He could not find the Exhaust Pipe he needed for his race bike. What ever floats your boat.In 1972 David Rash had a problem. OEM exhaust systems usually use a double wall system which makes them quiet at the expense of weight-FMF and others claim to shave weight and add performance maybe at the expense of 'silence'.
#Remove packing pro pipes to be louder how to#
FMF probably knows as much as anyone about how to get the best of both. Usually 'quiet' and 'performance' are at odds with each other. The selection of packing material is therefore germane to that issue. The trick is to 'silence' the exhaust without interfering with the unrestricted flow of gases out the exhaust.
#Remove packing pro pipes to be louder free#
I think you want a free flow of gas throughout the exhaust system so that the expansion chamber works as designed.
In my view anything that interferes with those 'pulses' -such as an additional back pressure caused by an oil soaked packing only degrades the engine performance. When we talk about 'back pressure' I think we are talking about that 'timing pulse'. The 'timing pulse' that bounces the raw fuel back into the chamber just before the piston closes off the port -and the 'reverse pulse' which occurred earlier in the stroke (which pulled a charge into the chamber in the first place) is resultant from the shaping and location of the cones in the expansion chamber. Sound issue aside-(I understand your reasoning)-I prioritize 'performance' and like the way the Scotch Brights lower and widen the powerband on my bikes-But I'm not sure that this is universal for all bikes-probably the make and models of the pipe, muffler and stinger size all play into that formula Of, simply replace them -which is what I do because the cost of the pads isn't hardly worth the effort to wash the old ones out. When this occurs one can take the muffler down and simply wash the pads out with a soap solution -the pads to not disintegrate as do fiberglass or ordinary steel wool. The Scotch bright pads are much courser and tend not to clog with oil-eventually the raw oil collecting in the muffler sill start to blow out the back. They come packaged about 4 to a package and it takes two packages to do a muffler-total cost maybe about 6 bucks? I've also used fine and extra fine steel wool pads in the past but these are not 'stainless and both the fine and extra fine wool pads tend to become oil soaked and in that condition probably do not allow gases to pass through as they did when new and clean. Just to be clear-I used the small "Scotch Bright" scouring pads-you can get them at a grocery store in Stainless steel or in Copper. now I just use FMF packing because I can get it for cheaper and I like the sound +1, ive used steel wool with good results as well back then. On my 220 KDX this method of re-packing the FMF turbine core has resulted in the bike pulling lower and into the powerband at a lower rpm and keeping the bike pulling hard farther up into the band-but I can't say one way or the other what effect it has way up on top of the RPM range because I just don't ride it up there-don't have to. The bikes, packed in this way do not run quieter-nor do they run louder-in my experience. In fact, I have a WR 250 (two stroke) that runs much stronger with a wider powerband than it had before. These allow gas flow through without getting clogged up with oil like the stock fiberglass blanket material-and at the same time they must provide sufficient back pressure to keep the bike running strong. Deseret Rider wrote:I've used stainless steel scouring pads-donut shaped-slid over the perforated tube-about 8 or nine of them-with great success in repacking mufflers.