AZDrifter
True Classic
I installed an AEM wideband oxygen sensor while putting in the Allison exhaust so I could see how bad the air/fuel ratio is with all of the modifications I have done. Modern OEM computers compensate for unexpected additional air by running the motor extremely rich. We have to buy "piggyback" computers and tune out the extra fuel and get them back into a reasonable range.
The X computer is 34 years old. You would expect it to be a mess after trying to compensate for an aftermarket cam, a bit more compression, and a free-flowing long tube exhaust. Plus I have new fuel injectors. Quite the contrary. Once it got up to operating temperature, it maintained an ideal Air-fuel ratio for fuel economy. It bounced between 14:1 and 15:1 for the whole test drive, except during throttle lift off, where it went a tad rich. I can't wait to start tracking gas mileage with the new header. I think I can top 35 mpg. :headbang:
I am guessing that early computers were a lot less complex and just stuck to the task at hand. Plus they didn't have to deal with ignition timing. The ideal ratio for making power is 13.5:1, but the benefit of getting there is not worth the cost.
The X computer is 34 years old. You would expect it to be a mess after trying to compensate for an aftermarket cam, a bit more compression, and a free-flowing long tube exhaust. Plus I have new fuel injectors. Quite the contrary. Once it got up to operating temperature, it maintained an ideal Air-fuel ratio for fuel economy. It bounced between 14:1 and 15:1 for the whole test drive, except during throttle lift off, where it went a tad rich. I can't wait to start tracking gas mileage with the new header. I think I can top 35 mpg. :headbang:
I am guessing that early computers were a lot less complex and just stuck to the task at hand. Plus they didn't have to deal with ignition timing. The ideal ratio for making power is 13.5:1, but the benefit of getting there is not worth the cost.