High Impedance Injectors

[Chicken Patty]

Guys, is there any downside to running High Impedance injectors? I know you can eliminate the resistor box and do it but is there any downside?

Reason I ask is because I had bought Bosch 1600cc injectors and I got rid of them because I couldn't get them to idle. Would high impedance fix this, or would I still need the FIC Easy Tune?

Thanks guys!

 

[the_mork]

Whether you'll be able to get big injectors to idle or not is going to come down to the injectors individually. Are you trying to run gas or e85? There wont be big penalties or gains just because injectors are high impedance so don't let that part be your decision maker and instead buy injectors based on reports of whether they respond well to small enough pulse widths to idle on the fuel you choose.

 

[Chicken Patty]

Whether you'll be able to get big injectors to idle or not is going to come down to the injectors individually. Are you trying to run gas or e85? There wont be big penalties or gains just because injectors are high impedance so don't let that part be your decision maker and instead buy injectors based on reports of whether they respond well to small enough pulse widths to idle on the fuel you choose.

I'm running E85, why do some people have problems with big injectors then? I read the description from FIC on the easy tune, but kinda seems like it would do a similar job as to having high impedance injectors. Or did I read that incorrectly?

 

[the_mork]

There are a number of reasons why people have problems with big injectors. First of all is hardware. ECMlink rocks but it relies on an older style of ecu that has a slower injector driver. For almost all cases this slower injector driver is entirely unimportant but when it comes to really large injectors such as 1600cc Boschs and 2000+cc injectors of other manufacture every little bit counts. This is not a failure of the product but the platform itself. Later ecus such as the H8 or evo7+ ecus use more modern injector drivers that cut down deadtime a bit. Second is tuning ability. Sometimes it just isn't enough to set the deadtime and injector size correctly because the injectors have odd characteristics in certain areas. Under these conditions you can use MAF smoothing or SD MAPvsVE scaling to smooth ill effects but this requires an understanding of what you are doing that goes beyond following a simple tuning guide.

As for the easytune, the easytune increases voltage at the injector, high impedance injectors receive a higher current because the current is not reduced by the resistor pack. Below are links to some explanations that are far better than I could pull off in explaining what the difference between these methods happens to be.

Water circuit analogy to electric circuit
Water circuit analogy to electric circuit

 

[Chicken Patty]

I'll check that out when I get home, thanks bro.