The other day we posted this pic of Minichamps’ 1981 Group 5 Race Ford Capri and remarked on the stratospheric levels of boost it uses to make 500hp from its tiny little 1.4L turbo 4. That got us wondering where that little dynamo ranks in history in terms of specific output (the term for measuring horsepower per cubic-inch/cc displacement.)
Conventional wisdom says that smaller engines—with their lower friction and reciprocating mass—trump big thumping mega-motors in terms of specific output. And recent advances like direct fuel injection and variable valve technology have allowed modern engines to produce more horsepower from less displacement than engines from past eras. We wondered how much truth there was to those assumptions, and how the best modern motors — big and small — compare to the Capri and the most power-dense motors of all time, so we crunched some numbers to find out. What we found may surprise you!
[A couple of caveats:
1 – Engines employing turbos or superchargers have a huge advantage over motors that rely on ambient air pressure, so we are focusing on solely on the boosted engines here. We’ll do second list of the best naturally aspirated engines as a follow-up.
2 – We are focusing on conventional piston engines, as they are overwhelmingly the most common. But we did toss in a rotary engine for comparison.]
Now, on to the results! Here are the 20 best production engines in terms of horsepower per displacement:
2015+ Dodge Challenger/Charger Hellcat Supercharged 6.2L V8
Let’s start with the epitome of the modern muscle motor—Dodge’s Hellcat V8. As the most powerful motor ever sold in an American production car, you might think that would put it near the top in terms of specific output, but at just under 115hp/L the blown pushrod V8 only manages 20th on this list.
Diecast: Jada makes a 1:24 and Hot Wheels a 1:64 (sans the “Hell” term for marketing reasons.) Neither is super-detailed, so there’s room for an upmarket version for sure.
No. 19 (tie)
Cadillac CT6 and 2017+ Lincoln Continental twin-turbocharged 3.0L V6s
2990 (2956) cc | 404 (400) hp | 135.12 (135.32) horsepower/liter
We list the Caddy and Lincoln 3.0L V6s as a tie because—despite coming from competing Detroit firms—they are essentially identical in layout, displacement, output and market position. And at 135hp/L these smooth luxury V6s rival exotic sports cars in power density!
Diecast: None yet, but the Lincoln is a decent prospect.
2016+ Acura NSX twin-turbocharged 3.5L V6
Acura’s beloved mid-engine sports car makes its return as a full-fledged exotic, stuffed full of tech goodies like a hybrid electric-assist driving the front wheels and adding an extra 73hp to the already world-class 500hp V6.
Diecast: Hot Wheels does a nice 1:64, while TSM does 1:43 and 1:18.
2007-2016 Mitsubishi Lancer Evo X turbocharged 2.0L Inline-4
1998cc | 303hp | 151.65 horsepower/liter
There are a whole host of high-strung 2.0L mills in the sport-compact segment, but the rally-inspired Mitsubishi is the most impressive of the lot, boasting more than 300hp channeled through a sophisticated all-wheel-drive system. Sadly, it wasn’t enough to keep the Evo in production past 2016.
Diecast: Hot Wheels has 1:64 covered. Larger scales are out there, but the brands can be obscure.
2016+ Ford Focus RS/Mustang 2.3L Ecoboost turbocharged Inline-4
2261cc | 350hp | 154.80 horsepower/liter
The new king of the Hot Hatch segment, the Ford Focus RS trumps the WRX/Evo guys by 50hp and lays down performance numbers that rival European exotics. No wonder the Mustang has poached it’s powerplant for its 2017 refresh!
2015+ Nissan GT-R Nismo twin-turbocharged 3.8L V6
3799cc | 600hp | 157.94 horsepower/liter
Affectionately nicknamed ‘Godzilla,’ this monster is perhaps the ultimate example of Japanese engineering. That a car this big could be this powerful and also this nimble seems to defy physics. That it also outruns cars costing triple or more its price defies economics!
Diecast: 1:64, 1:43 and 1:18 are all available, so take your pick of scale and price-point! This one is from GT Spirit.
1987-1992 Ferrari F40 twin-turbocharged 2.9L V8
Maranello’s signature supercar for the modern age, it was the final Ferrari that Enzo himself oversaw. For many it remains the archetype for what a supercar should be—and much of that can be chalked up to its race-bred 2.9L V8 which was capable of pushing the F40 past 200mph.
Diecast: Many companies have made F40s over the years. One of the nicest currently available is this Kyosho high-end resin piece.
2016+ Ferrari 488 GTB twin-turbocharged 3.9L V8
3902cc | 661hp | 169.40 horsepower/liter
After a quarter century Ferrari has re-embraced the magic of turbocharging—and to awesome effect. The spiritual successor to the mighty F40, the 488 GTB just edges out the legendary supercar’s 163 hp/L specific output, while utterly obliterating it in every objective performance criteria. Plus it has air conditioning!
Diecast: Bburago makes this excellent model in 1:18.
2010-2011 Porsche 911 GT2 RS twin-turbocharged 3.6L Flat-6
3600cc | 620hp |172.22 horsepower/liter
Porsche’s most powerful 911 ever was essentially to the standard Turbo what the track-hero GT3 is to the naturally aspirated 911 Carrera. Among the quickest accelerating cars on the planet, the GT2 was also among the most exclusive 911s made.
2014+ Mercedes-Benz CLA/GLA 45 AMG turbocharged 2.0L Inline-4
When Mercedes decides to engineer something, it doesn’t do half measures. Though not traditionally known for 4-cylinder engines, when it decided to remit its entry-level CLA Sedan and GLA crossover to the in-house skunkworks AMG, the result wasn’t merely half a V8—this junior-sized hammer packs a full-sized 375hp swing thanks to a 20hp upgrade for the 2017 model year!
Diecast: 1:18 from GT Spirit and 1:43 from Spark.
2013+ Volvo S60/V60 Polestar “Twincharge” turbo+supercharged 2.0L Inline-4
1969cc | 362hp | 183.85 horsepower/liter
Say what now? Did a Volvo—a Volvo station wagon!—just outgun Porsche, Ferrari and a host of other supercars? Yah! Bolting a turbocharger and a supercharger to the flanks of a high-tech 2.0L four compounded the boost efficiency and resulted in a motor with more power density than anything on 4 wheels this side of a million bucks.
Diecast: There’s this dealer-edition 1:43, a 1:64 from Matchbox, but no 1:18 yet.
2014-2016 McLaren P1 twin-turbocharged 3.8L V8
3799cc | 727hp | 191.37 horsepower/liter
Turning the wick up on its already rambunctious twin-turbo V8 resulted in the highest specific output of any street-legal road car (never mind that they bolted a hybrid system to it that adds another 177hp on demand!) The result is the hypercar that outmatches the LaFerrari and Porsche 918 Spyder.
Diecast: 1:64 from Hot Wheels — 1:43 and 1:18 from TSM. AUTOart also makes this 1:18.
2015+ Kawasaki Ninja H2 supercharged 1.0L Inline-4
Notice that for the McLaren P1 we said “any street-legal road car”? Because the Ninja H2 hyper bike is street legal, and thanks to a factory-equipped centrifugal blower it crests the 200hp/L threshold—making it the highest specific output production engine available…for now.
Diecast: Bike models are rare, but this one would be a great choice for 1:18 or 1:12
We aren’t giving the Mazda Rotary a numeric ranking because it technically doesn’t measure displacement in the same way a piston engine does. Its more properly ‘swept volume’—but busting out 276hp in its final (Japan-only) spec (the USA got a 260hp version that would pencil in at 199 hp/L) is still some serious beans from a tiny little 1.3L motor, so we’re giving it kudos!
Diecast: Years ago there were several, but now that the RX-7 has been out of circulation a while models of it are less prevalent. Most of what you find now have been given the tuner treatment like the 1:43 Fast & Furious models from GreenLight, but Ebay might unearth some stock 1:18s from Kyosho or AUTOart.
And that does it for the road-legal motors, but competition engines are a whole different animal, and it’s not really fair to compare mega-buck race engines with zero emissions gear and an expected lifespan of a single afternoon with a street vehicle motor that must pass smog tests and run reliably for 100,000+ miles. Which is why the top 6 are all purpose-built competition motors:
2017 Kawasaki Ninja H2R supercharged 1.0L Inline-4
That 200hp Ninja street bike looked pretty impressive until you see that the full-boost track-only version makes 310hp from the same basic setup!
Diecast: When they make an H2, the R can’t be far behind.
1986 Lancia Delta S4 Group B Rally Car turbo+supercharged 1.8L Inline-4
Volvo wasn’t the first to bolt both a supercharger and a turbocharger onto a 4-cylinder motor to get it to act big. Lancia did it back in the ‘80s to craft their dominant Delta S4. Had the Group B rules not been outlawed shortly after it debuted, there’s no telling how many championships it might have racked up.
Diecast: Tons. But this weathered 1:18 AUTOart replica is hard to beat.
1981 Ford Capri Group 5 Touring Car turbocharged 1.4L Inline-4
The car that got us thinking about this story is the oldest here, but its specific output stacks up pretty well even against cars decades newer. Just goes to show that huge boost never really goes out of style!
Diecast: Minichamps 1:18 is where its at.
2015+ Formula 1 1.6L turbocharged V6
The current crop of Formula 1 engines are truly exceptional pieces of engineering. Rules strictly limit boost and fuel efficiency requirements further constrain the engineers, yet these little V6s are rumored to now make as much as 1000hp in testing trim—plus their hybrid systems add hundreds more at key points during a lap.
Diecast: Minichamps produces an extensive array of F1 models from various teams in both 1:43 and 1:18.
1986 Honda FW11 Formula 1 turbocharged 1.5L V6
The pinnacle of Formula 1 engine output arrived during the “Turbo Era” during the mid 1980s, and the most dominant example was the Honda aboard the championship-winning Williams FW11. In qualifying trim it was capable of an insane 1400hp. It was dialed down several hundred hp in race trim to prevent obliterating the tires.
Diecast: The FW11has been modeled a number of times. This 1:18 is from Spark.
2016 NHRA Top Fuel Supercharged nitromethane 8.2L V8
That’s right—the most potent piston engine—road or race—as measured both by peak power and by specific output is not some little turbo engine stuffed with outrageous amounts of boost. It’s a good old-fashioned Hemi big-block pushrod V8… stuffed with outrageous amounts of boost from a giant Roots-style blower and what amounts to liquid dynamite for fuel. Most often these 500 cubic-inch monsters destroy themselves during their 4-second runs, but they can blast out as much as eleven thousand hp for however long they hold together!
Diecast: Top Fuel rails are made at various scales and detail levels. The 1:24 models from Action are among the prolific.
So there you have it. Half of the engines on this list — road and race — are less than 2000cc in displacement, and all but two are less than 4000cc. So it seems specific output does favor the smaller motors—with one explosive exception!