Black Mountain whooped my butt !!
I've been dreading our trip to Gatlinburg since we planned it and most of my fears came true. I just flat out ran out of horses coming up. When I got to the top I was in second running about 40mph a...
Forum Discussion
Ron Gratz wrote:marcsbigfoot20b27 wrote:
AIRFLOW. Creeping up a hill at 35 you will have terribly low airflow to cool your radiator, transmission, AC, intercooler (if you have one) etc.
Now suddenly your fan kicks on and has to scream and rob another 20 hp to keep things cool enough (barely). Going 55-65 your airflow is (I didn't look up the math) maybe triple to quadruple.
A combination weight of 15000# and frontal area of 85 sq ft moving up a 6% grade at 60 mph will require about 190 hp to overcome aerodynamic drag and about 150 hp due to rate of climb.
The same weight and frontal area moving up the 6% grade at 40 mph will require about 56 hp to overcome aerodynamic drag and about 100 hp due to rate of climb.
If going up the hill at 60 mph requires 340 hp, and going up the hill at 40 mph requires 156 hp, the higher speed will require an addition of about 180 hp.
If the non-boosted airflow through the radiator at 40 mph is not sufficient for proper cooling, the fans will provide necessary increased airflow -- and the fans will not be consuming 180 hp.
The OP stated he was going about 40 mph at the top of the grade and "the trans never really got hot, just a tad over 200."
Doesn't sound to me as though he had a cooling problem.
Ron
I am wondering about your math?:h If it only takes 156 hp to go 40 mph, then why was the OP struggling to maintain 40 mph, his 2005 6.0 should have more than 160 hp.
Well yes it does rated at 360 hp, so why then the issue, maybe not 60, but should have been and easy 50 mph.
