Phase 9 Silencer Exhaust System

Why the Phase 9 Silencer Exhaust System?

A race prepared Porsche 911 engine with straight pipes produces about 115 decibels of terrific noise at full song. Unfortunately, some folks (especially those living near race tracks) aren't as excited about this music as the racers are. A pair of Phase 9 Silencers alone reduces this noise to approximately 105db with no significant power loss. By adding the Phase 9 Cross Chamber, the db level is further reduced to 87-95db at 50' with negligible power loss.

Until now, a stock muffler was the only practical method of reducing a 911 race car's db level enough to legally race at tracks such as Laguna Seca and Sears Point. The Phase 9 Exhaust System is the product of hours of engineering by automotive designer and engineer William Beekhius; hours of dynamometer testing by Porsche engine specialist Jerry Woods, and final design, fabrication, and packaging by Pete Weber. This system comes complete with all the necessary mounting hardware to allow 914-6 and 911's race within sound levels permitted by the SCCA. And let's face it, there is nothing more disappointing on race day than getting a mechanical black flag for noise!

Quiet Horsepower for your Porsche 914-6 and 911 system includes:

  • Equal length headers
  • High gas flow collectors
  • Heavy gauge (.065) mandrel-bent tubing 304 stainless or mild steel
  • High efficiency Phase 9 Silencer mufflers that are packed with stainless steel to resist corrosion and deterioration
  • Phase 9 Cross Chamber System with the optimum volume for maximum performance.

The Mufflers are sized/designed for a specific HP requirement.


    These mufflers shown above are ceramic coated. This coating is not on the standard mufflers, which come with SST in and out tubes. Housing is mild steel.

  • 2 1/8" Phase 9 for the Porsche 911 ($305.00 each)
  • 2 ¼" Phase 9 for Sports 2000 and engines around 200 HP ($315.00 each)
  • 2 ½" Phase 9 is popular for Formula Atlantic Series, and engines approaching 225HP-250HP ($315.00 each)
  • 3" Phase 9 is for engines using a 3" diameter secondary pipe ($500.00 each, made only in Stainless).
  • 2 1/8" and 2 1/4" Phase 10 ($295.00).
  • 2 1/2" Phase 10 ($315.00).
  • Historic Porsche Container ($275.00).

You can see some Mounting Tips within our Pictures Page!

Quiet HORSEPOWER © 2007 All Rights Reserved