Post by
l33th41 »
https://forums.nicoclub.com/l33th41-u93000.html
Tue Jul 15, 2008 8:50 am
AEM's DYNO TESTING PROCEDURES AEM performs its dynamometer testing in a consistent fashion in an effort to deliver the most accurate results. Our dyno testing procedures are carried out with the hood up, with a fan placed in front of the radiator and another fan at the rear of the vehicle to force exhaust gases from the testing area. We perform the testing in this fashion because it most accurately reflects actual driving conditions.
We have performed extensive temperature studies using thermocouples placed throughout the engine compartment and air filter inlet to determine nominal operating temperatures of inlet air. We have found that underhood air temperatures are best replicated by performing dyno testing with the hood up. Without an open hood or fan to replicate what the car would experience if it were on the street and not on a dyno, the testing would not be an accurate representation of either the car's performance, or the functioning of any performance parts.
For example, the open hood allows air to flow through the engine compartment as it would if the vehicle were moving, and the fan in front of the radiator mimics the flow of air that would pass through it if the car were not stationary on a dyno. Think of it this way, for a 180 HP car that revs to 8,000 rpm, a third gear dyno pull to redline is equivalent to a run of approximately 90 mph, depending on gear ratio and tire size.
Furthermore, all numbers are corrected to SAE (Society of Automotive Engineers) standards for altitude, ambient air temperature and humidity per the program supplied with the Dynojet Dyno that we use (in this case it was a Model 248C Dynojet Chassis Dynamometer). We do this because, according to SAE, horsepower should be measured under a consistent set of conditions.
When we perform dyno testing, we monitor engine temperatures and inlet air temperatures to achieve consistent data. We DO NOT move the vehicle off of the dyno once it is strapped down, and install the performance part we are testing with the car still strapped to the dyno once we have established a baseline number. This is because we have found that vehicle alignment on a dyno will affect the results of a test-and moving a car once it is strapped down can lead to incorrect data.