Is there a “cap” so to speak to that? As in is there a point where only so much heat is made? 15° seems to be outgragiously high. I know you said approximately, but still even if it was a 10° increase 50° seems like an outstanding increase
Sounds about right. I can get a 5.3 with the matching 4l60 that’s been rebuilt for $1,500. Kind of torn between the turbo and a motor swap
See the below article to explain how you get there.
Learn about basic air compressor theory, including thermodynamics and the physics of compressing air. We'll cover Boyle's Law, Charles' Law, and more!
www.vmacair.com
I deal with pneumatic conveying systems that convey dry, granular products from point A to point B using pressure, typically created using Roots-Type straight lobe positive displacement blowers (yes, actual Roots blowers, similar to what is installed on a car/truck, but MUCH larger).
In all our rough calculations, the heat of compression averages (for practical speed of calculations) about 15°F per PSI of compression of ambient air. That changes as you increase in elevation because the air is less dense and it takes more energy and more rotations to compress the air to the same amount in density. Our systems operate between 3 PSI and 15 PSI to do what we do (if we go above 15 PSI (1 ATM) then we end up in ASME coded pressure vessels and that's too expensive for the industrial market) So, temp increases over ambient are between 45°F and 225°F increase over ambient. So, if ambient air temp is 105°F on a hot day, then our output temp is approximately 225+105=330°F if we are operating at 15 PSI. That's hot enough to burn the paint off the piping and silencers (mufflers) during operation.
Elevation is such a factor when using positive displacement (PD) blowers that the electric motor HP must increase by one full size (ie go from 50 HP to 60 HP or 60 HP to 75 HP), not because it requires more HP to do it, but because the cooling density on the exterior of the electric motor is not enough to keep the motor cool with the lower density of air.
Since the PD blower must turn MORE times to get the same mass of air, the PD blower becomes less efficient at elevation because it is engine RPM specific and the engine air/fuel ratios will continue to suffer.
However, since a turbo is spun at a direct ratio of the amount of exhaust gases, it will spool up according to the amount of gas expansion through the exhaust and will increase the intake air in a direct relationship to the amount of exhaust gases and will maintain air/fuel ratios through elevation changes.
@scottryana is MUCH better versed on this than I, but I wanted to advise that the heat of compression of a PD type blower is significant. Turbos will also have heat of compression (again, see the attached article) but they will be different due to less mechanical input and better efficiencies of compression.
Even though it "seems" excessive......it's SCIENCE!
