Eric Hysteric wrote:
Griff, your carburator engine had less emissions than a EFI engine in all speed range? Never heard about it. I think that it possible but it's a complicated adjustment and the EFI can do it better and cheaper, even when the engine is cold. I admire your talent to prove, that old technology can do it as good as high tech EFI.
Yes. The installation, adjustment, and tuning of the rebuilt engine was done in the Ft. Wainwright (U.S. Army) Auto Skills Center (aka auto hobby shop).
The carburetor was also rebuilt, adjusted, and tuned. Likewise, the ignition system had new or tested-good components.
We spent around six hours tweaking everything using a very expensive computerized diagnostic machine. (The shop staff got 'hooked' on the project and went 'above and beyond' ... because they had gotten unusually involved, they didn't charge me normal fees for using the machine.)
The next day we spent around four hours testing the Bronco and the nearly new car, running identical tests over and over ago. We considered a wide range of variables, in an effort to make the tests as equal as possible. The measurements were taken over a range of RPMS, from idle to almost redline, as well as cold and hot starts. (We even stalled the engines while measuring, to see if extreme load caused any changes in the test results we were getting.)
The staff actually took longer than I'd planned because they were determined to find a case where the EFI car was better than the Bronco. They finally gave up because the Bronco kept coming out ahead, each and every time. (Actually, I was surprised, because I was sure the EFI car would be better, at least in some cases.)
The guy who owned the car was so upset he challenged me to a mileage (MPG) test over the same course and speed, with independent observers in each vehicle. (Yes, things had started to get out-of-hand.) He finally threw up his hands in disgust ... the Bronco get 20 percent better fuel mileage than his car. (It also increased his annoyance because the Bronco's engine was around 40 percent larger than his engine.)
Bear in mind this was effectively a new vehicle 'under the hood.' Likewise, it was adjusted and tuned using a sophisticated analysis machine. (Things probably would have been different if we'd tuned it to published factory specifications.)
Furthermore, things would have been significantly different over time, if the Bronco was subjected to the typical maintenance neglect.
It's not so much the EFI as the on-the-fly, microsecond by microsecond adjustments made by the computer that makes newer vehicles, on average, come out ahead.
And,
ALL comparisons go out the window when you add various driving styles into the mix. (The 'loose nut behind the wheel' is the biggest factor.)
