550cc low impedance..help
#1
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okay..i read the manual but didn't quite get it.... my injectors are 550cc low impedance...i'm on constant page 1 and set my fuel requirement engine displacement at 1599cc and dail 550cc for injectors size and 14.7 for air fuel ratio..and caculated out a 4.9 / 4.9 ....what do i set my PWM current limit at? and my PWM time threshold (ms) ? any help? i'm lost...anyone running the same setup?
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#2
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Do a search for "low impedance" then read all the threads in the megasquirt subforum. You questions are answered there.
If you are using the PNP I strongly suggest you use resistors inline with your low z injectors. The Low z injectors sink alot of power to ground and the PNP doesn't have sufficient grounding in original form to support them. So basically it can be done, but it won't be easy and adding resistors will make your life a whole lot better.
The PWM settings you need are listed in the forum and in the megamanual.
If you are using the PNP I strongly suggest you use resistors inline with your low z injectors. The Low z injectors sink alot of power to ground and the PNP doesn't have sufficient grounding in original form to support them. So basically it can be done, but it won't be easy and adding resistors will make your life a whole lot better.
The PWM settings you need are listed in the forum and in the megamanual.
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There are resistor packs on a ton of cars from the factory, I know alot of late 80's Toyota's use them. They're often in aluminum cases, maybe about the size of a pack of cigarettes, sometimes with fins like a heatsink. The MegaManual covers alot of this (www.megamanual.com), but basically you wire it in so your low impedance (2-6 ohm) injectors are seen by the ECU as high impedance injectors (12-16 ohm). The add resistance and sink away the heat...
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Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
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That's definitely the easiest solution....
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Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
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I opted for the $30.00 flyback board for my MS1-V2.2, that will allow you to run low-z injectors without resistors.
http://www.diyautotune.com/catalog/m...ecus-p-44.html
http://www.diyautotune.com/catalog/m...ecus-p-44.html
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The v2.2 with flyback board, and better yet the v3.0 board, absolutely will run low impedance injectors with no problem. Using the stock grounds in the Miata becomes the limitation very quickly and I suspect is why many have had issues on these cars. I don't see these issues on other cars with dedicated grounds and proper wiring, including big nasty twin turbo V8's with 160lb low-z injectors...
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Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
Jerry a.k.a. 'FoundSoul'
DIYAutoTune.com
'91 Miata BEGi S3 GT2560 w/ MSPNP - 14.1psi - 253whp, 232wtq
'95 Miata n/a
A few other cars....
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