I was getting the flex joints fixed on the exhaust system so I decided to get new catalytic converters and a cat back exhaust system fitted while I was at it.
The catalytic converters are now 200cpi high flows and I got my hands on an APR RS6 Cat Back Exhaust System. The APR kit is a stainless steel, mandrel bent, cat-back exhaust which runs dual 2.5" pipes. More information can be found on the APR website http://goapr.com.au/products/apr_exhaust_rs6.html
The work was done at Mild 2 Wild Exhaust on Moss Street at Slacks Creek (07 3209 3309). The guys down there knew what they were doing and did an excellent job.
Comparison time. First, a couple of shots and videos of the stock cats and exhaust.
Now for the high flow cats and APR exhaust.
I managed to quickly shove my head under the car after they finished.
They put flanges before the cats which sit fairly close to the transmission sump. I've got the car booked in for a scheduled service in 2 weeks so I will have a look to see if its rubbing or hitting when its on the hoist. The slip joints after the cats were kept in their original location so if I ever want to go back to the OEM exhaust there shouldn't be a problem.
Im not 100% sold on the new system yet. While it doesn't sound overly louder outside the drone inside is quite a different thing. Between 60 and 70kph with slight load the drone is very noticeable. Cruising at 100kph on the highway is ok with it being only slightly louder than the stock system. It's just a pity that it drones every time your around the 1000 to 2000rpm mark with load.
It's early stages at the moment but I personally think that the stock exhaust sounds better, at least while it's free revving. The drone is the major downside for me and the power gains, if any, have yet to be seen. Are the quad tips really worth the in cabin noise?
Total cost from Mild 2 Wild was $880. This included the new cats, flanges, custom pipework and fitting the APR exhaust.
For now, the stock exhaust sits in a shipping container.