GM Gasoline V6 90 Degree - Manual (Page 73)

ENGINE APPLICATION MANUAL GM Powertrain
Gasoline 4.3L V6 90 Degree Revised: 08/15/2000
File: c:\data\manuales\v6-truck\am43v6#3.doc
Contact:Luis Nespolo - (248) 857-1558 Printed: 8/15/00 71
6.3 ENGINE LOAD
Sustained high engine loads (loads in excess of 90% of W.O. T. torque) should not be applied below
peak torque - engine rpm, See paragraph 2.3.2.1.
Torque Fluctuations.
Torque Fluctuations at WOT, will not exceed a value of ± 5% of the nominal torque value between
1000 RPM & max. rated speed.
Brake Specific Fuel Consumption
The engine brake specific fuel consumption (bsfc) shall be as follows:
1.
The engines nominal brake specific fuel consumption point on a W.O.T. curve is shown in
table 6.3 -I.
2. The engine nominal specific fuel consumption shown in table 7.3 -I are for an operating range
between peak torque and maximum power at full load.
3. The engines best part throttle bsfc (on a fuel map) is shown in table 7.3 -I.
Table 6.3 -I V6 4.3L Engine BSFC
Engine Brake Capacity
FMVSS requires engine braking in at least one of the lower ratios, below 25mph.
For a transmission type similar to the 4L60-E this is equivalent to 2nd gear. For another type of
transmission combination the braking capability should be verified.
For manual transmissions, engine braking is calibrated with the GM transmissions to occur in the
highest ratio in each forward selector range
Some off road applications or very heavy load situations might require additional subsystems to
increase engine brake capacity.
Depending on the application, the GM release engineer and the customer will determine the
necessity of auxiliary or additional engine brake aid sub systems.
RPM L35 L35 Notes
Truck Marine
Applications Applications
800 0.529 0.495 lb./BHP-Hr
1200 0.521 0.478 lb./BHP-Hr
1600 0.484 0.481 lb./BHP-Hr
2000 0.470 0.471 lb./BHP-Hr
2400 0.471 0.466 lb./BHP-Hr
2800 0.469 0.472 lb./BHP-Hr
3200 0.478 0.458 lb./BHP-Hr
3600 0.483 0.452 lb./BHP-Hr
4000 0.500 0.460 lb./BHP-Hr
4400 0.525 0.479 lb./BHP-Hr
4800 0.532 0.506 lb./BHP-Hr
5200 0.556 0.550 lb./BHP-Hr