I suggest you stay away from 3" and stick with 2.5". You'll lose low end power if you went with 3". Even with a standard ZZP SC Kit. This of course is my own opinion. The Vibrant Header/DP combo is great if you want a high quality polished stainless steel system. I love mine and wouldn't change to anything else. Welds are flawless and the tubing is without rust after 2 years. You'll get mixed reviews on here but you should really consider the LONG RUN. Going cheap isn't always the best thing to do if you daily the car.

 

thank you for clarifying.... is there not an added feature or 2 that trifecta can do over what hptuners can do? im pretty sure i read that on a vendor site

 

yes hptuners is more detailed in what they can control

 

hmmmm... thought it was the other way around.... must do more research
tho i do know that trifecta can set you back to stock for warranty purposes.... dont believe hptuners can do that

 

HPT can write the stock tune but they would still see the calibration change.

 

ZZP told me to go LT with 3 inch... I did all my exhaust at once so I couldnt tell you how much/if there is a noticeable difference with a 2.5 while you are still N/A waiting for your SC kit, but I haven't put my TVS on yet and I still have plenty enough power to roast the wheels.