Good header tech info.

[Paulumbo]

With so many people buying headers and such, I dug up this article online. I've dealt with Burns Stainless on a few of my other cars and I can say that they do their homework. While there are many header theories out there, Burns works and it works well. I know the math behind what goes into selecting headers or designing from scratch-not an expert by any means, but I know enough to not be bullshitted! Anyway, read the article and THINK before you shell out your hard earned money on that flashy header everyone else is using....is it really that good for YOUR car and mods?

Enjoy:
http://www.popularhotrodding.com/tech/0310phr_jack_burns_exhaust_manifold_header_tech/index.html

[coppertop_01]

Thats kewl.....my friend and I need to know the cam specs though, cause we wanna build a header for the RL........but actually put some research behind it, like tuning the header to a certain RPM band......I am going to check out this site, but he says he has all the info needed, just need the cam specs for the LSJ engine.

Jer

[Cat Ion]

I guess I'm just playing devil's advocate, but don't you guys think that the manufacturers of headers that fit our car already did flow tests to see if there are any improvements? I doubt they just sat there and made the pipes merely fit the car. Especially if they're going to spend the effort to mass produce them for us, I'd think they put a little R&D into them. What I'm getting at is will there be anyone here that can really make a vast improvement over what's already offered and be competitively priced? Not knocking the effort. I like to tinker too, but now you're delving into witchcraft, I tell ya'!

[Paulumbo]

Yeah, Burns has a good deal. If you need research guidance or design advice, they are the DEFINITE go to peeps. I'd be interested in seeing how the tri-y design would do on an LSJ with 1 5/8 primaries

[Paulumbo]

I guess I'm just playing devil's advocate, but don't you guys think that the manufacturers of headers that fit our car already did flow tests to see if there are any improvements? I doubt they just sat there and made the pipes merely fit the car. Especially if they're going to spend the effort to mass produce them for us, I'd think they put a little R&D into them. What I'm getting at is will there be anyone here that can really make a vast improvement over what's already offered and be competitively priced? Not knocking the effort. I like to tinker too, but now you're delving into witchcraft, I tell ya'!

I'm certain they did, however, do they offer the technical data behind their claimed improvements? Were the tests done in a real world setting or something less than that. I can make a header flow some HUGE numbers with the flow bench, but is that typical of what the car will see? Where does the flow increase come from? High RPM or mid range where you actually drive the car.
For example of a big company mass producing products for our cars, let's look at K&N and the Typhoon Intake for the IRL.

http://www.kandn.com/dynocharts/69-8431.jpg

Notice on the dyno sheet the intake makes the same amount of power as the baseline (without cold air intake) until about 4700 RPM then it begins to make more power reaching a max increase at 6000 RPM which is 14HP. You have to ask yourself-how often do I drive in this RPM area? and is it worth the $200 or more dollars for the gain? It flows more, but is it USEABLE in the every day drive-slightly.

I used that as an example because the results are easily accessible-headers and exhaust are much the same-where are the gains? Are those gains useable? Is it worth the money? Going the custom route allows you to tailor it to your application so you can actually gain some useable powa.

[Cat Ion]

I'm certain they did, however, do they offer the technical data behind their claimed improvements? Were the tests done in a real world setting or something less than that. I can make a header flow some HUGE numbers with the flow bench, but is that typical of what the car will see? Where does the flow increase come from? High RPM or mid range where you actually drive the car.
For example of a big company mass producing products for our cars, let's look at K&N and the Typhoon Intake for the IRL.

http://www.kandn.com/dynocharts/69-8431.jpg

Notice on the dyno sheet the intake makes the same amount of power as the baseline (without cold air intake) until about 4700 RPM then it begins to make more power reaching a max increase at 6000 RPM which is 14HP. You have to ask yourself-how often do I drive in this RPM area? and is it worth the $200 or more dollars for the gain? It flows more, but is it USEABLE in the every day drive-slightly.

I used that as an example because the results are easily accessible-headers and exhaust are much the same-where are the gains? Are those gains useable? Is it worth the money? Going the custom route allows you to tailor it to your application so you can actually gain some useable powa.


Thank you for explaining that to me. I was looking for that sort of answer. I wasn't seeing it from that perspective. But you don't know me or my driving style so I can tell you that I use 4700 - 6500 a lot! How do you think I get to work in less than 10 minutes? Oh wait, that's because I live 2.6 miles from work. I see your point though.

So if we can get a header better suited for everyday driving, won't the top end get sacrificed then? Wouldn't it act more like the OEM manifold? I assume that Saturn R&D did that when they made the manifold - made it work best at stop & go driving and normal cruising. Am I missing another point here?

[Paulumbo]

Well you tend to look at an average RPM band and tune for that target. In normal street driving rarely are you going to see consistent 6000+ RPM. What you can do with a custom tuned header is try to gain some midrange back-yes you'll sacrifice SOME top end powa, but you can often more than make up for it in the midrange. That's why you see these shorty headers claim to add another 20-30 HP but they never tell you where they made that power-typically up top when you rarely use it. It's almost like tailoring it to your needs. The LSJ being an overhead cam engine-it won;t make massive power below about 3000 RPM-that's the nature of the design. But you can make good power from there to about 5-5500 and not sacrifice too much off the top end as well.

[coppertop_01]

Paul yeah man, and yes I do use 6g's quite abit........you make some good points.

Cat.......actually I have talked to a guy that had a vibrant header for the LSJ's, and he said that it clearly rob'd power on that engine. That and I want to build a header thats built for my driving type, not what somebody thinks will work good for 90% of the people out there.

As for a Tri-Y setup, that would help for gains over the whole power band, but has less peak power gains than a 4-1, also from what I have heard, tri-y's help out NA better than boosted cars.......but I am thinking that I am going to a 4-1 higher RPM header, problem is that you need long ass primaries to bring the power band lower in the RPM's.........which makes placing the cat kinda difficult.

Jer

[Cat Ion]

Paul yeah man, and yes I do use 6g's quite abit........you make some good points.

Cat.......actually I have talked to a guy that had a vibrant header for the LSJ's, and he said that it clearly rob'd power on that engine. That and I want to build a header thats built for my driving type, not what somebody thinks will work good for 90% of the people out there.

As for a Tri-Y setup, that would help for the lower power band........but I am thinking that I am going to a 4-1 higher RPM header, problem is that you need long ass primaries to bring the power band lower in the RPM's.........which makes placing the cat kinda difficult.

Jer

Philly938 from RLF is my Saturn Tech here in Tucson. He has the Vibrant 4-2-1 and I rode in his once and that thing screams. But he also has LSD, so I'm not sure if the power felt was from the two tire grip or the power on demand in the go pedal.

[coppertop_01]

Interesting, not sure if it was a 4-1 or a 4-2-1 design of the vibrant that I heard sucked, but I was talking to the guy from SCAP with the yellow IRL showcar, and he was saying that the vibrant header he got on it sucked power out of that car

Jer

[Cat Ion]

interesting....hmmmmm

[coppertop_01]

Ok........so I got the cam specs, and with some ROUGH calculations my friend and I have figured to have peak torque at around 4400 RPM, the header has to be 1.5" primaries that are 36" long, with a 4-1 header design..............I dunno where I am going to fit 36" primaries

Jer

[Paulumbo]

Ok........so I got the cam specs, and with some ROUGH calculations my friend and I have figured to have peak torque at around 4400 RPM, the header has to be 1.5" primaries that are 36" long, with a 4-1 header design..............I dunno where I am going to fit 36" primaries

Jer

That sounds about right. Notice how those are considerably smaller in diameter than what's on the market now?

You can fit 36" primaries in there-may have to bend them a bit. If I ever do a header, I think I'm gonna do a bung on each primary to tune afr or you could do one in the collector too.

Keep us posted on the progress!

[coppertop_01]

If I built something like this, it would be some major work, cause the cat would have to be relocated (drive clean testing up here, so I have to keep it), and I think my car would be down for a week or so, which I can't do, since my car is a daily driver, even in the winter

Jer