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Inertia Dynamometer Brake Squeal Noise Test Procedure for Vehicles without Regenerative Systems
- Ground Vehicle Standard
- J2521_202210
- Revised
Sector:
Issuing Committee:
Language:
English
Scope
The SAE J2521 procedure applies to high-frequency squeal noise occurrences for on-road passenger cars and light trucks below 4540 kg of GVWR. The procedure incorporates high-temperature and low-temperature test matrixes but does not fully account for the effects of the environment on brake squeal.
For this test procedure, squeal occurs when the peak noise level is at least 70 dB(A) between 1.25 kHz and 16 kHz for tests using full suspension corners or full axle assemblies or between 2 kHz and 16 kHz for brakes not using a full suspension corner.
Before using this recommended practice for chassis dynamometer testing, review in detail the specifics related to at least (a) instrumentation, including in-cabin microphones, (b) threshold levels for noise detection, (c) temperature control priority between the front and rear axles, (d) vehicle loading and load distribution, (e) cooling air and environmental conditioning, and (f) detailed nomenclature and labeling of channels and sensors.
Rationale
The current revision of this SAE Recommended Practice includes updates and extensions to (a) reflect the taxonomy and guidelines from the SAE J3152 Information Report for fixture design, fabrication, and installation; (b) expand individual sections with low temperatures and speeds; (c) expand the sections for friction characteristic to include 30 km/h events at colder temperatures (-5 °C and 40 °C), at 10 bar of brake pressure; (d) increase the maximum fade temperature for rear disc brakes to 300 °C and 400 °C, for the standard and optional schedules, respectively; and (e) include metrics to report the coefficient of friction per the VDA 300.
Recommended Content
Ground Vehicle Standard | Wear Test Procedure on Inertia Dynamometer for Brake Friction Materials |
Ground Vehicle Standard | Dynamometer Global Brake Effectiveness |
Ground Vehicle Standard | FMVSS Inertia Dynamometer Test Procedure for Vehicles Below 4540 kg GVWR |
Topic
Data Sets - Support Documents
No Datasets Available
Issuing Committee
The Brake NVH Standards Committee of the Foundaiton Brake Steering Committee develops and reviews information reports, recommended practices and standards related to brake NVH testing in the laboratory and in vehicles. Included are passenger car and light truck transportation.
Reference
Number | Title |
---|---|
IEC61672-1 | This document is not part of the subscrption. |
IEC61672-2 | This document is not part of the subscrption. |
IEC61672-3 | This document is not part of the subscrption. |
J2598_202012 | Automotive Disc Brake Pad Natural Frequency and Damping Test |
J2625_201707 | Automotive Vehicle Brake Squeal Test Recommend Practice |
J2786_201712 | Automotive Brake Noise and Vibration Standard Nomenclature |
J2789_201809 | Inertia Calculation for Single-Ended Inertia-Dynamometer Testing |
J2933_202209 | Verification of Brake Rotor and Drum Modal Frequencies |
J3001_201604 | Brake Insulator Damping Measurement Procedure |
VDA300 | This document is not part of the subscrption. |
VDA303 | This document is not part of the subscrption. |
VDA305 | This document is not part of the subscrption. |
VDA306 | This document is not part of the subscrption. |
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