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Deadtime comparision low and high impedance injectors

EFI Tuning Fundamentals

Discussion and questions related to the course EFI Tuning Fundamentals


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According to your explanation, about the deadtime differences between high and low impedance injectors, can someone please make some examples? I would like to have an idea of the range of dead time for high impedance and low impedance.

I know that the values are really low calculated in MS (milliseconds) but it would be rather interesting for me to have an example to know how much significant is this difference.

I'm actually using low impedance bosch on my car and for me there's too much lag as you told in the lesson.

Many thanks

So your ECU doesn't have the proper peak-and-hold injector drivers required for Low Impedance injectors, but is using current-limiting resistors resulting in increased latency? You are looking for what the deadtime changes are as a result of using the resistor pack instead of a proper driver. Unfortunately I don't have that information.

One solution I have used when faced with the need to use a specific injector, is this box containing proper peak-and-hold injector drivers. You can remove your current limiting resistors, and drive the injectors properly. Here is the one I used:

http://www.acceleronics.com/versafueler.htm

I see there are others now offering this type of device:

https://www.fueltech.net/products/peak-and-hold-4a-1a-driver

https://www.mapecu.com/2014/05/injector-driver/

My ECU is Microsquirt with 0280150450 bosch EV1. Sorry i wrong, the injectors are High impedance, but i still hearing a little lag in the fuel delivery, so it's not a good example for my question.

The comparision that i would like to ask to the forum is:

Avoiding resistors pack or external controllers (that for sure will add latency in the circuit) let's take as example an ECU that can provide peak and hold drivers or high impedance injectors, how much the impedance of the injectors will affect the deadtime?

If we compare the same flow rate, same trademark injectors, how much could be the difference in 4 ohms low impedance injetors, and a 14 ohms injectors deadtime? will the deadtime be significatly high between this comparision?

Is just to understand that "lag" that Andre was talking about

The impedance is really only one aspect of the injector that can affect latency. By far the biggest consideration is the mass of the internal valve assembly as this is what needs to move in order to open and close the injector. In this regard the modern crop of high impedance injectors are likely to offer less latency than the older low impedance injectors.

Thank you Andre!!