Interesting. Is that an apples to apples comparison? In other words, is that pulling off a modern TBI unit and dropping on a carb and picking up 5% or does that include an intake or other changes as well? What kind of engines? What kind of EFI?I put this very question to a friend who has a serious speed shop, with a chassis dyno built into the floor. He said it's easier to get good performance from EFI, but for balls-out maximum performance the carburator beats it by maybe 5%. It's just harder to get there. He has the advantage in experience, and of course his dyno makes it possible to operate cars at wide-open throttle while setting adjustments.
I could easily see picking up 5% by going from the stock comb-over EEC IV setup to a single-plane on a 5.0 but that's more to do with intake than fueling but also with the EEC being 20-30 years old. EFI tech is moving pretty quickly now.
What does he think of the Engine Masters segment on EFI vs carb? The carb lost about 3% power (12.5hp peak) consistently under the curve above ~4k. The EFI was easier and quicker to tune than the carb too once they got past some sort of issue running a dual plane intake.
Seems like fuel is fuel. A carb and EFI should be neck to neck in peak power all other things equal. :shrug: EFI would have the edge in precision though, so I would expect it to potentially make more power under the curve and be more drivable. EFI also does baro adjustments for you so you don't have to change tunes due to DA changes.
All I have access to is a butt dyno and it's not very accurate!