Snowmobile Performance Upgrades


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Performance Snowmobile Exhausts and More

Helping an to engine breathe easier can help free up additional horsepower.  This is one of the fundamental principles in increasing the performance of any engine - be it in a snowmobile or otherwise.  An internal combustion engine is like an air pump in many ways.  Essentially, an engine is pumping air along with a fuel and this air/fuel mixture burns to create power. Once this combustion takes place, the exhaust gases need to have a place to go.  A less restrictive exhaust system for a performance snowmobile will allow the engine to more efficiently expel the exhaust gases.  This in turn helps the engine to draw in more fresh air/fuel mixture.  The result can be an increase in horsepower, torque, and overall snowmobile performance.

Snowmobile Peformance Exhaust - 2 STROKE

Example of a 2 Stroke Snowmobile Performance Exhaust

A 2 cycle snowmobile engine usually responds more dramatically to a good performance exhaust system.  Since most high performance 2 stroke engines use an exhaust with a tuned pipe and an expansion chamber, it is possible to modify the shape and length of the expansion chamber to help tune the engine for different RPM ranges.  Tuned pipes provide a scavenging effect that help to suck out burned exhaust gases from the cylinder, which in turn can result in more of the fresh air/fuel mixture being drawn into the engine.  Reflected shock waves in the expansion chamber return back through the tuned pipe and to the exhaust port, and there they help to stuff the fresh air/fuel mixture back into the cylinder so that it doesn't escape out the exhaust pipe.  In effect, a 2 stroke snowmobile tuned pipe works to suck out exhaust gases while at the same time pushing back fresh air/fuel mixture into the cylinder.  It is a balancing act.  The shape of the expansion chamber and length of the exhaust pipes will affect (tune) the place where the maximum power is achieved by the engine.  Performance exhausts for 2 cycle snowmobile engines will often raise the powerband higher up in the RPM range where the engine can produce more power.  As a result, a dramatic increase in power is often possible on 2 stroke snowmobiles with an upgraded exhaust.  As an example, increases from 15-30 HP (and much more) are possible for big bore 2 stroke snowmobile engines.    

Snowmobile Performance Exhaust - 4 STROKE

Example of a 4 Stroke Snowmobile Performance Exhaust

Snowmobiles with 4 cycle engines respond differently to exhaust changes.  Don't expect to gain as much power on a 4 stroke when adding a performance exhaust system as compared to a 2 cycle engine.  By the nature of the way a 4 cycle engine operates, a 4 stroke snowmobile will not respond as dramatically to a performance exhaust system.  That doesn't mean that you can't gain some performance from an aftermarket 4 stroke snowmobile exhaust, but it will usually be a modest  increase in power along with a reduction in weight.  This combination can help boost overall performance of your sled.  In addition, an aftermarket exhaust is likely to have a more aggressive, louder sound which may be more pleasing to the ear (or more annoying - depending on your perspective).  Whether you have a 2 or 4 stroke snowmobile, upgrading the exhaust can help increase the performance of your snowmobile.  If you have a 2 cycle snowmobile, then expect a more dramatic change in the powerband.  A high flow exhaust for a performance snowmobile can give your sled a more aggressive sound, free up additional horsepower & torque, reduce weight, and increase the overall fun factor of your sled!   

An exhaust upgrade is not the only way to increase the power output and performance of a snowmobile.  There are some other ways to extract more power from many snowmobiles.  The number of aftermarket parts available will probably depend on the popularity of your particular sled.  In other words, if you own a newer sled that is currently very popular, then you are more likely to find parts and accessories to upgrade your snowmobile.  If you happen to own a really old sled or one that was not popular, then it might be harder to find performance parts for your machine.  Below are a few different ways to boost performance of a snowmobile.


Snowmobile Nitrous Kit

A nitrous oxide kit is an easy way to add big power to your sled.  Nitrous oxide is a gas which is made up of nitrogen and oxygen.  When nitrous oxide is injected with additional fuel, the result can be a BIG power increase!  The power level can be adjusted by changing the jets for the nitrous and fuel to adjust your power level.  Nitrous oxide might not be the most practical way to boost performance of a snowmobile, because of the need to constantly refill the bottle.  It is also possible to add too much nitrous and ruin your engine.  Look for a kit specifically made for your sled and start off with a small power increase and work your way up. 



Performance ReedsAnother way to increase the performance of a snowmobile with a 2 stroke engine is to install a high performance reed block.  A reed block essentially acts a one way valve.  The reeds help control the flow of the fresh air/fuel mixture going into the engine.  Specially designed reeds can reduce the resistance of the incoming air, and increase the air flow for additional power, torque, and improved throttle response.  The flexibility and characteristics of the reed material can be used to tune a sled engine.  To install them, you need to remove your carburetors and intake so that you can access the reed block.  If a set of performance reeds is available for your machine, then it might be worth a try.




Performance Clutch

Finally, the clutches in the CVT transmission of snowmobiles can be fine tuned by using different springs, weights, and profiles.  In this way, snowmobile clutching can be tuned to better match peak performance RPM of the engine with the CVT transmission shift pattern.  Technically, modifying the CVT may not increase power, but it can drastically increase how the power is put to use.  A clutch kit is an important upgrade to consider when modifying any snowmobile engine. 


As you can see, in addition to a performance exhaust, the snowmobile owner has quite a few other ways to increase the performance of their sled.  This is just a small sample of the different parts available to upgrade a snowmobile.  Aftermarket companies manufacture a wide variety of products to help boost the performance and enjoyment of your snowmobile.   If you can not find off the shelf performance products for your particular sled, then it's still possible to make custom upgrades if you are experienced with working on engines.  The principles of increasing the performance of an engine are applicable regardless of whether the engine is found in a snowmobile or some other type of vehicle.