after buying an exhaust and intake i am looking into buying the SLR headers. i have searched in past post but not all my questions have been answered completely. my first question is will it work with my supercharged model, 2nd is are there any reason not to get it (i.e. will it hurt my engine in the long run) and 3rd will it be a pain in the ass to install/ will all the O2 sensers work and other misc things. Keep in mind that i have all the tools, i have a rubicon i can drive while im working on it, and i dont really care about emitions standards and taking of the cat converters

i can tell you for certain it will hurt your engine over time. anyhting aftyermraket going on or in your engine puts more stress on it and makes it wear quicker...not noticable at first but will wear it down faster than it should be.

today i decided to call slr and answer my question if the headers will work with a supercharged engine and the guy said that it should not be a problem. also he said that they have worked out the problems that they had with there being too many holes or whtever the past posts said before. i am still needing input from anyone that has them to see if they are having any problems with them.

so intake and exhaust are bad also.?

-Robb-

I have the same type of upgrades, and have searched everywhere to find headers. where did you find them or where is the best place to get them?

I'd like to see some proof of this.

fastburn, the only place i have found is slr-- wwwspencerlowracing.com

hmm......
what about clear tail lights??

sorry to post whore but....

the opinion that aftermarket parts will ruin your engine is just that. an opinion from a conservative person who doesn't like change. i can tell you that i will be getting intake and exhaust, and will do a before and after dyno to compare. after i check out the jet ecu reflash out some more. i think that the jet reflash, intake and exhaust will be a good increase.

I want headers!!! I skeerd of what the dealer might say.. They might void my ext warranty and regular warranty..

OK, so I just had to register to get a reply into this one. To make it short headers WILL NOT damage your engine. In fact headers actually HELP with engine longevity due to the release of backpressure. They increase HP, lower torque, and increase gas mileage. As far as factory warranties are concerned the headers will void your warrenty, so not a good idea for newer vehicles. I used to be a 240 fanatic, and did extensive modification, so please do not tell me I have no idea what I am talking about. To the original poster: If you can afford headers and want to do it I say go for it. Probably won't make quite the power gains you are looking for, but definately an interesting mod on an SUV

Greetings and welcome - I totally agree with your assesment. I used to be a hot rodder in high school and put headers on both my '65 El Camino and my '70 GTO. It only makes the exhaust flow more efficient. How is that going to hurt the engine - it doesn't. BUT, if the engine is under warranty - I would hesitate ONLY because the dealer could use it as an out if your engine needed repairs. They can be very underhanded - some of them anyway.

that's not so bad but things liek headers and superchargers make the engine work harder. higher rpms and such make it go quicker. i mean i would hope you arent putting headers on an offroad X. you would lose a considerable amount of torque for the gain of more hp which is worthless for most of us

Your engine only works harder if YOU make it to. Headers alone does not make the engine work "harder" in any way; it only enhances combustion efficiency (though at higher rpms).

The onlything that can really hurt your engine is adding forced induction (turbo, blower, nitrous) on engines not designed for it.

Now you're just making stuff up.

Please explain, other than increased horsepower makes you step on the gas harder, how incresing engine flow will damage the engine faster???

any pics of headers installed in an Xterra?

Although this is old(Jul '05) I wanted to weigh in. A supercharger or a bottle might wear an engine down but I can't see how headers could hurt anything. In fact, we will most likely have to replace our factory headers because of the factory heat shields that are in place. The shields act as header rap (which can be found in a racing shop) to keep the created heat away from the engine compartment. Less heat equals more performance but at a price. The heat will eat holes in the headers, so if you need to replace them, why not go aftermarket?
The only concern is not to expect much horsepower in return. A number of years ago a Mustang Mag dynoed aftermarket hearders on a 5.0 and the swap neted only 1 additional horsepower on a 225 horse motor. So without an intake, or cat back system, please don't look for much. Headers were all the rage for choked 1970's performance cars, but the 2003 and up X's have a pretty decent factory exhaust. If anything, the Y pipe after the headers needs the help.

Thats the most assenine thing i have ever heard in my life. and i am the master of useless posts.

Wow.. I had to wade waste high in BS to find anything informational.

Still didn't.

Amen Brother!!!!

A Set of Coated Headers and a catback will reduce back pressure and inturn Reduce under hood temperatures.

Don't know about the X, but the 5.0 example is an extreme one. Most 5.0s with catbacks will dyno about 10 - 15 on shorty headers and 20 hp on full lengths.

Age is really not an indication of header potential. The LS1 Camaros routinely dyno 30+ from long tubes. The LS7 Z06 dynoed 50 hp higher from only long tube headers, exhaust, and K&N.

How long are these SLR headers btw?

i wouldnt mind puttin headers on mind

Sorry, got to defend my post, the article I was talking about dynoed the headers on a bone stock 5.0 without a cat-back system. On the other hand GM cars have always landed huge power gains when the exhaust was opened up. They traditionally have some of the most restrictive exhaust systems. You make a good point, a person probably could get some serious numbers on GMs. I just don't want someone to purchase headers thinking that it will solve all the ills of the Xterra's pre '05 power issues. Nissan's own web site credits their $600 cat-back system with 3.7 additional horsepower, not a lot of bang for the buck if you know what I mean.

Ok, just think about it, say you upgrade your throat, lungs and asshole,,,,you can take in more air and run better.....you can hold more air and exchange more blodd cells for increased stamina, and with a bigger asshole you can get rid of more poo and keep a healthier and more efficient system. I don't really know why I wrote that but it seemed funny at the time.

There's so much BS in this thread, I don't know where to start.

All I'm going to say is:

1. Headers won't hurt your engine
2. Putting on headers but keeping your cats is pointless
3. If you're gonna do it right, put on headers, get rid of the cats, and get rid of the 1" exhaust all the way back

There are a lot of people that are in states that require the cats to stay to register the vehicle.

Texas is a totally different story.

Federal law prohibits removal or replacement of properly functioning O.E. catalytic converters.
However, you're from Texas so this may not apply to you.

Has anyone ever been tried in a federal court for removing their cats?

Also FL, no emissions testing. Hell half the cops around here have mustangs/cameros with no cats.

State law prohibts me from speeding on highways too

Sucks you live in a state where you can't mod your cars

I too doubt that you will be sentenced hard time for removing your cats, would make one hell of a prison story though....as long as you bribe your inspection dude(or lady for you sexist pigs) very well.

How about you can't get your car smogged and if you don't get it smogged you can't get it registered and then you don't get a little sticker so you get pulled over all the time for having expired tags.

Also depends on what state you reside in mister tough guy moderator! How about that?

Not really, we just do our mods and get the horsepower without breaking the law. Also, for a state that can't mod our cars we sure have alot of the manufacturers here SLR,Calmini, Fabtech, Stillen, Edelbrock, Foose, Boyd, etc.

If you want to remove your cat converter it's your truck I wasn't telling you not to do it. It was just a post of what the federal law is about the cat converter as I found on the wesite of the exhaust manufacturers.

New Joisey's got sucky laws like that too.....

I thought if you removed your cats the Check Engine light would always be on, no?

Stone

Well I haven't had cats on my car for 6 years now. I know Cali is a little more strict on emissions standards, but you just have to know the right person to get that little sticker.

A simple resistor/MIL eliminator/O2 sim will do the trick.

Well it's getting a little rediculous on what California sees as illegal now. Don't you need your intake to be CARB certified there? Kind of sucks you can't just run some generic $20 cone filter since it doesn't have that magic little sticker. It also sucks that longtubes (manufactured by Edelbrock) are also illegal there.

Modding your car the California way leaves alot of power on the table.

Sure.

You enjoy your toxic sespool. Are you going to say anything that makes sense any time soon?

It's amazing how much courage people get over the internet.

Since I'm guessing you haven't read the whole thread allow me to catch you up.

The discussion and concerns were in regards to people who have to follow emissions standards to register their vehicles legally. It is quite easy in the few states where there are no restrictions but a totally different situation where we are required to pass an inspection to register our vehicles.

Now that I've done my manifolds and I've seen what makes up the exhaust system, this statement from SLR's website does not make sense:
Here's a picture (sorry for the quality ) of the so-called "pre-cat" and what is behind it taken off my '00 Xterra:


Notice anything? There IS no "main catalytic converter"... just a long piece of pipe (the next thing in the system is the Y-pipe that connects the exhaust coming from the other side of the motor, and then the muffler, and then the exhaust pipe.

The little cat that connects to each exhaust manifold appears to be the ONLY cat in the system.

Some of the earlier federal 2000 models like mine (originally from Iowa)and yours only have 2 cats. All the CALIF models in 2k and those after a certain production date ? came with 4 cats including all of 01-04's.

I would love to have some CA smog legal headers like those that JBA offers for the new models. I just replaced my passenger side manifold and if the other side goes I may looking into modifying some pathy that fit the VG30

Thorley makes a CA smog legal set for the VG30 and I’ve been told with some work they can be made to fit the VG33.

So, have we established what the SLR headers will do for the 3.3 liter emmissions? If anything at all..

My exhaust manifold has been cracked for a while, if it get's worse then I might fail inspection for safety here in NY, not emmissions.

If/when I need to replace the manifold, I wanted to replace it with the SLR headers so I wont have the cracking problem again.
I am not removing the cat. converters on my truck.
I just wanted to make sure that I'm not causing any potential problems in the future.

Anyone?

All of the previous cars I've run headers on before were emmissions exempt because they were 25 years old or older. I never dealt with installing headers on an emmissions car.

OIC

Right, and it pisses me off that SLR calls the upper cats the "pre" cats, since they are actually the primary ones. The non-california-emissions 2000 models only have those, not the secondary/cleanup ones that are beyond the point where the headers go.

Actually, not to be too big of a butt or anything, but you CAN remove the 1st set of cats, install the headers, relocate the rear 02 sensors to BEHIND the 2nd set of cats, and it WILL clean the exhaust enough to keep it within emissions specifications. This HAS been done, this is PROVEN, not supposition. So in that regard, you CAN still be within emissions specs, both visually AND sniffery (is that a word??) AND OBII, with the headers.

However, you wouldn't have the fancy schmancy CARB approved sticker, so in California, odds are, they'd still fail you since you can't prove the headers are CARB approved (they're not).

It obviously makes sense if you're responding to it

But yeah, Texas is definitely a toxic sespool since I don't have cats. Enjoy your cats and CARB intakes

The "secondary/cleanup cats" further down the exhaust stream are actually resonators, not "cats" at all, even on the California emissions trucks.

Removing the resonators does not impact emissions.

Removing, or even moving the catalytic convertors from their original location (with respect to heat), can cause the truck to not pass emissions.

I drove my 02' X without catalytic convertors for 8 months. All it did was illuminate the SES light a couple times. After the light was cleared, it would take a few months or more before the light comes on again. Driveability wise, there was no difference in the operation of the truck.

Oh yeah? Why would California and a few other states require a "resonator" then?

See item #9 and its label in this diagram from the service manual...
http://mywebpages.comcast.net/xterra/tech/04exhaust.gif

Yeah, they're cats.

I don't care what your website and ripped off manual page says...mine were resonators.

Have you looked inside what you are claiming are "secondary" cats? They are resonators.