Almost all the race motors we build get fuel injected and go across the dyno, they get broke-in with a carb and then get switched over to fuel injection, engines will almost always make more horsepower with a carb but usually overall driveablility and fuel control is better with fuel injection.
Most of the EFI vs. Carb testing that I've done on the dyno shows that a carb has a slight power advantage at peak power, but generally gives up some power in the mid-range. This isn't always true but seems to be true about 80% of the time. I don't worry about it or pay much attention to it since the power difference is irrelevant for the customer. If we were building EMC type engines then we would explore it.
The couple of experts I've talked to say it has more to do with the intake design than anything else. The intake for dry air should be designed differently than a wet manifold. Most aftermarket EFI systems use wet manifolds for port injection just because that is what they already have tooled up. Eventually we might see the aftermarket start to design dry air intakes. Once that happens the power difference will swing the other way. The G3 Hemi guys are seeing this.
