The Holden VE and VF SS Commodore is one of the most common vehicles we work on, we have a lot of knowledge about what works well, why it works well and what combination of products to use to achieve a specific result.
The first question I always ask customers is how loud they want it and how much drone they can put up with. The louder you want your exhaust system to be, the more it will drone. It isn't that straight forward though, any model with AFM, being where the engine only runs on 4 cylinders while cursing will drone a lot worse. Then you have the differences in body types and how that effects drone, sedans will drone the least, wagons are worse and then ute's drone the worst because of the smaller cabin. Particularly if they have a hard cover on the tray as it acts like an amplification chamber. Besides this everyone will have a different sensitivity to drone, exhaust drone doesn't phase some people at all, while others can be highly sensitive to it.
There are two packages we generally offer for the VE/VF V8 Commodores; a cat back sports systems or a full system package. The full system is generally made up of Pacemaker extractors, our own 100cpi stainless steel hi-flow cats and usually an X-Force cat back system.
For a cat back system we usually recommend a twin 2.5" or a twin 3" X-Force cat back system. I recommend twin 2.5" for a more subtle note with less drone and then twin 3" for a louder, meaner note. Naturally twin 3" comes with more drone. While there is some speculation around just how well X-Force systems fit, we have found them to be the most reliable and best value for money cat back bolt on systems on the market.
For a full system depending on how low the vehicle is we recommend Pacemaker try-y extractors for a lowered vehicle as the extractors sit higher and give better ground clearance. If the vehicle isn't too low we always recommend Pacemaker 4 into 1 competition extractors with our own 100 cpi stainless steel hi-flow cats and the choice of X-Force twin 2.5" or twin 3" cat back sports system. We're very competitively priced and these full package deals are quite affordable.
We have done a few wild and unique system combinations. For a very good customer of ours, with a very nice blacked out VE SS sedan we fitted ceramic coated Pacemaker extractors with our 100 cpi hi-flow cats and our own hand made full stainless steel twin 3" sports system with black powder coated quad 3" tips. This particular customer had lowered his commodore a lot. As a result it was scraping badly and the bolt on twin 3" cat back system wasn't as high as it could have been, so we hand made a twin 3" stainless system with maximum ground clearance in mind.