Originally Posted by GTB Liberty

Gday all,

Finally got my Phat Performance Parts Dump Pipe Version 2 (PPP DP) installed and well . . . it now pulls like a freight train. The PPP DP was 3" mandrel bent mild steel with ceramic coating inside and out. It also has a large bell mouth with splitter for the waste-gate. Got it installed by Mettams in Morley (a bit of a drive) and Pat was a great help. All went without any fuss and in no time at all. The pipe was well accepted by the Mettam's boys and the fit was a "breeze" in comparison to "other dump pipes" that they had fitted. Essentially, another vote for Phat's exceptional work in making sure his dump pipes are the correct fit for our AUDM cars. Currently, the PPP DP is attached with the 2 1/2" OEM centre and OEM GT mufflers. The PPP DP have a 3" piece to replace the 2 1/2" outlet if a 3" system is installed. This easy swap with only two bolts was a big plus for me.

I did do an ECU reset immediately after the install and drove the car home - what a drive it was. The increased spooling response is obvious as is the increased flow. Having to get used to all kind of new noises but none are obtrusive. Induction noise is greater, the OEM BOV is obvious now but the in cabin sound with windows up is a negligible increase. Most wouldn't notice.

Previous boost maximums were in the 14.8-15.1 range. Now , the highest I have logged is 16.24 psi. No "spikes" yet. So, approx 1.2 PSI increase or 8% and that 8% seems to be translating into Kw by the bum dyno.

I drove home and the ambient air temp was approx 24-25 degree C. When I finally caught up with my girl and took her for a drive it was night and closer to 14 degree c. A scary moment for me was when we went for a run there was many moments of massive air rushing sounds with a noticeable decrease in boost. Initially I was wondering if I had popped a post turbo gasket or hose. I believe I have worked it out to being the waste-gate opening. The "air rush" noise was very loud and something I never noticed previous to the PPP DP. I have put it down to the ECU managing the much colder air leading to much higher boost and a just reset ECU to gate out aggressively. The gating sound is now able to be heard via the HUGE splitter section of the PPP DP in comparison to the flat section on the OEM DP. Regardless, was a very new sound and initially had me preturbed. This morning I went and logged again with 16.1 Psi max. Opinions please.