EFI: Back to the Future
Bobby Williamson
Wednesday April 13 2011, 2:30 PM

Yeah, it was WAY cool back in the day, the 1960's. "Stacks" poking through the fabricated hoods of '37 chevy coupes. Hilborn fuel injection was a hallmark of the modified scene for years.

Come-to-find-out, it's deja'-vu all over again....NASCAR is rolling FI back out. But don't be looking for the tell-tale injector stacks, or anything, for that matter, to look, sound, perform, or actually do anything any different that the cars are presently doing. This a'int your dad's fuel injection....it's electronic. Big Time.

True, production cars have been using electronic fuel injection systems since the mid-1970's. The last carbureted vehicle rolled out of Detroit in the mid-80's. So, the electronic system is hardly new. AND, for that reason, NASCAR has faced considerable criticism. The argument goes something like this: modern hot-rodders, and modern fans (sitting in multi-colored grand-stand seats), never will be interested in such antiquated vehicles. Is the reasonwe are race fans, in any way connected to the carburetor or lack thereof? That'sNASCAR's problem? Fuel Injection? Folks aren't interested in NASCAR because of its fuel delivery system?? Dream on. Right, 5-second leads, aero-pushing and cookie cutter tracks just aint the problem..........it's those dad-gummed old Holley carbs......!

EFI involves a high-pressure (50-ish lbs/in2) fuel stream generated by an electric fuel pump. The fuel is delivered directly into the manifold via an electronic nozzle or "injector", with each cylinder having its own injector (multi-port). Since the system over-pumps, excess fuel is returned to the tank through a system of pressure regulators and plumbing.

Even us old hot-rodders, know that combustion requires fuel AND air (specifically,oxygen). "Air" enters the system through a filter, is monitored for quantity, throttle position, manifold pressure, and temperature by sensors by monitors placed in the "plenum" chamber.

Other factors, including exhaust-oxygen-content and water temperature are involved, but the timing (including ignition) and length of duration of the injectors and all the "air" parameters are controlled by an on-board computer, which optimally calculates........everything.

I'd assume the NASCAR version will be somewhat different, but the basics are necessary, and the main basic is the on-board computer and its operating system(s). Hackers anyone? If Smokey and his hidden gas tanks were a problem, just wait! Can you say GOAT RODEO?

Jeff Gilder
@jeff-gilder   13 years ago
A proverbial field day for todays geekish tuners. A whole new section of grey area from which to create a possible advantage. Hmmmmmmm.
Johnny Mallonee
@johnny-mallonee   13 years ago
Next thing you know LAPTOPS will be outlawed in the pits Power up those cellphones boys