holy crap, what a difference swapping to the 3inch in/out moroso spiral flow... deeper, no rasp and barely any drone at speeds and slow driving around neighborhoods... what a huge change.. the LM1 has nothing inside it.. its a widened piece of straight pipe. ill try and post pics soon.

 

Thread back to life!

When installing my long tubes I took a spin with open headers. Silly power gain!. not sure 100% of its because of the long tubes or because the open header having no resistance. I'm thinking that the cheap bullet style 5" muffler I put in place of the cat is adding more restriction then I think, especially now that I take a close look at the design (pic below). I thought it was a straight threw design like a cherry bomb but its not. So I want to put something there that will be quiet without snuffing out the HP. I really do not even care about sound. I would love it to be as quiet as stock - I just don't want to loose to much power. I have a SLP loud mouth 1 running from the (original location of) the CAT back. Now I am running Pacesetter off road long tubes and non pace setter 3"/3" Y pipe. That leaves me a few feet to work with to put something in there. Something small - no larger then 5" at the widest point (That is what I have in now and it fits, but tight). I see "DYING BREED" installed a Moroso Spiral Flow, Jegs Link -at only $50 or so that looks intriguing. What are you running for headers, where did you install the muffler?, any way you can post pics and maybe a sound or video clip if you still have it? much appreciated.

Any other suggestions as to what to put there?. I hear they have mufflers out with spring loaded baffles that let go under pressure. Anyone know of a bullet style like that, or recommend something. I would really prefer to keep the back half (LM1) intact so I would prefer a bullet style I can install in place of the stock cat since I am already doing work there. Thanks a bunch and sorry to bring it back to life :-)

 

If you are running open headers, with the O2 sensors in the collectors, the backwash of air in the collector will screw up the engine's A/F ratio control.

The best flowing mufflers I have seen, and this is backed up with dyno testing on a buddy's 8-second 30th SS convertible, are the Borla XR1 Sportsman Mufflers. They are unbaffled, and not very quiet.

http://www.injuneer.com/images/photo.../DCP03675a.jpg

 

Yea I could tell the first time, Ran great until closed loop. But I flashed it to stay in open loop. I guess there is no telling for sure if it was the exhaust change or fueling change or air temp change or anything else that made it feel better.

That pic looks like it would make a easy install but much to loud for that I need. I don't think I would have the required ground clearance. I think I have maybe 6-7 inches between the floor pan and ground.