James, wouldn't it be cheaper to get some quieter mufflers?

He briongs a really good point thgouh, gutting those cats will make a BIG difference in sound. I left my hollow shells there, because they act as a resonator and tone it down, and give it a deeper tone.

One more thing ... I've done this on 2 different trucks and both times ended up at the eye doctor with some cat dust in my eye. It is not any fun at all getting this dug out or ground out, which ever the doc prefers, of yor eye with a very small hypodermic needle or a miniature grinding wheel. Trust me on this one ... wear some googles that seal around your eyes. Regular eye glasses are not enough! BTW, if you have to go through the eye doc stuff, your eye will more than likely hurt and be very light sensitive for 2-3 days, and you will have some cream to put in your eye for the next 2 weeks. Enough of the horror story, just be sure to wear eye protection!

 

Happened to me also, so were saftey glasses.

 

mine are gutted as well. and yay that stuff goes everywhere just like fiberglass particles.

 

its gonna backfire and carry on but do what you like, just be aware that you can get high flow stainless cats from summit made by catco for 65 dollars each and it will sound a whole lot better than what your about to do.

 

As long as we're on the subject, I need to select replacement high-flow 3" cats for the Tahoe.

I originally went with Magnaflow 43009 stainless 3" oval-body units because they are California Air Resources Board and OBD-II compliant. I know other people with non-CARB cats that are passing the smog test just fine. In fact, I had my truck smogged with the Magnaflows (Carsound) and cam and 200cc runner aluminum heads and it passed like a brand new car, so I know I have room to work with now that the stock cam is back in.

I am looking round-body 3" high-flow catalytic converter options now. I think the round ones stand a better chance of holding up to the extreme heat due to more uniform expansion, and $180 a piece for cats is more than I want to spend on the damn things again.

What are you guys having good fortune with?

 

If you're going for performance, you might as well gut them, then run a piece of pipe thru them and weld it back up. Just think of the exhaust flowing thru that large area with chunks hanging from the walls and stuff. That can't be good for performance like a piece of pipe the same size. And louder is better

 

hey james b you might want to check with FLP and look at there oval cats. I have a set off my ypipe and there about 2-3 inches long. There real little almost like a little bullet.



Oh yea chop them cats off, you'll see a big gain.

 

Hahh! Louds sucks. Watch and listen how seriously bad it is with no cats:

http://james.jaguar.net/pics/flyby4.mpg

That is interresting. It's hard to imagine something like that actually working! The whole point is to pass smog I guess. That tiny they would likely not even get through visual if they looked!

 

James .. have you thought about getting a set off of a new truck, like the ones on out trucks? I've not heard of one failing yet, and I know we have some nasty trucks out there running them.

 

You're right ... yours doesn't sound all that good. I will say that the newer trucks sound much better without them than yours. Not at all slamming you.

Here's a few sound clips of mine. THe last one listed is the latest. ALl of htese are with gutted cats.