Has anyone done Nyroc's Muffler mod to their P700? I want to do it to mine, but the pipe looks alot different. I'm not sure exactly how to do it. I have the tools and the welder, just waiting for some feedback.
Thanks

 

The muffler is different. I couldn't see inside completely to tell you what to do.

The exhaust has to go radially through little holes in pipes in the inlet and outlet. I think there is a series of baffles in the middle. For this reason, you can't really mod it like the 650 muffler. I think it will be a toughy.

I would consider cutting the muffler in half, right in the middle, and make many small holes in the baffles. However, the inlet and outlet pipes will restrict you with their small holes. You could try to drill holes down the center of these to get more flow into the baffle area. Cutting the muffler in thirds might work better to help you drill holes in the end of the perforated tubes. I don't recommend cutting the rear cylinder pipe off the muffler. Rewelding the muffler together after it has been cut in half would be VERY easy, in my oppinion.

I could be wrong. I am guessing on the construction of the muffler from what I saw of BigOnes muffler and the welds I saw on the side of the muffler.

Come to think of it I would never go to this much trouble. I would make my own collector and put an FMF custom fit Q series on it, sized for a 650 motorcycle. That way if would be lighter and forest approved.

On the other hand, if you are successful you will enjoy the prestige of having a muffler mod named after you.

 

Does the holes in the exhaust hurt the back pressure when coming down a steep?

 

No, the engine braking is created by the helix slots in the driven pulley. I holds the engine RPM up and uses engine compression and friction to slow the ATV. It has almost nothing to do with exhaust back pressure.


Engine braking technically means allowing the engine to slow you down using it's compression and friction alone. A gasoline engine is far superior than a diesel (without added components) at doing this, since the gasoling engine has a throttle and the compression of the engine sucks against the throttle. Gasoline engines can engine brake as well as a diesel engine that has twice the displacement. Diesels do not have an intake butterfly and do not engine brake very effectively at all without some other device.

Some types of diesel engines use a butterfly on the exhaust pipe to enhance compression braking. It closes during braking. This makes a diesel engine have a whole lot more engine braking than a gasoline engine. Jacobs exhaust brake is an example.

The jake brake, created by Jacobs Vehicle Systems, allows the diesel engine to compress the air, then the exhaust valve dumps it at the top of the compression stroke, turning the engine into a big aircompressor. This is the "Loud" exhaust braking that 18wheelers have and there are noise ordinances against. As far as I know this is the most effective engine brake. Jacobs calls it their Jacobs Engine Brake.

Commercial airliner turbofans reverse the flow of the fan airflow with ducting to provide reverse thrust. This is necessary to slow down large aircraft. The brakes on the wheels just help.

Turboprops with variable pitch blades can produce even more reverse thrust.

Some of this info is not relevant to your V700, except in Alltoy's case, he might use all kinds of advanced technology on his ATV.

 

Nyroc,
Technology for breaking, get this. My neighbor uses a paint can filled with cement and piece of rope tied to the can and the back of his old Honda 300. I seen him try to use the can thrown out behind him going down a hill the can ended up beating him down the hill, LMFAO. I wish I had my video camera that day I would have sent it to Worlds Funniest videos LOL.

 

I just finished the muffler mod on my 700. Not sure how everyone else does it, all I did was cut the baffle in the end in to 4 sections with a sawsall then I used the sawsall to cut just inside the weld at the tip, pulled out the packing, used vice grips to break off the 4 sections and finished it by cutting the other end of the baffle loose. When you look in the pipe now there is a hollow chamber at the end. I'm pretty sure the muffler is the same design as the 650, just looks different on the outside. You can look down the middle of the pipe and see the spark arrestor but I left it alone. The sound is awsome and it only took about a half hour to do, now i'm off to see what it did for performance.[img]i/expressions/face-icon-small-smile.gif[/img]

 

I don't know why I said what I did about the P700 muffler. I thought he wrote V700 muffler.

I have never seen a P700 muffler up close. I would assume you could do exactly like I did.