I asked this question before, but not properly worded, so I got no response.

My car has the dual cat system.

I have to keep the cats so no way to get around that. But since cats are very expensive, i want to keep the stock cats. I am wondering whether this defeats the purpose in performance?! I'd like to put on headers (Hedman or Hookers is what I am looking at right now), connect them to a ypipe to connect to my stock cats, then a aftermarket muffler system, most likely flowmaster, but also thinking Borla and others. Will this still give me a good performance boost or will the cats just defeat the purpose in which case I have to get them aftermarket too? I know headers themselves will give me a boost, so i am just wondering what kind of restriction will the cats pose in this setup. Thanx.

 

ive heard that the stock cats suck. im kinda in the same boat. the hedman 68491 headers are designed for a duel cat car but they are $330. The 68470 headers with the 17470 y-pipe run about $225 from jegs. you can get a single high flow cat on ebay for about 30+shipping. that is still less than the duel cat headers, and you get a better high flow cat. i am planning on doing this and ordering a cat back for a single cat camaro. it should bolt up if i get the right length cat.

 

That sounds promising. Going to one cat is something I haven't considered, but if it means good power boost, I'll do it, especially since the headers are cheaper. I'll definitely look into that. However, will the single cat be as efficient at breaking down molecules then the dual? Not that it matters, i always fail the emissions test until I put methanol in my car, so it can't get any worse anyway, but please let me know if it is rated to break down molecules according to the law.

 

here is a link to one of the cat's. there are other brands as well
http://cgi.ebay.com/ebaymotors/ws/eB...category=33629
it says it is epa approved. another thing to think about. if you have visual inspections, i dont know if the 68470 headers will work for you. they dont have air tubes on them. im planning on removing all my air system and the smog pump, so these will work great for me. the 68471 are the same as the 68470, except with the air tubes. they are 280 without the y-pipe though, so they are almost as pricey as the 68491's.

 

Get the Hedmans for the dual cats. The factory did a lot of dumb things with regard to exhaust, but dual cats was not one of them. A single high-flow 3" may flow as much as factory duals, but not as much as dual high flow replacements. And, the single cat Hedman y-pipe is a pretty poor effort, so that set-up with a single 3" high-flow cat will probably flow less than the factory dual cats. If you go single cat and want a good y-pipe, go with Hooker 2055's. But, they cost more than the Hedman duals (which don't have a y-pipe restriction problem).

Those 3" universal cats are a red herring. Avoid them and get a direct-fit if you go single cat. (As I've said other places, voice of experience talking here.)

 

hmm, I wish you could be more specific. Now I don't know if you're telling me to go dual cat or single cat, you seem to be telling me both are good and both are bad.

Are you saying get the hedman headers but not the y-pipe, rather get the hooker 2055 y-pipe? Why not just get the 2055 hooker headers that come with the y-pipe already?

I wouldn't mind keeping dual cats, but here in Canada cats are extremely expensive, even just stock replacements, let alone aftermarket. Of course I could always order from the states, but can't find a good source.

I just cancelled my order for the Hedmans, told them i need more time.. they also sell Hookers so I told them I just need to do more research and I'll order again.. so how about the 2055's headers that come with a ypipe already? How does that sound?

Where to get two high performance cats that will replace mine, or am I ok keeping my stock cats for now? I am thinking of flowmaster exhaust behind the cats.

Also, I have no idea about turbo, but want to consider in the future.. Will this be impossible to achieve after headers are on? thanx in advance bud, you've been a help, I am checking out the 2055's right now.

 

Okay, I'll try to be more clear.

Recommendation #1: Keep the dual cats, get the Hedman hedder set for dual cats.

Recommendation #2: If you decide to convert to single cat, get the Hooker 2055. That set has a superior y-pipe, does not have the restriction that the Hedman single cat y-pipe has.

To try to be completely clear: The dual cat system is better than a 3" single cat. The Hedman hedders for dual cats are very good. If you think that the dual cats will be too expensive to replace some day so you want to go ahead and convert to a single cat, go with Hooker 2055 headers instead, because the Hedman single cat y-pipe isn't very good and the 2055 y-pipe is very good.

I hope I am clear now that I am making a different recommendation depending upon what decision you make, based on economics, about keeping the dual cats or converting to single cat.

If I had dual cats, I'd do whatever I could to retain them.

 

Thanx five7kid, you've been a help, and I appreciate it. However, i am still confused. I thought the 2055's by Hooker are also made for the dual cat? You're saying either go for the Hedman 68491's which are for dual cat or 2055's if I go single cat? You have convinced me to go dual cat, and I will keep the stock ones for now, until I find two aftermarket ones for a good price, although who knows, perhaps my stock ones will do ok, you say they'll do as good as a single aftermarket replacement. You said you don't like the pipe for the single Hedman, how about the 68491 headers with the y-pipe for duals? Is that ok? That kit includes everything right up to the dual cats or what? thanx in advance.

edit: I just found out that the collector size for the Hedmans is only 2.5".. I'd really like a 3" size there. Now if Hooker doesn't make a dual cat system, what could I go with? Edelbrock, Mac, SLP?? How are those companies' headers and y-pipes? i don't have the means to do any custom work on the pipes themselves, so the kit has to come with a dual-cat system already in place. anything?

edit: sorry for editing again, but before I write off the Hedmans because of 2.5" collector, let me know what you think first. I see that a lot of people are going this route and saying it does a great job. The 2.5" would probably fit better anyway, since the stock one is what, 2.25", and so are the stock cats (i really think I will replace the stock cats though, at the same time as I purchase the headers/ypipe). I have decided on Flowmaster 3" exhaust system behind the cats, so that is written in stone.

 

http://www.hedman.com/pages/hedmanmain.html

68470 says 3" collector. 68481 & 68491 say "stock". I was under the impression the basic header itself for all of these was the same (A.I.R. notwithstanding), but I could be wrong there.

Hooker apparently used to make a set (2052 or 2054, or something like that) for dual cats, but it has been discontinued and 2055 is for single cat only.

 

I have a quick question. I have read elsewhere that the duel cat's arent good. If they really are a good option, I want to keep them as well. Will the duel cat hedman's require any fabbing or will they just bolt up? also wouldnt the 2.5" collectors be ok since they dont y together untill after the duel cats?

 

I've never heard that dual cats aren't good.

If the header collectors are smaller than 3", it's not going to be a problem as long as they are at least as large as the down-pipe (assuming the down-pipe is at least 2-1/4").

 

so they just mount up to the factory exhaust?

 

That's the idea. I can't say from experience.

 

The factory did a lot of dumb things with regard to exhaust, but dual cats was not one of them. A single high-flow 3" may flow as much as factory duals, but not as much as dual high flow replacements. (quote)

Regardless of how many cats you run you are still running into a
single 2 and 3/4 or 3 inch exhaust. Maybe back in the eighties the inefficiency of the stock cats required two to flow enough, but nowadays a single high flow unit will be more than adequate.

I see no reason to waste money on a dual cat setup without a true DUAL EXHAUST.

I quarantee you two cats of any kind will not outflow my 3 inch
( HI-FLOW ) gutted one.

P.S. No preaching allowed about the gutted cat......in other words go hug a tree and leave me alone.

 

I am an enviromentalist, but not an idiot, and I love big V8's. I am also a scientist, so I know a thing or two about global climate, and I certainly know that your V8 with no cat is not doing anything to contribute. The scaremongers make me sick..

Now, explain what you mean by a gutted cat? you just bought a cat and removed the insides? doesn't that defeat the purpose, wouldn't it be better to just bypass the cat alltogether? The only reason I want to keep the cat is because I will need to pass the emission test in a year and a half or so. I'll probably stick to the dual cat system since its the same price anyway, but it will cost me more when I decide on two aftermarket units. So far I am just planning on headers that connect to the cats and a flowmaster exhaust. But it is so difficult to make a decision now that I have read all this.

 

When I upgrade my exhaust I will most likely be switching to a dual high flow cat setup. The way I at it is, its basically a one time deal. The amount I drive the car per year I wont have to replace the cats or the exhaust and most high flow cats have a very good warranty anyways.

 

[QUOTE]Originally posted by Trypt
[Now, explain what you mean by a gutted cat? you just bought a cat and removed the insides? doesn't that defeat the purpose, wouldn't it be better to just bypass the cat alltogether?

Mine plugged up and after buying a new one and having it loosen up and fall apart and nearly plug my muffler I am done with convertors.

Visual check only so.....keep the cat...gut it.....best way to go would be to put a straight pipe through it. But for the visual check only ...I am covered.

Hope this helps....don't waste your money on two high flow units.....you are not gaining a thing over one....just remember you are still reducing them to one 2 and 3/4 or 3 inch pipe.

If you have a TRUE dual exhaust then TWO high flow units or even better two gutted/piped units would be the ticket.