JCR Porsche 992 GT3 exhaust: Raw noise!

Michael Ledoux heads Transakauto, a network specializing in secure car transactions between private individuals. It currently has 200 outlets and 600 employees across France. And there's more to come: the network has just launched Transakmoto, an identical concept dedicated this time to the world of motorbikes, with the first 25 centers already signed up, and the first branch opened at the time of filming. Rapid growth for a network that relies as much on sales performance as on animating its community of franchisees, through events, rallies and trips organized throughout the year.

The 992 GT3 is one of Porsche's most sonically sophisticated cars. Compared to previous generations, it has improved. But when it comes to road rallies in the company of Ferrari 488s and Lamborghini Huracans, the GT3 has a clear advantage. The Italian V8 and V10 express themselves at low revs, whereas the Porsche flat-six, restrained by its standard particulate filter, remains discreet until the revs are reached. For Michael, the conclusion was clear: it was time to change lines.

On Porsche 992 GT3s, there are several references when it comes to sports exhausts: Akrapovič, IPE, Brooke, Capristo, and JCR. Michael hesitated for a long time between Akrapovič and JCR. The Akra is a safe bet, with its 3D-printed titanium finish and sophisticated sound.
JCR is a different register: more metallic, more direct, more violent. It was the desire for real sound volume that made the difference.

The chosen configuration is a complete line with manifolds, the most committed yet on this model. Manifolds, elimination of the DPFS, large-diameter tailpipes: the original exhaust system has disappeared altogether. A remote-controlled valve management module completes the installation, allowing the valves to be left open at all times without depending on driving style. As a result, the noise is present from low revs, and explodes above 6,000 rpm.

for track enthusiasts, this configuration exceeds the decibel thresholds imposed by the majority of circuits. Spa, Magny-Cours and others require the installation of a specific output called DB Killer during trackdays. The accessory can be fitted in just a few minutes and is essential if you want to drive around a circuit without the risk of a black flag.

The car was still on the deck, barely at 3,000 rpm, and Michael's reaction was immediate. The sound is there, and so is the smile. Impossible to finish a sentence. The JCR line on a 4.0 L flat-six without a particulate filter is in a different category. The next step was the power bench test, with noise-cancelling headphones compulsory.

At Shiftech, the dyno is first and foremost a measurement tool. The aim is to check that the mechanics respond well after modification, and to have a reliable figure to compare. On the well-ventilated 992 GT3, the power output is unsurprisingly within the values announced by Porsche. But what really stands out here is the sound experience at full load, above 8,000 rpm. Michael sums up the session in a few words: "Guys, I'm over the moon

507bhp, 460Nm: the GT3 is in good health

At the end of the dyno, the 992 GT3 boasts 507 bhp and 460 Nm of torque. Porsche claims 510 bhp from the factory: the measurement is in line, with the usual variability due to dyno conditions and engine ventilation. The power is there, and the sound is now up to scratch.

The total budget for the project is €22,400. This amount includes the complete JCR line with manifolds, the remote-controlled valve management module, the OBD plug module and labour. The line comes from the United States and includes customs duties, which partly explains the price. A substantial investment, but one that Michael has no hesitation in making.