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Author Topic: 8.5Ohm or lower impedance injector on ME7.5?  (Read 7019 times)
warsuperior
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« on: April 04, 2019, 01:58:15 AM »

Has anyone tried and do they even work 8.5Ohm injector or lower impedance on ME7.5?
I need to find 1500cc injector but cant find 12ohm ones, everything is 8.5Ohm but since Im not sure will it work, I cannot order them.
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adam-
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« Reply #1 on: April 04, 2019, 04:55:12 AM »

Why not put a resistor in parallel with your existing injectors and see?
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k0mpresd
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« Reply #2 on: April 04, 2019, 06:58:55 AM »

i did this with some 1000cc low impedance rochester injectors back in 2007.
resistor inline and all worked ok.

i think i still have the harness with resistors installed actually.
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warsuperior
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« Reply #3 on: April 04, 2019, 07:59:53 AM »

I actually have Ignitron ECU but they support same as ME7.5 since its based on it.
Is there any downsite of trying resistors? cant break anything?
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nyet
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« Reply #4 on: April 04, 2019, 09:04:45 AM »

one issue: resistance != impedance.
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IamwhoIam
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« Reply #5 on: April 04, 2019, 04:18:15 PM »

Why not put a resistor in parallel with your existing injectors and see?
An 8 ohm resistor in parallel with your 8 ohm injector will bring resistance to 4 ohm. this is electronics 101
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nyet
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« Reply #6 on: April 04, 2019, 05:21:53 PM »

Except that impedance is inductive, not resistive, since injectors are solenoids.
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vwaudiguy
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« Reply #7 on: April 04, 2019, 09:30:29 PM »

LOL
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BlackT
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« Reply #8 on: April 04, 2019, 11:12:13 PM »

Except that impedance is inductive, not resistive, since injectors are solenoids.
Yes, but the speed injectors open and close on engine is too slow that impedance can have any influence.
Maybe at 5 kHZ you will notice a difference, but since engine runs to about 50-60hz that is waaaay to slow
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adam-
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« Reply #9 on: April 04, 2019, 11:51:41 PM »

An 8 ohm resistor in parallel with your 8 ohm injector will bring resistance to 4 ohm. this is electronics 101
I know, that's why I suggested it.  Then re-read the OP and I was tired.  I thought he wanted to go lower, that's why I said it.  LOL
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warsuperior
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« Reply #10 on: April 05, 2019, 07:16:29 AM »

Sorry english is not my OEM language.
Im trying to find out do the 8.5Ohm injectors work with Me7.5/Ignitron.
12ohm injectors seems to stop on 1300cc and I need 1500cc or bigger.
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nyet
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« Reply #11 on: April 09, 2019, 11:48:39 PM »

Yes, but the speed injectors open and close on engine is too slow that impedance can have any influence.
Maybe at 5 kHZ you will notice a difference, but since engine runs to about 50-60hz that is waaaay to slow

Yes and no, injector latency is measured in milliseconds, and the rise time (and thus opening time) is directly related to impedance, and how well the drivers are matched to supplying current quickly enough during opening...

I could be wrong, though, perhaps in this region of operation it doesn't matter. I suspect that it does alter latency though.
« Last Edit: April 09, 2019, 11:51:13 PM by nyet » Logged

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amd is the best
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« Reply #12 on: April 10, 2019, 11:52:26 AM »

I'd advise getting new injectors.
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