WHEN Newsletter - Q4 2014 Federal Safety Standards for Heavy Trucks -Part 2

WHEN — Q4 2014

7

Dayton Parts LLC (continued from page 6)

Unlike FMVSS-121 this makes the test results all a real “apples to apples” comparison. No using a 6" slack arm drilling to “enhance” the test results as mentioned in Part 1. The QPL records a primary brake torque output value at the 40 psi application, one for normal stopping at 20 psi and a panic stop at 80 psi. These brake torque output values recorded in the QPL come from the brake effectiveness (or retardation) part of the FMVSS-121 test. Below is the brake effectiveness graph for our DP23 friction material from Part 1.

Brake Effectiveness

Link Testing Laboratories, Inc.

0.80

Actual Wheel Load (lb) — 11451.7 2 Actual Inertia (slug/ft ) — 950 Brake Type — Meritor Drive Rolling Radius (in) — 19.6 Slack Adjuster — Haldex 5.5" Air Chamber — MGM 3030 Brake Drum — Webb 66864

0.70

0.60

0.538

0.481

0.50

0.400

0.40

0.344

0.410

0.370

0.277

0.30

Dayton Parts DP23 Friction Material 0.310

Retardation Ratio

0.191

0.250

0.20

0.128

0.180

FMVSS-121 Minimum Retardation Ratio Baseline Pass/Fail

0.10

0.120

0.050

0.00

0

10

20

30

40

50

60

70

80

90

100

Line Pressure (psi)

continued on page 8