
Fuel And Exhaust S ys t ems Page G-3
Page G-3
2 Exhaust System General
Information
The development of unique HSV Exhaust Systems has been necessitated by, and conducted in parallel with, the
development of engines and transmissions. A range of exhaust systems has been developed to satisfy the demands for
specific applications. Each development has been designed to operate with a specific engine and has been proven by
extensive testing.
For WK the exhaust has been developed with different levels of refinement in mind. The 285 kW ‘sports’ system has been
developed to produce a sports oriented note, that still meets legal requirements. The design of the sports rear muffler is
similar to the straight through, low backpressure design used on GTS, although it has bee retuned to provide differentiation
in the exhaust notes. All of these systems are common from the headers to the intermediate muffler assembly.
For WK there is also a specific low backpressure muffler design, which incorporates a machined alloy tailpipe to provide
further differentiation.
Although HSV and Holden exhaust systems are different, the general principles are the same. Service notes specified in
relevant Holden Service Information Supplements provide useful information. Particularly, the relationship between exhaust
components and the clearances between exhaust components and the vehicle body are important. Information on the
relationship of HSV components, torque settings and clearances between exhaust components and the body of the vehicle
is presented in this section.
2.1 Grange 285 Exhaust System
General Descript i on
Much of the exhaust system fitted to the HSV WK models is carried over from VY 2, using a larger diameter header system
for primary and secondary pipes, and a larger diameter pipe on the converter. Also, there has been a change in muffler
design, to give the dual outlet sports muffler a more sporty note along wi th a new intermediate muffler design to incorporate
core vehicle changes to the propeller shaft. The intermediate muffler now incorporates a single balance pipe shorter, straight
through mufflers and revised pipework past the differential.
For Grange models, the exhaust system is common with the SWB model up to the intermediate muffler, which is 150mm
longer for LWB models, still using the same muffler elements. Grange models also require a new rear muffler, which uses
the same muffler element as the part used on VY2 Senators, but has a revised tailpipe, due to the extra length in the rear
section of the vehicle.
Service Operations
When servicing the exhaust systems fitted to HSV WK vehicles, refer to Drawing 08I-030003.
NOTE
The exhausts on HSV WK model before 17/10/03 are
fitted with an exhaust alignment shim. If the RH
header (Part No. 08C030602) requires replacement
for any reason it will be replaced by the later version
header (Part No. 08C030608). If the later version
header (Part No. 08C030608) is used the exhaust
alignment shim will no longer be required.