While the swooshy-swooshy sounds of a turbocharger can be downright intoxicating, there is nothing quite like the feeling of a high-strung, high-revving naturally aspirated engine. When turbos get added into the mix, usually the rev limit goes down, not up (and that makes us sad). Thus, if you want to rev out an engine to the moon and beyond and maximize every horsepower per liter, you might just need a motorcycle.
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- Base Trim Engine
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2L I4
- Base Trim Transmission
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6-speed manual
- Base Trim Drivetrain
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Rear-Wheel Drive
- Base Trim Horsepower
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240 HP @8300 RPM
- Base Trim Torque
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153 lb.-ft. @ 7500 RPM
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- Base Trim Engine
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4L H6 ICE
- Base Trim Transmission
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PDK 7-speed auto-shift manual
- Base Trim Drivetrain
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Rear-Wheel Drive
- Base Trim Horsepower
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518 HP @8500 RPM
- Base Trim Torque
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342 lb.-ft. @ 6300 RPM
- Base Trim Fuel Economy (city/highway/combined)
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14/18/16 MPG
However, if you value your life and need a seat belt, then your options for high-revving, naturally aspirated engines (even in sports cars) become rapidly limited. While it’s impossible to replicate the exact feeling of pushing a high-revving motorbike full tilt, two particular vehicles emulate the sensation quite well. Those two vehicles are the Honda S2000 and the 992 Porsche 911 GT3 RS. These two drivers’ cars may be light years apart in age and price, but they both share the unique title of featuring the most powerful four-cylinder and six-cylinder naturally-aspirated engines ever made. Let’s get into it!
To give you the most up-to-date and accurate information possible, the data used to compile this article was sourced from various manufacturers and other authoritative sources.
The Honda F20C Is The Most Powerful Naturally-Aspirated Four-Cylinder
When Honda debuted the S2000 Roadster at the turn of the millennium in celebration of the company’s 50th birthday, we knew it was destined to be a special vehicle. What we didn’t realize was that the Honda S2000 would be more than special; it would become an icon among driving enthusiasts. At the heart of the Honda S2000 is Japan’s masterpiece, the Honda F20C1 engine, which shocked the enthusiast community to its core with its high output and even higher 9,000 RPM redline.
Honda’s well-established lineage of crafting high-revving motorcycle engines since the company’s inception all culminated into one legendary engine that remains as impressive as it was when it arrived stateside 25 years ago. The F20C1 broke all conventions and skyrocketed the Honda S2000 into its own tier of roadster magic, firmly taking the crown away from the dominant Mazda MX-5 Miata. The Mazda Miata’s primary weak point back then was its mediocre and uninspiring engine, and Honda realized this detail was where it would gain its advantage. They were right. Once you touch the 9,000 RPM limit of the F20C1 for the first time, you never think about the lackluster four-banger found in a Mazda Miata again.
Honda Are The Masters Of Four-Cylinder Tuning
With 240 horsepower (247 horsepower in Japan) from a 2.0-liter inline-four engine, the Honda F20C1 dismantled the preconceived boundaries of what was possible with a naturally-aspirated inline-four engine. With an output of 123.5 horsepower per liter (in Japan-spec), the F20C1 was, by far, the most powerful production naturally-aspirated engine of any cylinder count when it debuted.
The Honda S2000 would hold this record for a decade before the Ferrari 458 Italia and its 4.5-liter V-8 engine took the top spot with a max output of 124.5 horsepower per liter. Not really fair, right? Because you could buy ten or more Honda S2000s right now for the same price as a single Ferrari 458 Italia. Well, this just goes to show how stunningly impressive Honda’s tuning and engine-building capabilities really are. If there is any company that can claim they build the best naturally aspirated inline-fours, it is Honda.
The Honda F20C1 Is The Peak Of Inline-Four Engines
The fact that the Honda S2000 still offers the most powerful naturally aspirated four-cylinder engine ever made 25 years after its debut shows you how ahead of its time this Japanese roadster was. While Honda’s development of the inline-four platform expanded, no product in Honda’s line-up (or anybody else’s) has come close to matching its charm and capability. Making an engine rev to 9,000 RPM is a feat few automakers have even attempted, but Honda turned this spectacle into its selling point.
Nowadays, Honda has lost part of its identity because there are no longer any high-revving naturally aspirated engines left in their line-up. It was the K20Z3 inline-four found in the FA5 generation Honda Civic Si that would mark the last application of a high-output, high-revving Honda inline-four. Since then, turbocharging has become synonymous with Honda’s performance products, and sadly, the Honda driving experience isn’t the same as it once was. Thankfully, you can still experience the peak of Honda four-cylinders for about $15,000 or so on the used market.
The Porsche MA2.75 Is The Most Powerful Naturally Aspirated Six-Cylinder
If you thought that it was unfair that a Ferrari 458 Italia took the naturally-aspirated horsepower crown from the Honda S2000, let us introduce you to the 992 Porsche 911 GT3 RS. Even if you can swing the $250,000 starting price, can you even get an allocation? We hope you also have an excellent relationship with your local Porsche dealership and the patience of a saint, because you may have to wait a year (or five). Let’s say you do get your hands on one. Well, you can now rest assured that you have the most powerful naturally-aspirated six-cylinder car ever produced.
With its 4.0-liter MA2.75 flat-six pushing out a total of 518 horsepower, the 129.5 horsepower per liter output of Porsche’s leading flat-six blows the Honda S2000’s legendary F20C1 inline-four out of the water. Yet, once you consider that the 992 GT3 RS can also rev to 9,000 RPM like the Honda S2000, you understand how special it is to have an engine like this still available in a production vehicle (despite its rarity).
The Magic Of Porsche’s MA2.75’s 4.0-Liter Flat-Six
In 2011, Porsche introduced the largest displacement flat-six ever at 4.0-liters in the 493-horsepower 2011 997 Porsche 911 GT3 RS 4.0. Despite its increased size and capability, the 123.25 horsepower per liter output of the 4.0-liter flat-six did not surpass the Honda S2000’s 123.5 horsepower per liter output (although close). Yet, without increasing displacement or size, the 4.0-liter unit found in the 992 GT3 RS ushers in a new standard of power-to-displacement ratio.
Compared to the standard 992 Porsche 911 GT3 (508 horsepower) that shares the same engine, the GT3 RS’s 4.0-liter flat-six has upgraded camshafts, valvetrain, and a new single-throttle intake system. This all functions to maximize the airflow potential of the MA2.75’s unique individual throttle body system. If there was potential for optimization, Porsche did it. These numerous details allow the full range of the 9,000 RPM band to be maximized, and the reason the 992 GT3 RS can make so much power with a relatively small displacement is that it can rev so high.
Other Notable Landmark Naturally-Aspirated Engines
The 992 Porsche GT3 RS offers one of the most powerful and extreme naturally-aspirated engines ever produced, but are there still naturally-aspirated vehicles even more exclusive and powerful? Yes, there is (and both are produced by the same legendary British engine builder, Cosworth). First, there is the Aston Martin Valkyrie, which features a 6.5-liter Cosworth RA V-12 engine that makes 1,000 horsepower with an 11,100 RPM redline. This engineering achievement is made possible by the collaborative effort of genius minds at Cosworth and Red Bull Racing that sought out a 1990s-style F1 screamer of an engine while utilizing the latest and greatest technical advancements of the last 30 years.
Another vehicle of great significance in the realm of high-powered naturally-aspirated engines is the Gordon Murray Automotive T.50, which is powered by a 4.0-liter Cosworth GMA V-12 that produces 655 horsepower and is capable of revving to a sky-high 12,100 RPM. This gives the GMA T.50’s landmark V-12 engine an output of 163.7 horsepower per liter.
A Naturally Aspirated Powerhouse For Any Budget
This horsepower-to-liter ratio is so outlandish and inconceivable that we still don’t understand how Cosworth made this powerplant viable for a production vehicle. Yet, we can attribute part of its stunning output and free-revving capability to its shockingly low weight at only 392 pounds. For comparison, Ferrari’s iconic F140 V-12 engine is closer to 500 pounds, but the Ferrari unit makes up for that with its increased displacement and, as a result, increased torque. If you dream of owning one of the greatest high-revving and high-output engines of all time, a multi-million-dollar hypercar sounds great, but for anywhere from $15,000 to $20,000, on the low end, you too can experience greatness behind the wheel of a Honda S2000.