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To cat or not to cat, that is the question

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Old 05-16-2012, 08:08 AM
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Arrow To cat or not to cat, that is the question

so im about to pull the trigger on some LTs for TSP (1 3/4). I have a hooker cat-back super comp. w/ shorties.

My question is should i run a catted y or an O/R y from TSP?

I dont want the gas smell that comes into the car (some say they smell it when using an O/R y) and i dont want rasp, but do want the sound and performance of the O/R y.True duals are out the question. Thanks for you .02 guys
Old 05-16-2012, 08:57 AM
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I just installed a set of QTP 1 3/4" with a custom 3" y pipe (no cats) that was very well put together. It's feeding into a 3" cat back that I think was an SLP option from the factory. I changed out the muffler years ago for a flowmaster (not sure which model). Center mount exhaust.

Man, it's freakin loud. I didnt think it would change this much since my cat-back was the same. Now that I have gotten used to it a little, I'm liking it more and more however, I can't give the throttle more than about 10% before it sounds like a nascar. People complain a lot about rasp on here, I guess mine makes noise that could qualify as rasp, but it pretty much sounds like straight pipes always sounded to me.

As far as smell, yeah, I'm getting fumes in the car which are only noticeable when sitting in traffic. I think I have some significant leaks in my v-band clamps though which I'm hoping to fix shortly.

Bottom line, if you want to poke around without anybody hearing you all the time, beware of catless y-pipes. If it's not a daily driver and you want to sound like a beast...go for it.

P.s. My wife hates it.
Old 05-16-2012, 09:23 AM
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^ thanks man

it is a DD, about a 10 mins commute mostly highway time and some traffic because ppl dont know how to drive. The fumes is what im worried about. I know rasp is based on someones opinion. Some love it some like me hate it. Loudness im not worried about. There are harleys and jacked trucks that are WAY TOO loud around here in Louisville, Ky.

Anyone else care to put there .02 in on this?
Old 05-16-2012, 09:55 AM
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A good set of cats won't hurt, I have headers, ory and a hooker cat back and I want to switch to a catted y eventually. I haven't tuned it yet and while it does run rich I don't get much of a gas smell inside. I don't notice much rasp since switching to the hooker either.
Old 05-16-2012, 10:08 AM
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Originally Posted by '00_Z
A good set of cats won't hurt, I have headers, ory and a hooker cat back and I want to switch to a catted y eventually. I haven't tuned it yet and while it does run rich I don't get much of a gas smell inside. I don't notice much rasp since switching to the hooker either.
why do you want to go to a catted y? thanks for the reply
Old 05-16-2012, 10:11 AM
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I don't think gas smell would be that bad with the smaller cam your running. With a big cammed car your gonna have the raw fuel smell alot worse.
Old 05-16-2012, 10:22 AM
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Originally Posted by NC98Z
I don't think gas smell would be that bad with the smaller cam your running. With a big cammed car your gonna have the raw fuel smell alot worse.
good point, yeah i have a 218/218 cam,(prev owner installed it). so the gas smell wont be bad eh, next is rasp. cant stand it/ wont stand it.

A cam is in my future(not the near future) but by then my z-cam will be a weekend/nice day driver.

so if gas wont be bad, how about rasp?
Old 05-16-2012, 10:32 AM
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I have a huge cam, and no cats. And the smell is horrible! your hair,clothes, etc. reak of exhaust. even walking by the car running in the drive way, you can smell it on you when you walk in the house. my wife absolutely hates my car, and refuses to ride in it since if done h/c etc. because her hair smells so bad after..... If you dont want fumes, cats are a must!
Old 05-16-2012, 10:47 AM
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Originally Posted by stunna p
I have a huge cam, and no cats. And the smell is horrible! your hair,clothes, etc. reak of exhaust. even walking by the car running in the drive way, you can smell it on you when you walk in the house. my wife absolutely hates my car, and refuses to ride in it since if done h/c etc. because her hair smells so bad after..... If you dont want fumes, cats are a must!
thanks for the reply. I dont have a large cam (thats what she said) so fumes shouldnt be an issue, so im told. As long as rasp is not there then an O/R y is the way im leaning.

Also would i need a new tune?

thanks again guys
Old 05-16-2012, 11:17 AM
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I ran pacesetters/ory/hooker catback for about 6 years and the car was a DD. Gas smell wasn't bad at all, overall sound volume was pretty nice at first but did wear on me after awhile. When you were out just having fun it was great, but more than I cared for while commuting to work, longer highway drives, etc.

Rasp was not terrible like it would be with a loudmouth catback, but was definitely there and got annoying. I hated the rasp and it made the car sound like *** around 2,000 - 2,500 RPM. If you are running an ORY, you WILL have rasp.

With all of that being said, last month I welded in some high flow bullet cats and a high flow merge and wish I would have done it 5 years ago. The car is just as loud at idle, has ZERO rasp, is much quieter inside the car while cruising and has a way more refined exhaust tone. It's also still plenty loud when you put the pedal down. Finally, I haven't noticed any loss in power.
Old 05-16-2012, 11:32 AM
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Originally Posted by 01formula6
I ran pacesetters/ory/hooker catback for about 6 years and the car was a DD. Gas smell wasn't bad at all, overall sound volume was pretty nice at first but did wear on me after awhile. When you were out just having fun it was great, but more than I cared for while commuting to work, longer highway drives, etc.

Rasp was not terrible like it would be with a loudmouth catback, but was definitely there and got annoying. I hated the rasp and it made the car sound like *** around 2,000 - 2,500 RPM. If you are running an ORY, you WILL have rasp.

With all of that being said, last month I welded in some high flow bullet cats and a high flow merge and wish I would have done it 5 years ago. The car is just as loud at idle, has ZERO rasp, is much quieter inside the car while cruising and has a way more refined exhaust tone. It's also still plenty loud when you put the pedal down. Finally, I haven't noticed any loss in power.

thanks for the reply man. This is interesting. Like i stated before, i hate rasp. Rasp = CRAP (IMO). I do like TSP catted Y, just not the cost. My main concern is sound quality( you can hear me coming and going) and fumes. Im afraid a catted y will tone it down too much compared to a o/r y?

keep the opinions and personal experiences coming guys. thanks again
Old 05-16-2012, 12:05 PM
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I'm thinking about getting a catted y. The fumes get pretty bad. If you start the car in your garage, your whole garage is going to stink like fumes. Sitting in traffic is no fun either. I also seem to get a lot of dirty looks from people passing me which I assume they got a good whiff of my fumes. Everytime I drive my car, all my clothes stink like gas.
Old 05-16-2012, 12:23 PM
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Originally Posted by Bramlok
I'm thinking about getting a catted y. The fumes get pretty bad. If you start the car in your garage, your whole garage is going to stink like fumes. Sitting in traffic is no fun either. I also seem to get a lot of dirty looks from people passing me which I assume they got a good whiff of my fumes. Everytime I drive my car, all my clothes stink like gas.
well thats sounds like fun, NOT . ok so it looks like a catted y.

would i need a tune as well? anyone
Old 05-16-2012, 12:38 PM
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BBK LTs, ORY into slp LM2 muffler....... Very minimal gas smell (only at start up and outside the car) and the rasp is nowhere near as bad as I thought it would be. I guess cause I have an LM2 (dumped before the rear) my exhaust is not too raspy. I love my sound.... Will get an audio clip up very soon.

I vote for no cats

Tune is really not necessary, but if you want to get the max out of the headers.... TUNE IT!!!
Old 05-16-2012, 12:55 PM
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Originally Posted by Blownbayou
BBK LTs, ORY into slp LM2 muffler....... Very minimal gas smell (only at start up and outside the car) and the rasp is nowhere near as bad as I thought it would be. I guess cause I have an LM2 (dumped before the rear) my exhaust is not too raspy. I love my sound.... Will get an audio clip up very soon.

I vote for no cats

Tune is really not necessary, but if you want to get the max out of the headers.... TUNE IT!!!
way to keep me on the fence. LOL thanks for the reply. Yeah im not sure of any tuners close by louisville, ky, so i want to make sure that if i dont get a tune it wont hurt the motor.

I figured LTs and ory and my hooker catback wouldnt have any rasp, but if the gases are bad then i will go with cats.

im scratching my head now on what to do at this point, need more opinions/experiences please.
Old 05-16-2012, 12:58 PM
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I had a ory on my car with a 224/224 cam and my wife complained that i stink like gas every time i drove it. Welded a pair of $60 magnaflow cats in there and no more gas smell and all the rasp went away too. Did make the exhaust much quieter so I ended up putting a cutout on it. Now its perfect.

Last edited by speedgoat; 05-18-2012 at 01:24 PM.
Old 05-16-2012, 01:08 PM
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Originally Posted by speedgoat
I had a ory on my car with a 224/224 cam and my wife complained that i stink like gas every time i drove it. Welded a pair of $60 magnaflow cats in there and no more gas smell and all the rask went away too. Did make the exhaust much quieter so I ended up putting a cutout on it. Now its perfect.
thats a good idea with the cutouts. I dont think i can squeeze out the cash for them right now.

so im leaning towards the catted y, but can be persuaded the other way.

it almost seems like a damned if you do and damned if you dont.

Would i need new header bolts as well?

thanks again guys.
Old 05-16-2012, 03:05 PM
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You stated your main concerns were sound quality (no rasp), and no fuel smell. Yes it costs more up front, but you need cats to hit those objectives. You can always add a cutout or change out the Hooker muffler at a later date if things are too quiet. There is no perfect setup, which is why you see guys messing with their exhaust so much.

I wouldn't bother getting the car tuned after LT's unless you notice it's not running right. You can also reuse your stock manifold bolts.
Old 05-16-2012, 03:08 PM
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Originally Posted by 01formula6
You stated your main concerns were sound quality (no rasp), and no fuel smell. Yes it costs more up front, but you need cats to hit those objectives. You can always add a cutout or change out the Hooker muffler at a later date if things are too quiet. There is no perfect setup, which is why you see guys messing with their exhaust so much.

I wouldn't bother getting the car tuned after LT's unless you notice it's not running right. You can also reuse your stock manifold bolts.
thanks for your input. Good point all around. Well after sitting at work thinking about this, i suppose i will go with the catted y, and if all else fails, i will get a different cat back.

screw the tune for now unless it falls on its face, and reuse header bolts.

if anyone wants to put any clips or give their input still, feel free. Wont buy for about another week.
Old 05-16-2012, 04:03 PM
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IMO, just get the 1-7/8" TSP LT headers and the ORY-pipe, then if the smell bothers you too much, then just put a Magnaflow(#59959 3" in/out about $100) HF cat on the end of the Y-pipe. You also could go with a Magnaflow#59930(3.5" in/out about $120) for higher flow,with minimal modification to the exit of the TSP Y-pipe.

It'll still get hot enough to reduce any fuel smell, but you won't have to worry about it reducing you ground clearance or getting damaged. It's just an option I thought you should be aware of. The only down side I see it that it won't be as efficient as having HF cats right after the headers.

Last edited by 99Bluz28; 05-16-2012 at 04:25 PM.


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