Hi all!
Been a long, long time since I've been on the forum!
Wanted to talk about the dyno figures the car made, drivetrain losses and how the Maha dyno actually operates.
I dyno around 7-10 RS3' a week, their is never a point where we don't have a CZGB/DAZA/DNWA Engine based car all together at the same time in the workshop. I know what these cars make stock day in, day out and then tuned.
I am exceptionally proud of my MAHA MSR500 dyno facility, this is the same dyno used by ABT, Brabus, Lamborghini, the AMG Project One and many, many other car manufacturers.
The dyno measures the power of the car at the wheels (blue line on the graph), at the end of each pull the car is put into neutral and allowed to coast down and the dyno measures drivetrain loss aka drag (green line). Drivetrain losses are measured individually for every single dyno run. We do not just use a percentage as this is a joke method to calculate losses. This is the only accurate method to measure drivetrain losses as they can and do change each run due to hot vs cold tyres, hot vs cold drivetrain, tyre brands, tyre condition, alloy type, alloy weight, air pressure within the tyres, air temperature within the tyres, roller temperature, condition of the haldex and transfer box units themselves, status of the haldex on coast down (engaged vs non engaged), how tight the car has been strapped down to the dyno and so on. The dyno then adds the drag to the wheel power to get the figure at the crank. Once it gets the figure at the crank the data then gets corrected for ambient air temperature, air pressure and relative humidity then outputs the crank power (corrected) via the red line on the graph. Again this is done at the end of every single dyno run. The data is corrected using a method called DIN 70020 and both the corrected and uncorrected power is shown on the dyno graphs.
The car made 445hp/529nm in stock form. 460hp/562nm with the OPF and catalyst removed. As mentioned, I dyno so many RS3's that I can confirm the figures are more than accurate, DNWA cars in stock form make around 400-410hp. DAZA cars make up to 440hp in stock form.
Their are a million factors to consider when looking at a dyno graph with the main one being cooling and fuel. Was the car cooled sufficiently on the dyno? Was the load set up correctly? When intake air temperatures rise rapidly due to insufficient cooling the ecu pulls timing and lowers boost to stop the engine detonating. These are major factors and so important. We have the best available, 15kw fan to cool the cars down for the runs, I can't even stand infant of the fan without it blowing all 80kg of me clean away and even still the cars are cooled better on the road than on our dyno. Most dynos in the uk have little carpet driers at the front which are used for cooling, how these dyno are able to get anywhere close to an accurate reading of any car I don't know. Stick your hand out the window flat again the wind at 70mph for perspective.
I have an upcoming video talking about the differences and dyno test all three generations of RS3's and all 4 different engines 2016, 2018, 2019 and 2021. Stay tuned!