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367 Posts
Discussion Starter #1 (Edited)
Koenigsegg produces the most powerful road going 2.0L engine (and it's from 3 cylinders!).

Tiny friendly giant engine - Koenigsegg
How Koenigsegg’s 2.0-Liter No-Camshaft Engine Makes 600 Horsepower

Koenigsegg Gemera's TFG ("Tiny Friendly Giant") 2.0L Twin Turbo I3 engine
Power: 600 HP @ 7500 rpm & 443 LB-FT from 2000-7000 rpm (on ethanol flex fuel - "only" produces ~500 HP on pump gas)
Redline: 8500 rpm
Displacement: 2000cc (95mm bore x 93.5mm stroke)
Specific Output: 300 HP/L (AMG M139 2.0L I4 has 208.9 HP/L)
Compression: 9.5:1
Peak Boost: 29 psi (Sequential twin turbo system)
Full Boost: 1700 rpm
Weight: <70kg (~150 lbs & can fit in a typical carry-on luggage case)
Dry-sump oil system
Flex fuel capability including E100, Methanol and sun fuel
High power ion sensing coil-on-plug ignition system

The stroke is unusually high for the redline yielding a piston speed of 26.5 m/s (the same as an F1 engine at its 15,000 rpm redline). For example, the S2000's naturally aspirated 9,000 rpm redline had a max piston speed of 25.2 m/s.

The engine also features Koenigsegg's Freevalve technology. There are no camshafts, but it instead uses pneumatic actuators to control the valves individually. This allows infinitely variable valve lift, duration & timing.

How are their two turbochargers on a 3 cylinder? One of the exhaust valves from each cylinder is routed to each turbocharger.

Koenigsegg claims that the 2.0L I3 would be capable of ~280 HP in naturally aspirated form. For comparison, the S2000's JDM F20C produced 246 HP. I wonder what the F20C could have done with E85 flex fuel, dual injection (port & direct injection allowing for higher compression & advanced timing), and more advanced valve control. The F20C was developed in the late 90s and only had Honda's VTEC, but not the VTC system later developed for the K20a.

An alluring engine sound:
Fitted with a custom titanium Akrapovič exhaust, the TFG’s 2-liter three-cylinder engine gives lag-free response and comes with an evocative and deep-throated growl. The TFG may be a small engine but it has a big and “thumpy” sound thanks to its large bore and stroke, combined with the “open” sound of Freevalves. The result is a deep, throaty, responsive and alluring sounding engine.
This is a very impressive engine and engineering feat.. but then again it should be considering the price tag :)


367 Posts
Discussion Starter #2 (Edited)
In comparison to AMG's 416 HP M139 2.0L 4 cylinder..

How Mercedes Made The Most Powerful 4-Cylinder Engine In The World - YouTube

I'm thoroughly impressed with the engineering that AMG has put into the new 416 hp 2.0L 4 cylinder turbo (M139) engine. They've really raised the bar for other manufacturers. The specific output (HP/L) is something that I would have expected from a Honda 4 cylinder (if they still manufactured engines like they did in the '90s/early 2000s). It's exciting to see engineering teams continue to push the envelope with combustion engines like this as the industry is advancing towards automated electric vehicles.

I'll be interested to see how far the aftermarket can push this engine, especially with E85.

  • Turbocharged 2.0L inline 4 - handbuilt at AMG
  • 416 hp @ 6750 rpm, 369 lb-ft @ 5000 RPM
  • Redline: 7200 rpm
  • Peak Boost: 30.5 psi
  • Displacement: 1991cc (83.0mm bore x 92.0mm stroke)
  • Compression: 9.0:1
  • Specific output: 208.9 HP/L
  • Engine weight: only 353.8 lbs
  • Twin scroll, roller bearing turbocharger w/ electronic wastegate actuator
  • Forged crankshaft, rods & pistons
  • Aluminum closed deck block
  • Nanoslide cylinder coating
  • Larger & baffled oil sump
  • DOHC 16 valve aluminum cylinder head
  • Adjustable intake and exhaust camshafts w/ roller cam followers
  • Camtronic valve timing on the exhaust side (2 camshaft profiles)
  • Larger, hollow-bored, sodium-filled exhaust valves
  • Dual injection - Direct & Port Injection
  • Electric water pump w/ 2 radiators
  • Air/water intercooler w/ additional cooling from the A/C
  • 8 speed dual-clutch auto
  • "Advanced" 4MATIC AWD system with a "Drift" mode
  • Estimated: 0-60 < 3.9 sec, 1/4 mile < 12.3 sec - depending on the "45" chassis
And for those that love to "hoon", it comes with drift mode like the Focus RS.

The AMG A45 S with this engine reached 0-62mph in 3.9 seconds.
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