Efi - Bank to Bank or Sequential?
 

Is sequential efi worth the extra money for the ecm compared to bank to bank? Will you build more HP? Get better fuel mileage when running part throttle

Re: Efi - Bank to Bank or Sequential?
 

I think that unless you are going to monitor each cylinder/EGT/O2 why bother. SOme say it will lessen the FP 'bounce' when each bank fires. You need a crank signal also. Sometimes just because we can doesn't mean we have to.

Re: Efi - Bank to Bank or Sequential?
 

I recently bought a Holley Bank/Bank WB02 FI setup for my car. Was told by the Holley guys as well as by Dennis Moore (who frequents this board) that SFI didn't buy you much over bank/bank. Other research revealed that the auto mfgrs like SFI because of reduced emmissions and idle quality improvements. A well set up bank/bank should make similar power to an SFI.

Re: Efi - Bank to Bank or Sequential?
 

Turbojack
We Build Some Of The Fastest Turbo Engines In The Country And Hold Records In Many Sanctioning Bodies . From My Experience With Efi I Can Personally Tell You If Your Going To Make Serious Power Sfi Is The Only Way To Fly If Your Going To Puts Around Then A Batch Fire Set Up Is Fine. You Can Take A Look Even At Carb Engines Such As The 500hp One Of The Most Successful Engines Ever Merc Stagger Jetted The Carb To Obtain What You Would With A Sfi Set Up More Fuel Were Its Needed And Less Fuel Were It Did Not Need It Run A 500 Hp Straight Jet And Drop 35 Hp Now Picture That In A High Hp Application And It Does Make A Big Difference. Good Luck With Your Selection Laz Mesa

Re: Efi - Bank to Bank or Sequential?
 

Nicely put Laz, Just me first explain the 2 systems for those who are not familiar. Sequential Fuel Injection vs. Batch Fire: the manner in which injector pulses are dictated is very important to engine performance and environmental variables as well. A sequential fuel injection system triggers one injector at a time following the firing sequence of the engine. Batch fire systems trigger multiple injectors simultaneously, sometimes grouping cylinders to receive fuel in “banks.” Due to the fact that batch fired injectors pulse more than once per cylinder cycle (usually twice), only half the fuel is delivered at a time. Essentially, the first pulse of fuel is fired with the intake valve closed, and then a second pulse is released just when the valve opens. Crude but a much better system than a TBI (which is the worlds most sophisticated carbonrator) and billions of generations better than a "carbonrator" cough, cough wheeze, wheeze. SFI systems triggered by a crank and or cam sensor fire one shot as the intake valve opens. SFI systems are much more precise to optimize all engine performance characteristics. SFI systems are more expensive build and program.

If anyone is considering serious horsepower and decides to use a carburator in this day & age I believe are not truly serious. Fuel injection is the way to go and if you got the bucks then the SFI system is the best. Laz mentioned that it was the best for all out horsepower. But I would go further and say that SFI is better no matter what you are going to do with your boat. You can build a smaller engines that make more HP, use less fuel and last longer than a carbonrator engine. I truly believe that supercharged and turbocharged carburetor engines are a joke in this day in age. It is just like getting a new Pentium 4 computer with the best of everything and putting DOS 5.0 as the operating system. You guys can slam me all you want but I'm right about this.

Roby

Re: Efi - Bank to Bank or Sequential?