In the late 90’s a new diet roared across America at Bubonic speeds, promising that you could drop waist sizes faster than Christian Bale if only you would stop eating carbohydrates forever. Pancakes were quarantined. Burgers came wrapped in pre-wilted lettuce instead of golden sesame seed buns. But then the Great American Diet Pendulum (commissioned by President Hoover in 1929) swung back the other way, and we returned with gusto to our Bisquick and Barilla.
But not all carbs have recovered in the same way. The ones we really care about are those musical gasoline suppliers of antiquity- carburetors (because exactly none of you considered a lettuce-nested burger in 1999). Although the last production carbureted car was a 2006 Lada, the majority bowed out in the late 1980s, when a tsunami of imports surged onto the American market, bearing their newfangled fuel injectors and boasting higher fuel economy and lower emissions. Best of all, like James Cameron’s stop-motion Terminator of the same era, they were controlled by computers.
Today carburetors are relegated to the performance drag racing and classics restoration markets, which are often intertwined. NASCAR, too, still uses carburetors, though they announced in January that they would allow fuel injectors for the 2012 season. The fear was that electronic, computer controlled fuel injectors would become too complicated and that such systems would make cheating much easier and much more difficult to track. That’s to be expected of a racing league born in the moonshine-watered backwoods of Appalachia. And it’s an apprehension many amateur racers and hot rod enthusiasts share–a computer system is too complicated, and too expensive, to find a home on the rubber and octane simplicity of the drag strip.
The import market has been quicker to adopt the high tech petrol sprayers, and EFI has become a standard on touring and rally circuits around the world, but according to top carburetor manufacturers, some of whom also make fuel injectors, carburetors are not ready to settle into museums just yet. In a 2009 interview with Car Craft Magazine, Steve Johnson of BG products said that with EFI, “You only gain about 10 hp at the peak, so for a lot of guys it isn’t worth the money.” And Butch Bass of Holley said, “A properly sized manifold and carb can make as much absolute power as EFI.”
But a new generation of autoholics (of which the author is a part) is quickly approaching. This younger breed is very comfortable around computers and computerized systems. So comfortable, in fact, that if you touch our smart phones or tablet PCs, you can expect to lose your hand at the wrist. This techno-servitude has perhaps led to an overconfidence in and mystification of EFI. It may be time to take a simple, honest look at EFI and find out just what makes it the greatest thing since the iPad 2.
The “E” in EFI (Electronic Fuel Injection) means that a series of sensors send input to the system’s computer. Here we go. First, the Crank Position Sensor reports on the engine’s RPMs. Next, the Throttle Position Sensor helps the EFI’s computer determine how much load is on the engine. The computer throws those numbers into a data set called a Fuel Map, which does a simple equation to determine how long a fuel injector should actually remain open. For example, an engine running at 2,100 RPM with throttle open to .5 is assigned a fuel value of 14. When the throttle is opened all the way to 1 (fully open), the fuel value goes up to 16.
Next, the computer gets a bit more complicated, deciding if it needs to make any adjustments to the Fuel Map equation. It starts with the engine temperature. If it is a cold engine, the Fuel Map values are raised by a predetermined percentage to get more fuel to the engine. This works rather like a carburetor’s choke. When an engine is cold, the Fuel Map values can go up as much as 20%. As the engine warms, the value returns to normal.
The Intake Air Temperature Sensor is next up, relaying the outside temperature to the computer, which makes yet another adjustment to the Fuel Map. It has been programmed to account for the fact that lower air temperatures require a richer mix.
Finally, the computer pulls a number off the final Fuel Map and applies it to the actual fuel injector, allowing the nozzle to remain open for that specific length of time. Fuel, air, spark, speed.
It seems intimidating to imagine that all of this happens in the blink of a Red Bull-addict hummingbird’s eye, but if we’re honest, computers will always be faster than cars. What’s even harder to comprehend, however, is that some of the carbs manufactured today eschew Fuel Maps and sensors for precise machining and natural processes like Bernoulli’s Principle–and can still sometimes outperform EFI systems.
Now it’s time for my opinion, so you can feel free to click away if you like and continue down your browsing road. I’m something of a purist, so I don’t think I could bring myself to plug an EFI into a vintage Mustang or Challenger, regardless of how fast I wanted it to go. To me, that would be akin to covering the glorious art deco styling on the top floors of the Chrysler building with hulking, ugly solar panels, then sticking a windmill on its airship mooring mast. I mean, what if an airship wanted to dock?
Thankfully, with some of these new carburetors from Holley and Edelbrock, I wouldn’t have to devise such a generationally confused Frankenstein. They retain the classic, inexpensive simplicity of the carburetors of old while challenging the performance of the EFI’s Android-powered brain. Nothing drives innovation like competition, so I’m happy to hear that the carburetor lives.
What do you think? Are carbs going the way of the Atkins diet, or are they here to stay? Is your carbureted system better than an EFI? Any cool stories of your carb-loaded classics beating the latest iMports?