mark kibort

I dont really understand what you are arguing about, or what your point is.

My point:
1. 248e ynos are great for tuning a car that is going from 60 to 100mph in about 4-7 seconds (range) at Full throttle.
2. it is almost perfectly accurate, in that any measurement is directly based on the engines ability, through the drive train to accelerate an inertial load, which never changes,( only the speed at which the drums are accelerated, based on different HP potential, or lower gears of different cars. the ONLY variance of this method (*as it is repeatable on any 248e dyno or very close to any other inertial dyno) are the correction factors based on ATM conditions. but , using actual values gives the power of the car (including all losses but aero) , that day during its test.
3. i do like the rolling dyno as it simulates how the engine draws fuel, incorporates heat, and produces and stabilizes full throttle profile in a similar , max power potential vs time period process.
4. compared to brake dynos which have a LOT of "moving parts" to get to the end result of producing HP values, i prefer the more simple, repeatable , more similar to racing use, inertial dynos.
5. since we are talking about the power plants and what they are rated at and what they actually produce, the rolling dyno is a near perfect way to compare cars and it is VERY similar to how the engine will be used on the road, taking into account all system inertial. brake dynos do not, as they usually take force measurements , statically, (no acceleration) at many different RPM points, and hold RPM constant, than ever is used on the real road, during real use.

YOUR point:
PLEASE FILL IN THE BLANK OR CORRECT MY GUESS
1. there is better dyno equip out there that incorporates aero factors, partial loading and engine efficiency detection to optimize fuel consumption
2. rolling dynos missing things like ram air effect , that boosts hp by 0.11% at 80mph (was this the reason for your (38,000cfm fan comment?)
3 rollling dynos are missing the true road friction, increased by the fact that the front wheels are stationary on inertial dynos (sans 4x4 dynos)


I dont understand your point and am very curious at to what it is.