Ferrari Says It's Turbo Time. Yikes.
(Image Credits: www.cincity2000.com)
Let's be real honest about something: it is possible to have too much of a good thing. Eat too much chocolate and you'll get fat. Drink too much and you'll either create a hurricane of vomit or end up in the hospital. Create a car with too much power and... well...
That is why
the reports coming out that
Ferrari is planning to turbocharge its engines in the future are so alarming. It's not that the Prancing Horse badge hasn't had breathing assistance in the past. The Autoblog article rightfully points out that the old F40 was a blown-V8. However, everyone had turbochargers back in the 1980s;
even the Plymouth Voyager. Turbochargers were like fringed bangs, mullets, and shoulder pads; everyone had them, but not everyone was sure why.
A momentary interruption to our normally scheduled rant as we present material that
MAY CONTAIN ENGINEERING LIKE SUBSTANCE
Turbocharging: A Simple Primer
The benefits of turbocharging are simple: take a smaller, more efficient engine, strap on a vacuum, and get the power of a much larger engine when you want it. Simple, effective. This power boost is made possible by forcing more air into the combustion chamber; more air means more oxygen to react with fuel; more reaction means more power. Superchargers work in a similar fashion--ramming air into cylinders--however, they have the downside of being belt-driven; that is, it takes some of the power that you are making to run the supercharger. Not so, the turbocharger.
Hot exhaust gases created from combustion leave the cylinder and rapidly expand down the exhaust pipe at high velocity. This volume change is wasted in normal (or, to use engine parlance, normally aspirated) engines. However, by placing a turbine (turbo, get it?) upstream of the cylinder, it is possible to take advantage of this expansion and power a compressor off the same shaft as the turbine with a much smaller penalty paid in lost engine power. Turbochargers are lithe devices that operate at extremely high speeds and temperatures making them some of the most advanced, and fragile, systems in place on cars today. Despite their lightweight, though, turbochargers still require time to accelerate to operational speed; enter the dreaded turbo lag.
What is turbo lag? Well, when you put the foot down in your normally aspirated car you get what engineers refer to as a "linear" response. The more that you put your foot down, the more acceleration that you perceive. This tends to progress in a very natural and expected fashion; the further your foot goes down, the faster the car goes, by proportion. Whether or not this is in fact linear is inconsequential. Now put a turbocharger onto the engine. Rather than increasing proportionally with throttle opening, the amount of air entering the engine with increasing engine speed is in fact exponential. The faster a turbocharger runs, the more air that it will pull into the cylinder, further accelerating the turbocharger. To get this reinforcing feedback, though, requires the engine to be running at sufficient speed to generate enough exhaust gases to be expanding fast enough down the cylinder to power the turbocharger. Furthermore, turbocharging allows the carmaker to use a smaller engine than they otherwise would. A small engine with no boost is not a very powerful engine. Yet, when the turbocharger reaches operating speed, the power will not come on gradually. Instead, it often slams home with frightening effect. Driving an unfamiliar turbocharged car can be a harrowing experience. The effect of turbo lag is exacerbated by having larger turbochargers; obviously, larger turbines mean larger inertia, mean more torque required for the same acceleration (thanks, Mr. Newton).
There have been several attempts over the years to
mitigate --note, no one has
ever claimed to be solving or to have solved the problem of turbo lag before the gents in Maranello -- the effects of turbo lag. The Supra Mk V had what are called
"sequential" turbochargers. On these engines, a smaller turbo is placed in series with a larger one. At lower engine speeds, the smaller turbo "spools up" faster, giving boost at the low end. By the time the smaller turbo has reached its maximum operational velocity (at which point it produces no more boost pressure) the larger turbo is, theoretically, reaching its operating point; picking up where the little guy left off. This requires a very testy and time consuming development process. The two turbochargers must be sized properly such that one gives way to the other in a seamless fashion across a broad range of engine speeds. Rally cars have utilized "
anti-lag systems" for years. For these systems, air from the intake side is admitted to the exhaust to keep the turbo spinning at a higher speed than if it were simply allowed to "stage down." Finally, VW has taken the novel approach of using both a supercharger and a turbocharger in what it calls
a "twincharging" system. Despite initial expectations--and having driven one--I can say that the engine is marvelous. It delivers fantastic power down low and keeps on the boost well into the higher reaches of the tachometer. Even more impressively, it makes 160HP feel like all you will ever need, with the right 6-speed transmission, of course.
END TECHNICAL BANTER
With all this technology currently available, I really do wonder what Ferrari could be cooking up. They are masters of style, yes. Masters of advanced technology and innovative solutions to long-standing problems in automotive design? Not hardly. Back in the 1980s, automakers were putting turbochargers onto cars to get ghastly amounts of horsepower from engines that could barely handle it. Unsurprisingly, pressurizing an engine occasionally led to detonation. Today's computer-controlled engine management systems are vastly improved over their great-granddaddies from the "Me" decade, but they can't stop an over exuberant driver from spending a bit too long with the "go" pedal down a few too many times. Ferrari drivers are not known for restraint.
It will be necessary for Ferrari to increase their average fuel consumption if they intend to continue selling cars in California (see the marvelously ludicrous rumored Ferrari hybrid). Yet, I remain unconvinced. A turbocharged Ferrari has all the appeal of a monkey strapped to a stick of dynamite. He might be fun for awhile, but at some point he's going to bite you... or explode.
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