Thisstudyrepresentstheinfluenceonexhaustperformancebyactivemufflervalvespring.Themainexperimentalparameterswereenginespeedsandtorsioncoilspringconstantsintheactivemuffler.Whenthemufflervalvespringhasalowspringconstantofk=0.75,thesoundpressurelevelwaslowattheregionofenginespeed2000to2500r/min,andthevelocityofexhaustgaswashighatspringconstantk=0.75.Whentheenginespeedwasunder1500r/min,themeanconcentrationofCOwashighincasewithoutmufflervalve.Whentheenginespeedintherangeof1600to2600r/minwithspringconstantk=0.75,themeanHCconcentrationshowedthelowestvalue.Withoutmufflervalve,thetemperatureinthemufflerwashigherthanthecasewithmufflervalve.Thisresearchrepresentedthattheperformanceoftheactivemufflervalvespringconstantk=0.75washigherthanthatwithoutmufflervalveandvalvespringconstantk=0.70.Amongthethreecasesofexperimentalcondition,withaspringcon
