Quote:
Originally Posted by slowmover
Two overdrive gears is about ideal.
The top gear for running empty under light load.
Next gear down for running without quite a maximal load, but with more challenging terrain.
Then the rear gearing to fit.
As Direct needs to be able to handle a loaded condition and not downshift until the grades are notable.
An empty vehicle doesn’t exist
|
I am not sure what your stand is.
You seem to support my idea, but at the end seem against it.
The two Over Drives seem to be the limit n those gears, I have not seen any lower. So the only way to lower my RPMs is in the rear end. Up until lately that meant a BIG drop in take off and hill climbing power, now the ONLY thing I am concerned is can you run in lower gears as long as you want/need.
With the Ford the only thing I do not have numbers for is wind/air resistance and rolling resistance. As these are car and fairly streamlined I do not think wind/air resistance will be a big problem nor rolling resistance.
I have found driving these cars that maintaining speed like 85 MPH not hard at all and can be maintained with light throttle and fair vacuum by gauge.
I feel the only thing causing high fuel consumption is the higher RPMs (2400) caused by the gearing, I don't think running at 1700RPM all that major a drop in torque so it should be able to do it.
Now the Van I do feel as it IS a box, wind/air resistance will be a major problem BUT I believe a Chevy 350 with a stock cam advances 4 degrees running a factory stock TPI (NO Hot Rod tuning to either it or the heads) should have enough torque to handle the lower RPMs .
IF not I have engine to convert to a 383 which has even more low RPM Grunt, and again running a small cam called a peanut cam with it torque peek at 2200 RPMs.
Rich