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?

• 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!

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

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

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

• 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

LBSS – Benefits

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

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

Model Drive Fuel Usage (l/hr)

Neutral Fuel Usage (l/hr)

Percent Improvement

1000/2000 3.02 1.89 38%

3000 2.87 1.02 64%

4000 3.88 2.03 48%

Reduced Engine Load at Stop (RELS)

Optimized fuel efficiency.

• 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

Reduced Engine Load at Stop (RELS) – Summary

RELS – Benefits

3000 (TC418) 4000 (TC541)

Idle Speed 650 rpm Idle Speed 650 rpm

Drive: 2.87 l/hr Drive: 3.88 l/hr

RELS: 1.44 l/hr RELS: 2.47 l/hr

Neutral: 1.02 l/hr Neutral: 2.03 l/hr

RELS – 50% improvement while vehicle stopped in drive

RELS – 36% improvement while vehicle stopped in drive

Torque Converter selection impacts benefit

Torque Converter selection impacts benefit

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

• 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

Startability and Ratio Coverage

• 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

Key Benefits of an Allison Automatic

• When talking startability and transmissions, some only want to look at 1st gear ratio

• However, we should always talk about ratio coverage

1st Gear Ratio vs. Ratio Coverage

• 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

Axle Ratio

Systems Are Equivalent

• Both systems have the same OAR in 1st and the same OAR in top gear, so the vehicle systems are equivalent

Diesel

Engine

Transmission Ratios

Rear Axle Ratio

1st = 10.00

Top = 1.004.00

Overall Reduction

Diesel

Engine 1st = 8.00

Top = 0.805.00

1st = 10.00 xTop = 1.00

4.00 40.00

x 4.00 4.00=

=

1st = 8.00 xTop = 0.80

5.00 40.00

x 5.00 4.00=

=

Common Factor – Ratio Coverage

• Ratio coverage = 1st gear ratio / top gear ratio

Diesel

Engine

Transmission Ratios

Rear Axle Ratio

1st = 10.00

Top = 1.004.00

Overall Reduction

Diesel

Engine 1st = 8.00

Top = 0.805.00

1st = 10.00 xTop = 1.00

4.00 40.00

x 4.00 4.00=

=

1st = 8.00 xTop = 0.80

5.00 40.00

x 5.00 4.00=

=

Coverage = 10.00 1.00

Coverage = 8.00 0.80

= 10.00

= 10.00

• 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

Startability

Ratio Coverage =1st gear ratio

Top gear ratio

Startability – Calculate Ratio Coverage

Input Splitter

Main

Gearbox

Range

Pack Clutch

Ratio Coverage = 1.0 x 1.17 x 3.77 x 3.78 = 16.70

Main

Gearbox

TC

Ratio Coverage = 2.0 x 5.48 = 10.96

L = 3.25….

4 = 0.86

L = 3.78

H = 1.00

L = 1.00

H = 0.85

1.0

1 = 3.51

6 = 0.64

2.0

(avg)

So it looks as if the manual / AMT does have an advantage!

Manual / AMT

Allison 4000 HS

Tout = Output Torque

Tout = Output Torque

TE = Engine Torque

TE = Engine Torque

Startability – Calculate Ratio Coverage

Input Splitter

Main

Gearbox

Range

Pack Clutch

Ratio Coverage = 1.0 x 1.17 x 3.77 x 3.78 = 16.70

Ratio Coverage = 2.0 x 5.48 = 10.96

L = 3.25….

4 = 0.86

L = 3.78

H = 1.00

L = 1.00

H = 0.85

1.0

…but, both trucks (system level) are not set up the same!

Manual / AMT

Tout = Output TorqueTE = Engine Torque

Main

Gearbox

TC

1 = 3.51

6 = 0.64

2.0

(avg)

Allison 4000 HS

Tout = Output TorqueTE = Engine Torque

Startability – Determine the Axle

• Gear both to have identical cruise speeds (same OAR in top range)

– The AMT System (assume a 500 rev/mi tire & 1400 erpm):

Diesel

Engine

AMT / Manual

Rear Axle Ratio

RC = 16.70

Top = 0.733.83

– Thus, the equivalent Allison 4000 HS (same specs):

Diesel

Engine

Allison 4000 HS

Rear Axle Ratio

RC = 10.96

Top = 0.644.38

Startability – System Defined • Now that our system is defined, let’s find the 1st range OAR

Diesel

Engine

AMT / ManualRear Axle

Ratio

RC = 16.70

1st = 12.193.83

Diesel

Engine

Allison 4000 HS Rear Axle Ratio

RC = 10.96

1st = 3.514.38

TC

2.0

(avg)

1st Range OAR = 1.0 x 12.19 x 3.83 = 46.68

1st Range OAR = 2.0 x 3.51 x 4.38 = 30.75

It looks again that the manual / AMT has an advantage!

Startability – System Defined • Now that our system is defined, let’s find the 1st range OAR

Diesel

Engine

AMT / ManualRear Axle

Ratio

RC = 16.70

1st = 12.193.83

Diesel

Engine

Allison 4000 HS Rear Axle Ratio

RC = 10.96

1st = 3.514.38

TC

2.0

(avg)

1st Range OAR = 1.0 x 12.19 x 3.83 = 46.68

1st Range OAR = 2.0 x 3.51 x 4.38 = 30.75

…but, we have neglected Allison’s key feature!

• 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

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”

Startability

• 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

Startability – Engagement Torque

Startability – Engagement Torque

Allison Manual and AMT

• 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

Startability – Torque Converter

Startability – Wheel Torque • Determine Wheel Torque (TW):

Diesel

Engine

AMT / Manual

RC = 16.70

1st = 12.193.83

Diesel

Engine

Allison 4000 HS

4.38

TC

2.0

(avg)

TE

TE RC = 10.96

1st = 3.51

TW, AMT = 850 lb-ft x 1.0 x 12.19 x 3.83 = 39680 lb-ft

TW, Allison = 1350 lb-ft x 2.0 x 3.51 x 4.38 = 41510 lb-ft

5% Higher !!

• 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

Startability – Additional Thoughts

• 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

Startability – Engine Rating

Higher Rating with Higher Rating• Determine Wheel Torque (TW):

Diesel

Engine

AMT / Manual

RC = 16.70

1st = 12.193.83

Diesel

Engine

Allison 4000 HS

4.38

TC

2.0

(avg)

TE

TE RC = 10.96

1st = 3.51

TW, AMT = 850 lb-ft x 1.0 x 12.19 x 3.83 = 39680 lb-ft

TW, Allison = 1650 lb-ft x 2.0 x 3.51 x 4.38 = 50730 lb-ft

28% Higher !!

Higher Rating with Wide Ratio Trans• Determine Wheel Torque (TW):

Diesel

Engine

AMT / Manual

RC = 16.70

1st = 12.193.83

Diesel

Engine

Allison 4500 RDS

RC = 14.03

1st = 4.704.38

TC

2.0

(avg)

TE

TE

TW, AMT = 850 lb-ft x 1.0 x 12.19 x 3.83 = 39680 lb-ft

TW, Allison = 1650 lb-ft x 2.0 x 4.70 x 4.38 = 67930 lb-ft

71% Higher !!

DriverDemand Torque

Engine Speed

OutputSpeed

Net Engine Torque

296

356

2610

1.5s Decel

566536

1s Shift Time

Avg. Torque 1354

40MPH

12-Speed AMT

Full Throttle Acceleration

Driver Demand Torque

Engine Speed

OutputSpeed

Net Engine Torque

1500

368

2233

No Decel!

0.5s Shift Time

Avg. Torque 2020

40MPH

Allison Wide Ratio 4000Full Throttle Acceleration

• 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

Performance When Moving

Actual SituationFocus on First 20 MPH of Travel

12 Speed AMT (3.42 RAR) vs. Allison 4000 HS (4.11 RAR)Engine Speed Against Road Speed

600

800

1000

1200

1400

1600

1800

2000

2200

0 10 20

Road Speed (mph)

En

gin

e S

pe

ed

(e

rpm

)

1C

2C

A1 A5A4A3A2A6

AMT shifts 5 times beforeAllison is out of TC mode!

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

Acceleration vs. Axle Ratio0 - 60 mph Acceleration Time (sec) vs. Axle Ratio

0

10

20

30

40

50

60

70

80

3 3.5 4 4.5 5 5.5 6 6.5 7

Axle Ratio

Ac

ce

lera

tio

n T

ime

(s

ec

)

Reasonable Axle Ratios80% C.E.

gradeability is less than 12%

UncommonAxle Ratios

• Torque converter is main differentiator between Allison and AMT/manual transmissions

• Allison 6-speed has better startability than manuals and AMTs

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)

Summary

• 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

Applying Shallower Axle Logic

With a More Shallow Axle Ratio• Determine Wheel Torque (TW):

Diesel

Engine

AMT / Manual

RC = 16.70

1st = 12.193.83

Diesel

Engine

Allison 4500 RDS

RC = 14.03

1st = 4.704.11

TC

2.0

(avg)

TE

TE

Still 61% higher with a 7% faster axle!!

TW, AMT = 850 lb-ft x 1.0 x 12.19 x 3.83 = 39680 lb-ft

TW, Allison = 1650 lb-ft x 2.0 x 4.70 x 4.11 = 63750 lb-ft

Questions.