. It can be a long process and it can cost a lot to buy performance parts.
Sometimes it economically makes sense to buy a brand new engine instead of upgrading your already existing engines.
You can even buy a modified version of an engine on websites such as GoPowerSports etc.
Buying a bigger engine such as GX390 will increase the power by a lot in comparison to small blocks.
Engines such as Tillotson 212 can be an amazing upgrade to your Honda Clone engine, check our list for Best Go-Kart Engines.
You can use some methanol alongside gas and re-jet the carburetor to run the go-kart smoothly.
It won’t make much difference to speed on a “stock” engine, i.e engine as you get it out of the factory.
But if you increase compression and advance timing on the engine, you can increase the power, and this is where methanol can be useful.
Methanol has a great cooling effect which will help the engine survive long when it has high compression and advanced timing.
Gearing is another factor that determines the top speed of your go-kart.
It is the ratio of rpm of the engine crank and rpm of the axle.
Your engine could be producing a lot of power and rpm but if your gearing is low then you won’t go very fast.
How to Calculate Gearing of your Go-Kart?
Go-Karts with Clutch:
Gear Ratio = Teeth on Axle Sprocket / Teeth on Clutch sprocket
Go-Karts with Torque Converter:
Gear Ratio = (Teeth on Axle Sprocket / Teeth on Jackshaft sprocket) x (Belt diameter in Driven pulley/ Belt diameter in Driver Pulley)
Go-Karts with Jackshafts:
If your Go-Kart has jackshafts, you need to multiply the factor of (teeth in the driven sprocket of the jackshaft/ teeth in the driver sprocket of the jackshaft).
How to choose Gearing to make your Go-Kart Faster
By definition of gearing, it’s a ratio of the speed of the engine to the speed of the axle.
For example, if your gear ratio is 6:1 and your engine’s top speed is 3600 rpm, then your axle can go at a speed of 600 rpm.
If you increase gearing and make it 5:1, now your axle’s top speed is 720 rpm.
To gain higher speed you should use higher gearing. But that comes at the cost of Torque, it’s important to find the right balance, check our chart for gear ratios.
3. Tire Size
The third factor affecting the speed of your go-kart is your tire size.
Let’s say your Axle is spinning at 600 rpm and your tire is 12″ in diameter. Your Go-Kart will be able to cover 21 miles in an hour.
If you increase your tire size to 15″ and maintain the same 600 rpm spin of the axle, then your Go-kart will be able to cover 27 miles in an hour.
The bigger your Tire is, the faster you can go.
But you cannot just simply swap to a bigger tire and be done with it.
Bigger tires require more torque from the engine, i.e, more powerful engines or lower gearing.
That means, just like gearing, finding the right balance is important, the tires can’t be too big or your engine, clutch, etc will fail.
4. Weight of Go-Kart
This one is common knowledge, light go-karts will go faster, reduce as much weight as you can.
Most racing Go-Karts are light and use engines that produce a lot of power but not too much torque, therefore producing high rpm.
5. Transmission System
And finally, let’s talk about the transmission system. You have 2 options with go-Karts, which are, clutch and Torque converter.
Torque converters are preferred with off-road go-karts and clutches are preferred for racing go-karts.
Let me explain why this is the case, Torque converters are belt drive systems. A lot of power is lost during power transfer from the engine to the axle.
The clutch on the other hand is a chain drive system and only loses a very small amount of power in comparison to the Torque converter.
If you want more speed, you should go with a clutch but torque converters have their own benefits. Check our detailed comparison between Clutches and Torque converter.
To make your Go-Kart faster, you need a more powerful engine, higher gearing, and bigger tires.
But there is a need to maintain a proper balance for gearing and tires. If you increase the gearing by too much or use huge tires, your engine and transmission system will fail.
Using Clutches instead of Torque converters as the transmission system will also help increase the speed of the go-kart.