Its at the wheel 480hp its 612hp at the flywheel.

Mark

 

2.4 pressure ratio is 20.5psi.

 

I think on the graph it's not absolute pressure so this is around 37 psi of boost.

 

2.4 bar is 35.28 psi.

pressure ratio is defined as the ratio of the stagnation pressure as measured at the front and rear of the compressor

 

I am curious, he made 612whp in the earlier dyno he posted at an unknown boost level.

He then posts the 480hp dyno showing 2.4bar boost (or as pointed out above, ~37psi).

So how did he go from 480whp @ 35psi to 612whp? Didn't look like the turbo had much more boost in it, so where did the extra power come from?

Something is not adding up IMHO.

 

this is why

 

Ahh, Missed that, didn't see there was another page.

 

Ok, academic question here: 480 is about 21.57 percent off of 612. That sounds pretty reasonable to me. Can anybody explain how this is arrived at? Does it somehow come from measurements on the particular car in the test? Or is this more like a rule of thumb that is arrived at from other data? Or what?

 

Dyno Dynamics workout loss by having a ramp down run after a dyno run is conclude to figure out the mechanical drag and add it back into the on wheel figure to obtain flywheel hp
Same goes to Dastek dyno

 

So for fun and profit figure out how many BTU 132bhp lost through the drivetrain is and how fast it would heat 3 quarts of 75/85

 

i dont buy a static % of loss. i think its really close to a fixed # with a small multiplier. say 40hp loss x .05% for each additional horsepower added.

 

During that ramp down I suppose you have to put the clutch in or put it in neutral to remove engine drag, then the dyno can figure out how much the drive train is dragging? - wait a minute, that's just drag with very little load, right? I guess I don't get it. How does that tell you how much power is lost when the whole drivetrain is under full load?

 

I believe there is no way finding engine power unless you have it on a engine dyno. Use the dyno as a tool and use the same dyno to compare if you have done changes.

 

 

HP to BTU calculator : http://convert.web-max.ca/index.php?select=58

132hp = 5602.08 BTU/min

Or 93 BTU/second.

So over a ~7 second dyno pull it is putting 650 BTU's into the drivetrain.

For anyone not fermiluar with BTU's, a BTU is how much energy it takes to raise the temp of a pound of water 1 degree.

So 650 BTU's is in theory enough energy to raise the temps of all the drivetrain fluids a few hundred degrees in a single dyno pull.

Only way I trust crank HP numbers is if it is on an engine dyno.