Low impedance vs High Impedance injectors
09-30-09, 01:11 PM
#1
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Low impedance vs High Impedance injectors
OK can someone help me out here what is the difference between the two injectors?
My car is an 87 i heard some 87's have high impedance injectors how do i tell?
is there a visual difference?
what is the deal with resitors?
will high impedance fit in a low impedance rail?
is it possible to convert the setup from low to high?
My car is an 87 i heard some 87's have high impedance injectors how do i tell?
is there a visual difference?
what is the deal with resitors?
will high impedance fit in a low impedance rail?
is it possible to convert the setup from low to high?
09-30-09, 02:10 PM
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not trying to do anything I am just wondering the differences and if he high impedance are better and if it is easy to convert them cuz the low imp are hard to find
09-30-09, 02:35 PM
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nothing is wrong I will be upgrading to larger injectors but I have read that low impedence injectors require a resistor and that hey can fail I just want some general info on them if you send me to a thread or tell me what you know
09-30-09, 02:49 PM
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Alright, Low impedance injectors have a resistance of around 2.5-3 ohms, and high impedance injectors of around 12 ohms. This can easily be measured by a DVOM or Multimeter across the two electrical terminals. There is no size difference cosmetically as far as I know.
"Low impedience" injector is essentially an engineers way of saying "High current." And vice versa.
There is not really much performance differences between the two as far as i know. Correct me if I'm wrong, I think its more personal preference? In my experience I have not noticed any difference between the two, but then again I have never ran with stock injectors
. Hope this helps a little.
"Low impedience" injector is essentially an engineers way of saying "High current." And vice versa.
There is not really much performance differences between the two as far as i know. Correct me if I'm wrong, I think its more personal preference? In my experience I have not noticed any difference between the two, but then again I have never ran with stock injectors
. Hope this helps a little.
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09-30-09, 03:08 PM
#10
k, and to answer your question, yes you can get resistors for low imp injectors. But if you mean run highs in your S4, I doubt it because the ECU probably sends enough power for the low imp where as the high imp would require a stronger amount of electricity.
09-30-09, 03:08 PM
#11
DILLIGAF
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Yes but I don't see a reason why would you do such a thing. For one since the highs have a high resistance value, those injectors would build up more heat (depending on how you drive it.) If the temp in the injectors remain high, it can **** some **** up like driver transistors in the ecu as an example.
But if you were to change to a high impedance, it might take a little more work than usual. It's not as simple as changing the brightness on a led light or any light for that matter with a resistor. Just doesn't work.
But if you were to change to a high impedance, it might take a little more work than usual. It's not as simple as changing the brightness on a led light or any light for that matter with a resistor. Just doesn't work.
09-30-09, 03:41 PM
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Low impedance injectors were installed on cars through SN 550168. The break came in mid 87.
Low impedance injectors have (in general) a slightly faster response time, i.e. they open more quickly than high impedance ones.
The low impedance cars (like mine) have a solenoid resistor (actually a network of 4 resistors, one for each injector) mounted on the front of the right shock tower, down below the boost sensor.
Theoretically you should be able to install high impedance injectors if you remove the solenoid resistor, but I do not know of anyone who has tried this. There may be a difference in the outputs from the ECU as well--don't know.
There is to my knowledge no performance advantage to going to high impedance, other than reducing the parts count, unless you are trying to go to some aftermarket injector that does not come in a low impedance version.
Lows should measure at 1.7 - 3 ohms; highs 12 - 16.
If you ever once put 12v directly on a low impedance injector (without the soleniod resistor), it will most likely instantly convert from a fuel injector into a fuel preventer.
Low impedance injectors have (in general) a slightly faster response time, i.e. they open more quickly than high impedance ones.
The low impedance cars (like mine) have a solenoid resistor (actually a network of 4 resistors, one for each injector) mounted on the front of the right shock tower, down below the boost sensor.
Theoretically you should be able to install high impedance injectors if you remove the solenoid resistor, but I do not know of anyone who has tried this. There may be a difference in the outputs from the ECU as well--don't know.
There is to my knowledge no performance advantage to going to high impedance, other than reducing the parts count, unless you are trying to go to some aftermarket injector that does not come in a low impedance version.
Lows should measure at 1.7 - 3 ohms; highs 12 - 16.
If you ever once put 12v directly on a low impedance injector (without the soleniod resistor), it will most likely instantly convert from a fuel injector into a fuel preventer.
Last edited by calpatriot; 09-30-09 at 03:46 PM.
09-30-09, 05:15 PM
#13
I don't mean to post hondata here, but it is relevant.
http://www.hondata.com/techlowohminjectors.html
Personally, I would stick with what ever your car came factory unless you're running a Standalone.
http://www.hondata.com/techlowohminjectors.html
Personally, I would stick with what ever your car came factory unless you're running a Standalone.
09-30-09, 05:29 PM
#14
All FC ECU's must 'see' a high impedance injector circuit .
The early cars use low impedance with a resistor to attain the high impedance for the ecu.
Later cars use high impedance injectors without the resistor to attain the same impedance for the ECU.
An early car can use high impedance injectors if you remove the resistor pak.
A later car can use low impedance injectors if you add a resister to the circuit.
If you use low impedance on *any* FC ECU, (early or late) without a resistor in the circuit, you will burn out the ECU.
If you are asking if there is an appreciable difference between the performance, reliability, general usefulness, the answer is no.
The early cars use low impedance with a resistor to attain the high impedance for the ecu.
Later cars use high impedance injectors without the resistor to attain the same impedance for the ECU.
An early car can use high impedance injectors if you remove the resistor pak.
A later car can use low impedance injectors if you add a resister to the circuit.
If you use low impedance on *any* FC ECU, (early or late) without a resistor in the circuit, you will burn out the ECU.
If you are asking if there is an appreciable difference between the performance, reliability, general usefulness, the answer is no.
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