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FMVSS Inertia Dynamometer Test Procedure for Vehicles Below 4540 kg GVWR
- Ground Vehicle Standard
- J2784_202101
- Revised
Downloadable datasets available
Annotation ability available
Sector:
Issuing Committee:
Language:
English
Scope
This document derives from the Federal Motor Vehicle Safety Standards 105 and 135 vehicle test protocols as single-ended inertia-dynamometer test procedures. The test sequences enable brake output measurement, friction material effectiveness, and corner performance in a controlled and repeatable environment. This SAE Recommended Practice (RP) also includes optional sections for parking brake output performance for rear brakes. It applies to brake corners from vehicles covered by the FMVSS 105 and 135 when using the appropriate brake hardware and test parameters. The FMVSS 135 applies to all passenger cars and light trucks up to 3500 kg of GVWR. The FMVSS 105 applies to all passenger cars, multi-purpose vehicles, buses, and trucks above 3500 kg of GVWR. This document does not include testing for school bus applications or vehicles equipped with hydraulic brakes with a GVWR above 4540 kg.
Rationale
This revised document takes into consideration new technologies for braking systems like (a) vacuum assist, (b) electric parking brake (EPB), and (c) regenerative braking. The inertia calculation references the latest version of the SAE J2789 to calculate the test inertia, including two methods to reflect the brake blending for the regenerative system. This revision also addresses formatting and grammatical corrections and clarifies items about FMVSS 105, FMVSS 135, or both. Other aspects of the rationale from previous revisions of this SAE Recommended Practice (RP) are still applicable.
Recommended Content
| Ground Vehicle Standard | Wear Test Procedure on Inertia Dynamometer for Brake Friction Materials |
| Ground Vehicle Standard | Brake Rotor Thermal Cracking Procedure for Vehicles Below 4 540 kg GVWR |
| Ground Vehicle Standard | High-Preload Deflection and Compressibility Test Procedures for Friction Materials |
Topic
Data Sets - Support Documents
| Title | Description | Download |
|---|---|---|
| Unnamed Dataset 1 | ||
| Unnamed Dataset 2 | ||
| Unnamed Dataset 3 | ||
| Unnamed Dataset 4 | ||
| Table 1 | Equations to calculate corner test inertia per section and axle in combination with SAE J2789 | |
| Table 2 | Default deceleration levels | |
| Table 3 | Service brakes test procedure - FMVSS 135 | |
| Table 4 | Service brakes test procedure - FMVSS 105 (except school buses) | |
| Table A1 | Example calculations for hill-hold torque values | |
| Unnamed Dataset 10 |
Issuing Committee
Brake Dynamometer Standards Committee
The Brake Dynamometer Standards Committee is part of the Foundation Brake Steering Committee that reports to the Motor Vehicle Council. The committee is responsible for developing standards, recommended practices, and information reports for brake dynamometer testing, for on-road vehicles below 4540 kg of Gross Vehicle Weight Rating. The committee also maintains liaison activities with other Standard Development Organizations or industry consortia.
Reference
| Number | Title |
|---|---|
| ISO/PAS12158 | This document is not part of the subscrption. |
| TP-105-03 | This document is not part of the subscrption. |
| TP-135-01 | This document is not part of the subscrption. |
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