What about re-routing the water lines ( just like the RIVA instructions for free flow exhaust) with out the free flow exhaust? Is there enough water to keep exhaust rubber hoses from melting? I thought that may be one could reduce some of the back pressure by reducing water flow. Just port the intake water line directly outside and don't go thru the exhaust. It is my understanding that APBA rules allow changes to water lines. But, no changes to the mufflers themselves.