David Floyd

I will use spade connectors, since bigger is better, I will change to the larger piece for the heat sink and I think it should be mounted some way, maybe just a ziptie would work.

mwc951

I am considering attaching the heat sink plate to the large mounting bracket that the DME & KLR are bolted to. Then running wires from the resistors(soldered) to where ever I tap the gray and gray/black wire exiting the DME box(soldered again). Do you think running a 4-5in piece of wire from the resistor to the splice point would be a problem?

shortyboy

sorry for being a noob...but im still lost with installing the ballast resistors...can someone possible show a diagram on how to install it!much appreciated....

Bri Bro

Setup: Two 25 watt 1 ohm resistors connected in parallel on a 5x7" aluminum 1/16 inch plate. No heat sink compound was used and the resistors were both secured to the plate with two brass bolts. The resistors are rated at 50 watts total. To stay under this limit, 40 watts of power was supplied for 10 minutes. This is more then the typical application will see due to the changing nature (duty cycle) of the fuel injection pulse.

Results: Temperature on the heat sink was measure at 210 F one inch from the resistors. The temperature on top of the resistor was measured at 320F!! That is very hot. So imagine how hot the resistors would get without any heatsink.

David Floyd

Wow, that's hot !!!

So, would it be ok to mount the heatsink in an area where the heat would not cause any problems, like setting the carpet on fire !!! or is it best not to run any extra wire length ?

Thanks for the info, Brian

Bri Bro

Resistance of wire is measured in ohms per 1,000 feet. Lets say you get some good 14 gauge extension cord wire to add 10 feet of lenght to the leads to tuck the heat sink under the dash. Fourteen gauge wire is around 2.5 ohms per 1,000 feet. Ten feet would be 0.025 ohms. The voltage drop across this extra wire length with say 10 Amps going through it is:
E=IR = 10*0.025 = .25 volts. Not much.

Twelve gauge is 1.6 ohms per thousand feet and would drop 0.16 volts
Ten gauge is 1.0 ohm per thousand feet and would drop 0.1 ohms.

David Floyd

Ok, now since I am a idiot, that went right over my head

Should I just add the resistors inline or can I add a few inches (5??) of wire (same size as the harness wire) to mount the heat sink out of the way.

Sam Lin

What he said is: You can add as much wire as you want to mount the resistors wherever you want with no problems, as long as the wire is thick enough gauge.

Sam

David Floyd

Thanks