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dsmking101

10+ Year Contributor
224
2
May 13, 2009
????, Utah
Ive seen a few people do this and just will like to know how i can hallow out my stock cat for highier top end speed. please be detailed and if anyone out there has done this let me know how you like it and if you can feel and hear a diffreance thanks: :thumb:
 
replace the cat with a straight peice of pipe. prob will sound raspy but will be better and way less time than drilling the cat. im gonna guess the max hp gain you would see is 2-4 whp.
I have drilled out a exhaust on a 02 zx6r and it was a pain in the ass. its a mesh of metal in there and you need a long drill bit and alot of time. A cat may be different slightly but i doubt
 
sounds good but staight piping it idk i dont want that raspy sound i rather go thew the pain and hallow out the cat i know a few people who have done it and it sounds good what do i need and how do i hallow it out thanks for the segg tho
 
Its easy, I've done it many times. First remove the cat, then you will need a long bar or screwdriver/pry bar and a hammer. Cram the bar down in the cat and hammer/chisel away at the ceramic insides (guts). Just keep poking and hammering and shaking the ceramics out. When its all out you'll need some pliers to pull out a steel mesh net and your done. Bolt it back on and enjoy.
 
Its easy, I've done it many times. First remove the cat, then you will need a long bar or screwdriver/pry bar and a hammer. Cram the bar down in the cat and hammer/chisel away at the ceramic insides (guts). Just keep poking and hammering and shaking the ceramics out. When its all out you'll need some pliers to pull out a steel mesh net and your done. Bolt it back on and enjoy.


Did it in my Trans am too, sounds all throaty now. Also the Talon has a sound like no other not riced I guess. What I did was since I was putting on a new downpipe, I cleared it out as well. That steel mesh was a bit of a bi*** to get a hold of but it came out. With the stock exhaust it sounds like a turbine back there when your beating on it LOL.

I been planning on getting a new exhaust, I was thinking pacesetter. I was going to get a Magna flow, or a flow tech, and weld it on. I can't find a decent price on 2.5 inch exhaust pipe anywhere. Or an affordable 2.5 inch down pipe.

G/L
 
kool thanks i appreicate the intell kyndl7 since you have done it many times how is it dose it sound good not really that raspy and dose it really give a push at top end speed
 
snakeyes711 when you put it back on did it sound sick i know you mentiond it sounds good but how good and did you feel a diffrence at high end top speed ....

oh and dose any dsmers out there have any videos on how there dsm sounds with a hallowed cat?
 
kool thanks i appreicate the intell kyndl7 since you have done it many times how is it dose it sound good not really that raspy and dose it really give a push at top end speed

I hollowed the cat on my 96 eclipse n/t, and on this car i had a flowmaster delta 44 on stock pipes the exhaust did not sound the least bit raspy. I dont know about a straight flow type of muffler it may be a little raspy? As for the power it does feel a little more powerful on the top end (according to the ass dyno), but you may notice a little less torque in the lower RPM range.
 
Not worth it. Get a high flow cat. The effort put into gutting it will gain you the smallest amount of hp, and it doesn't change the sound much at all. I don't have sound clips, but I went from a gutted cat to a normal one in one day, it made almost no difference. You will most likely fail the OBDII scan too.
 
i understand what your saying tkelly27 but even tho it might not be worth it i think it is because even tho you gain a little hp from it its hp you dident have even if its 1-2-3-4hp its a lil more then what you had this is just what im going to do no one else has to do it its just me thanks for the intell tho appreicate it
 
Step 1 First issue is to remove the Cat. In most cases it is bolted on, at either end, on the exhaust system. Removing the bolts will loosen the cat, however the crimping done may require you to pry it off. (you can also use a blow torch to soften the crimped ends and tap it off.) ** IF YOU HAVE TO USE A JACK- USE JACK STANDS**

Step 2 Once the cat is off you will see a honeycombed white/gray powdery looking core. Put the Cat in a vice facing up with the bottom a couple inches off the ground. Take the pry bar and the sledge hammer and begin breaking up the honeycomb. Once there is a couple inches of powder built up, turn the Cat the other way (other end up) and do the same to that end. Repeat until all is out.

Step 3 The powdery mess has a high concentration of Platinum, recycle it for CASH. Now it is hollowed out. Reinstall in the reverse manner.
 
1-5hp at what cost to the environment? The diesel Audi in Le Mans runs a particulate filter, you can live with a catalyst
Letting off gas RET-Monitor

Also, this sounds like a real pain in the ass to gut it. It's worth your time and money to get a fake one or a high flow.
 
Be careful. I think the cat has many bad dust in there you don't want to breathe. What I did to my civic was put the cat in the bag and then just started pounding away with the handle of the hammer. You will not notice anything or anything to brag about. The least is mid to high end. Cat are hard to find when smog comes, ESP in Cali. It is really best to just by one on eBay.
 
thats weird did not know about the platinum how would you get cash for it LOL?? and thanks for the step by step project 2g
 
Please don't gut your cat. I dont understand... you are talking about how you dont want a raspy exhaust and your running a boosted 420a? If you were all motor then it would be really raspy.

just get a test pipe if your boosted, straight pipe will help more with the hp because the stock cat is not perfectly round. your will have less back pressure with a test pipe.
 
do you have proof that it sounds raspy or your just assuming it will sound raspy?

dammm couldent take off my cat i was inspecting it finding out how can i remove it and found out its WELDED suxs but what can i do whatever how did you remove yours anyone whos done it
 
On a all motor car it will sound raspy as hell.. like a honda, but if you have a boosted 420a it wont sound bad.

the cat is not welded on. its rusted on.

and my proof is that I made the mistake by taking off my cat and put on a test pipe. loud and ricey...

I personally (by experience) say its not worth the time or effort.

correct me if Im wrong Please...

your profile says your a boosted 420a.. and your profile also says you have an OBX high flow cat.. which is it? kinda confusing..
 
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