Ok, need some header info ....

[shadyphi]

I've started to save for headers... I think I'm going to go with long tubes(unless people convince me otherwise )

So, here are my questions :

1) What BRAND??? I have no frickin clue!

2) How about emissions? Do I want headers with or without it?? I live in Missouri, and we DO have emission tests here. However, since my car is OBDII, I believe I can sorta 'fake' out the PCM to think emissions are good with 02 sims? Correct?

3) If I do headers, is it recommeded to get rid of the cat & have an ORY, or just get a high flow cat?

Sorry for the questions, but I need to figure out what is up before I dump alot of cash.
I have a 97 WS6 LT1.

Thanks !

[Dan B. 96 T/A]

1) Some header brands:

*SLP
*FLP
*AS&M
*Hooker
*Grotyhoann, which I think is being made under a different name now.
*Heddman
*many, many more...

First you must decide if you want Long Tube headers for best HP and performance gains, mid-length headers, or shortie headers. First, consider your HP goals and future build-up plans. Where do you want to go with the car? Stock? Heads & cam? NO2? Turbo or supercharger?

2) How about emissions:

Correct. You can "fake" out the OBDII test with a good tune thru a reputable tuner. It will cost you about $100-$250, but that's the price you pay to play. Whether your headers have EGR and AIR provisions is your choice. If you are getting a tune, then you don't need them.

3) ORP (off-road pipe) vs. high-flow catalytic converter:

Up to you. Are you going for all out performance and don't care about ruining the environment? I'd opt for high-flow cats. The exhaust smells cool with ORP's, but if you're stuck in traffic or at a stoplight, it can get nauseating. The HP difference can be 5-15rwhp with ORPs vs. high-flow cats, F.Y.I.

Hope this helps.

[Injuneer]

A caution on emissions.... If you live where all they do is connect to the OBD-II ALDL connector, and pass you if there are no codes, you may still have a problem. The "O2 sims" will "fake" out the PCM into thinking the cats are still there, so no problem. But you will also have to address the AIR and EGR systems. Typical approach, as outlined in the post above is to simply "program out" the diagnostics from the PCM so they don't set a code. But when you do that, the systems will show up in the emissions scan as "not ready". In most states, you are allowed to have only one or two "not readies".... so you may have a problem with them. It is possible to "fake" the EGR diagnostic, with a little circuit that puts a resistor into the MAP circuit when the EGR vacuum solenoid is commanded to actuate. Then you would have only the AIR code.

The question is...... WHY? Neither the EGR or AIR system hurts performance in any way. And the loss through a high flow cat (or cats) is negligible. I managed to build an 800HP nitrous/stroker with full emissions compliance and capable of passing NJ rolling emissions testing. Cars without cats stink, plain and simple. I can spot them when they are in front of me all the time, just by the exhaust fumes. Its your choice, but mine was for "clean air"......

[shadyphi]

A caution on emissions.... If you live where all they do is connect to the OBD-II ALDL connector, and pass you if there are no codes, you may still have a problem. The "O2 sims" will "fake" out the PCM into thinking the cats are still there, so no problem. But you will also have to address the AIR and EGR systems. Typical approach, as outlined in the post above is to simply "program out" the diagnostics from the PCM so they don't set a code. But when you do that, the systems will show up in the emissions scan as "not ready". In most states, you are allowed to have only one or two "not readies".... so you may have a problem with them. It is possible to "fake" the EGR diagnostic, with a little circuit that puts a resistor into the MAP circuit when the EGR vacuum solenoid is commanded to actuate. Then you would have only the AIR code.

The question is...... WHY? Neither the EGR or AIR system hurts performance in any way. And the loss through a high flow cat (or cats) is negligible. I managed to build an 800HP nitrous/stroker with full emissions compliance and capable of passing NJ rolling emissions testing. Cars without cats stink, plain and simple. I can spot them when they are in front of me all the time, just by the exhaust fumes. Its your choice, but mine was for "clean air"......

Thanks for the responses so far. After gaining a better understanding now, I definately want to stay 'emissions legal'. SO, that brings me to a new question :

1) What are my options ? Can I still get LT headers with a catted Y pipe? If so, where & what do you recommend.
2) How about mid-lenghts with catted Y? ( I do not want shorties)
3) Oh, and no matter whether I get either of the two above, do I need to make sure the headers have provisions for AIR & EGR ? ( I need them both active to pass emissions).

Thanks!

[shadyphi]

bumping for help!

[joe ws6]

I also live in MO and i think the last time i had the emissions they looked under the hood for cats. I believe mid lenght headers add more power to the mid rpm while long tube put more power in the upper rpm. I may be wrong. You may also want to consider ground clearence with long tube. I hear of some brands being redickuless and you hitting them on the ground alot. When i do headers i will be puting on hooker longs. their very good quilty. Yet porformence between brands will not be that much differ. I dont know if you can put cutouts between headers and cats but, you would have both worlds but im not sure if you can do this.

[raroZ28]

I have mac mids with the ORY, my car is a 97 as well. I got the 94-95 kit. I love it. Just put that on, and put a high flow cat under the car, you're set.

There are a lot of people running 10's on this header. 1 5/8" primaries. Nice design. Best spark plug access of any header, easy installation. The last two things were important to me, which is a lot of the reason why I chose MACs.

Whatever you get, get them coated or you'll be buying new wires shortly.

[Hemogoblin]

All I can suggest is that you STAY AWAY from SLP headers. Their header fit on my 93 was absolutely terrible! First, they use 2 bolt flanges (with non-SS flanges and bolts - at which point I broke a bolt removing the Y-pipe to try and fix a leak) to the Y-pipe and the pipes didn't line up. The Y-pipe also hung so low that it would hit the ground on speed bumps, and you could visibly see that it was hanging low. Once the cat was "somehow" installed, it didn't line up with the Borla cat back, and I had to fab up a new bracket to hang the cat from Seriously, it was such a bad fit it was rediculous. These were brand new headers, Y-pipe and Borla cat back. Never buying their headers again.....

Cheers,
Steve

[joe ws6]

Iv also heard of them being a bad fit. and having no clearence. Not to mention puting them on.

[Ouija]

While I don't have anwsers on "what brand" for a LT1, I know that for my LS1 I have a set of FLP long tubes with quick change from cats to ORY. Takes 5 minutes to go from catted to Off Road. I've turned off my Rear O2's through programming, but that won't stop the effectiveness of the cats when they are installed, so I don't have to kill the environment if I dont' want to.

I believe the LT1's are the same on their EGR. I know LS1's EGR turns off at WOT so the only reason to remove it is if you don't want all the extra weight of the components. It has such a minor difference on performance that you will probably never notice it.

The purpose of the AIR system is to warm up the CATS so they can hit an appropriate temperature for reducing emissions. AIR is only effective for when it's cold outside, and it turns itself off once the cats are up to proper temp. Again, if you will probably never notice any difference from removing the AIR system, and you dont' need to remove it unless you just want to clean up the engine compartment, and reduce your car's weight.

I'm sure someone makes a Long Tube LT1 setup with high flow cats. Most people don't need the extra 2-10HP that cats rob you of. You could rip out your back seat, or use lightened rims and get the same performance gains.

Remember though, if you want to remove that much weight, your passenger seat weighs more, and so does your stereo. Might as well rip out the spare tire, jack, dash top, while we're at it, who needs carpet or interior panels!

2¢

[darkz711]

not to bring an old thread back... but to address the same thing, I want some long tubes for a 1995 z28 and i have OBDI, will I hav to worry about not have egr/a.i.r? I'm in new york state. I've never really paid attention to how rigorous the tests are

http://cgi.ebay.com/ebaymotors/93-97...QQcmdZViewItem

im looking at those