Ok so I have an intake/headers/exhaust/test pipes right now. The car has amazing rasp from about 3.5-4K but after 4K the rasp is gone. I have helix test pipes on the car along with a greddy evo2 exhaust and top speed headers. Now if I were to throw my stock cats back on but gut them first, would that get rid of the rasp? I've done a few searches and a lot of people seem to think it would but some also say that since I have headers that will cause the pipes to get raspy regardless. So will gutted stockers combined with headers cause rasp or no?

 

i will be gutting my cats as soon as i get an extra set hopefully this next week. i'll let you know if you havent alreaqdy done so.

p.s. did you just use the crowbar/screwdriver method to gut the cats?

 

well.. keep in mind they are over $900 each for when you are going to be needing to put a new set on for SMOG testing...

But, I woul dnot recomend gutting the stock cats because there will be soo much empty space for the air to tumble and turn...

 

if any one needs to buy an extra set of stock cats, ill be more than willing to sell mine since I dont have to worry about emission.

 

I had gutted the stockers before my stillen. No rasp at all.

 

I also have a set for sale. Cheap way to get HP, way cheaper than TP's.

 

what did you use to hollow em out? crowbar? screwdriver?
thanks

 

I havent gutted the 350z cats yet... but on previous cars (that had smaller cats) I used the metal handle off a plastic paint bucket...

 

metal bar, screwdrivers, long drill bit, drill bit for boring 1" holes in wood, hammer and a few other tools. Make sure to wear a dust mask also.