By Steve Dinan
Exhaust Theory
Rear Exhaust Design Approach
by: Steve Dinan
1) Elastic Deformation
2) Natural Frequency
3) Fatigue Failure
Torsional Vibration (Natural Frequency)
Harmonic (sine wave) Torque Curves
Critical RPMs
Major and Minor Critical RPM’s
Harmonic Dampers
DISPELLING PERFORMANCE SOFTWARE MYTHS
By Steve Dinan
DYNAMOMETER TESTING AND THE MODERN BMW ENGINE
By Steve Dinan
About Dynamometers
Sample Data Aquisition Display
Figure #1: E39 M5 Intake Air Temperature Measured on the Road
Figure #2: E39 M5 Engine and Radiator Temperatures Measured on the Road
Figure #3A: E39 M5 Dyno Graph
Figure #4: Intake Air Temperature Sensor Comparison
Figure #5: Radiator Temperature Comparison
Figure #6: Engine Block Temperature Comparison
Figure #7: Fuel Mixture Comparison
Figure #8: Ignition Timing Comparison
Figure #3B: E39 M5 Dyno Graph.
Figure # 9: Intake Air Temperature Comparison- Hood open vs. closed
Figure #10: Radiator Temperature Comparison
Figure #11: Engine Block Temperature Comparison
Figure #12: Fuel Mixture Comparison
Figure #13: Ignition Timing Comparison
Figure #3C: E39 M5 Dyno Graph
Figure #14: Intake Air Temperature Comparison
Figure #15: Fuel Mixture Comparison
Figure #16: Ignition Timing Comparison
Figure #3D: E39 M5 Dyno Graphs
Figure #17: Radiator Temperature Comparison
Figure #18: Block graph
Figure #19: Fuel Mixture Comparison
Figure #20: Ignition Timing Comparison
Engine Wear
Figure #21: Year old E39 M5 Dyno Graph
Figure #3E: Current E39 M5 Dyno Graph
Drivetrain Temperatures
Data from a Stock E46 M3
Figure #22: E46 M3 Dyno Runs
Stock E46 M3 Ignition Timing Adaptations
Figure #23: 91 Octane Knock Adaptations Diagnosis
Figure #24: 93 Octane Knock Adaptations Diagnosis
Intercooled Forced Induction Systems
Corrections
Once Dinan has determined the specific baseline procedure for a vehicle, the car is allowed to sit until early the following morning when the temperature is as close as possible to 77° F, the SAE standard. There are formulas for temperature, humidity and barometric pressure corrections from the SAE; however the correction tables are not completely accurate for a digitally controlled car. This is due to the corrections the car’s computer is making based on the conditions previously discussed. Dinan reduce this error further by performing all tests as close to 77° F as possible. An alternative would be to turn the corrections off in the software but this is a potentially dangerous approach. The most accurate results are obtained when the tests are performed in a climate-controlled dyno-room where temperature and humidity can be completely controlled for each test. By running Dinans tests as close to 77° F as possible, Dinan still must employ the SAE correction tables, but the amount of correction necessary is reduced and accuracy improved. Be aware that not all dynos correct for temperature, humidity and barometric pressure!
Conclusion
THE FUTURE OF THE INTERNAL COMBUSTION ENGINE
By Steve Dinan
Great days ahead:
Be careful:
Pitfalls of small turbos:
Computer controlled boost issues:
Some additional points:
By Steve Dinan
Performance without sacrifice
OCTANES & PROGRAMS
RACE FUEL INFO
ETHANOL INFO
OCTANE BOOSTER
LEADED FUEL
WATER / METHANOL
NITROUS OXIDE
ACCIDENTAL LOW QUALITY FUEL
ROUGH AKI to RON CONVERSION GUIDE
TERMINOLOGY