badass951

Hey everyone. I was told there was a website that sold resistors very cheap and I was wondering if someone could post a link to the exact resistor I would need. I would greatly appreciate it.

Thanks!

Chris

David Floyd

I am guessing you want the ones for injectors ?

http://www.newark.com/NewarkWebComme...jsp?id=01F9895

badass951

Yes, the ones for injectors, sorry. These are for low impedence injectors, but what exact range will these work for? Injectors with a 2.5 ohm, 2.8 ohm, etc.? Also, how many resistors do I need to buy? And how exactly does the setup work?

I apologize for all of the questions, but answers are greatly appreciated.

Chris

Danno

The maximum current-draw on the driver-injector is 16-amps. And you usually don't want to run electrical components at their maximum rating, usually 1/2 is the standard de-rating practice. In the stock configuration with four 5.5-ohm injectors, you have a combined impedance of 1.4-ohms. With a 12v output voltage, you have 12/1.4 = 8.6amp draw.

Using aftermarket 2.0-2.8ohm injectors would require roughly the same overall impedance. So four 2.0ohm injectors gives 0.5 ohms. Driving this with the DME would require a current-draw of 24-amps! Some people have installed one ballast-resistor per injector out by the connector. This allows you to use sequential fueling with aftermarket EFI systems. You'd need a 2-ohm 15W resistor to give the following load:

Injector 2.0ohms + 2.0ohm resistor = 4ohms each
4 injectors in parallel = 4 ohms / 4 = 1 ohm total
12v /1ohm = 12 amp draw

Another way to wire them is in the injector ground wires coming out of the DME. Since there's two lines connected to two injectors, you'll just need two 1-ohm 25W resistors. The scheme would then look like this:

Two injectors in parallel per wire = 2.0 ohms / 2 = 1.0 ohms per ground wire
Each wire 1 ohm + 1 ballast @ 1 ohm = 1.0 ohms + 1.0ohms = 2.0 ohms per wire
Two ground wires per DME = 2.0 ohms / 2 = 1.0 ohms TOTAL
12v /1 ohm = 12 amp draw

Here's some threads of interest:

PelicanParts: 944 turbo injectors
Ballast Resistor Installation?
DME and relays getting hot (good EE posts in this one)

When building your resistor packs, make sure to apply heat-sink compound between the resistors and the aluminum backing-plate, which acts as a heat-sink. Then use male & female 1/4" spade connectors soldered onto the resistors to splice them into the wiring. This allows you to insert and remove the resistors quickly in case you revert back to stock injectors for troubleshooting.

toddk911

how important is the wattage?