W210 e55 (DYNO TEST PROBLEM)

Hello

Yesterday spent 4 hours tuning mercedes w210 e55 5.5 engine fitted with kleeman supercharger +headers +water intercooler pump and methanol mix . Boost only 6-7 psi..room temperature around 20 deg problem that horspower vary greatly between dyno runs up to 15 hp reduced so we have to wait 20 min at least to let engine cool although IAT Does not exceeds 55 deg at ramp run so coolant temp around 85 maximum

Any ideas to improve the time and consistancy of the test are welcome .

I was using kess v2 to load tuned files (2min write time )

Thanks to all

Getting repeatable dyno runs requires making sure all the conditions are the same at the start of each run. Particularly important are engine oil temperature, engine coolant temp and air temperature. I have recently added remote control of my dyno cooling fans, allowing me to keep the coolant temp consistent while waiting for the oil temp to return. I will turn the fans off when I stop the engine to analyze data and make changes. It often takes me a few minutes to restore the conditions before making another run.

If you don't have instrumentation for oil temp, and air temp (few do), then I suggest you to make several runs back-to-back with no changes to until the vehicle reaches a steady state and two runs are virtually identical. Make your change, then repeat the process until two back-to-back runs are consistent. Now compare the last two runs of each set to know how your change really affected the results.

Thank you david for the usefull information you share

I was monitering air temp and coolant temp but missed oil temperature .

Back to back run is my next try ..

Thanks alot .

One common factor that results in run to run inconsistency is knock activity that causes the ECU to retard timing during a run. This can be a real issue with a supercharger as it's very hard to get consistent air temps run to run and it's easy to see the air temp rise significantly from your first run to subsequent runs. You've mentioned that IAT reaches 55 degrees but is it the same for each run?

Thank you andre .

Of course no IAT keep rising run after run!!

I hope you got a usefull method andre than back to back method which david advised .