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A Look Back At The Porsche 963 LMDh Hypercar Powertrain In Detail

Porsche 963 Hypercar

At the start of 2023, after a few years of teasing and testing, the Porsche Type 963 LMDh Hypercar was set loose on the track at the 24 Hours of Daytona. While the final design was revealed months before, and much of the talk leading up to Daytona was on how Stuttgart had approached the new top-tier class of endurance racing, the fact is that not much information regarding the technical and mechanical side of the car was available.

Now that the debut has happened, for better or worse as can be read about in the 24 Hours of Daytona recap, information regarding the way that the car generates its immense 700+ HP across the internal combustion engine and the new hybrid system has started to be released. As such, we thought that it would be a great subject to really drill down into, looking at the incredible technological advancements made that will very likely be appearing in future Porsche road cars.

Not Just An Updated 919: A Full Powertrain Rethink

We are all, by this point, intimately familiar with all the workings of the Porsche 919 LMP1 Hybrid, the race car that won the 24 Hours of Le Mans four years back to back. In brief summary, it used a 2.0L twin turbo V4 engine mounted amidships, generating just about 500 HP and revving to 9,000 RPM, that powered the rear axle. A single hybrid unit developed by Porsche Motorsport sat between the front wheels, generating about 250 HP and drove the front wheels. The battery and recharge system for the hybrid motor was mounted in the cockpit for weight distribution reasons, and the hybrid would activate either on preset conditions or, with a button push, could be manually deployed by the driver.

Porsche 963 Cockpit
“The Office,” where the driver of the Type 963 will be able to control how much hybrid boost is applied, when, and even be able to manually deploy it via button press… among many other controllable settings for the car. Image via Porsche

That was then, however, and for the Type 963 LMDh, a whole new set of rules and regulations were in place for the new car to meet. Instead of being an internally developed hybrid, every team that is taking part in the Hypercar class is provided a standardized hybrid system developed by a joint team of Williams Advanced Engineering (battery packs), Bosch (hybrid motor, ECU, and other components), and Xtrac (Motor Generator Unit – Kinetic (MGU-K) in the transaxle for recharging). The hybrid system is also much less powerful than the previous LMP1-H units, being capped at just 50 HP, and are intended for use in corner exit, launches, and push-to-pass situations.

Hybrid unit on the Porsche 963
While hidden a bit by the brake master cylinders, the 50 HP Bosch Hybrid unit is located within the tight confines of the nose of the Type 963. You can also just make out one of the two pushrods for the front suspension behind the brake cylinders. Image from Porsche

This meant that the internal combustion engine was brought back as the primary means of motivating the car, and with the new rules, also had to be compatible with renewable fuels such as ethanol/hydrocarbon blended fuels and carbon-capture derived hydrocarbon fuels. To further simplify the entry into LMDh, the rules also stated that the cars had to have one of four provided chassis, from the constructor’s choice of Oreca, Ligier, Dallara, or Multimatic. Porsche, after evaluating all of the options they had, chose to go with Multimatic.

Diagram of the Porsche 963 systems
The powertrain layout for the 919 LMP1 Hybrid. Note the battery in the cockpit, with the tiny 2.0L V4 engine nestled as far forward to the firewall as possible. That engine produced about 500 HP, and the Porsche-designed hybrid motor on the front axle provided another 250 HP, effectively making the car AWD whenever both systems worked together. Image via Porsche

Since the chassis and hybrid systems were standardized and cost capped, this is where Porsche’s expertise in racing over the past decades came to the fore. A new engine needed to be made, and it needed to be efficient, powerful, reliable, and light. Stuttgart had already made an engine that met all four of those criteria, and with the knowledge gained in the years since its original design, the new engine is perhaps the best V8 that has come from the quaint little German company.

The Technologies & Materials In The V8 Powerplant

First thing’s first, the engine that is in the Type 963 has appeared three times before in both race and road cars for Porsche. Its original engine code was 9RD, and appeared in the 1999 Porsche RS Spyder. That engine became the basis for the development of that V8 system which was fed into Project 918, which became the engine for the 918 Spyder hypercar. By the time it appeared in the 918, it had had its stroke shortened, been bored out to 4.6L, a flat-plane crank developed and implemented, and could have the nuts revved out of it to 9,000 RPM for hours on end and still be as reliable as a wood burning stove.

Taking the 918’s 4.6L V8, Stefan Moser and his team of 18 engineers and designers broke the engine down to the bare block, and started to build it back up. New cylinder heads were developed, with two turbochargers from the Dutch company Van Der Lee mounted in a hot-V configuration. This means that both turbos, each providing a boost of just 0.3 bar (4.35 PSI), sit between the cylinder heads in the 90 degree V, as close as possible to the exhaust ports to gain as much specific energy as possible. These turbos then feed to two separate intake manifolds that sit on the sides of the engine, feeding boosted air in where most engines have their exhaust ports.

The twin-turbos of the Type 963’s engine in the “Hot-V” layout.
The twin-turbos of the Type 963’s engine in the “Hot-V” layout. The blue tubing on either side are where the boosted air is fed into the intake manifolds on the sides of the engine. Image from Porsche

This provided two distinct advantages, the first being that the engine was already fairly squat, as it had been worked through its history to be sat ever lower in the middle of a pretty short car as is, which improves the center of gravity for the Type 963. The second, more important benefit, is that it keeps all the heavy bits of the forced induction system and exhaust as close to the centerline of the car, to reduce lateral weight shifts.

Porsche 963 LMDh Hypercar exhaust
With the bodywork on, you can see just how narrow the Hot-V layout actually is, as well as how short the exhaust pipes are. This exhaust layout also helps with the aerodynamics of the car, as it joins with over-body air to flow to the rear wing. Image from Porsche

As well, by keeping the boost pressure low, the turbos spin up to full compression very low down in the rev range. While it might seem counterintuitive, as turbos are usually used to boost high rev power, this is a very intelligent choice. Since the pressure is low, and the spin up is almost instant, the turbos act more like a supercharger than turbochargers, giving a ton of torque way down low. You want grunt low- and mid-range grunt in a race car, as when you’re accelerating out of a corner or pressing the pit limiter off button after a pit stop, you want that instant, but tractable torque to catapult you up to speed. Combined with the hybrid grunt that kicks in for both situations, this gives the Type 963 some awesome mid-range acceleration.

Another advantage of using the 9RD engine mostly from the 918 Spyder’s implementation is that it had already had all the research and development done for tying with a performance hybrid system. While the hybrid boost is a mild 50 HP, as already stated, keep in mind that this is a car made out of polymer-reinforced carbon fiber, motorsports grade aluminum, and scrapes in at just over 1,000 kg (2,205 lbs). This is more than enough power, especially with the instant torque of an electric motor, to provide a real, tangible benefit to corner exit and hard acceleration, while the engine itself is more for the higher speed straights as it is chucking out a healthy 621 HP.

The back end of the engine block on Porsche 963
The back end of the engine block is a busy place, with the heave spring in the middle for the rear axle, and the two pushrod suspension towers bolted to the outer sides of the engine making it a fully stressed member of the chassis. Image via Porsche

Inside the engine is where the latest and greatest technology was implemented. The crankshaft, which weighs in at just 12 kilograms (26.5 lbs), is made of forged steel, and features 180 degree crank throws for the connecting rods, giving the Type 963 the classic Porsche burble and scream at idle and wide open throttle, respectively. Those connecting rods are motorsports grade titanium, with the cylinders, block, and cylinder heads all being made of motorsports-grade aluminum. The difference here is that the aluminum alloy used is nearly twice as strong, without any significant weight increase, than the aluminum used just 9 years ago for the 918’s engine. There is a reason that Porsche has a department that is quite literally named “Aluminum Engineering Excellence.”

The 4.6L 9RD 90 degree V8 engine
The 4.6L 9RD 90 degree V8 as it was used in the 918 Spyder. The only differences are new cylinder heads, two turbochargers in the V, new intake manifolds, and motorsports grade materials used throughout, but the basic layout is the same. In the 918, the exhausts were in a Hot-V configuration, just without turbos attached. Image via Pinterest

This is an important factor for a race car engine as, like in the 918, the V10 in the Carrera GT, and the RS Spyder, the engine is a fully stressed and load bearing member of the car. The rear heave spring mounts to the center rear of it over the transaxle, just behind the turbochargers, and the pushrod suspension for the rear axle anchors to the outer edges. This gives the Type 963 incredible torsional rigidity, as it would take a force nearly equivalent to being at the center of a  nuclear explosion to twist the engine block even a degree out of alignment.

This new alloy and the lightweight internal components means that when fully assembled, but without any liquids (Oil, fuel, water) in the engine, the whole thing weighs in at 181 kg (399 lbs). The minimum weight for an engine in LMDh cars is 180 kg (397 lbs), so it just goes to show that Germans… They really know how to engineer to a specific target! Even further to that point, the entire Type 963 LMDh Hypercar, without driver and at a dry weight, tips the scales at almost precisely 1,030 kg( 2,271 lbs), which is the minimum weight limit of all LMDh cars.

How This Translates To Future Porsche Road Cars

Porsche, along with all of the companies under the umbrella of the VW Group, has made the “Green Promise” to be selling mostly (>80%) electric vehicles by 2030. Mostly, however, does not mean all. With the advances in the aluminum alloys of the engine block, and knowing that Porsche builds their engines to be both road and race ready, it is very possible that we’ll see the same type of forged steel crankshafts, titanium connecting rods, aluminum cylinders, blocks, and heads coming to the latest and greatest 911s in the future.

Type 992 911 Turbo S 3.0L engine
It may not look like much, but this is the 3.0L beating heart of a Type 992 911 Turbo S. One of the most advanced engines currently made by Porsche, it still pales in comparison to the tech used in the 4.6L Type 963’s engine. Imagine what this beast could do with the motorsports materials and tech from the race car? Image via Porsche

There is also the possibility of using the Type 963’s engine, with the mild boost, hot-V boost setup, in a future road going supercar or hypercar. They’ve done it before with the RS Spyder to the the 918 Spyder, and from their forays into Formula One in the 1990s to the Carrera GT.

The other aspect of the possible transition into road cars is the ultra-advanced hybrid control system. While the ECU of both the 918 Spyder and all variants of the 919, including the Evo, was excellent, we’re in a totally new era of performance hybrid systems now. With the 911 GT3 Hybrid pretty much all but confirmed, and the future of the Cayman and Boxster both looking to have three separate powertrains (ICE, ICE + performance hybrid, full EV), getting the knowledge and research done now only means that it gets to us, the average Porsche enthusiast/consumer, all that much faster.


Engine Water cooled V8 twin turbo
Displacement 4,600 cc / 280.7 cu in
Hybrid System Single specification Bosch motor generator unit (MGU) at the rear axle providing 50 HP
Combined Power 670 HP @ 10,000 rpm
Valvetrain 4 valves / cylinder, DOHC
Fuel feed Direct Fuel Injection with redundant secondary pump setup
Location Mid, longitudinally mounted
Gearbox XTrac. Single specification hybrid system, 7-speed racing transmission, pneumatically actuated
Drive Rear wheel drive