the high impedance injectors draw less current wich the stock ECM can handle. the low impedance injectors draw alot of curent and would fry the stock computer. there is a impedance converter that you can buy for a few hundred that will allow the stock computer to control the low impedance injectors. you can get low impedance injectors as large as you would ever want, like 100lb/hr and up.

i believe that low impeadence injectors like a 83lb/hr are faster and easier to tune for than really big high impedance injectors like the 50lb/hr ones. the extra current makes them open faster and allows for a stronger closing spring.

to complicate the whole injector thing even more... there are diferent styles of injectors, diferent ways they use to block the fuel. here is a link with some great injector info, might help you or it might just get you more confused but as you learn more it will all make sence. http://www.supras.com/~riemer/sonict...rs/RCtech.html

 

Interesting info, I need to sit down and read that all the way through and I am pretty sure it will make sense.