Hey,
I just gutted my cats a few days ago and am going to try and run a pipe through them today to get rid of the tinney sound. My next step is going to be the flowmasters because i hear that they sound awsome. I have to do things in steps because of a low budget right now. Wouyld the Flowmaster 80 series sound better without a cat or with a high flow cat? 86 Iroc-Z 305 tpi manifolds (for now) 3" to cat and 2 1/2" cat back. single exaust two outlets.

 

Well, it is really up to you in the end. But I can say that no cats and the 80 series Flowmaster is really quite loud (myself and my friends agree - it sounds wicked :rockon: ). There are some sound clips of mine on my site when it had a gutted cat on it with the 80 series Flowmaster. I have since put in a test pipe. I have a stall as well and I really have to be careful not to wake up the rest of the city when I come in after hours. Adding a cat will make it somewhat more reasonable for noise if you are concerned about pissing off neighbors and attracting cops. Either way will sound very nice (especially with a high-flow cat).

 

I have a flowmaster 80 series w/ a 3" straight pipe in replace of my cat. I also have a 3" cat-back and Edelbrock TES Headers (3" collector) This is what it sounds like roughly.

http://hometown.aol.com:80/j007golden/Exaust1.wav

 

It depends a lot on your motor. Matt87GTA, based on his sig, looks like he has a pretty bad a$$ engine in his car, so his would definitely be pretty loud. I have a stock (for now) LG4 with an 80 series Flowmaster and a gutted cat, and it sounds mean, but is not overly loud. It doesn't make the car shake or anything, but you can definitely hear it at idle, and when you nail the gas, it actually sounds like I have some kind of powerful engine under the hood.