Ported stock mani good for 550hp+, so whats the point of headers?

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Originally Posted by OmniLuvr

the problem with this was to much effort to keep turbo in the stock location, personally I hate where our turbos are located. move the turbo over where the TU log manifold is, throw a slight angle on the mounting flange to angle the compressor inlet more towards the front of the vehicle instead of towards the fender and you would be onto something... just my idea... and this wouldn't have to be a log header, just an example, this would allow more room for 4-1 or 4-2-1 header, and more room for downpipe to p/s pump clearance...

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Yes that header was basically my first fab/welding project of any kind..pre-machining, pre-everything pretty much. I cant even remember why I wanted to keep the turbo in the stock location, I think it was just the challenge of it. There doesnt appear to be much of a benefit from that besides saving some $/time on certain things attached to the turbo that would have to change if it were moved about. Its probably more crack resistant since the turbo and head flanges are so close together in the stock configuration that I could easily brace them very well, so the primaries experience less stress. But you could still maintain that with a custom header that moved the turbo over.

I think what I should do is replace it with a ported stock manifold, and then design a crazy large diameter, large centerline radius swingvalve/downpipe, and call it a day.

As indicated many times throughout the thread, there are some excellent points being made here.

With every application, there are numerous considerations that need to be accounted for.
In this case, the size of the turbo being utilized will play a large part into the effectiveness of a header.
This is due to the amount of upstream back pressure (before the turbine housing) in turbo applications.
This is also the reason that large camshaft over-lap arrangements are counter productive unless a significant back-pressure drop can be realized.
As Rob indicated, many strive for any advantage but the gains will be minimized unless one is able to address the above issues.

In short...
Flow is less of a concern with high restriction and is why the stock hardware performs so well for a large portion of the community.
Introduce a large turbo/turbine housing unit that reduces the back pressure, then pulse tuning and flow will then become a measurable factor.

One of the primary advantages a well designed tubular header has over a common log or plenum style exhaust manifold is its ability to divorce the exhaust pulses from each other for a length of time (depending on primary tube length)
In a common plenum log manifold, where there is high back pressure and reverse exhaust flow during overlap, (usually from small turbine) the potential for mixture dilution is high, everyone agrees.
What a tube header does in effect is to move the cyl. to cyl. "cross talk" away from just outside the exhaust ports, to farther downstream (depending on the primary lengths) to a common collector which tends to nullify some of the mixture dilution.
A 4-2-1 header usually dampens reverse flow better than 4-1 style because the exhaust pulse velocity is sustained longer, and the paired pulses are out of time for back flow to easily occur.

Back before I was running a header, the most mph I could muster with my race car was about 125-126. I built my header, removed the ported stock manifold, reinstalled the same turbo (.63 ar Chrysler hsg.) with the header and promptly ran 128+. ET went from a best of 10.88 with ported stocker, to 10.60's with header. It allowed me to run a more aggressive cam and feed the engine more before the small turbo became the absolute restriction.

Don't do it this way! Put on a better flowing turbo first. It is easier and cheaper, but I had planned on a header and larger turbo anyway so I decided to see just how far I could go before upgrading, and I learned some things. A tube header is always better.

I love threads like this. What makes Rob and Warrens car stand out from the crowd, and what defines a true tuner and racer, is getting the most out of what they have before upgrading. Most people don't do this and just start throwing parts at there cars without fully understanding where there "cork" might be. Pretty much upgrading the wrong parts.

Tubular headers will always outperform a log header. But most people don't understand ad well that other things need to be upgraded a long with it. That's where the log header shines. Typically people will never get into that range of needing a tubular header. I think Rob has proven that point.

Now on my build I opted to build my own tubular header with a hx35 divided housing holset. Reason being is that my build is high compression, with a target boost. I will also be on e85 and meth injection. So I need something that flows. And my setup I am hoping will be efficient.

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Originally Posted by 85boostbox

I love threads like this. What makes Rob and Warrens car stand out from the crowd, and what defines a true tuner and racer, is getting the most out of what they have before upgrading. Most people don't do this and just start throwing parts at there cars without fully understanding where there "cork" might be. Pretty much upgrading the wrong parts.

Tubular headers will always outperform a log header. But most people don't understand ad well that other things need to be upgraded a long with it. That's where the log header shines. Typically people will never get into that range of needing a tubular header. I think Rob has proven that point.

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well said

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Originally Posted by 85boostbox

Typically people will never get into that range of needing a tubular header. I think Rob has proven that point.

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"Need" is purely subjective here so you can't even say that. Nothing has been proven "need" wise. Results are interpreted by your goals. Everyone has different goals. You can't determine someone elses goals.

With cars, you choose your own challenge. Anyone who says you chose the wrong challenge can get bent. If you want to do things with a narrowband o2 sensor and a fuel pressure regulator, a junkyard turbo that has a lot of shaft play and your ears for tuning and you accept the consequences, hats off to you. :thumb: If you want tubular manifolds, Motec engine management, Thousand dollar injectors, custom intake, custom valvetrain and head porting, CNC billet crankshaft...for your showcar that will never race, :thumb: sounds cool bro!

The oddball stuff is what I like to read about or help with. Shadow's setup is oddball because after many years he got faster and faster without changing certain things people normally change. His "vanilla" approach is interesting because of what he didn't do. If everyone had the same setup, I wouldn't be interested. To say he did things cheaply is wrong. He changed a lot of parts to save weight that are not "cost effective" but that is what he wanted to do. He got a lot more joy doing it his way. He runs expensive fuel at the track where others might be interested to see how little octane they can get away with. Some people just want a certain 1/4 mile track time with the least $ spent. If that is what someone wants, that is the only time speed/$ really matters. If you have a complete obsession with speed/$ this is the wrong platform. You can catalog build a very nasty Merlin engine and turbocharge that into any old RWD rolling chassis. When you see the bill for the Funny Car cage & other safety equipment that you need, you will wonder why you were so worried about speed/$

I'll just leave this here.
Beautiful work of Mr. Slowe:nod:
http://i60.tinypic.com/ta0qw6.jpg

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Originally Posted by BoostedDrummer

I'll just leave this here.
Beautiful work of Mr. Slowe:nod:

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Gorgeous and it brings up some great points.
Headers alone may or may not prove to be beneficial and depend strongly on the applications corresponding hardware and operating conditions.
For example, extreme boost conditions have fuel requirements to support knock suppression but comes with extended burn well into the exhaust stream.
This is terribly inefficient if the flame-front occurs after the turbine housing and well into the exhaust system.
To optimize turbine efficiency, the greatest heat expansion and its related flame-front should occur in (or slightly before) the turbine housing.
Therefore, adding a header into this environment will improve performance but is not solely based on upstream tubular flow alone.
The photo also identifies a key consideration of how the relocation of the turbine housing can eliminate down-stream abrupt/restrictive turns into the exhaust stream and coincidentally contribute to induction system improvement.
This is now beginning to cover the wide range of improvements beyond simply adding tubular hardware while also considering the applications corresponding hardware and operating conditions.

As a side note:
The original DC header was abandoned largely due to fabrication issues and cost but even the first few units proved to hinder boost response with no significant gain in output, for moderate performance applications.
In this case, the boost response was negatively affected by having the flame-front too far upstream of the turbine housing which is the opposite condition listed above.

I'll add into what Ken is saying. There is a lot more to building a good designed tubular header than meets the eye. Runner length takes a big factor into spool and backup into the header. You don't want to short but at the same time you don't want too long. Also as you increase length you also lose heat which we all know here, that helps with spool and transient response across the board. But then if you make a header to short, you get a lot more heat, which raises egt's, which we don't want. Which compliments what Ken is saying about knock suppression. It all adds up to what you want to do with your application. Now there can be a balance of drag, track, and street, but it takes a lot of math and research to find it. And on top of that, one of those will still suffer.

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Originally Posted by Ondonti

"Need" is purely subjective here so you can't even say that. Nothing has been proven "need" wise. Results are interpreted by your goals. Everyone has different goals. You can't determine someone elses goals.

With cars, you choose your own challenge. Anyone who says you chose the wrong challenge can get bent. If you want to do things with a narrowband o2 sensor and a fuel pressure regulator, a junkyard turbo that has a lot of shaft play and your ears for tuning and you accept the consequences, hats off to you. :thumb: If you want tubular manifolds, Motec engine management, Thousand dollar injectors, custom intake, custom valvetrain and head porting, CNC billet crankshaft...for your showcar that will never race, :thumb: sounds cool bro!

The oddball stuff is what I like to read about or help with. Shadow's setup is oddball because after many years he got faster and faster without changing certain things people normally change. His "vanilla" approach is interesting because of what he didn't do. If everyone had the same setup, I wouldn't be interested. To say he did things cheaply is wrong. He changed a lot of parts to save weight that are not "cost effective" but that is what he wanted to do. He got a lot more joy doing it his way. He runs expensive fuel at the track where others might be interested to see how little octane they can get away with. Some people just want a certain 1/4 mile track time with the least $ spent. If that is what someone wants, that is the only time speed/$ really matters. If you have a complete obsession with speed/$ this is the wrong platform. You can catalog build a very nasty Merlin engine and turbocharge that into any old RWD rolling chassis. When you see the bill for the Funny Car cage & other safety equipment that you need, you will wonder why you were so worried about speed/$

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Well said Bro! :clap:

One other thing to take into consideration, is the flow of the head, intake, turbo and everything before the header. It is possible to run your engine out of "breathe" with a well designed header. Warren stated in an earlier post when he went from the log style, to his header, his motor was breathing so well that compressor side of his turbo could not keep up.

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Originally Posted by 85boostbox

I'll add into what Ken is saying. There is a lot more to building a good designed tubular header than meets the eye. Runner length takes a big factor into spool and backup into the header. You don't want to short but at the same time you don't want too long. Also as you increase length you also lose heat which we all know here, that helps with spool and transient response across the board. But then if you make a header to short, you get a lot more heat, which raises egt's, which we don't want. Which compliments what Ken is saying about knock suppression. It all adds up to what you want to do with your application. Now there can be a balance of drag, track, and street, but it takes a lot of math and research to find it. And on top of that, one of those will still suffer.

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All good points!

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Originally Posted by Warren Stramer

A tube header is always better.

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And has a Really Nice ring to it as well!

Something that most seem to miss though, Not just Any tube header is Better, it has to be done Right to reap the full benefits! ;)

There is one thing i found on a ported stocker as found on BoostGeeks SC and my LS is serous heat soak between runs so bad that i cooked a pizza on boost geeks intake for a joke between his runs and have even melted are alky lines

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Originally Posted by bakes

There is one thing i found on a ported stocker as found on BoostGeeks SC and my LS is serous heat soak between runs so bad that i cooked a pizza on boost geeks intake for a joke between his runs and have even melted are alky lines

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Interesting, I can hot lap the Charger leaving it running the whole time (no cars in staging lanes) and lose Nothing. (same or better MPH and ET depending on how good I Drive it)

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Originally Posted by 85boostbox

One other thing to take into consideration, is the flow of the head, intake, turbo and everything before the header. It is possible to run your engine out of "breathe" with a well designed header. Warren stated in an earlier post when he went from the log style, to his header, his motor was breathing so well that compressor side of his turbo could not keep up.

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Quote:

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Originally Posted by 85boostbox

I'll add into what Ken is saying. There is a lot more to building a good designed tubular header than meets the eye. Runner length takes a big factor into spool and backup into the header. You don't want to short but at the same time you don't want too long. Also as you increase length you also lose heat which we all know here, that helps with spool and transient response across the board. But then if you make a header to short, you get a lot more heat, which raises egt's, which we don't want. Which compliments what Ken is saying about knock suppression. It all adds up to what you want to do with your application. Now there can be a balance of drag, track, and street, but it takes a lot of math and research to find it. And on top of that, one of those will still suffer.

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Both well said and exactly.

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Originally Posted by Shadow

Something that most seem to miss though, Not just Any tube header is Better, it has to be done Right to reap the full benefits! ;)

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Again, well said !
There's a science to it and without considering ALL of the factors and conditions, it's may lead to disappointment after significant effort.

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Originally Posted by bakes

There is one thing i found on a ported stocker as found on BoostGeeks SC and my LS is serous heat soak between runs so bad that i cooked a pizza on boost geeks intake for a joke between his runs and have even melted are alky lines

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Originally Posted by Shadow

Interesting, I can hot lap the Charger leaving it running the whole time (no cars in staging lanes) and lose Nothing. (same or better MPH and ET depending on how good I Drive it)

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Same here, I have a ported stocker and do not have anything more than normal heat. Sounds more like an inefficient or too small intercooler. I have a AWIC w/ no reservoir and can run 3 times in a row easily before the outlet side of the IC starts to even get warm, let alone hot.

dicks car loose a sec each lap and are Ic are over kill

Weird, what turbo?

Dick is hy35 and mine is modified S60