Hi All
I am new memeber and this is my first post as it is something i have spent some time on.
I have a SV6 with Alloytech 190 and we have tried four different systems that are available here in NZ.
The twin system gave more top end and nice note but was boomy :cry: down at 1500rpm. Ended up making custom (mate works at exhaust place) two into ones out of the cats (2 1/4") that are about 600mm long, then through a single 2 3/4", a small resonator and into a Stainless Steel rear muffler that is made by a company in NZ (Coby) for the GenIV v8.
Final outcome is lots more torque, will now hold 4th from 1250rpm and pull without kicking down (have the 5 speed auto), no boom at all, and when you give it the beans she sounds like a muffled v8, in fact i have de-badged it and even the local holden dealers were asking what it was.
Both definatley freed up the top end and it revs cleaner, got half a car length against a std SV6 at 100kph. Next step to remove the cat's to get a decent note down low and free up some more power. :yeah:
Also trying to find a decent CAI, anyone got any suggestions.