Anybody who likes Honda, can spell VTEC right and knows what VTEC stands for, knows that Honda is faithful for the longest time to naturally aspirated engine. Every known popular Honda cars are naturally aspirated, it can even be said that nowadays Honda is the purveyor and champion of naturally aspirated car engine maker. Honda S2000 F20 engine is considered to be the best 2.0L engine available in the world, producing 250ps (246hp) on the high spec Japanese Domestic Market. Honda newest K24 displacing 2.4L in America even produce 190 horsepower in the 8th generation Accord, using regular gas, the most powerful engine of its class. Moreover, Honda Fit RS produces 120ps from a 1.5L, and it is just a simple SOHC engine, wonder what number it can churn if the car uses DOHC type engine.
All Honda venerable Type R cars even have a trademark of using only naturally aspirated engine, from Integra, to Civic, to Accord Euro, and the everlasting NSX. None has ever needed a force induction to make the car go fast around the tracks. Sure sure people will mock Type R cars for having no torque and pit it with a forced induction engine cars and the Type Rs will go bye bye. But what naturally aspirated engine cars with displacement below 2 Liters can go toe to toe with the Type Rs? Answer… Only a few and most often than not they uses bigger displacement engine to win (hints: Nissan and BMW).
With all of this naturally aspirated engine affection, do you know that in the 80s Honda had a brief affair with turbo?
After the advent of CVCC engine that put Honda in the long road to fame, Soichiro Honda’s son Hirotoshi Honda decided that Honda needs a proper “enthusiast” car, one that can go fast but still showcase the spirit of Honda. Then, he took the unjustified tame looking Honda City and installed a turbo in it. So who is this snobby son of Soichiro who can decide what Honda needs? Well, he is after all the founder of Mugen, the-not-so-affiliated-but-actually-is Honda tuning division.
So after the turbo installation, Hirotoshi named the City appropriately as City Turbo, and the car was an instant classic. The engine now produce 100ps up from the measly 70ps, it seems small but consider this… The City Turbo only weighs around 700 Kilogram!! That gives it a power to weight ratio as good as today’s Civic Type R, and that car is fast. When Honda facelift the car, giving it the designation of City Turbo II, the power was upped a little to 110ps. However, according to many various resources, the boost pressure for the engine is limited to preserve engine life, and the car can be boosted easy to more than 150ps (I’m guessing, but being conservative). That’s just insane!
The small car that could
Then, there is the thing about 1989 Honda Legend, the first ever 2L V6 with a variable geometry turbo. This variable geometry turbo that Honda created was aptly named the Wing Turbo as it uses some kind of a winglet inside a turbo that variably change the boost pressure depending on the engine load. This beats out conventional turbo concept because it can change boost on demand depending on the engine load, unlike the static boost single turbo charger and the “low-high” characteristic of twin turbo chargers. However, even though the engine was ground breaking, the price reportedly was “too much” for a car of that class back then. Furthermore, I personally suspect that the effect of force induction that is detrimental to the engine was one of the main cause Honda ditch turbo engine.
A legend in its time
When VTEC was integrated into Honda product lineup starting from Integra back in 1990, suddenly turbo development was put into stasis, and nobody ever talk about it anymore. Like turbo, VTEC allows for a surge of extra power when the engine is forced to its limit however unlike turbo, VTEC allows daily driving to be efficient. This is because Honda introduce a cam profile changing system that allows “soft” cam to be used for slow driving and “hot” cam to be used for full throttle condition. Furthermore, unlike turbo, the engine is not forced to operate beyond its limit, giving that longevity trait of naturally aspirated engine compared to force induction engine. Now, Honda has this miracle engine that can be driven efficiently but can produce power at high RPMs and have a long life time. It’s a no brainer, turbo is dead! Until recently…
When Acura (Honda lux division) RDX, Acura answer to BMW X3 was launched, enthusiast and media gasps with what type of engine the car used. It is a factory spec turbo, a first for Honda after nearly 20 years! The K23 as it is called produces 240hp and 260 lbs-ft, the torquiest engine Honda ever made. As it code sign gives away, it is a K series engine, the engine that can be found anywhere in the Honda product line, ranging from Accord, Odyssey (JDM), Accord Euro, Civic, Civic Euro, Edix, Element, and others. However Honda engineers strengthened the engine block and added the turbo unit, a variable geometry turbo… The past has return, with a vengeance!
Acura RDX: Variable geometry turbo in action
With this in mind, speculations about another engine used by Acura TSX replacement (Honda Accord Euro outside US), is a turbo engine producing at least 260hp are running rampant throughout the web. With Honda proprietary torque vectoring all wheel drive system (Super Handling All Wheel Drive, SH-AWD for short) will be adopted by every Acura cars, they need high power high torque engine, and what could give that kind of power except for turbo or large displacement engine? There is something else though, and it is called the A-VTEC.
In the late 80’s Honda ditch turbo for the favor of VTEC. From the looks of it, turbo seems to be a short answer to the long awaited completion of VTEC mechanism. Now does history is repeating itself? Honda new variable geometry turbo engine is faaaaaaaaaaaaaaaaaaaaaaaaaarrrrrrrrrrrrrrrrrrrrrrrr from complete. It doesn’t feature direct injection like many advanced engine featured in the Lexus (expensive Toyota) line. Therefore its performance can still be increased with the addition of this simple mechanism. However, 20 years and Honda only took an existing engine, lower its compression, strengthen its structural integrity and adding turbo… Skipping the important direct injection technology? I smell something fishy. I smell Honda is going to repeat history again, introducing stop gap turbo technology before the real “true” advanced engine to be introduced.
A-VTEC or Advanced Variable Valve Timing and Lift Electronic Control, is a more advanced version of I-VTEC (Intelligent VTEC), which itself is a more advanced version of VTEC. I won’t try to be a smart guy, you can check how VTEC works by clicking the links I provides at the end of the article.
Anywho, that’s that for now. Will Honda introduce direct injection or not is up to them, but one thing for sure, the existing K23 turbo engine is far from complete. Will Honda repeat history and introduce next generation of their venerable VTEC, or will they soldier on with turbo is still up in the air.
Honda A-VTEC dissected
Honda Wing Turbo
Honda City Turbo Forum
How VTEC works
Honda Very Own VTEC Documentation
Pictures are taken from Acura.com, Asia.VTEC.net, wikipedia.