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Extracting 100bhp per litre must be easy from a Mezger engine, right? The legendary and talented engineer achieved this back in ‘67 with the 911R that screamed its way to 6200rpm, although with much smaller cylinder capacity. Arguably amongst the most thrilling 911s to drive, it’s also one of the least practical for the road.

Porsche’s own quest to reach this level once again in a road car only came in 2011 with the GT3 RS fitted with a four-valve cylinder head as opposed to the two valve version we are using. Subsequent iterations of GT3 have, of course, surpassed this almost mythical level of power and you will easily find plenty of turbocharged moderns that can lay claim to be part of the club; but for an air-cooled engine, it’s still bloody hard to achieve. So have we managed this? Yes, finally!

It’s a hell of a lot easier to get 100bhp/litre if you are building a track car and a power curve that will have you, the valvetrain and everything else in the red zone. But our cars are for driving; picking up kids from school, grabbing pastries for a partner, or cruising to the gym (not to go inside). So, it has to be tractable, neighbour-friendly (no rattling windows), compatible with everyday fuel (98 RON), and equipped with an air filter that well, actually filters air. Let’s not also forget the adaptive knock sensor compensating for altitude, fuel and temperature. We want our cars to run well wherever they are.

That’s a whole world of pain harder than just pumping in cold air on the dyno or dumping in some 100 RON to get the magic printout.

First you need a team – For KALMAR that’s Lorrtech, the engine builder extraordinaire, and Celeritech, the wizard exhaust builder.


And our own superhero, Raimo Hallas.
We have to tell you more about him some time.



Round 1 and we hit 390PS. Tweaking a few parameters could see us hit 400 but that wouldn’t be fair to anyone, so we go back to the drawing board. We changed the pistons, optimised the exhaust system, enhanced the intake manifold, camshafts and calibration. The result: a proper, pukka 401bhp and a mind-boggling 431Nm. All achieved on a static dyno not the rolling road! But it’s not just about hitting a number; it’s about creating a power band that delivers abundant torque at low rpms – that’s about 300Nm at 3000rpm, ensuring a thrilling and responsive driving experience.

We called it the Triple 4: 4.0 litre, +400bhp, +400 Nm. This engine project stands as a testament to the power of dedication, innovation, and our refusal to compromise.

Want to hear what it sounds like? Press play…


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