991.1/991.2 GT3, GT3RS, 911R, Cup,



Jamie I am madly in love with my 991 RS with Dundon Race Headers now honestly its transformed. Was out on the track and an instructor friend who had driven it previously drove with the Dundon Race Headers yesterday and got out and said I quote"what have you done to it" read more

Ahmad, UAE
991 GT3RS Race Headers

Intake kit Dual Reverse Cone Airbox, 93mm Throttle Bode and Plenum 991 RS


Click on a photo to enlarge.

Help your 991.1 or 991.2 GT3RS BREATHE!!!

We found in our exhaust development and testing of the 991.2 GT3 and RS that they are intake limited both through the factory airfilter box and throught the 82mm Throttle body.  A bit of history.  The Bosch 82mm Throttle body is the largest Bosch makes and was used as far back as the 996 GT3 which made 380hp.  The Air filter box used on the 991.2 GT3 and the 991.2 GT3RS originally showed up on the 2013 991 Carrera S which makes 350hp.  Your 991.2 GT3RS is rated at 520hp, so you can see just from these numbers that the intake side of things is a constriction.  

In our testing we found the the stock airbox to be about a 0.2-0.3psi pressure loss and the 82mm throttle body to be about 0.3-0.4psi of pressure loss.  Naturally aspirated engines make power from the force of the atmosphere pushing air into the engine, so every 0.1 psi helps!  Our combo of 93mm Throttle Body and Dual Cone Airbox reduces the losses to under 0.1psi.

Further on top of all of this is the Ram Air effect of pushing air into the engine when driving at speed is enhanced as there is substantially less restriction in the intake system!

  • 93mm Throttle Body has  28.6% more area than the 82mm throttle body.  
  • Stock Filter Area :1.77 ft2
  • Reverse Dual Cone Filter Area: 6.25 ft2
  • 353% more than stock.

More filter area means slower air speeds through the filters and less pressure drop across the filter element.


Let her Breathe!!



ACE Performance from Tewksberry, MA
Fitment and detailed instructions were excellent. The R&D that has gone into this product as well as the support are second to none. We are proud to be a dealer and install center of these awesome products.

The sound of the airbox coupled with headers makes the GT3 RS sound incredible and the power gain throughout the RPM range is noticeable.

Michael from West Linn, OR
The torque increase exiting corners and down long straights is impressive. I’m so happy I decided on this modification.

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