Has anyone ever gutted the cats in their aftermarket exhaust system? I started playing with the stock catalytic converters to see exactly how restrictive that stuff is and was amazed at how dense it is.

Obviously, I realize that the 200 cell cats on my speedtech are less restrictive, but I feel like having a free flowing exhaust is useless with a web of metal catalyst for the air to go through.

I wonder a couple things- 1. How it sounds- can yuo hear the turbo spool? I think it would do wonders for the sound of the exhaust without the sound of the air squeezing through the hundreds of little holes.

2. How hard is it to get all that stuff out? I am thinking to drill a hole in it to break the seal, then hammer it out while turning the cans upside down (since they are attached) to empty it.

If it doesnt work well, or ends up with jagged edges, I can always bring it to a muffler shop and have a pipe welded in the place of the cats which leads me to #3... Anyone run no cats on 2 can mufflers- fabspeed, speedtech, agency, ect? Thoughts?

 

have euro pipe 100 cell cats now i wondering about taking my stock cats apart gutting the and reinstalling them .
had a 80 corvette and removed the cats , it made a real difference ofcourse that was in 80s and stuff was way different in the dark ages

 

Have the 100cell Milltek and wondering about the same thing. I heard more turbo spool with the TJW mod, but this system does sound great under load >3k rpm.

 

With our exhaust everything is modular, you can take out the cats and place in these pipes so you do not have to 'gut' them. You can swap them out in 15 minutes...

 

Any decent tuner will get your car to pass OBD plug in emissions w/ out cats and your car will make more power and spool faster.

I think the only place where you will run into a problem is CA where they use sniffers on the tail pipes.

 

The sound will be amazing and yes you will hear more turbo action.

 

if you guy the factory cats, this will set off the cel correct?

 

I now run a Cargraphic exhaust w/o cats and I purely adore the sound !!

 

Great to hear- I'm going to do it. What about the smell - I would imagine the unburnt gasses would have to smell bad when the engine comes off a load.

 

that is something else pray that the wind will not be from behind when you have the windows down

 

With a tune/flash its all good. My B5 S4 and MKIV Supra both had no cats.... no bad smell.

 

Can you run these with the stock exhaust? Can you PM a price shipped to 21144?

Thanks!
-V

 

I also have CarGPH. To drill out the cat. Kind of PITA. Drill, Hammer, Big long screwdriver and Numb hands. Took around 3hours. Now I could hear the turbos whistle. I like it .

 

any sound clips? any power gains?

 

Nope,sorry. But from seat of the pant, yes on power gain. Not much but it is there.