150cc exhaust silencer
 

i have seen a few professional adds, and also on youtube of people adapting car mufflers to the exhaust outlet on 4wheelers, although from the videos its hard to tell ig it significantly drops th db's down. i really dont like too loud of an exhaust on my buggy, although it sounds "mean", i really preffer "stealthy",lol...i was just curious if anyone has tried this mod on a gy6 platform. i cant find anyone who has. i also cant really see a drawback to power either since a car exhaust usually has an exhaust inlet/oulet of 2". it wouldnt be very hard for me to fab one up, all im lacking is a 90* elbow and a little motivation in the shop. any comments or suggestions?

As much as I like the loud grunt of any dirt bike, atv, or buggy; stealth is always a great thing.

Pros: Riding around the neighborhood at night, close to or on private property:suspect:, or not to disturb nature. Maybe even reduce emissions:confused:

Cons: Large muffler, loss of space ( maybe in cargo area), funny looking, as stated maybe loss of power.

I can't seem to come up with that many cons.
I say get some motivation and make this thing happen. Just to see what happens. Maybe use a smaller muffler from say a GEO tracker or metro ( I think those are 3 cylinders).

exhaust mods can be tricky. You've got to remember that to get the best performance from an engine, both the intake and exhaust have to be considered and the intake-to-exhaust flow ratio affects performance and should be in a mathematical ratio designed to put the performance/power where you want it. Putting on too large of an exhaust can impact performance, as can one that's too small. Tubing length, diameter, bend restrictions, muffler volume, size and shape all play into it. Toughest part of it is that there's no easy way to tell what kind of change you've made unless it's so drastic that the seat-of-the-pants lets you know for sure. Rare occurrence! Just like modifying the intake with a Uni etc., changing the exhaust will likely require going back into the cab to re-jet.

The way I see it, with a small displacement 4 cycle engine, you need to very careful about adding a large muffler to it. Most automotive type mufflers have a series of baffles and matting inside to diffuse sound waves. These baffles can make or break an engine.

Typically you want a 4 cycle engine to breathe freely to produce max power, adding some bends and baffles can produce better torque, but the top end suffers if you go too far. I would look into stock mufflers for the smaller quads and trikes, they are mega huge compared to the stock or performance ones for the GY6.

My parents acquired an older B&S 8hp generator years ago, and it had a parts store 'turbo' muffler grafted to a pipe for the exhaust, and while it was quieter than normal, it was a pain to jet properly and it guzzled fuel. Just food for thought.

I really like the Yamaha TTR 125 muffler that I put on my HH. For my engine modifications, it has worked out really good. In stock form it is really quite, but if you need to open it up a little, the prices is just the cost of a couple of washers. It does get a little louder when you do the washer mod, but it is still quieter them most AM mufflers, plus it has a spark arrestor.