Installing resistors

[reuhzaki]

Hi everyone, been a while since I've been on. My rb20det is completely rebuilt and ready to drop into my s13. I put dsm 450cc injectors in it and now I need to put in resistors. I'm getting 6.5 ohm 10W resistors and need to know how to install them. Please shed some light on this for me. Pics would help a ton too. If you need pics of my set up please text me (405)613-6824

[centralcoaster33]

Um, RB20DET into an S13? This is a car enthusiast forum, of course we need pics of your setup! Remember when soldering that you want to heat the wires and contacts, not the solder.

[Ken@PTUNING]

You need to solder the resistors in-line with the power wires for the injectors (red on the S13's).

[reuhzaki]

Thanks for the replies I'll get pics up if I can

[reuhzaki]

And yes rb20det into s13. Will be looking at a little over 400 hp

[Ken@PTUNING]

450cc is too small of an injector for over 400whp.

[reuhzaki]

I will do a little more research on injector size in that case. From what I've heard and read so far it should be fine. I can't get pics on here. From what I understand I can cut the were a few inches behind the injector plug, run some gauge wire to and from each individual resistor to each injector and to the wire leading to the ecu right?

[Ken@PTUNING]

The minimum injector you should run is 550cc. This will keep you from hitting 100% DC and give you just enough head room left over. Personally, I'd choose a 650cc or 750cc injector. You may possibly be able to hit 400whp on the 450cc injectors by raising the base fuel pressure to 56psi (effectively creates a 500cc injector) but the trade off is that you'll lose total flow capability of the fuel pump (fuel pump total flow decreases with pressure).

The following calculators are nice tools to spec injectors for whatever your goals may be. They're theoretical so should be used as a reference.

Target HP Based on Injector Size:
http://fuelinjectorclinic.com/hp-calculator

Fuel Injector Size Based on HP Target:
http://fuelinjectorclinic.com/flow-calculator

I will do a little more research on injector size in that case. From what I've heard and read so far it should be fine. I can't get pics on here. From what I understand I can cut the were a few inches behind the injector plug, run some gauge wire to and from each individual resistor to each injector and to the wire leading to the ecu right?

Correct, you can mount your resistor box remotely and run the wiring. 16-18GA should be sufficient. You can also install each resistor inline on the harness if you want provided there's space.

[reuhzaki]

What is meant by install them in line?

[PapaSmurf2k3]

450cc injectors should get you somewhat close to the 400hp goal. Remember, there's 6 injectors instead of the usual 4.

Ken is right though, I'd probably want a little more wiggle room if it were my car.

[Ken@PTUNING]

Inline:


Remote Box:

[reuhzaki]

Wouldn't it be bad to install the resistors that close to the injector plugs? Heat issues?

[reuhzaki]

Guess what I'm asking is, is it okay to run about a foot of 16ga wire from the injector plug to the resistor? Wandering if the extra length will cause a lag in the signal from the ecu and I won't get fuel at the proper time. Could this be an issue?

[PapaSmurf2k3]

It shouldn't be an issue. You should be able to put the resistor wherever you want.

...you could also get properly sized injectors that also don't require resistors.

[reuhzaki]

Thank you for the info everyone. Only reason I'm using these injectors is because I got them for cheap from a friend. And as far as the hp goes in going to keep it close to 350. I appreciate everything guys