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Old Mar 28, 2004 | 08:05 PM
  #1  
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header question

ive been reading threw the 6billion posts on headers and they all confuse the life out of me soo... if i want paceheader long tube coated headers and slp loudmouth exaust what else do i need for my car to 1) get max the hp but to 2) still be emission frendly

thanks in advance

a confused,
BMJ
Old Mar 28, 2004 | 08:19 PM
  #2  
chpmnsws6's Avatar
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1) no LT's are emmissions legel

2) LT's with a LM will sound like trash.... WAY to loud
Old Mar 28, 2004 | 08:55 PM
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then what should i get short headers? id like to stay with the loudmouth if possible
Old Mar 28, 2004 | 09:18 PM
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shorties or mids can keep you emissions friendly. You can pay good money for an entire system by (some company who I forgot for some reason,....FTP maybe?) and have the cats exchangeable. Get a cut out as well for an extra 30 bucks. Hope this kinda helps.
Old Mar 28, 2004 | 09:24 PM
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I think hooker headers are 49 state legal and Mac Midlengths are legal
Old Mar 28, 2004 | 09:52 PM
  #6  
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mids and LM too loud?
Old Mar 29, 2004 | 06:31 AM
  #7  
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the question is:

what kind of emissions do you have to pass? the sniff test and/or visual inspection?

because most longtubes can be setup to pass the sniff test with a proper set of hi-flow cats. but anything that moves or alters the position/function of the STOCK cats would (or at least should) not pass a visual inspection.

that being said:

just sniffer you can do anything really. shorties w/ stock cats for minimal gains (almost not worth it), mids with a cat-ed pipe for decent gains w/ good clearance, or longtubes with cats.

if you maintain cats they will help keep the LM under control but it will still be very loud.
Old Mar 29, 2004 | 07:13 AM
  #8  
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Originally posted by BMJ
mids and LM too loud?
Asking a bunch of car guys if a car is too loud islike asking a group of chefs if something is too salty.....everyone's opinion will differ....

Some people don't thinkn that LTs and the LM is too loud....some people think stock is too loud. It's all what you think, not someone else....
Old Mar 29, 2004 | 10:30 AM
  #9  
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Originally posted by red91tsiawd
1) no LT's are emmissions legel

2) LT's with a LM will sound like trash.... WAY to loud
I think whether they're legal or not depends largely on the state you live in. In Boise, all I do is pull up to a van at a gas station, and the guy plugs into my OBDII port for 10 seconds, I pay $15 and im done.
Old Mar 29, 2004 | 02:24 PM
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There is a Federal emission law that states you can not relocate cats from the factory position. That means all midlength and LT headers are illegal in all 50 states based on that law. So the only true "legal" headers are the shorties and they are not gonna gain much if you have a 01 or 02 LS1. However there are so many places that do not do a visual or even the sniffer test that it makes LT's easy for most F-body owners to get away with. Best bet is to talk to f-body guys at the track closest to you and find out which testing station in your general area is the most laid back.

LT's + Loudmouth do not go well together. However if you want to keep it then there are two things that will make it sould much better. First is get hifh flow cats. The cats not only help make you emmision friendly to sniffers but also act as mini mufflers. They will also help a lot with the rasp. If you still think your too loud/raspy even with highflow cats then you can replace the resinator with a 18" dynomax bullet muffler.

The LT headers are the only way to go IMO. But with a loudmough catback I highly recommend the aftermarket cats and bullet muffler in place of the resinator. The car will smell better and the sound should be pretty decent.

Good Luck

Last edited by darrens99formul; Mar 29, 2004 at 02:27 PM.
Old Mar 29, 2004 | 03:00 PM
  #11  
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Originally posted by darrens99formul
There is a Federal emission law that states you can not relocate cats from the factory position. That means all midlength and LT headers are illegal in all 50 states based on that law. So the only true "legal" headers are the shorties and they are not gonna gain much if you have a 01 or 02 LS1. However there are so many places that do not do a visual or even the sniffer test that it makes LT's easy for most F-body owners to get away with. Best bet is to talk to f-body guys at the track closest to you and find out which testing station in your general area is the most laid back.

LT's + Loudmouth do not go well together. However if you want to keep it then there are two things that will make it sould much better. First is get hifh flow cats. The cats not only help make you emmision friendly to sniffers but also act as mini mufflers. They will also help a lot with the rasp. If you still think your too loud/raspy even with highflow cats then you can replace the resinator with a 18" dynomax bullet muffler.

The LT headers are the only way to go IMO. But with a loudmough catback I highly recommend the aftermarket cats and bullet muffler in place of the resinator. The car will smell better and the sound should be pretty decent.

Good Luck
Was unaware of that law .. can you point it out to me?
Old Mar 30, 2004 | 10:49 AM
  #12  
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Originally posted by Flat_Tire_
Was unaware of that law .. can you point it out to me?
Here is a link to the clean air act by the EPA. You want to see section 203 (3) (A)

(3)(A) for any person to remove or render inoperative any
device or element of design installed on or in a motor
vehicle or motor vehicle engine in compliance with regula-
tions under this title prior to its sale and delivery to the
ultimate purchaser, or for any person knowingly to remove or
render inoperative any such device or element of design
after such sale and delivery to the ultimate purchaser; or

Now that seems like a lot of jibberish to me but the key is the first part of that. You can not legally remove or render inoperative any emission control device which specifically includes cats. Now somewhere out there is a federal law that talks about catalytic converters. It states that car manufacturers have to warranty cats for 8 years or 80k miles regardless of when the factory warranty expires. Or is it 7 and 70k? It's one of those two.

There was also a paragraph that stated you can not remove a Cat that is functioning if the car has less then 55k miles on it or relocate the cat (s) to a non factory location. I was told the reason for this is that the cats need to be as close to the engine as possible to be most effective. I think it has something to do with heat and cats like to be as hot as possible. By installing LT or midlengh headers you have to violate the federal tampering act on emission devices and relocate them further from the engine.

I tried to find the link I read some months ago on the 55k and relocating but could not find it. But I assure you I read it and it was from some official government agency/webpage. But the tampering act I quoted above is the catch 22 they can get anyone on who removes/guts/replaces or relocates cats if they want to.

But LT headers are very common because most places do not care. If you pass the OBDII or sniffer then your usually GTG. Some places like Michigan and Florida have no testing at all. Then you have California that is the hardest and most **** of any place in the U.S. to pass emissions. Even the cops out there are trained to do visual inspections (or so I'm told). Anyone with LT headers will fail a visual inspection in any state. But the reality is not many places actually do visual inspections. They got a line of cars they want to move along so most of us get a computer scan and or sniffer test followed by have a nice day.

Here is the link to the EPA clean air act but again a lot of it seems jibberish to us average folks.

http://www.epa.gov/air/caa
Old Mar 30, 2004 | 10:00 PM
  #13  
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so whats the bestway if i dont care about emissions but care about loudness? just dont wanna get pulled over and get tickets like last car also making it not noticable by smell or lest as possible
Old Mar 30, 2004 | 11:21 PM
  #14  
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Originally posted by BMJ
so whats the bestway if i dont care about emissions but care about loudness? just dont wanna get pulled over and get tickets like last car also making it not noticable by smell or lest as possible
With my Jet-Hot's and offroad y-pipe to a flowmaster muffler, my car was surprisingly louder than I thought it would be... anything above 2500 rpms will attract attention ... And without cat's it actually doesn't smell too bad unless you're standing behind the car while it's been sitting still for a while. I'm actually planning on picking up a Valentine One or Passport 8500 radar detector so that I can concentrate on driving in stealth mode when I need to

You might want to consider a catalytic converter in your intermediate pipe if LT's and an offroad ypipe are too loud for you.
Old Mar 31, 2004 | 08:55 AM
  #15  
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Originally posted by BMJ
so whats the bestway if i dont care about emissions but care about loudness? just dont wanna get pulled over and get tickets like last car also making it not noticable by smell or lest as possible
Honestly the best thing you can do is still run cats. High flow cats will keep the rasp/volume/smell in check. And your not adding to our polution problem. You have to remember that the clean air act was created for a reason. Yes your gonna give up a few ponies by running HF cats (5 maybe?) but in the end your doing yourself and the air you breath a favor.

If you don't want to go that route then you want to get a quieter catback like the slp dual/dual or maybe the hooker. Then if it's still too loud you can get a dynomax bullet race muffler added to the I-pipe between the headers and muffler.

Good Luck
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