Against many folks wishes, I am bumping up my 7mgte with a 57 trim, Lexus afm, SAFC, and 550's. I have refrained from asking questions on here because many members seem to get off on making themselves feel smart with unnecessarily complex answers. You are all better than me, and I understand that I'm an idiot for not building my car the way you did. Now that that is out of the way, could someone (in layman's terms) please tell me which injectors will plug in and work? I just tried to read a thread on "the other site" and it was more complex than my college text books. THANK YOU And yes, although overly complex at times, you have ALL been very helpful.
High Impedance vs Low Impedance injectors
- Thread starter Supra Noob
- Start date
Both will work with the 7MGTE no modifications necessary.
The 7M has low impedence injectors stock. Only difference between low and high is that high imp. react slightly slower and they use less current to pop/stay open. The current flowing through the wires is all that you need to be worried about.
Low imp injectors use lots of current, so switching to injectors that use less current is A-OK. Vice versa won't work: wires that were spec-ed out for low current injectors might burn up if too much current flows through them.
tl;dr you're fine whichever injectors you pick. 550cc RX7 injectors are high impedence and swap right in.
The 7M has low impedence injectors stock. Only difference between low and high is that high imp. react slightly slower and they use less current to pop/stay open. The current flowing through the wires is all that you need to be worried about.
Low imp injectors use lots of current, so switching to injectors that use less current is A-OK. Vice versa won't work: wires that were spec-ed out for low current injectors might burn up if too much current flows through them.
tl;dr you're fine whichever injectors you pick. 550cc RX7 injectors are high impedence and swap right in.
EVO 8-9 560cc Injectors are also work very well.
But you will have to wire in the correct style injectors clip.
But you will have to wire in the correct style injectors clip.
SupraSport was selling stock injectors resized. I have no comment on how good they are. I don't know. You can also cut the harness, solder on the RC clips, and save the old ones just in case. Nothing wrong with your build. I have a Boss Jr T04E 57 trim, the Lexus meter, and 550's. And no tuning device. The car runs as designed by Toyota. If I back out the bypass, the mixture leans up a bit under load, timing advances, and fuel cut is raised. If you don't have 93 or 94 at the pump, you might want to keep that bypass at a minimum.
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I've got a bolt-on 60-1 turbo, 550cc injectors, and Lexus AFM. No tuning device here either. I do have an adjustable fuel pressure regulator and upgraded fuel pump, which I'd recommend, but that's it.
You'll be able to use either low or high impedance injectors just fine.
As I understand it, low impedance injectors run higher current, and are able to react somewhat faster, and therefore go "static" at a higher duty cycle. I also understand that the stock ECU will never allow the injectors to go into the range where even the high impedance ones would do this. There is supposedly a slightly higher accuracy of fuel delivery to this as well, but so long as the result is consistent, which it will be with decent injectors, the ECU will be able to adjust. (This paragraph is based on my own layman's interpretation of other things that I've read, and may have varying degrees of accuracy. YMMV.)
You'll be able to use either low or high impedance injectors just fine.
As I understand it, low impedance injectors run higher current, and are able to react somewhat faster, and therefore go "static" at a higher duty cycle. I also understand that the stock ECU will never allow the injectors to go into the range where even the high impedance ones would do this. There is supposedly a slightly higher accuracy of fuel delivery to this as well, but so long as the result is consistent, which it will be with decent injectors, the ECU will be able to adjust. (This paragraph is based on my own layman's interpretation of other things that I've read, and may have varying degrees of accuracy. YMMV.)
Supra Noob;1838599 said:
Sometimes complex answers can be helpful, only reason people are doing so is they want you to know why your putting stuff on, not just telling you what to put on. And honestly dude, no matter what you do in this world somebody is going to talk shit, if somebody isn't you aren't doing something right. Keep chugging and build the car the way you want.
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Thank you to everyone, you have all been super helpful! Now I get to chew on your info until I get my turbo back 
Nick M - I f-ing love your license plate!
Nick M - I f-ing love your license plate!
Correct me if I am wrong but don't you need a resistor pack for the high impedance style? Also AEM told me that if you don't it will not only burn up your wiring but the drivers in the ECU.
No. The high impedance is what limits the current. Think of it more as resistance than impedance. Consider yourself corrected...
Turbo Habanero;1839025 said:
It doesn't. The altitude effects your cylinder pressure.
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Higher elevation is less absolute pressure.
Side note, this is also the reason why people in coastal areas will hit FCO at ~10 PSI, whereas people in places like Calgary Alberta (~3500ft) will be able to run 12PSI boost on everything stock with no fuel cut.
If your car normally runs high impedance injectors (ie: 7M-GE) and you want to install low impedance injectors, then you will need the resistor pack. If however your car normally runs low impedance injectors (ie: 7M-GTE) and you want to install high impedance injectors, then you could bypass the resistor pack that is present, but I believe that you do not need to, as it's a relatively small amount of additional resistance, and will not have an impact on the injector's performance.
Side note, this is also the reason why people in coastal areas will hit FCO at ~10 PSI, whereas people in places like Calgary Alberta (~3500ft) will be able to run 12PSI boost on everything stock with no fuel cut.
If your car normally runs high impedance injectors (ie: 7M-GE) and you want to install low impedance injectors, then you will need the resistor pack. If however your car normally runs low impedance injectors (ie: 7M-GTE) and you want to install high impedance injectors, then you could bypass the resistor pack that is present, but I believe that you do not need to, as it's a relatively small amount of additional resistance, and will not have an impact on the injector's performance.
Humidity doesn't affect a mass airflow sensor. Unlike ours. Sad. Now if 3P would get his butt in gear. *pulls tongue from cheek*