by PhreakdOut » Sun Oct 02, 2005 7:11 am
Typically, exhaust does not get louder unless:
1) There is a major hole, leak or crack somewhere. You should be able to find it by looking for carbon leakage. (Traces of carbon build up around a joint.)
2) Catalytic converter substrate has broken up and blown out the exhaust. If your exhaust is pretty straight through (in other words: the exhaust flow does not reverse direction inside the muffler) then the chunks of substrate would just blow out the tailpipe. Tap on the converter (carefully) to see if you get a hollow sound or a solid thud. If hollow, disconnect the outlet end and shine a flashlight inside to see if the substrate is there. Contrary to belief, the substrate naturally reduces exhaust noise when it goes through the honeycomb.
3) Internal failure in the muffler. Odds are that Apexi does not use conventional muffler tuning. (Such as expansion chambers or hemholtz tuners.) They are most likely a single perforated tube from inlet to outlet with a glass fiber injected inside to fill the body of the muffler. Sometimes, if the muffler manufacturer goes cheap, they will not wrap the perf tube with stainless wool or they will use larger holes to reduce tooling costs instead of many small holes. (Diameter of 3mm or less) The issue is that glass wool (even in continous strand) will chaff against the perforations and break the fibers. Broken fibers will blow out the holes and reduce effectiveness of a muffler. (In one case, I've see a four foot strand trailing out the tailpipe of a car going down the interstate. )
Again, tap on the muffler to see if it sounds hollow. If properly filled to a density of 120 Kg/m3 to 200 Kg/m3, it should not have a ringing sound.
When this occurs, the only fix is replacement. Check with Apexi to see what the warranty period covers if you suspect it has lost its packing.
PM me if you still have any issues and I'd be glad to help.
Last edited by
PhreakdOut on Sun Oct 02, 2005 8:08 pm, edited 1 time in total.
-- The Phreak
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