b'Exhaust Sound Control Muffler Tech: When Ron owned nine race teams6 USAC Ford Focus Midgets & 3 NASCAR Modifiedsthe tracks were really clamping down on sound. His NASCAR Modifieds ran 600HP+ small blocks with decibel ratings at 50 of 107db with mufflers. The NASCAR tracks implemented a 89db rule or dont race. 107db to 89db was a long way to go. The competition was to see who could lose the least amount of power & get to 89db.Rons teams were well funded (almost 2m) so they tested a lot. They tested all 3 Modifieds with 9 different muffler & sound reducer combinations. Through exhaustive testing, first on rolling chassis dynometers, then track testing, they found the absolute best combination that lowered the sound by 18db & only lost 15hp! Here is what we learned. First, Dynatechs Vortex Cones hurt power anywhere you place them, EXCEPT in the collector, like shown below. The Vortex Insert Cone, installed near the exit of the header collector outlet, provides a large friction area to reflect and dissipate sound energy, thus reducing the dB level.You dont want a merge collector, as the Vortex Cone acts as a merge collector, initially slowing the exhaust flow & increasing torque, then speeding it up, like a venturi effect. The open area of the cone is actually greater than the area of the collector, thus reducing the back pressure condition after the initial pulse & increasing the rate of exhaust flow. In the collector, the Vortex Cones dropped the sound by 7db & actually INCREASED power! The Vortex Cones flat out work in everything RSRT ran them.We heard every BS muffler claim & theory from every corner of the industry. Flowmasters chambered mufflers dominated the tests. They have a interesting trait. The larger the muffler volume, the lower the sound & the MORE POWER they make. Over the years, Ron tested them all & proved over & over again, that the larger volume Flowmaster chambered mufflers ran, the more power made (lost less) and lower sound.Flowmaster offers many series & size that can be a little confusing. The series number doesnt always convey size. Look at the volume we listed below. Flowmaster offers a few versions inside of each seriesOriginal, Delta Force, Super & special ones like the 44, HD & Big Block. These do matter. We dont use the Original. The Delta Force is RSRTs go-to race muffler in each size series, as they have the best power to sound reduction traits. The Supers make about the same power as the Delta Force, but are louder (higher db). The strategy of running the Vortex Cones in the collector & the largest volume Delta Force mufflers you can fit on the car, creates the most power & least sound. Here are the dimensions of the mufflers we use & sell: Delta 40: 288 volume / 9 long, 8 wide & 4 tall / In & Out 3 Delta 10: 400 volume / 10.25 long, 9.75 wide & 4 tall / In & Out 3 or 3.5 Delta 10: 450 volume / 7.5 long, 12 wide & 5 tall / In & Out 4 Delta 40: 507 volume / 13 long, 9.75 wide & 4 tall / In & Out 3 or 3.5 Delta 40: 650 volume / 13 long, 10 wide & 5 tall / In & Out 4 Delta 50: 663 volume / 17 long, 9.75 wide & 4 tall / In & Out 3Delta 30: 840 volume / 14 long, 12 wide & 5 tall / In & Out 4 HD 50: 900 volume / 18 long, 10 wide & 5 tall / In & Out 3 or 3.5Delta 30: 1020 volume / 17 long, 12 wide & 5 tall / In & Out 3.5 or 4 Delta 60: 1320 volume / 22 long, 12 wide & 5 tall / In & Out 4 If you dont care about sound while building your track car now, we assure you later you will regret it as you rush to figure out how to comply with race tracks implementing strictor sound requirements.691'