Monday, March 23, 2015

Power factor

So on my trip yesterday I encountered and had too much time to think about what I am now calling a 'Power Factor".
It’s a hypothetical figure derived from a combination of speed, horsepower and torque.

ie; my truck is 4,000#, it has a measured 150 hp at rear wheels and 200 tq at rear wheels.

My current max tq is around 3500
My rpm in second at 45 is 2500, 3,000 at 55, 3500 at 65
In third i am 1700, 2000, and 2500


On my trip yesterday I figured out I need to move my power levels up and my powerband down.

A semi truck with 2,000 tq at road speed with 80,000# load is moving 40 pounds for every 1 of tq for a PF of 40.

My truck with that huge 12,000# total load
had a power factor of 80

with my 10,000# load yesterday I was crawling at 25mph up some 6+% grades with a 66 PF, and was only able to maintain a 45mph average speed between Chico and Reno via hwy 70. 

Coming home I was able to maintain a normal road speed at any time with a 36PF due to only 5500 total load. 

So with an average 10,000 load I need to keep a 36PF to maintain a normal road speed.

So in order to do that I have to gain 125 torque at the given RPM.

Next is to find out how. I’m going to start with cam timing first then an updated dyno run.

After that simple change, the hard change with be EFI.
Then after that will be a new custom cam.

If that won’t cut it, then I will be looking at superchargers.



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