I want to free up my exhaust and get a few extra hp but I can't really afford the Racing Beat system. So I was thinking straight pipe from the stock manifold to the stock mufflers aka cut out all the cats..

1. Will this sound good or would it give it a nasty tin can sound?
2. Will this provide enough back pressure for my 5/6th ports to open up?
3. Would this make a noticeable difference on the butt dyno?

 

Mine was like that for a while (stock manifold>Bonez race pipe>stock y-pipe and mufflers)

1. Didn't sound that good. It was a little throaty down low, but then it got buzzy up high
2. Couldn't tell you, mine were wire open
3. Again, couldn't tell you, I never drove it with the cats (they were clogged when I got the car)

Sorry I couldn't help with the technical part, but the sound wasn't that great. As for the 5/6 ports, I don't think they'll open with no cats. Not sure though. I'm still not 100% sure on how they even open normally.

I think I have a vid actually, hold on...

Edit: here's the vid. Only from inside the car. http://www.youtube.com/watch?v=A4dE5...e=channel_page Keep in mind my car was kind of fucked up in this video, so it will probably sound different for you. In the end, it will probably sound just like stock, only a little louder. If you have the means, go right ahead.

 

i have a str8t pipe to my stock mufflers.. Sounds ok. Low end sound. not to loud. sorta hard to hear the radio the low end bass cuts right through the car.. My 5th n 6th ports are wired open

 

Not relavant

 

on my N/A ive got a racing beat manifold straight through to the standard TII rear boxes.
The aux ports open fine (ive got a vacuum guage that proves this), you can even hear them.

the sound is alright actually, couldn't explain it to you though. It also still pops loads

 

Okay neat so I should be safe. If the ports fail how do you wire them open?

 

I have stock mufflers and stock gutted cats. My ports still open, but I don't like the sound all that much. It's not too bad at idle, but there is some rasp the more you get on it. Although it could be coming from the small holes all over my exhaust. lol

 

Sig says you have a '91, and S5s don't use exhaust backpressure to open the aux. ports.

My ports would not open when I was running an open exhaust on my S4 NA engine. I ended up using an rpm switch, emissions solenoid, & the stock airpump to rig up a system like the S5 NA uses to activate them.

 

Snap. My bad.

 

bonez make 2 different race pipes, one for s4 and one for s5, im assuming the onle difference is that on the s4 pipe there is a place to hook up the back pressure piping for 5/6 ports, but we'll see when i get mine in next week haha