When you are an RC car enthusiast, you eventually get caught up in the fun of it, especially when you discover racing or drifting. These activities require special upgraded RC cars, or specifically designed racing RC cars.
Upgrades are mods are a usual thing in the world of racing RC cars. Basically, any component of your RC car can be tuned or upgraded to suit your specific needs on the track.
Some upgrades and tweaks can be done by you, by using simple tools and following some instructions. Exhaust pipes are used for one thing, namely for keeping the noise of the engine down. But there is a clear relationship between the amount of noise and the amount of power that a nitro engine produces.
Moreover, your car’s exhaust pipe plays an important role in engine performance. There are a couple of changes you can make to your RC exhaust pipe. Before doing any upgrades or modifications, you should know how an exhaust pipe actually works. It is designed in such a way that is uses bounced pressure waves, so if you change the length of the header pipe you can control how these waves affect the engine. The length of the header dictates where the power is. You can use a shorter pipe if you want more low-end power and a longer one if you want more top-end power.
The divergent cone of the exhaust pipe can also be altered in length and improves torque. The process goes like this: exhaust gases go through the header and into the cone. As the pipe widens, gases slow down and create a low-pressure void, which sucks any remaining fuel vapor away from the exhaust port. So, a short divergent cone is good for improving torque, while a long one is especially useful for high-RPM applications.
There are other components of the exhaust pipe which influence performance. The size and shape of the belly of the pipe affect engine performance. While a short belly is great for high-RPM, a long one will do some good for torque. The component which regulates the amount of air exiting the pipe is also extremely important. A small one will cause the engine to stifle itself, but a large one will allow too much exhaust to escape during the first cycle. The pressure fitting of the exhaust pipe should be placed at the fattest section of the pipe belly.
However, why tune an exhaust pipe? The need for a tuned pipe arises from some tiny flaw of the two-stroke engine. While it does wonders with handling power, it is not really fuel-efficient, because on these engines, the intake port, and the exhaust port are opened simultaneously. As fuel enters the intake port, a large amount of it travels through the combustion chamber and into the exhaust port without actually burning. This is where a tuned exhaust pipe comes in because it will do a great deal for enhancing performance and fuel efficiency. It uses a series of expanding and narrowing cones to take advantage of exhaust gases on their way out and forces raw fuel back into the combustion chamber. This operation is called scavenging. What’s better is that when you upgrade to a tuned pipe, you are not forced to make any trade-off whatsoever.
Besides enhancing fuel efficiency, the tuned pipe plays an important role in delivering fuel. As your car increases its speed, the need for fuel also increases. A properly tuned exhaust pipe will deliver more power, better fuel economy, and longer engine life because exhaust pressures build with RPM and accelerate fuel delivery to the carburetor.