anyone have a link to what ohm resistors i should use?
s5 high impedence is like 12-13 ohm and se 680 cc are like 2-3 ohm so i need a 10 ohm resistor but what wattage? any info helps. been searching long to no evail.
I plan on using a multimeter to make sure but just getting a ballpark right now...

 

the factory resistors are actually 6 ohm. You can use 10 watt 6 ohm.

 

should i figure in the resistor box too? or is that what you're talking about?

another guy posted this... but it could be not for an s5 cause of the resistor box?

http://www.rotaryresurrection.com/2n...ctor_info.html

would you recommend just deleting the resistor box? i had it bypassed at one point but was wanted as much mpg as i could get. thx for info

 

Ok I'm confused now. You have an s5 T2 harness and you want to install S3 GSL-SE injectors?

 

^^this is correct

 

An S5 TII harness would not have a resistor pack (four 6-ohm resistors), since the corresponding injectors would have been high impedance (12-13 ohm). I think you may be mixing up the resistor pack with the fuel pump resistor/relay. To use low impedance injectors with an S5 harness, you'll need a 6 ohm resistor wired in for each injector. I use 6 ohm, 10 watt resistors from Mouser Electronics.

 

you were correct about the fuel pump resistor relay mixup not sure why i went there.

wouldn't i need 10 ohm tho? because high impedance (12-13 O) and low imp (2-3 O)
so 13-3= 10?
am i missing something?

 

The S4 setup worked/works with only 8-9 ohms in the circuit (2-3 from the injectors and 6 from the resistor pack). You can use larger resistors to get the 12-13 ohm total found in S5 saturated injectors, but it's unnecessary and will reduce the response times of the injectors. The ECU will be safe with either resistance amount. I know some people have also experimented with smaller resistors to try to maximize response time.

 

The whole point of the resistors is to keep the wattage down in the factory saturated injector drivers. It has to do with ohm's law (V=IR) and joule's law (P=I^2R). I have broken down a full example here (using a Power FC, we don't have full data on the factory injector drivers): https://www.rx7club.com/power-fc-forum-47/power-fc-injector-resistors-849993/ .

V=I*R (Ohm's law. in this case voltage equals the injector's current multiplied by resistance across the injector itself)
P=I^2*R (Joule's law. In this case, the injector's power/wattage equals the injector's current squared then multiplied by the resistance of the injector driver transistor)

 

i'm starting to understand thanks ya'll