Dundon Race Header/Lifetime Loud Muffler on 991.2 GT3, FLAT OUT



Super cool client Frank in his 991.2 GT3 Manual on a deserted air strip!  

Here's more about the Dundon Race Headers from our website:

Constructed from 321SS tuned length stepped headers and flapped side connector, the exhaust combination offers a 25whp increase at 8400rpm and 40lbft at 4300rpm for 991.2 GT3 owners with no ecu flash required.

Please note: Race Headers are for Non US or for racing vehicles. 

By understanding exhaust flow and resonance tuning, Dundon Motorsports developed the combination of 321SS tuned length stepped headers and the flapped side connector. The use of the the OEM center muffler and flaps allow for drone free, quiet cruising and a glorious Porsche roar when on the throttle! This is a bolt on setup and can be selected with or without the exhaust flaps. 

The weight of the system is lighter than stock configuration by far. Stock is 86 lbs, the weight of the Race Headers and stock GT3 muffler flaps is 36lbs This is complete header flanges to the exhaust tips including ALL hardware, clamps, straps etc, a savings of 50lbs!

More on our Lifetime Muffler:

Most of us have experienced the many issues associated with both the stock Steel and Ti rear mufflers on our beloved 991.2 GT3. cracking, holes, not passing sound etc...  We've been reinforcing both the Steel and Ti versions for years after they crack and understand why they fail quite well.  We set out to fix the weakness of the OEM center muffler and include an option for those that want their car to pass the more and more prevalent dB restricted tracks without losing power.  We finalized the design and have tested at numerous tracks both for longevity and for dB reduction.

We're happy to announce our GT3 Lifetime Center Muffler.  It's available in 2 "flavors" Quiet and Loud.  The Quiet is for those customers looking for no drone* while cruising and to quiet the car at full boogie to attenuate some of the dB levels on the track or on the street.  The Loud is the muffler for those looking for no drone* at cruise, but a pronounced bark when getting on it!

We've tested the Quiet on a 991 GT3 with side muffler deletes that was 104dB before the muffler and passing a 90dB day after .  We've tested on a stock 991 GT3 and the car passed where it hadn't previously. And we tested on a 997.2 GT3 that had not passed at Laguna and passed a 90dB day.  We've recorded the Orange GT3 Center Muffler in our own testing at 10-12dB reduction over the OEM GT3 Muffler.  All of the testing was done on cars WITHOUT GPS Exhaust flap closing devices.

  • Lifetime Guaranteed including track use.
  • 321 Stainless Steel coupled with a high strength design.
  • Quiet has no power loss (up to 450whp engines), sounds great and reduces sound levels 10-12dB over stock.
  • Loud less restriction on higher powered cars (>450whp) and wicked flat six waiil!
  • 4" rolled exhaust tips in PVD Black are Standard.  Titanium Tips are optional!  Add our Nurburgring Quiet Tips to further quiet your car down!
  • Direct replacement of the OEM muffler, will fit existing modification if they work with the OEM Center Muffler.
  • OEM 63mm or 3" lower inlet sizing for increased flow.

* for no drone performance, the cars must maintain valves and use both the upper and lower exhaust paths in the muffler.