Do RC Boost Bottles Work?

If you look back in the history of nitro RC vehicles, you will find a lot of innovative ideas that were once in high demand. However, with the changing technology, some of those things have fallen to the side and people have moved on. 

One of those innovative things from years gone by was the boost bottle. If you have seen an 80’s bike or have to ride it yourself, then you probably already know what a boost bottle is but will a boost bottle work on an RC car like it does on other fuel powered motors like ATVs and motorcycles?

In simple words, a boost bottle is nothing but an empty bottle that is fitted between the reed block and carburetor.  It is normally made of molded plastic or aluminum. 

So now that we know a little bit about boost bottles the question still remains of whether they will work with an RC vehicle. 

Unfortunately boost bottles really do not work with a nitro RC car simply because they are either designed wrong, or because they are installed wrong. Even if you are able to find a boost bottle with a good design and installed properly on your RC car it would have to be tuned perfectly to see any real gains from the boost bottle. 

In the rest of this article we will go a little bit more in depth about what exactly boost bottles are and how they work on some 2 stroke engines but don’t work well on RC cars. 

If you want to see what a boost bottle can do to your RC car (it’s not good) check out the video below. WARNING: there is some language in this video that might not be safe for work or with younger children around. 

What is a boost bottle?

To define it in simple terms, a boost bottle is just a tuning tool. They act as a resonator that needs to be tuned just like you tune an exhaust pipe.

To get the right resonance effect, you need to tune the length, hose diameter, and bottle volume. It is better to get it right at the start, instead of messing it up.

Boost Bottle: How does it work?

The main function of a boost bottle is to release and absorb pressure pulses. It helps the engine breathe. To understand the function of a boost bottle, you need to have good knowledge of fluid dynamics and physics.

The fuel is sucked into the engine, while it’s on. This is aided by the suction created by the moving crank. With every rotation, fuel is absorbed into the intake tract. It is then sucked into the lower end of the engine as reed valves open.

With the rising RPM, the flapping and sucking increase too. The hose of the boost bottle is fitted just in the right location which helps siphon the liquid or fuel that is not sucked in by the reeds.

A proper boost bottle can be described as a mini supercharger. It not only gives you extra storage for fuel but also gives you an extra supply of fuel when the engine vacuum is in the right direction.

Boost bottles were once considered to be very effective. Despite that, they couldn’t make it until the present time as they are no longer used in many instances. They existed for a long time but suddenly disappeared from the market and they never worked well at all on RC cars. 

Benefits of An RC Boost Bottle

The main function of a boost bottle is to absorb and release pressure pulses within the intake. It helps in engine breathing and hypothetically should allow your RC vehicle to have some extra power. 

Air is absorbed through the intake manifold at a great velocity at the time of intake stroke. It is because of this velocity that the air has inertia. The moment the intake valve is closed, the kinetically charged air creates a high-pressure area because it has nowhere to go. As a result, the air travels back the way it came and this leads to the formation of a pressure wave in the opposite direction. 

This affects the low RPM and also wastes a lot of energy. But if you use the same engine with a boost bottle, the air will travel down the intake manifold until the valve shuts off. As the air tries to escape back it is met with a residual vacuum. The vacuum helps absorb most of the pulse inside the boost bottle. This helps in storing energy. After that, the intake valve opens and results in a low-pressure area inside the boost bottle. This pushes the gases out of the boost bottle into the intake manifold. This causes more air to be sucked into the manifold and this gives you the extra power that you want. 

The main issue with using a boost bottle with a nitro RC car is that the RC car is rarely ever tuned perfectly which in turn means that the boost bottle will actually cause issues (as seen in the video above). 

Boost Bottle: Things You Need To Know

Here are some important things you should take note of before using a boosting bottle. Here you go with the details:

1. The main function of a boost bottle is to remove the flat spots in closed and fast open throttle acceleration and deceleration.
   
2. Not all vehicles have the same carbs or intake problems. This is why boost bottles are used only in certain types of 2 stroke motors such as bikes, snowmobiles, and ATVs.
   
3. You cannot just install a boost bottle on any RC vehicle that you want.
   
4. When it comes to installing a boost bottle, you should know that the size of the hose, displacement, placement, and routing makes a very big difference.
   
5. The only time a boost bottle will prove to be beneficial for you is when you are running flat slide 34 mm carbon a ported blaster while racing.
   

A fine example of using the boost bottle is YZ490. The bike would run completely fine until you ride it in the tight tech trails. This is when the problem arises. This can be taken care of using a boost bottle but again, this is on a bike and not with an RC car. 

If you want to see how a boost bottle should work on a bike then check out the video below. 

Conclusion

You should not mistake boost bottle kits to be Nitrous Oxide. Boost Bottles can work without any maintenance or fuel additives and they can last as long as the engine. Also, they are not at all dangerous to your engine in any way if installed correctly and on the type of vehicle that they work best for. 

Unfortunately boost bottles for RC cars simply don’t work and if you try it you could certainly end up destroying your RC car if the boost bottle is the wrong size or if it is installed improperly. Save the boost bottle for your ATV and don’t use it on your RC car!