Got my DC controller working 100%!!!

[baskin]

On the Camaro, there's a couple of things that'll cause the problem, given your gauge is reading correctly. Placing the sensor on the front of the radiator will consistently throw off the temperature by 20 degrees. If it's very near the fan blade, the heat is drawn down the coolant tubes, placing it near the outlet moves it away from the blade. If the sensor is pushed in past the ridge, the fins don't contact the main part of the sensor, this will cause a delay in turning the fan on and will throw the temperature off.

If you need to bypass it temporarily, an easy way to do it is by connecting the AC input to either the ignition or a switch

[CAMAROBOY69]

I have the probe on the inside/ back of the radiator. The engine side. Right now it is in the lower passenger side. However I think it is a couple inches from the bottom. I will move it tonight as soon as I get to my car to see if it turns on quicker.
So the 3rd jumper wont do me any good? No one ever answered that question.

[baskin]

Which third jumper are you referring to? You can only place two on at a time to set the temperature. At what temperature does it just start to spin. When it starts, does it ramp up smoothly or does it ramp up hard and then settle down?

[CAMAROBOY69]

There were 3 jumpers in the bag and I am only using 2. That answers my question. I guess I can only use 2 of them.
My thermostat opens at 160 and that seems to be when the fan just barely starts turning. Then around 190-200 it starts spinning faster. It seems to slowly gain speed. At 205 its only spinning about 50% then around 210 it spins faster closer to probably 80-90%

[baskin]

Is the temperature changing over time? the earlier posts said it ran between 180 and 185 and 205 when the engine was at 6,000.

As far as seeing where the thermostat opens, that's not a valid way to test it. I have one customer who had tested his thermostat before putting it in and it opened at 180. He was setting up the first DK3535 kit with an electric water pump and was using the 10% U/D on the fan controller, he had an m8 fan and a high dollar radiator. With that, he couldn't get the car past 165, even revving the engine.

Thermostats don't hermetically seal the engine when they close, you still get some water flow, and if the inlet water temperature is at fifty degrees, which is where it probably is with the fan running WOT, it'll cool the engine lower than where the thermostat opens. The link that I posted earlier outlines a methodical way to figure out what is going on, and it's a lot faster to use that than to try to guess at what the problem is. You can get a candy thermometer for $2.99 at walmart and probably be done with it in less than an hour.

[CAMAROBOY69]

160 on highway (thermostat temp)
180-185 in stop and go traffic since I am still moving once in a while
205-210 if it just sits still

[baskin]

I'm assuming that this is a crossflow. Get the thermometer, start the engine with the radiator cap off and either disconnect the fan or tie the IGN input low. Place the thermometer in the radiator, start the car and note when the thermometer temperature change over time accelerates and when it slows down. This will tell you when the thermostat begins and finishes opening. Without the fan running, the inlet and outlet temperatures will match once the thermostat is fully open, so the gauge can be calibrated by waiting a minute or two after the thermostat opens and comparing it to the thermometer reading. Reconnect the fan and monitor the inlet verses the outlet temperature over the time that it takes the engine to get hot. If there's a significant change, then the engine is heat-soaking in that the oil temperature is getting much hotter than the coolant temperature. A drop in oil pressure as the car heats up will verify this. If that's the case, the correct fix is an oil cooler.

[CAMAROBOY69]

I moved the probe right next to the lower passenger side inlet. Still runs around 210.
All the numbers are still the same as a post #26. I dont have time to mess with it. If its hot at the track I will just wire the DC controller to run all the time.

[baskin]

If the sensor will reach the engine outlet side of the radiator, you can measure outlet temps until things are resolved. The operation won't be as smooth, but should still work pretty decent.

Something is definitely not right though if the m8 fan has to run near full speed to keep the car at 210 in 40 degree weather, on most setups, the m8 with a decent radiator will give about a 40 degree rise. At 40 degrees ambient, the fan should be running at about an amp in order to keep the car at 160.

If you're confident the temp gauge is correct, keep an eye on the oil pressure. Once the oil temp gets past a certain point, the pressure will drop off significantly.

[CAMAROBOY69]

Just got off the phone with Brian Baskin. He just gave me some extremely helpful information that will help me resolve this issue instantly. For now I can move the temperature probe from the outlet side of the radiator to the inlet side. SInce the inlet side is much hotter it will cause the fan to kick on quicker which is exactly what I need.
He also stated that getting an oil cooler will probably get rid of the hot engine problem since I seem to loose oil pressure as the engine gets hotter. Thanks for the help Brian. I will try relocating the probe to the inlet side on thursday.

[CAMAROBOY69]

I moved the probe to the inlet side of the radiator. It did lower the temp to 200 which is better than 210. It is about 2 inches below the driver side inlet. I think the car will do fine since I willl never be sitting still anyway. I might try to move it up right next to the inlet but not right now. I am happy with the way it works and it should easily get me thru tomorrow.

[gmachinz]

Adam, have you thought about trying any cooling additives? I never used to give them a second thought but after having tried the -40 Below additive, it dropped my temps on average by about 25 degrees on a motor that ran about 220 with a stock brass radiator and 10.5:1 comp. We stock them but you might be able to find them locally-they're about $25/qt. -Jabin

[engine]

When I installed my DC/MarkVIII kit, I did some experimenting with the jumpers. As of right now, I have the 7,9 and 8,10 jumpers in. Supposed to give a water inlet (to the engine) setpoint of 148*
With my 180* Hi-flow thermostat and Eddy 8810 waterpump, this brought my outlet temperature to about 186* idling all day long. Driving around and beating on the car brought it up to about 190* sometimes, but then it would go back down to 186*. So normally, my engine gives up about 38*
I installed the 13,14 "overdrive pulley" jumper, and now it idles at 180* outlet temperature. The fan moves relatively slowly all the time, at about 3.4 volts.
I did measure the radiator at the inlet and outlet with a Raytek infrared pyrometer. The radiator inlet indeed showed 179-180* and the radiator outlet showed 145* at idle, fully warmed. So the thing works and is pretty accurate.

The DC unit is designed to maintain a 180* water inlet temperature (to the engine) without any jumpers. When I first installed the unit without jumpers, it did just that. 180* out of the radiator into the engine, and my engine outlet temperature was about 215*. Installing the jumpers one at a time lowered my engine outlet temperature in steps of about 10*.
I'm guessing that if I drill a couple of holes in the stat to increase flow a bit, I would see less of a temp difference between engine in and outlets.
I'm using stock pullies (6.25 wp and 7.75" crank pullies, 1.24:1 waterpump overdrive ratio) and a 4-row copper/brass radiator.

here are pics of my installation. I made the shroud extensions from 18 gage stainless, and the top mounting brackets from 10 gage stainless. I have since replaced the "duct tape" edge guards with some real ones made of rubber with steel insets to hold shape.
https://www.pro-touring.com/forum/sh...ad.php?t=10876

[CAMAROBOY69]

With the 2 jumpers installed and the probe moved to the inlet side of the radiator the engine temp was still around 195-200 at idle. After 20 minutes of track time it still stayed around 200*. Sometimes a little warmer. I guess I could move the probe up right next to the water inlet side of the radiator. For now im not too worried about it.