Developments so far this week
Below you will see the recommendation for our VY by HM/Perry. We will be going with this recommendation from the people who know and take it from there.
Once the goods arrive and are fitted we will put some pics up
Recommended system for vehicle
HM8TCSS – Stainless Steel header with 1 5/8” primary pipes to suit twin cat setup.
HM718 – Twin high flow 2½” 1.7 litre Delphi cats with pipework and flanges to suit header and change front muffler flange to V8 position
HM8TIRS – Mild steel dual 2¼” front mufflers converting into single 2½” rear muffler and outlet complete with chrome tip.
I recommend this configuration for the described vehicle to provide good low down torque while maintaining high end performance, in our vast experience in dealing with these vehicles we have found that these pipe sizes have proved a very good package for all round performance.
The stainless steel header comes with a 10 year warranty, we do not recommend using anything but stainless steel in front of a catalytic convertor. The catalytic convertors used are the same units specified for our V8 systems therefore offering more than enough flow for this particular vehicle. And lastly the exhaust system specified merges into a single pipe as we have found that a full dual system on these vehicles will sacrifice low down torque required for a good all round performance