[scott coyle]

Cobrabill,

There is a peak hp improvement with efi. Mostly because of what map said in an earlier post. With a carb, you have to have a rich enough mixture to cover the leanest cylinder and you always have lean cylinders because of the varying length of the intake runners and the distance from the carb to the intake valve.

With efi, the o2 sensor in the exhaust collector can read a 13 to 1 air fuel ratio and I know that represents all cylinders. With a carb, a 13 to 1 reading would mean 12.7 to 1, in the rich cylinders and 13.3 to 1 in the lean ones. You would want to richen the carb to cover the lean cylinders. You would loose power but save the motor.

The increase at max hp is in the 3 to 5% range on a comparison basis for well set up systems. The biggest benefits are low end and mid range power which have to do more with big plenums hurting low end power in carbs because the fuel is so far away from the combustion chamber on tip in acceleration.

Scott