Originally Posted by Dr.Hess

EFI is far better than carb, IF 1. You have complete control of the computer OR 2. you don't plan on ever changing anything on the vehicle. Carbs will at best be "perfect" at two or MAYBE 3 spots, and "good enough" everywhere else. With proper tuning, and EFI system can be perfect everywhere. Now, most EFI systems don't give you access, so on one of those systems, you are OK if you don't change anything outside of the parameter range of the factory tune.

Early HD EFI had no barometric compensation, or closed loop. They ran pig rich at altitude. Outrunning most twinkies on I90 was easy. I think the current generation has that fixed, and those big 10x inch motors fly.

Originally Posted by 1997bagger

If you are using the Magnetti and Marelli thats on your 2000 Road King as your foundation of opinion against a carb, you don't have any bullets in your gun. Now the Delphi system has proven itself, been working since 2002 is a different story.

Yes emissions took over the engine world, got to see the diesel evolve in front of me and controlled by regulations. Although Cat developed EFI on it's mid and large engines, they were paying a hefty fines to the gov each year because the engine still wouldn't meet emission standards, they threw in the towel on road application engines so EFI wasn't a savior for them.

On Harley EFI, it allowed an engine to meet emission standards to stay in production, remember the nut roasting 96 incher, it took lean to a new meaning, crap they dropped a cylinder at idle when it got hot so yes the gov controlled the American Legend and nothing they could do about it except say yes sir or Harley would be dead like Cat.

EFI has the ability to control fuel delivery at every point of rpms, it can change fuel, timing by spark more precisely and quicker than the carb bikes. A ECM can process information at a unbelievable rate, make changes and deliver and a carb 3 circuit crossover is no match for it, carb timing is based of rpm using a voes as a control and no match for a ECM. Tuning a EFI can be a double edge sword, you are at the mercy of a dyno operator and his experience but a weapon when done right but takes tuning away from the above average mechanical Harley owner, carb can be tuned by anyone with some help.

I know for a fact that a carb will out perform the M&M on the same engine from past experience plus run a carb on the big cube engine and performs flawlessly. Yes I could put EFI on the big motor and would most likely run well also but I would be f***ing with the fuel more than riding it, going to stand by the carb.

Expect more advanced EFI to come, faster, smarter and more functions. Our trucks run a data link systems from computer to computer that can transmit signals thru 3 to 5 wires instead of individual wires and computers can talk to each other processing information, allows items like brakes, transmissions, cab controls engine controls link together. Turn the air screw out a turn you say lol

Originally Posted by Dr.Hess

EFI is far better than carb, IF 1. You have complete control of the computer OR 2. you don't plan on ever changing anything on the vehicle. Carbs will at best be "perfect" at two or MAYBE 3 spots, and "good enough" everywhere else. With proper tuning, and EFI system can be perfect everywhere. Now, most EFI systems don't give you access, so on one of those systems, you are OK if you don't change anything outside of the parameter range of the factory tune.

Early HD EFI had no barometric compensation, or closed loop. They ran pig rich at altitude. Outrunning most twinkies on I90 was easy. I think the current generation has that fixed, and those big 10x inch motors fly.