I am confused about the resistors needed with the PFC and datalogit. I have seen three different types, 10ohm - 10watt, 10ohm - 20watt, and 9ohm - 1watt. Which one is correct? Where can I get them?

 

10ohm-10watt. get them at your local radio shack . about 1 buck.

 

Radio Shack does not have them. At least the ones around here dont. We carry the resistors at the rx7store if you need them.

Jason

 

I got my resistors at Radioslack. The resistors were 5 dollars. I got the connectors for the injectors at Nissian for $12 each. The only question that I have now is which wire connects to which side? Can anyone post a picture showing which wires go where?

Thanks
Chris

 

all you have to do is run the resistor inline with the injectors harness. i don't have any pictures sorry.

 

It doesn't matter which wire goes to which side of the injector or the resistor. The electricity just has to flow through all of them:

either_wire----resistor-----injector-----the_other_wire

-Max

 

thanks Max

 

Pardon my ignorance here on using the resistors to raise the impedance for the injectors. But why can't we use only (1) 2.5 ohm resistor and hook that up in series, since (4) 10 ohm resistors in parallel has a total resistance to 2.5 Ohm. Am I missing something? Someone please explain using the resistors again.

 

You want to use 10 ohms in SERIES ("inline") with the injectors in order to raise the overall impedance of the signal net (or path). Do not use them in parallel as you know it will lower impedance.

I suggest 20W, but you may be able to use 10W.
I like to add margin in my circuits in case of unknown scenarios (current spikes, heat, etc).
Some people have used junkyards to find resistor packs (or boxes) from Hondas. I'm not sure which model cars.

You can use digikey or future active as online sources for electrical components if your local radio shack lacks these parts.

As Max stated, it doesn't matter as long as it's in the signal path. It can be placed near the source (+12V) or ground.

J

 

Sorry to veer of topic, but MANATECU, you mentioned you got the connector for the injectors at Nissan. Do you remember a part number or from what model/year the connectors came from. Additionally, when you say connect, did it include the unassebled pins for the connector. I'm still researching my Haltech install and wil appreciate the leads.

Hey Max, always read every one of your posts with interest. Thanks for your myriad contribution to this Forum!

 

carlos, u can buy the connectors for the bosch 1600 injectors from www.force-efi.com 5 bucks with the pins. they are in miami.

 

I am still waiting on mine.

 

4 10 ohm resistors in parallel would only need 1/4 the wattage rating of a single 2.5 ohm resistor since only 1/4 of the current will be flowing through each.

But I think most 4-resistor recommendations are that you two parallel circuits of two resistors in series. This will make the resistance 10 ohms again, but now the resistors only need to dissipate 1/4 of the wattage that a single 10 ohm resistor would have to dissipate.

-Max

 

Sorry guys I need some more clearity on this issue... there are two wires that go to the injectors, one is source voltage, and the other is a signal wire that goes to the ecu.. now which wire does the resistor connect to? does the resistor have to be near the injector or can it be buy the ecu? Thanks for the info...

 

It does not matter which wire. Either one will work. All that you need is for the completed circuit to have the same resistence as it did with the factory injectors.

Grant

 

Like Black93REW says, it doesn't matter which wire you put the resistors in. Electricity is like hydraulics -- you need a circuit so that the oil/electrons that flow in have a place to flow out. It doesn't matter which side of the component you put the resistors on, because they will resist the electron flow just the same.

That also means you could install the injectors anywhere on the circuit that you want to -- near the injectors, near the ECU, or anywhere in between.

-Max

 

So each secondary injector gets a resistor, not just one bsecondary injector.?

 

Off topic question....for those of you with aftermarket secondary fuel rails....what did you do with your fuel temperature sensor? Where did you relocate it?

 

toss it in the trash. the reading from it never realy change anyway...

 

Really? I was told that I would have to find another place to hook it up. Does it not effect anthing to not have it? What about the connector from the wiring harness? Can I just cut it off since I won't be using it? I am in the middle of hacking my wiring harness up...so if I don't need it, it's getting cut off.

 

i dont know about the PFC, but i would imagine you would put a resistor in there.
here i will do a search... https://www.rx7club.com/forum/showth...el+temp+sensor

sounds like they agreed

 

Just another info thing for some of us Guys. These resistors(10watt 10 Ohm) are HUGE or what I think is huge compared to the tiny wire wound ones I was thinking of. They look like ceramic with wimpy wires out of both ends and I hope they dont break. I used the conectors from Force-efi.com and made sure that I crimped, soldered, and heat shrunk all the conections. What made Me mad was that I just bought a new harness and had to hack off the stock conectors.

One question I have is that how hot do these suckers get or do they get hot at all?

 

I ordered the resistors from Rotary Performance, because the rx7 store was out...I asked them what resistance and power they were rated at, the guy didn't know, but he told me 'these are what we use in our installs'...
I got them and they are 3 ohm resistors...will this damage my injector circuit in the PFC?
I am a little worried.
-Dave