Gutting the Cat out, and trying out an open DP= :0

[DSMAddict]

After we pulled the cat off my friends GS-T to gut it, we decided to have some fun for an hour or so running an open DP. And all I have to say is ....... ive never heard any import sound so much like beat up truck heh. I could hear it two blocks away like it was right next to me and sounded horrible, but all in all fun scaring neighbors .

 

[KRAZYKOREAN]

 

[allwheelTSI]

Originally posted by KRAZYKOREAN

hahah,everyone does it once.

 

[DSMJim]

Thats because you should start with putting a pipe through the cat and welding the shell onto the pipe. When you just punch out the honeycomb it leaves this big open area for noise to bounce around in and makes the exhaust so much louder. Take that cat off, cut the flanges off the cat and ram a straight pipe through the shell and weld your flanges back onto the pipe. That way it's a test pipe with a shell of a cat on it. It will greatly reduce the nasty noise the exhaust is making.

 

[DSMAddict]

no no no, we only got the horrid noise when the dp was hanging open, no cat or TP. Once the gutted cat went back on, it went back to normal

 

[G-Ell]

My former roommate ran a 3" DP to a 3" borla muffler held in place by a couple hangers. On top of that he had the TRE modified 1G O2 w/external dump + an open atmosphere BOV...

Let's just say that car sounded like no other...

I'm amazed he was never pulled over.

 

[L2RTSiAWD]

I had to run an open DP once and it sucked.

Way to loud in the car and it vibrated the car so much it skipped my cd player.

 

[zac83]

ive been running open DP for about 2 months... i bolted on the o2 housing that i fabricated with the 3 inch main and 2.5 inch atmospheric dump. i finaly got it all patched back true 3 inch style to my apex'i cat back system. it sounds so quiet and sleeper, you can barely hear the 1g bov... at 5-10 psi, the car makes this horribly loud whistle then at 15 psi (boost controller setting) the wastegate slams open and the car gets VERY loud... ohh so sleeper. its fun to see the faces of people when you blast by them with the loud gate dumping then you sound completely stock at the next light.