Independent ESS (esstuning.com) E39 M5 S62 Supercharger Dyno Numbers Continue to Come up Short?
An ESS supercharged E39 M5 owner took his car to specialty Z to get a dyno and the results were not exactly what one would expect. Hitting 7.3 psi of boost with DIN correction the car only puts up 472 whp through an aftermarket exhaust. ESS portrays the car as over 500 whp on 6 psi through the stock exhaust. This is now a repeat pattern of the ESS S62 supercharger not living up to the claimed numbers by over 30 whp even with more boost than claimed.
When looking at the graph, the car is dangerously lean toward redline where max boost hits. The A/F ratio definitely needs to be cleaned up and we would advise the owner to get a new tune.
Car on the dyno:
Here are the numbers in SAE, big difference from the inflated figures marketed using correction factors which bolster the results: