Thread: How to size fuel injectors?

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There are two types of Injectors-LOW IMPEDANCE and HIGH IMPEDANCE (think about Subwoofers-they can take more power if they are low impedance)-

Most LOW IMPEDANCE injectors are engineered to "SNAP" open with more current than a HIGH IMPEDANCE" injector. They snap open faster because of less resistance in the coil, hence they are more controllable. Generally, the more horsepower you have, the more you need the peak and hold injector (faster reacting opening and closing). The high impedance injector was designed to accomodate the OEM market for reliability and lower flow arena where absolute reaction time of the internals are not as critical. This is a cost savings for the OEMs without hurting the performance of the total fuel control package (ECU, injectors, etc.). The reason MOST people ask for the HIGH IMPEDANCE injectors is that they want to use them with their FACTORY ECU. If you have the choice, I would suggest the LOW IMPEDANCE injectors to optimize your injector linearity (FLOW PERFORMANCE) and overall tunability. IMHO, not all Injectors are created equal, though-

In my Car, I am running a large, low impedance Injector (to handle 800 hp+), but I wanted it to have good manners around town, so my Injectors are from Injector Dynamics (IMHO, the best there is right now):
Injector Dynamics - The standard for tuners and car builders worldwide.

They also have a "Library" where they discuss various topics: The Library - Injector Dynamics

"What happens if you put on much larger injectors than needed? Can the control use only the amount needed or is a squirt one size no matter what?"

Basically, that is what I am doing-using larger Injectors than needed (most of the time)-you control the Fuel by "pulsing" the Injector (in milliseconds) to get the desired Fuel rate-the trick is to "controlling" the fuel rate on high hp engines-

As far as what size of Injector to use, this may help:
https://www.rceng.com/technical.aspx...BumsfW2BlNBghf

hope this helps-