Why are the OEM pipes so heavy ? If the aftermarket pipes are so much lighter and provide more horsepower, why can’t the sled manufacturers make their pipes that good right off the bat ? Are there some type of restrictions that limit their ability ?
The manufacturing techniques are different from OEM to aftermarket. The OEM pipes are made of relatively thick metal and mass produced with electric welding. This technique doesn’t work on the thinner (lighter) sheet metals that the aftermarket shops gas weld.
The OEM pipes are “over-engineered” somewhat for strength and long-term durability. Thinner metals are more apt to crack with the cold snow spray coming in and hitting the hot pipes. Since their sleds are used by a wider range of buyers, the OEM pipe is usually tuned for a broader powerband (so it is easier to clutch) at a lower operating RPM (for durability).
Contrary to popular belief, the manufacturers do not have a ton of people that can spend countless hours developing the “ultimate” pipe. They are faced with production deadlines, and need to have their dimensions figured out well in advance so that the (expensive) tooling and stampings can be made in time for sled production. Once they come up with their pipe specs (and spend over a hundred thousand dollars for the tooling to stamp the pipes) they’re less likely to make any changes (expensive) until the die wears out.
The aftermarket shops (since they are smaller) can make changes quicker, and actually get to spend far more time “field” testing their pipes. Instead of being stuck with the same pipe for years, they can continuously make it better – based on field testing and feedback. And, their pipes can be made to perform better in a specific application. For example, you can get better cylinder filling at a higher RPM for more horsepower, but the power will be concentrated in a narrower range (harder to clutch). Excellent for lake racing, but terrible coming out of corners on the trail. Or, they can make a “nasty” trail pipe with less hp at the top. It’s a give and take – they can even make them with a similar power curve to the OEM, but quite a bit lighter. It’s your choice.