Porsche 992 GT3 Undercar Overview

The 992 GT3 keeps the same 4-wheel steering as the 991 where this stepper motor takes the place of the toe link.  overall we would say the suspension changes in the rear look to be focused on weight reduction.  There wasn’t anything not good about the 991 rear suspension anyway.

The rear brakes have pretty trick ducting.  This rear mini diffuser looks like the ones sold by Professional Awesome. They feed air into these scoops that direct air to the caliper and the center of the rear hat for cooling.  GT3s have optional carbon-ceramic brakes and these brakes need a lot of airflow since they don’t have the thermal mass of iron.

The underbody has these NACA ducts that feed ducts cooling the CV joints.  Believe it or not, these get pretty hot and a car that has a fully sealed up flatbottom can probably use some cooling airflow.


  1. “Apparently, Porsche found that direct-injected engines make particulates like a diesel. We assume that the car probably has some sort of regeneration cycle to clean the traps that makes a lot of heat, hence this metal-lined scoop.”
    Dfi engines do create fine particules. It’s mendatory in Europe now to have a GPF on all engines. The only difference is EU spec cars (for PORSCHE) have a differential pressure sensor, US cars do not.
    The normal regen cycle on gasoline engines takes place when you’re coasting, it’s the only time where a gasoline engine has enough oxygen in the exhaust to burn the particules.
    There is also a forced regen mode. I’m not sure but I think it uses secondary air injection to get oxygen in the exhaust. Porsche informs that it must be performed with a lot or airflow passing under the car because with the car stationnary, the red hot GPF could potentially damage the road it’s on (and everything around it).

  2. I really like the diffuser to brake scoop design.

    My theory on the move to SLA double wishbone front is that the Cayman was posing a serious track threat and they needed to further differentiate the cars with a significant suspension upgrade on the 911.

    Also, they could finally put the real GT3 engine in the Cayman GT4 RS without actually eclipsing the 992 911 GT3.

  3. Great article. Would have been great to get some more zoomed out overall photos of the underside to understand how much of the floor is flat bottomed. The number of aero details is staggering

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