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2010 Western State Highway Equipment Managers Association

2010 Western State Highway Equipment Managers Association. 2010 WSHEMA Meeting. Allison Optimization What does optimization mean to Allison? Components of Allison Optimization Questions & Answers. What Does Optimized Mean to Allison?.

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2010 Western State Highway Equipment Managers Association

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  1. 2010 Western State Highway Equipment Managers Association

  2. 2010 WSHEMA Meeting Allison Optimization What does optimization mean to Allison? Components of Allison Optimization Questions & Answers

  3. What Does Optimized Mean to Allison? Delivering the best features aligned with a “known” duty cycle to attract new customers by delivering unsurpassed: Productivity acceleration average speed body utilization (I/O options) Uptime Driveline Protection Drivability Safety Fuel Efficiency Full power shifts and technology improvements (RELS, LBSS, Auto-Neutral, etc.) Delivering the most value at the best price!

  4. Components of Allison Optimized(As per iSCAAN) Shift Energy Management (SEM) Load Based Shift Schedule (LBSS) Recommended Shift Schedules Auto Neutral on Park Brake Apply Reduced Engine Load at Stop (RELS) Prognostics

  5. Shift Energy Management/Low Range Torque Protection (SEM/LRTP) What does it do? Provides better engine/transmission integration for a more optimized driveline system How does it work? Uses high speed communication between engine and transmission Momentarily reduces engine torque during the shift What are the benefits? Reduced stress on driveline components Reduced clutch energy Allows higher engine torque ratings The building block for other optimized features

  6. Load-Based Shift Scheduling (LBSS) What does it do? Automatically selects between Economy and Performance shift schedules based on the vehicle’s actual payload and the grade on which it is operating How does it work? Uses advanced estimation technology to calculate real-time vehicle load and operating grade Automatically selects the appropriate shift schedule What are the benefits? Maximizes fuel efficiency without sacrificing productivity Doesn’t rely on driver to select the best shift schedule Frees up Mode button on 3000/4000 Series shifter Eliminates need for OEM or customer installed switch

  7. LBSS – Benefits • Fuel economy impact • 2% to 5% based on preliminary on-road test results • Coupled with 110+ shift schedules to choose from, LBSS maintains the traditional Allison productivity benefit • LBSS will allow short shifting when productivity will not be impacted (i.e. light load or downhill acceleration) • Productivity advantage and fuel savings

  8. Auto-neutral on Park Brake What does it do? Automatically selects neutral range on the transmission when the park brake is applied How does it work? Detects hard-wire or J-1939 message that is active when park brake is applied Automatically shifts the transmission to neutral What are the benefits? Ensures transmission is always in neutral when park brake is applied Maximizes fuel efficiency Enhances safety Improves productivity

  9. Park Brake Auto-Neutral – Benefits • Simulations generally predict 1-3% FE savings dependent upon duty cycle • If a driver is already going to Neutral when park brake applied, this function would have no fuel benefit • Safety and productivity benefit

  10. Reduced Engine Load at Stop (RELS) Optimized fuel efficiency.

  11. Reduced Engine Load at Stop (RELS) – Summary • Load on the engine is reduced when vehicle is stopped, therefore reducing fuel consumption • Useful for city traffic; frequent stops with engine idling at traffic lights • At a stop in drive, engine must provide fuel to overcome resistance of stalled torque converter • Engine torque absorbed by torque converter

  12. RELS – Benefits

  13. Prognostics What does it do? Alerts the operator when it’s time to change the transmission fluid or filter, or if other transmission service is necessary How does it work? Oil Life Monitor – Indicates when transmission oil is nearing the end of its useful life Filter Life Monitor – Indicates when the filter is nearing the end of its useful life Trans Health Monitor – Indicates when the transmission clutches require maintenance What are the benefits? Maximum fluid and filter life Scheduled maintenance Reduced maintenance costs

  14. Startability and Ratio Coverage • Many new ‘concerns’ from the field about ratio coverage • Seemingly, Allison can not match the startability of a manual or AMT equipped truck without it • These same folks are in awe of our performance • They do not understand why we get up The Hill

  15. Key Benefits of an Allison Automatic • Torque converter is the big Allison differentiator • Together with overdrives, it enables • Fast gearing at highway speeds (for Fuel Economy) • Superior startability at launch • Coupled with Allison’s powershifting, it enables • Better vehicle utilization (i.e., higher average mph) • Better Fuel Efficiency and Fuel Economy

  16. 1st Gear Ratio vs. Ratio Coverage • When talking startability and transmissions, some only want to look at 1st gear ratio • However, we should always talk about ratio coverage

  17. Axle Ratio • Correct axle spec has far more impact on fuel economy than any other calibration or feature • Terminology review • Shallower / higher ratio / faster / numerically lower are equivalent • Deeper / lower ratio / slower / numerically higher are equivalent

  18. Both systems have the same OAR in 1st and the same OAR in top gear, so the vehicle systems are equivalent Systems Are Equivalent Transmission Ratios Rear Axle Ratio Overall Reduction Diesel Engine 1st = 10.00 Top = 1.00 4.00 1st = 10.00 x 4.00 = 40.00 x Top = 1.00 = 4.00 4.00 1st = 8.00 x 5.00 = 40.00 x Top = 0.80 = 5.00 4.00 Diesel Engine 1st = 8.00 Top = 0.80 5.00

  19. Ratio coverage = 1st gear ratio / top gear ratio Common Factor – Ratio Coverage Transmission Ratios Rear Axle Ratio Overall Reduction Diesel Engine 1st = 10.00 Top = 1.00 4.00 Coverage = 10.00 1.00 1st = 10.00 x 4.00 = 40.00 = 10.00 x Top = 1.00 = 4.00 4.00 1st = 8.00 x 5.00 = 40.00 Coverage = 8.00 0.80 = 10.00 x Top = 0.80 = 5.00 4.00 Diesel Engine 1st = 8.00 Top = 0.80 5.00

  20. Startability • Focus on ratio coverage • Do not allow someone to only look at 1st gear ratio • Allison has overdrives • This gives us a great advantage in ratio coverage 1st gear ratio Top gear ratio Ratio Coverage =

  21. Startability – Calculate Ratio Coverage Manual / AMT Input Splitter Main Gearbox Range Pack Clutch 1.0 L = 1.00 H = 0.85 L = 3.25 …. 4 = 0.86 L = 3.78 H = 1.00 TE = Engine Torque Tout = Output Torque Ratio Coverage = 1.0 x 1.17 x 3.77 x 3.78 = 16.70 So it looks as if the manual / AMT does have an advantage! Ratio Coverage = 2.0 x 5.48 = 10.96 Allison 4000 HS TC Main Gearbox TE = Engine Torque Tout = Output Torque 2.0 (avg) 1 = 3.51 6 = 0.64

  22. Startability – Calculate Ratio Coverage Manual / AMT Input Splitter Main Gearbox Range Pack Clutch 1.0 L = 1.00 H = 0.85 L = 3.25 …. 4 = 0.86 L = 3.78 H = 1.00 TE = Engine Torque Tout = Output Torque Ratio Coverage = 1.0 x 1.17 x 3.77 x 3.78 = 16.70 …but, both trucks (system level) are not set up the same! Ratio Coverage = 2.0 x 5.48 = 10.96 Allison 4000 HS TC Main Gearbox TE = Engine Torque Tout = Output Torque 2.0 (avg) 1 = 3.51 6 = 0.64

  23. Gear both to have identical cruise speeds (same OAR in top range) The AMT System (assume a 500 rev/mi tire & 1400 erpm): Startability – Determine the Axle Rear Axle Ratio AMT / Manual Diesel Engine RC = 16.70 Top = 0.73 3.83 • Thus, the equivalent Allison 4000 HS (same specs): Rear Axle Ratio Allison 4000 HS Diesel Engine RC = 10.96 Top = 0.64 4.38

  24. Now that our system is defined, let’s find the 1st range OAR Startability – System Defined Rear Axle Ratio AMT / Manual Diesel Engine RC = 16.70 1st = 12.19 3.83 1st Range OAR = 1.0 x 12.19 x 3.83 = 46.68 It looks again that the manual / AMT has an advantage! 1st Range OAR = 2.0 x 3.51 x 4.38 = 30.75 Rear Axle Ratio Allison 4000 HS Diesel Engine TC RC = 10.96 1st = 3.51 4.38 2.0 (avg)

  25. Now that our system is defined, let’s find the 1st range OAR Startability – System Defined Rear Axle Ratio AMT / Manual Diesel Engine RC = 16.70 1st = 12.19 3.83 1st Range OAR = 1.0 x 12.19 x 3.83 = 46.68 …but, we have neglected Allison’s key feature! 1st Range OAR = 2.0 x 3.51 x 4.38 = 30.75 Rear Axle Ratio Allison 4000 HS Diesel Engine TC RC = 10.96 1st = 3.51 4.38 2.0 (avg)

  26. Startability • The key difference is the Torque Converter • Allison torque converter, depending on model choice (STR) and torque rating, will stall in the range of 1400-1700 erpm • Engine will reach peak torque to launch

  27. Startability • Recommendations for a manual or AMT • Eaton: “The correct gear will allow you to start with your foot off of the throttle” • Caterpillar: “No throttle start” • Motor Truck Engineering Handbook: “Launch with engine at 800 rpm max”

  28. Startability – Engagement Torque • All diesel engines have a clutch ‘Engagement Torque’ for manual transmission equipped analysis • AMTs launch in this same range of engine speed • These values tend NOT to be openly obvious when scanning a data sheet • Most EOEMs publish these values, and they are typically in the range of 650-800 erpm

  29. Startability – Engagement Torque Allison Manual and AMT

  30. Startability – Torque Converter • At launch, an Allison equipped truck can take advantage of higher torque • AMT/manual-equipped trucks have to overcome: • Turbo lag at launch (and every range change) • Disadvantage of lower starting torque • In our simple analysis, it would follow that the engine torque at launch with the Allison is much higher

  31. Determine Wheel Torque (TW): Startability – Wheel Torque AMT / Manual Diesel Engine TE RC = 16.70 1st = 12.19 3.83 TW, AMT =850 lb-ft x 1.0 x 12.19 x 3.83 = 39680 lb-ft 5% Higher !! TW, Allison= 1350 lb-ft x2.0 x 3.51 x 4.38 = 41510 lb-ft Allison 4000 HS Diesel Engine TE TC RC = 10.96 1st = 3.51 4.38 2.0 (avg)

  32. Startability – Additional Thoughts • Simple example presented with low engine rating and with close ratio transmission for emphasis • What if we go to a higher engine rating? • What about vocational competition? • The Allison lead just keeps growing

  33. Startability – Engine Rating • Starting torque in a diesel engine family tends not to increase with increased torque rating • Allison Automatics can take advantage of higher torque rating at launch

  34. Determine Wheel Torque (TW): Higher Rating with Higher Rating AMT / Manual Diesel Engine TE RC = 16.70 1st = 12.19 3.83 TW, AMT =850 lb-ft x 1.0 x 12.19 x 3.83 = 39680 lb-ft 28% Higher !! TW, Allison= 1650 lb-ft x2.0 x 3.51 x 4.38 = 50730 lb-ft Allison 4000 HS Diesel Engine TE TC RC = 10.96 1st = 3.51 4.38 2.0 (avg)

  35. Determine Wheel Torque (TW): Higher Rating with Wide Ratio Trans AMT / Manual Diesel Engine TE RC = 16.70 1st = 12.19 3.83 TW, AMT =850 lb-ft x 1.0 x 12.19 x 3.83 = 39680 lb-ft 71% Higher !! TW, Allison= 1650 lb-ft x2.0 x 4.70 x 4.38 = 67930 lb-ft Allison 4500 RDS Diesel Engine TE TC RC = 14.03 1st = 4.70 4.38 2.0 (avg)

  36. 12-Speed AMTFull Throttle Acceleration 2610 Driver Demand Torque Net Engine Torque Avg. Torque 1354 356 566 Engine Speed 536 296 1.5s Decel 1s Shift Time 40 MPH OutputSpeed

  37. Allison Wide Ratio 4000Full Throttle Acceleration 2233 Driver Demand Torque Net Engine Torque Avg. Torque 2020 368 Engine Speed 1500 No Decel! 0.5s Shift Time 40 MPH OutputSpeed

  38. Performance When Moving • This power interrupt also requires the engine to re-accelerate very quickly once the next range is attained • Let’s consider an example of identical equipped trucks (engine rating, ratio coverage, etc.) EXCEPT for the transmissions

  39. Actual SituationFocus on First 20 MPH of Travel AMT shifts 5 times beforeAllison is out of TC mode!

  40. Allison Advantages • Torque converter and powershift is getting power and torque to the ground better than AMT • Further confirmed by • Acceleration tests • Allison handily whips similar specified vehicles at much higher engine powers • Higher average vehicle speeds (acceleration edge) • We outshine the AMT in average vehicle speeds over similar duty cycles • We routinely defeat AMT in fuel efficiency

  41. Acceleration vs. Axle Ratio 80% C.E. gradeability is less than 12% UncommonAxle Ratios Reasonable Axle Ratios

  42. Summary • Torque converter is main differentiator between Allison and AMT/manual transmissions • Allison 6-speed has better startability than manuals and AMTs

  43. Summary • Manuals and AMTs depend upon having more gear ratios • AMTs and manuals require deep gearing because they do not have a torque converter • Allison does more work and provides superior launch with less • More power-interrupt shifts (hurt fuel efficiency and emissions)

  44. Applying Shallower Axle Logic • Next slide is same as previous with only the axle ratio changed • Still shows superior startability • Leads into fuel consumption savings • Engine speed reduction • Spin loss reduction • Engine auxiliary parasitic reduction

  45. Determine Wheel Torque (TW): With a More ShallowAxle Ratio AMT / Manual Diesel Engine TE RC = 16.70 1st = 12.19 3.83 TW, AMT =850 lb-ft x 1.0 x 12.19 x 3.83 = 39680 lb-ft Still 61% higher with a 7% faster axle!! TW, Allison= 1650 lb-ft x2.0 x 4.70 x 4.11 = 63750 lb-ft Allison 4500 RDS Diesel Engine TE TC RC = 14.03 1st = 4.70 4.11 2.0 (avg)

  46. Questions.

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