A carburetor IS a computer

[Tommy]

From time to time I see (and participate in) good natured jousting between old school and new school hot rodders regarding the pros and cons of carburetors and electronic fuel injection (EFI). My sense is that some EFI proponents see them as more efficient and less mysterious than that carburetor they once had that they could never get to run right. Carburetors are also seen as primitive and unsophisticated by some. . . So I'd like to set the record straight by noting that carburetors ARE computers, and they can do much (but not all) of what EFI can do with a less complex system.

In today's world most people assume the word "computer" refers only to an electronic digital computer. But well before digital computers there were analog computers. An analog computer is defined as:

A type of computer that uses the continuous variation aspect of physical phenomena such as electrical, mechanical, or hydraulic quantities (analog signals) to model the problem being solved. In contrast, digital computers represent varying quantities symbolically and by discrete values of both time and amplitude (digital signals).

I was first introduced to an analog computer during engineering school back in the 1960s. It was a maze of electronic tubes, resistors, capacitors, etc. connected to an oscilloscope. By turning the dial on any of several variable resistors, the scope would produce any of an infinite number of wave forms. And that is one of two advantages an analog computer has over a digital computer.

The first advantage is that while a digital computer with sufficient memory can consider a huge number of possible inputs and outputs, the number for an analog computer is infinite. The second advantage is that an analog computer reacts to unintended inputs with whatever output it is configured to produce, while a digital computer will simply stop processing or enter its error routine. This means an analog computer (like a carburetor) can respond to a less that ideal input (e.g., the wrong size jet) with a less than optimum but still workable output.

So, am I saying that carburetors are "better" than EFI? No. I'm saying that both systems involve computers receiving inputs and producing outputs. Both are complex and the added complexity of the EFI system allows it to do a better job of tuning in real time - provided ALL of its systems are functioning correctly. But carburetors have their advantages too, including operating under less than ideal conditions. And they are not as mysterious as some think they are.