hollow out the cat?

i wanted to give my Z an more aggresive tone and was wondering if hollowing out my cat would be a good way, plus the obvious hp gains. It would be a good combo with the 17 SS wheels with 315s on the rear im bouta get. I have flowmaster now and yea it sounds good but i want it louder. Or if anybody has any good ideas bout what i should do to make it louder?

change to MagnaFlow.

think that muffler will make a big difference? and how much would it be?

hollowing out the cat sucks balls and will make it have a crappy echoing kind of sound because it would act like a big fart can muffler.

I have MagnaFlow and love it...it would make a big difference. don't know right off the top of my head how much it is.

oh and don't hollow it out just take it off and patch it with pipe.

Yeah, hollowing out the cat is a bad Idea....I really don't like the way mine sounds and I don't have any cats

Borla's sound better on an LT1 IMO

is the Borla exhaust adjustable, cuz thats what i heard?

i think so

Ye, it comes with different size restricter plates

gutting the cat increases the flow of exhaust by a lot, but it doesnt work as well as straight piping because the hollow cat basically works as an expansion chamber for the gases...

Unless you live in AK , hollowing out your cat will make you fail emissions , You don't gain HP with no back pressure either , lose at most. I am running around right now with only a Y-pipe on my 3rd gen and it makes all my other mods seem obsolete. 0-back pressure = Horrible performance.

Want loud exhaust? SLP loud mouth. Cost: 385-450. Leave the cat alone.

is that SLP loud moth cat-back? well i used to have a 90 5.0 and i had no cats, then i had to smog it, which meant i had to put the cats back on and when i did i noticed a whole lof of restriction... so i thought on my camaro it would do the samething if i took the cat off

Yep the loud mouth is cat back. Not sure what year your Z is, but, any decent muffler shop can mod it to fit. I put one on a friends third gen. Wasnt very hard.Here's a link:
http://www.slponline.com/view_product.asp?P=31039A
Hope this helps. I'm putting the GMMG cat back exhaust on my 99Z after Christmas

my Z is a 94, so do they make those loud mouth ones for that year cuz the link u sent me was for 98-02

u know what i think that one will work, my bad it says it will fit 93-02 thanx man i appreciate it

No, as far as I know, slp doesnt make them for the 93-97 ( LT1) but, the stock exhausts aren't that much different. Any muffler shop can install it and make any mods needed. BTW, this sounds great through the cat. I don't really like it if you have headers, but some folks do. Here's a site where you can go to hear different types of exhausts:

http://dodds.cc/chad/garage/z28/ls1_sounds/

These are all on LS1's, so your LT1 would sound slightly different, but, like I said, any of these exhausts can be made to fit a LT1.
Hope this helps! BTW, if you really want to not have the cat affect your car, just install a cut out before the cat, uncork it (or get an electric one) before you race, and have fun!
KevinD

Get some headers and a dual 3" exhaust

really appreciate the info kmdracer, hopefully by after christamas i weel have that done and will let u know whats up, thanx again

No prob 94Z, happy I could help. I've spent alot of time figuring out which exhaust to put on the 99Z. It's my daily driver. I really like the GMMG, so I've been saving up for it. I should have mine on after Christmas is done too. On the 91RS, i'm probably gonna go with a custom true dual exhaust using dynomax bulllets. I't going to be a quasi legal street/strip car. Right now, I'm researching swapping in a big block.
Later, KevinD


BTW..here's my cardomain site:

http://members.cardomain.com/kmdracer

I just hollowed out the cats on my car cause i had to. The were only at a 45% efficiency. So i bought o2 sims and hollowed out the cats. I love it. I set off all kinds of car alarms here at the apartment complex where i live. did it help i don't know but it sounds killer. oh yeah its an 00 z with 80 series flowmaster.

magnaflow sounds boo boo, its ok for a little bit of noise but the tone is sissy, on lt1 go with 80 series flowmaster, get a high flow cat: heddman-$50.00, get some headers. perfect combo. gutting a cat sounds raggedy and whoever said no backpressure=shitty performance said it right

all these new people here.....christ i only recognize like 4 people in this thread. lol

face it korndogg, we're just old salts on this forum...

i think i have an 40 series flowmaster on my Z, whats the difference between 40 and 80 series? if i do decide to go with the 80 series should i get the full cat back sytem 3''?

Flowmaster sucks ass

face it korndogg, we're just old salts on this forum...



apparently

40 series is less agressive, more for trucks, there is stuff out there that will give you more hp than flow but not for the money, personnally i think it makes everything else sound like shit

So am I a medium salt, or do I count as old?

And isn't Flowmaster the worst flowing for our cars? Or is that just on the 6's

your 3/4 salt

dirty old bastards.

The only true old timer's around here are Geno, Hypsi, 1992rs, 89 and chevyracincamaro.
Compared to those guys were all newbies

but we got the post count to run with the big dogs...lol

This is true, They basically sat around here with nothing to talk about til the new kids rolled into town

and VLAD!

Yeah and Vlad, How stupid was that and he has been the topic of many a discussion lately

no, you all just don't know when to stfu

ouch!!!, I don't know how I shall ever recover from that massive blow(yes you blow!).

just kidding man.....poop.

I knew you where kidding, I hardly ever take anything personally or else I would be on a ledge right now.

yea i know, but I hafta post that disclaimer to avoid legal problems.

Lol!!!.

Man I can feel the love in here...

post count????? hmmm..... looks at sig ;)

but anyway, why is it that everyone looks to hollow out the cat, it dosnt do much cept kill your chances of passing emissions, getting a high flow cat from random tech or something will give you just as much flow, and still pass the sniffer, if you are worried about exhaust backpressure, then go with headers, high flow cat, and a single 3in pipe out to an aftermarket muffler and 3in tips. Flowmaster, GMMG, Magnaflow, Borla, Corsa, are all valid options. go to their websites, and listen to sound clips of their products, and decide for yourself. although, i offer a peice of advice. dont judge based on how your laptop or PC speakers sound. wire your computer to a real sound system and play the sound file through that. this way youll have a better idea of what it will really sound like.

But it made my car sound really cool. I turned it on when we had the cats off man an ls1 sounds killer open header thats all i got to say.

to be honest, i bought my IROC with strait pipes, no cats at all, welded up strait pipe. I have sense then put on headers, a high flow cat, and a flowmaster american thunder catback, and it sounds MUCH better than it did before, and its louder. go figure.