1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW14450 Exhaust System Dynamic Clearance Copyright 2011 General Motors Company All Rights Reserved July 2011 Originating Department: GME Specification Center Page 1 of 6 1 Scope Note: Nothing in this standard supercedes applicable laws and regulations
2、. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. To identify exhaust system dynamic clearance. 1.2 Foreword. Measurement of the movements of the engine and exhaust system relative to underhood, underbody and fascia c
3、omponents, particularly at critical points. 1.3 Applicability. All passenger cars and trucks. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. None 3 Resources 3.1 Facilities.
4、 GM or equivalent proving ground with a suitable vehicle durability course, skid pad, gradient between 20 % and 30 %, Belgian Blocks and staggered/parallel washboard road surfaces. 3.2 Equipment. 3.2.1 Electronic, optical or mechanical travel sensors. 3.2.2 Soft clay or plasticine, not hardened or l
5、iquefied. 3.2.3 Scale, outside calipers and depth caliper gage. 3.2.4 Paint spray can. 3.2.5 Photographic and/or video equipment, for documentation purposes. 3.3 Test Vehicle/Test Piece. In order to achieve greater engine movements, tests shall be performed using vehicles with manual transmission, e
6、nables direct acceleration, and with a kilometer reading of 10 000 km, increased play as components have settled in, when possible. 3.4 Test Time. Calendar time: 1 day Test hours: 8 hours Coordination hours: 2 hours 3.5 Test Required Information. Not applicable. 3.6 Personnel/Skills. Not applicable.
7、 Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14450 Copyright 2011 General Motors Company All Rights Reserved July 2011 Page 2 of 6 4
8、Procedure 4.1 Preparation. 4.1.1 Vehicle. 4.1.1.1 Release Status. Check the following parts to the state of release and vehicle position: x Air induction system, heater hose, scoop x Radiator, blower, shroud x Engine and transmission mounts, check for cracks x Throttle controls x Underhood component
9、s near exhaust system x Underbody components near exhaust system x Body fascia near exhaust tailpipe x Exhaust system Test according to the availability of parts for non-series vehicles. 4.1.1.2 Modifications. If assemblies are expected to come into contact with each other during the tests using wor
10、n engine and transmission mounts, then consideration shall be given to a temporary repositioning or alteration of new parts so as to enable the maximum engine movements to take place unhindered. 4.1.2 Travel Sensors. Record the movements in the area of the engine and transmission mounts as well as p
11、oints of critical clearance simultaneously, as far as possible, using electronic, optical or mechanical positioning sensors which enable all three (3) directions to be recorded. Record the clearances between components before and after test. Use photographs and/or video as needed to document critica
12、l clearance conditions. 4.1.3 Resources. 4.1.3.1 Clay or Plasticine. Clay or plasticine may be used to determine minimum clearance between the components creating an impression in the clay or plasticine. However, this method only records the maximum movements. 4.1.3.2 Paint Coat. Opposite component
13、faces of moving parts may be painted. This method only provides visible evidence of contact. 4.1.3.3 Photographs and Video. Photographs and video may be used to document critical clearance conditions. Video offers the advantage of time based clearance visualization. 4.2 Conditions. 4.2.1 Environment
14、al Conditions. Not applicable. 4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 4.2.2.1 Road Surface. The surface shall conform to the corresponding test
15、tracks of a GM or equivalent proving ground. The road surface shall be dry, in order to achieve maximum movements. 4.2.2.2 Vehicle Load. The vehicle shall be evaluated at two loading conditions: curb plus driver and Gross Vehicle Weight (GVW). 4.3 Instructions. 4.3.1 General. The following safety re
16、lated components shall be checked for each drive condition: a. Brake system, ensuring depression, sealed oil system b. Steering, locking, stiff steering c. Cooling system, air and water tightness d. Gas regulation, unintentional increased engine speed, return to idle speed, distortion of the power t
17、ransmission elements 4.3.1.1 Checks shall be performed to see which components restrict the engine movements, see paragraph 4.1.1.2. 4.3.2 Procedure. The following drive tests shall be performed and the measured values determined before and after each driving condition recorded separately: Copyright
18、 General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14450 Copyright 2011 General Motors Company All Rights Reserved July 2011 Page 3 of 6 x Engine sus
19、pensions according to the state of release 4.3.2.1 Assessments during the Drive. 4.3.2.1.1 Driving on the Durability Test Track at the Maximum Posted Speed. x Manual Transmission (MT): 2nd and 3rd gear. x Automatic Transmission (AT): driving position D. 4.3.2.1.2 Starting Forward. This test shall be
20、 performed on the skid pad at a GM or equivalent proving ground. x MT: Select 1st gear and engage the clutch quickly at full load acceleration. x AT: In driving position 1 and with the foot brake applied, accelerate repeatedly up to stall speed revolutions, then drive off at full load acceleration i
21、n driving position 1. 4.3.2.1.3 Starting Rearward. This test shall be performed on the skid pad at a GM or equivalent proving ground. The driver shall aim for maximum movement, under power hop conditions if possible. If power hop can be achieved, the vehicle shall be driven within this range. x MT:
22、Select reverse gear and engage the clutch quickly at full load acceleration. x AT: In driving position R and with the foot brake applied, accelerate repeatedly up to stall speed revolutions, then drive off at full acceleration in driving position R. 4.3.2.1.4 Circular Course Drive. This test shall b
23、e performed on the skid pad at a GM or equivalent proving ground. 4.3.2.1.4.1 Perform the circular course drive at the maximum possible transverse acceleration. When reaching the maximum engine torque, see revolution meter, accelerate briefly and in sudden bursts. x Right hand bend. At the end of th
24、e test, slowly straighten the steering wheel to avoid over steering. x Left hand bend. Drive as described above. x Alternating circuits. In this test the vehicle shall effect a number of Figure 8 movements, with direct change of direction from right to left hand bend or vice versa. 4.3.2.1.5 Forward
25、 Starting on an Uphill Gradient. x MT: 1st gear. x AT: Driving position 1. 4.3.2.1.5.1 Smooth full load acceleration up an incline between 20 % and 30 % until the vehicle reaches maximum engine torque. Continue to the top of the grade at maximum engine torque and with repeated, sudden accelerations.
26、 See safety instructions in paragraph 6. 4.3.2.1.6 Rearward Starting on an Uphill Gradient. x MT: Reverse gear. x AT: Driving position R. 4.3.2.1.6.1 If power hop can be achieved, the vehicle shall be driven within the critical range. 4.3.2.1.6.2 Smooth full load acceleration up an incline between 2
27、0 % and 30 % until the vehicle reaches maximum engine torque. Continue to the top of the grade at maximum engine torque and with repeated, sudden accelerations. See safety instructions in paragraph 6. 4.3.2.1.7 Full Braking. This test shall be performed on a skid pad and downhill gradient at a GM or
28、 equivalent proving ground. x MT: 2nd gear without disengaging the clutch. x AT: Driving position D. 4.3.2.1.7.1 Perform a full braking in the plane in each case at speeds of 30 km/h and approximately 5 km/h, walking speed. x MT: Reverse gear without disengaging the clutch. x AT: Driving position R.
29、 4.3.2.1.7.2 Perform a full braking in the plane in each case at speeds of 30 km/h or the maximum attainable reverse speed if 30 km/h is unattainable and 5 km/h, walking speed. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or
30、networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14450 Copyright 2011 General Motors Company All Rights Reserved July 2011 Page 4 of 6 4.3.2.1.7.3 The following test shall be performed on a Downhill Gradient: x MT: 1st gear. x AT: Driving position D. 4.3.2.1.7.
31、4 Full braking in bursts on a downhill gradient between 20 % and 30 % from | 5 km/h, walking speed, in first gear, in order to obtain maximum exhaust movement. See safety instructions in paragraph 6. 4.3.2.1.8 Driving on the Long Wave Belgian Block Road. x MT: 2nd gear. x AT: Driving position 2. 4.3
32、.2.1.8.1 Drive slowly along the long wave Belgian block road up to a speed of 50 km/h, then brake slowly to walking speed. 4.3.2.1.8.2 Drive the vehicle along the long wave Belgian block road twice using a different lane each time while changing the speed several times. 4.3.2.1.9 Driving along the S
33、taggered Washboard. x MT: 2nd gear. x AT: Driving position 2. 4.3.2.1.9.1 Drive the vehicle slowly along the Staggered Washboard to a speed of 50 km/h, then brake to walking speed. Repeat this speed change several times along the length of the “washboard track“. 4.3.2.1.10 Driving along the Parallel
34、 Washboard. x MT: 2nd gear. x AT: Driving position 2. 4.3.2.1.10.1 Drive the vehicle slowly along the Parallel Washboard to a speed of 50 km/h, then brake to walking speed. 4.3.2.1.10.2 Repeat this speed change several times along the length of the washboard track. 4.3.2.1.11 Vehicle Return. At the
35、end of the test following work shall be performed on the test vehicle: x Restoration to production or test component state. x Check for any defects which have arisen and initiate the corresponding repairs. Finally, the vehicle shall be returned to the appropriate department. 5 Data 5.1 Calculations.
36、 Not applicable. 5.2 Interpretation of Results. 5.2.1 The free movement of parts in relation to each other shall be guaranteed under all client driving conditions. Evaluate any contact occurring individually. 5.2.2 Complaints which are not directly associated with the test contract shall be passed o
37、n in writing to the appropriate groups as stipulated, together with details of the test conditions. 5.2.3 Only the maximum values in each direction of movement from each individual test are recorded. The results shall be entered in the enclosed data sheets. The requirements according to paragraph 5.
38、2.1 shall be met. 5.3 Test Documentation. Add the completed data sheets with reference to this test procedure to a test report. 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated with its use
39、. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. When conducting starting and braking uphill, see paragraphs 4.3.2.1.5 and 4.3.2.1.6, it is necessary to make the track
40、safe with respect to other traffic. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14450 Copyright 2011 General Motors Company All Right
41、s Reserved July 2011 Page 5 of 6 7 Notes 7.1 Glossary. Power Hop: Alternating spinning and gripping by the drive wheels at very high torques, the accelerator pedal position shall be kept as constant as possible during the test. Walking Speed: Velocity 5 km/h. 7.2 Acronyms, Abbreviations, and Symbols
42、. AT Automatic Transmission CTS Component Technical Specification GVW Gross Vehicle Weight MT Manual Transmission SSTS Subsystem Technical Specification VTS Vehicle Technical Specification 8 Coding System This standard shall be referenced in other documents, drawings, etc., as follows: GMW14450 9 Re
43、lease and Revisions This standard was originated in September 2005. It was first approved by Global Exhaust Center in March 2006. It was first published in March 2006. Issue Publication Date Description (Organization) 1 MAR 2006 Initial publication. 2 JUL 2011 5 year refresh; transferred into new te
44、mplate Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14450 Copyright 2011 General Motors Company All Rights Reserved July 2011 Page 6 o
45、f 6 Appendix A Data Sheet Exhaust System Dynamic Clearance Test Vehicle: Test Date: Engine Type: Exhaust Type: Test Location: Test Technician: Clearance Location Clearance (mm) Remarks Before Test After Test Difference Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
