The time finally aligned where we had a customer car and some time to dyno!  

Dyno Video of 991.2 GT3 Manual



Street (Catted) Header with Stock Muffler



Dyno Results:

dyno vs catted exhaust graph

First thing to notice:  The 991.2 GT3 makes 456whp out of the box bone stock... To get an idea of the significance of this, a 991.1 GT3RS makes 430whp on the same dyno, tested under the same conditions, that's 26whp gain out of the new 4.0L engine.

The Dundon 321SS Street Headers (Longer runners than anyone claiming to make "long tube" headers) add a solid 40lbft at the wheel at 4500rpm and 20whp (at the wheel) at 8400rpm.  With final power numbers approaching 477whp!  We can see the ECU is torque limiting, we are investigating tuning options to really uncork this bad boy, but even without tuning, great increases in power on an already powerful NA engine!

To say the 991.2 GT3 with Dundon 321SS StreetHeaders is powerful is an understatement.    To put it in context:

  • 991.1RS was advertised 500hp from Porsche and made 430whp on our dyno stock: 14% Loss
  • 991.2 GT3 if graded similarly to the above using the 991.1 RS loss, 456whp= 530hp  
  • 991.2 GT3 with Dundon 321SS Street Headers using the 991.1 RS loss, 476whp = 553hp

Great sound, less weight, more power, lifetime warranty and keep the cats...