Do You Use Resonators in Your Exhaust Lines?
 

Last weekend I blew a hole in 1 exhaust hose in each of the two engines. These are 496 Horizon engines that have one 3 foot exhast hose from each elbow going down to the muffler (2 - 3' hoses per engine).

The hoses are several years old and both blew holes in the top of the hoses about 6" behind the elbows at about 3200 RPM. All of the exhast hoses have what Mercruiser refers to as resonators about 18" from the elbows, or midway between the elbow and the muffler. I am assuming their purpose is to help block any sea water from coming up into the back end of the exhast manifold, but I'm also wondering if they don't cause additional back pressure and heat

Prior to this, I had a combination riser/elbow setup with some cheesy studs going from aluminum manifolds through the risers and bolted to the top of the elbows. I stripped the studs out of the manifolds three times and finally went to cast iron manifolds the extended elbows. This got me out of using the risers and studs and now the elbows are bolted directly into the manifolds. No problem with stripped studs but it makes me wonder if the studs were stripping because of pressure buildup in the exhaust hoses, and the possibilty of the resonators contributing to this.

Sorry for such a long explanation, but I'd really like to hear your opinion on the use of resonators.