Header for 4.2L

[sk_trailblaz]

I'm hoping to find a company that makes a header for the 4.2L engine in my '03 trailblazer. I have looked everywhere with zero luck. I contacted Hedman Headers, they indicated that they make a replacement "header" for the factory setup but it is not yet into production. I also contacted The Other Guys Performance Products...they have yet to respond. Does anyone know of a company that makes a header for this application?

[Trailblazin]

I'm hoping to find a company that makes a header for the 4.2L engine in my '03 trailblazer. I have looked everywhere with zero luck. I contacted Hedman Headers, they indicated that they make a replacement "header" for the factory setup but it is not yet into production. I also contacted The Other Guys Performance Products...they have yet to respond. Does anyone know of a company that makes a header for this application?

I've searched the net hiiigh and looow, and no luck. I even sent Hedman an email about the headers and they told me exactlyu the same, not yet in production, although they alreayd have it listed on their website. its strange

[ParadoxJr]

I recieved an e-mail back from Heman's today.

"
The 69666 is the HTC coated version of the 69660. As a manufacturer, we do

not sell to the public. This is a new part number for us and has not been

developed yet, we are approximately 4-6 months away."

WOOOO HOOO Soon!!!

Russ

[tblazed]

A question I would need answered before I replaced the existing stock exhaust manifold... will this be a smaller tube header optimized to increase low end torque, or a large tube header to improve top end HP? Or just something "cosmetic" that will fit in the available space? Mine with 3.42 gears needs low end torque where I normally drive it, below 3500 RPM, not top end HP.

[sk_trailblaz]

I wonder why it takes so long for the aftermarket to develop parts for the 4.2L engine? Is it due to lack of interest by consumers? or vendors have bigger markets to serve? it seems as though the 4.2 has a lot of potential, it would be nice to have performance parts that allow this. If an "affordable" header were available, would any members here be interested? :undecided

[ParadoxJr]

Of course we would be... :p

Russ

[sk_trailblaz]

Judging by the poor response from this post, the interest in a 4.2 hedder looks dismal...maybe we should have a poll set up? :undecided

[Trailblazin]

well there is another alternative....I just went to one of the best exhaust garages in Kuwait today and they fabricate their own headers. I asked him about doing a Header for the 4.2L Inline-6 and he told me it was possible. Their work is not to the standard of lets say Flowtech or Borla, but my friend had his Mustang Exhaust system done there from Headers to Tailpipe, 3 inches all the way along and in turn his Stang is one of the fastest 5.0s in Kuwait so I do have some trust in their work.

I asked him a price and he told me it would cost around 140KD which translates into around $480. Lets add another $100 for shipment and bada-bing bada-boom. If people here were interested, I could tell him that I wanted to get in BULK and surely he'll drop the price lets say around $100. (This is Kuwait so anything goes, specially in bargaining terms :p )

If there was a demand let me know and I'll get some more info, he's already done headers for a Toyota Landcruiser, Nissan/Infiniti QX4 and lots of GM V8s. This is an alternative option for those who can't wait for Hedman. I'll take some pics of the headers he does with a final price and ill post them up. :m2:

[DouglasEsh]

I think the problem that you're seeing is that many Trailvoy owners don't know what replacing a header will do for them let alone identify the header on their own trucks. And if I remember correctly it isn't like swapping out headlights. You actually have to get your hands dirty. I mean the first poll I would do is to see how many change there own oil or even know how to. I think you would be surprise to find that there are not a lot of gear heads driving trailvoys. On top of which how old is the 4.2L compared to other engines. And how many other models use the 4.2L. I know it is a relatively new engine and after looking at GMs site the Trailvoy is the only platform using the 4.2L. It is easy to assume that the fewer platforms the engine is in (especially if those platforms aren't performance based like the Corvette or SSR) the few aftermarket parts that will be made for it. Also most if not all of GMs performance engines are Vs. The 4.2L is a small niche market and we won't see all the aftermarket parts that you see for like the 5.3L or the 6.0L

Kind of sad really, maybe they will come out with a mount set to drop a crate engine in but I would bet the transmission only bolts to the 4.2L also or has some other defect that would prevent this from happening.

GM engine list (http://media.gm.com/us/powertrain/en/product_services/r_cars/index.html)

[sk_trailblaz]

"I think the problem that you're seeing is that many Trailvoy owners don't know what replacing a header will do for them let alone identify the header on their own trucks."

Thats because no aftermarket companies have stepped up to the plate and manufactured a hedder to meet the 4.2 application. If they dont do it, how are we supposed to know what the net performance gains from such a product would be?

"I mean the first poll I would do is to see how many change there own oil".

That would not be a fair polling question, personaly I dont change mine b/c of the environmental taxes where I live for purchase and disposal of used oil. Its more economical to have the local GM dealer do it..besides they provide a good maintenance record also.

"On top of which how old is the 4.2L compared to other engines. And how many other models use the 4.2L. I know it is a relatively new engine and after looking at GMs site the Trailvoy is the only platform using the 4.2L. It is easy to assume that the fewer platforms the engine is in (especially if those platforms aren't performance based like the Corvette or SSR) the few aftermarket parts that will be made for it. Also most if not all of GMs performance engines are Vs. The 4.2L is a small niche market and we won't see all the aftermarket parts that you see for like the 5.3L or the 6.0L"

The 4.2L GM has been around since...2002/2003/2004/2005/2006..used in the trailblazer/envoy/bravada/saab 97X. The engine has been in the market long enough for someone to provide additional performance mods. I have no idea why many of the major tuners havent provided more products for this engine? I dont know the exact figures but GM has sold a considerable volume of these vehicles on this platform. It is certainly not a niche market but rather an untapped market.

We have seen this with the computer tuning for the 4.2, finally a well respected and reputed aftermarket company produces a product that meets the needs of the consumer. Why cant the Other Guys, Hedman, Edelbrock, Borla, Gibson, SLP and numerous other companies do the same? :(

[DouglasEsh]

"I think the problem that you're seeing is that many Trailvoy owners don't know what replacing a header will do for them let alone identify the header on their own trucks."

Thats because no aftermarket companies have stepped up to the plate and manufactured a hedder to meet the 4.2 application. If they dont do it, how are we supposed to know what the net performance gains from such a product would be?
I was thinking more general than specific. What does replacing the header do? More horsepower, better fuel economy, deeper growl. My bet is that if a person guessed the right answer they couldn't tell you why.
"I mean the first poll I would do is to see how many change there own oil".

That would not be a fair polling question, personaly I dont change mine b/c of the environmental taxes where I live for purchase and disposal of used oil. Its more economical to have the local GM dealer do it..besides they provide a good maintenance record also.
Ok, this wouldn't be a yes or no poll it would be like yes, no because of time, no because its cheaper to let someone else do it, no because I don't know how, and What is oil? I don't change my own oil either but it's due to not wanting to mess with it rather than lack of knowledge on how to do it. I think what you would find is that not everyone knows how to change there oil other than running down to quickie lube. If you get a pretty large group that doesn't know how to change there oil I seriously doubt that they know anything about headers. This is what I would call a pre-poll to see if people that drive Trailvoys know how to do simple maintenance. If they can't do simple maintenance then they probably can't to more complex work.

That is also not to say that they couldn't go pay to have it done but the Trailvoy is not what people would describe as your average tuner vehicle.
"On top of which how old is the 4.2L compared to other engines. And how many other models use the 4.2L. I know it is a relatively new engine and after looking at GMs site the Trailvoy is the only platform using the 4.2L. It is easy to assume that the fewer platforms the engine is in (especially if those platforms aren't performance based like the Corvette or SSR) the few aftermarket parts that will be made for it. Also most if not all of GMs performance engines are Vs. The 4.2L is a small niche market and we won't see all the aftermarket parts that you see for like the 5.3L or the 6.0L"

The 4.2L GM has been around since...2002/2003/2004/2005/2006..used in the trailblazer/envoy/bravada/saab 97X. The engine has been in the market long enough for someone to provide additional performance mods. I have no idea why many of the major tuners havent provided more products for this engine? I dont know the exact figures but GM has sold a considerable volume of these vehicles on this platform. It is certainly not a niche market but rather an untapped market.
Yes the 4.2L has been around for 5 model years but what about the two I mentioned? How long have they been around and how many more platforms are they in? I counted 7 different trucks in just the chevy line up that have the 5.3L LS7 engine in it. There are other 5.3L engines just in the chevy lineup (to include the optional one in the Trailvoy) and I don't know what is different between them but I would imagine that if you develop a part for one of them it would work for just about all of them. Now counting the TB EXT and the EV XL as different trucks than there smaller counterparts you've got 6 different vehicles in the GM line that use the 4.2L and just chevy has one version of the 5.3L in seven of there trucks. I didn't even bother to count the other makes of GM I could easily twice to three times the number across the entire GM line. So if I was a company developing parts what engine would I focus on, the one that is only in one body style (What I would call a niche market) or the engine that is across the full spectrum of trucks.
We have seen this with the computer tuning for the 4.2, finally a well respected and reputed aftermarket company produces a product that meets the needs of the consumer. Why cant the Other Guys, Hedman, Edelbrock, Borla, Gibson, SLP and numerous other companies do the same? :(
Yes we have just now seen it, five years after the initial release of the 4.2L. How much sooner do you think we would have seen this tune if the engine had been in many more trucks? Maybe three, maybe one? My feeling is that the other guys which BTW some do make some parts for Trailvoys, don't see an economic return by making the said parts.

Don't get me wrong I want the aftermarket parts just as bad as you do. I have a Borla Cat-back on my TB with an Airaid intake, would love to put a charger in and I can't wait till my Wester's PCM comes in. But I can see why your not going to see the flood of parts for the Trailvoy like you do for the 1500, Tahoe, Suburban set. All I can really do is thank those that have chosen to make parts for my particular truck and let those that do want to do the same upgrades know about the companies that are offering the parts. We can also hound the companies that we want part from to make the parts but that doesn't fix the here and now.

[DouglasEsh]

BTW I reserve the right to be wrong about the gearheadedness of those on this forum.

[sk_trailblaz]

I'm glad to see someone else is as passionate about their trailvoy as I am.. :)

I am hoping to receive my Westers tune any day now, I ordered it last week and am really looking forward to the performance/mpg gains...it will complement my airaid cai and tb spacer. I hope to have a custom exhaust on it shortly. :)

[DouglasEsh]

You got a TB Spacer? What do you think of it? I've been eyeing them but I've heard mix results.

I'm a product of my environment. There is a guy at work that has a Jeep Liberty and likes to flant his "trail rated" Jeep. I put it right back at him that what's the use in having a "trail rated" jeep if the biggest off roading you do is the mud puddle by the shop that won't even get our warehouse forklift stuck. So yea, I can get fired up, and it's always good to run into like minded people. Lets you know your not crazy. :undecided :laugh:

[ScarabEpic22]

On the TBS, I have the Airaid and in my opinion, it helps with the mileage. I know others have not had good results, but these are mine. Went from 18mpg hwy with a drop-in K&N to 20-21mpg constant with the K&N and TBS. This is over about 8-10 tanks of gas through the summer. I dont see as much improvement in the city, but I really care more about the hwy anyway. With the TBS, I can go with 2 people in the TB, full tank, and moderate gear from my house in the north end of seattle to I-90 (after downtown) all the way through Eastern WA going 75+ into my cabin 15miles outside of Coeur D' Alene, ID on one tank. Before, I would get to about Ritzville and have to fill up b/c I couldnt get to Spokane. :D

I would personally say get on, but it is really up to you. This is what happend to me, but it might be different for you. BTW, I have no whistle everyone talks about.

(Can you see how many times people have challenged this? :raspberry Waaaay to many. Its up to you.)

[sk_trailblaz]

I would have to agree with Scarab, I find that the TB spacer does provide for better fuel economy as well as a bit more hp/tq. I am happy with it. :)

[blandmiller]

TBS's :rolleyes:

The proof is on a dyno...... :yes:

Seat of the pants Hp/Tq gains, improved gas mileage (can you say 'placebo'), and apparently breaking the laws of fluid dynamics do not make me believe the claims of throttle body spacers on our vehicles. :duh:

[DouglasEsh]

I shouldn't have asked. I forgot, that is a touchy topic. :duh: Here is my problem with everything on TBS, I can not find any independent data. What I find when I do a web search is either companies selling them, a thread in just about every vehicle specific and some general automotive forums that sound just like this one. I have found one blog that the guy did a dyno test in a before after situation and the HP/torque went down. At the same time he admitted there were problems with the dyno that could have caused the drop. My problem is there is no true data one way or the other. The best we have is testimonials stating that it works AND that there are side effects and while it isn't the same as slapping it on a machine that doesn't invalidate the data because it isn't collect by one. If I sit with my record book and document every fuel stop, figure my MPG and the type of trip it was (better if you can do average MPH driven per fill), then if you notice a increase or decrease in MPG by the addition or subtraction of a part a case can be made that the product does or does not do as it claims. I will not discredit those that say it works any more than those that say it is snake oil. Those that claim it works provide some data. Those that say it doesn't usually quote others (hearsay) or say it doesn't make sense. Quantum physics doesn't make since to me but that doesn't mean it not valid.

So where do we stand?
Pros: we got people that have experienced improvements in there vehicles. (Possible buyers bliss / placebo)

Cons: we got people that have experienced no improvements in there vehicles. (Possible those improvements were swallowed by change in driving style)
High pitch noise experienced on several vehicles but not all

Theory: The TBS creates a turbulent area in the throttle body that help gets a better fuel air mixture.

TBS work with carburetors and TBI as the fuel air is mixed in the throttle body area.

Theory Con: TBS won't work with port injection (most modern vehicles use port injection) as the mix is happening in the cylinder and not the throttle body.

Theory Pro: Even though the fuel and air are not mixed until the cylinder, because the TBS creates an even more turbulent condition in the throttle body, the air is more turbulent in the cylinder which in turn creates a better fuel air mixture.

[sk_trailblaz]

A TBS works for me..what can I say? I thought this thread was about the hedder for the 4.2? :confused:

[DouglasEsh]

Actually it started as headers and then migrated to aftermarket part companies. Then I made the mistake of asking about TBSs and now we are here.

So on headers, how much does it run to have custom headers made. The reason I'm asking is for turbo installation. I've been thinking that the I6 should be a good canadate for a turbocharger. I mean the exhaust and intake are currently piped on the same side of the vehicle. But since no one currently makes a header I'm pretty sure that if a turbo was to be installed you would need a custom header anyways.

I'm also thinking what is the use in replacing the header if you don't do a full custom exhaust also. The back pressure on the system is still going hampered by the point of greatest resistance to air flow. Now I've got a Cat-back system in so I figure, in my situation (which I also figure if your serious about upgrading the exhaust this will be done or has already been done) the big restriction is going to be Cat forward and I don't think the header is the restriction. So I guess the first question is, how restrictive is the Cat? Second, if you replace the header would you need to replace the Cat to see the gain? Third, if you replaced the Cat with a bigger/better flowing Cat (I don't think there are to many people that can get away with running without a Cat) what becomes the restriction? And don't you need a little back pressure on the system? I guess the finial question after all of this is what would you end up with after you've done all this work?

Then again if the Cat won't restrict it and all you need is the header what's the net outcome of that?

[ScarabEpic22]

I said I liked my TBS, and I will stick by it. But, however, I will not get into anymore arguing matches over them, its personal preference and if it works for you or not.