Quote:
Originally Posted by 1in1969
Hey Mark, just curious the reason for using the Caddi fan and shroud instead of the Mark VIII fan I've heard so much about. Thanks Shawn
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The Mark VIII fan is still a great part but it is a brushed motor and 1990s technology two speed fan. Not sure it’s flow rate but its power requirements on high speed is 25 amps or it’s a 300 W fan. The SRX fan is a brushless PWM (Pulse Width Modulated) fan that is rated at 850W (70 amps at full power). But, it is PWM so it only runs as hard as it needs to based on three inputs to the ECM – Engine Coolant Temp, A/C head pressure and Inlet Air Temp. So just cruising around the fan is very quiet only running as needed. The SRX fan is the biggest most powerful fan in production on a GM vehicle. (Don’t go buy one unless you can PWM it!) A couple manufacturers are working on a controller for it. Also it is huge so it is a very special application to use it. If you are not making over 700 HP and attempting to road race it don’t mess with it.
The other benefit to the large fan and shroud is I get a lot more face area and I can thin my heat exchangers up a bit. This engine rad had a thinner core but 20% more face area than Mayhem. I also uncovered the top 25% of the radiator to help cooling on the first pass of the double pass cooler. With a double pass radiator you can package the engine oil cooler and the other coolers in the driver’s side end tank. The C&R engine oil cooler is HUGE. A 7 lbs stainless steel deal. The guys at C&R are the real deal and helped me size the cooler for my application. They could have built my whole radiator but the Dewitt guys are in MI and can custom build cores. I like to drive over to a shop and work hands on. I’m very happy how it turned out.
Dewitt also made a custom core intercooler radiator to nest in front of the engine radiator. Because Dewitt custom made the cores the cores are the exact same width. Nested in front of the intercooler is Vintage Airs larger condensers. Again more face area to help reduce pressure drop.
With the Anvil lower valance all opened up I’m mounting the A/C and the intercooler low to pick up that air flow. I will also duct all the air though the coolers with close out.
Mark