with piping all the way to to downpipe, bypassing the main cat, without an ECU upgrade.

all i have right now is a DP.

 

not safe at all. even an ECU upgrade only is not really safe with a completely open exhaust - the wastegate cannot adequately control boost with no backpressure in the exhaust system.

don't bypass the main cat unless you have good fuel mods as well as other bolt-ons like a larger IC.

 

well i had a custom 3" exhasut done and love it, although i have a high flow cat, but it sounds great, actually i have yet to hear something i like better, i had stock ecu when i had a dp and the exhasut and my engine still works, not saying its not bad, i guess its a huge gamble and its better to be saffe then sorry but i had mine like that for about a month before i got a ecu uprgrade, scott

 

you are asking for trouble.

 

oh yea i also had an intake, so i had dp highflow cat and a full exhaust on stock ecu, i guess i got lucky, but i was really never that worried because i always monitered my air fuel gauges and they always showed it running rich, scott

 

As long as you upgrade your ecu w/ a Apex Power FC or some chip(pettit or m2) you'll be fine. I've ran a straight through exhaust for 2years now. The stock wastegate may need to be ported. Mine was. After that I never had boost spike, at all.

 

where do you get your waste gate ported and how much does it cost?

 

KD Rotary did my work...