I've been goofing around with the Borg Warner MatchBot recently (Don't get any ideas. I'm too broke for turbochargers, but hey I can dream, can't I?). I can't find any volumetric efficiency maps for the Mustang 3.7L V-6, nor for any other modern DOHC V-6 engines (350Z/370Z, Genesis Coupe, etc.). However, I have read that VE can be measured from dyno pulls. I had my Mustang dyno'ed about a year ago and still have the HP/TQ charts somewhere. Can VE be calculated from those charts, or does it have to be separately measured?
Unless I'm missing something major, I don't think that there's a way to calculate the VE from dyno data without making assumptions about the combustion efficiency and thermal efficiency of the engine. In order to get any kind of accurate estimate of VE, the air flow rate through the engine really needs to be measured directly.
fanfoy
HalfDork
4/10/14 11:11 p.m.
To calculate VE, you need the theoretical airflow and the real airflow going in and out of an engine at a certain RPM. The theoretical airflow is easy to calculate with the displacement of the engine. For the real airflow, you can make a pretty good estimate with the power, AFR, and drive-train loss that are given by a dyno pull. It neglects the combustion efficiency, but for comparing engines, it's a good tool. Or you can simply plug into the engine's ECU, and pull the readings off the MAF.
