header fab advice needed

when i fab up my headers for my turbos is there any order the primaries should go into the collector? or can any pipe go anywhere in the collector?

i relize that it would work with any order but i was mostly wondering if it would work better in a certin order???

There are some very complicated calculations that go into high-performance header design. I cant claim to know much about it at all, but you may want to read about it because, just from the reading your question, I dont get the feeling that you know a terrible amount about it either. I could be wrong though, and forgive me if I am. FWIW I've always heard that equal length primaries was the way to go.

$.02 by Jeremy

If your worried about lost performance in your design I would look into getting some merge collectors as well.

if you are about to attempt to tackle this on your own, my advise will be based on my interperetation of your question which was, which primary to begin with in the actual construction of the manifold.

take a slat of wood which will resemble a flange that bolts to the head in the appropriate thickness.. I like 1/2" stainless (use 7/16" wood as you will likely need to machine the finished manifold to ensure sealing) but 3/8" is the bare minimum I would even consider. Get some flexible tubing in 1 3/4". Next determine where the turbo(s) will be located, be sure to leave room for downpipe(s) and other components such as wastegates and so forth. Brace the turbo in its location I use scrap steel and an available set of bolt holes on the engine or frame. bolt the wood to the heads, make sure there are holes drilled where the exhaust ports are in the wood to slip the flex pipe into and thumb tack it in place. As mentioned before trying to maintain an equal length is a good idea in a pressurized turbo system, as the pulses will move to the turbocharger in a more uniform pulse pattern generating more even force across the turbine wheel. Now begin your design idea with the flex tube.. this will save you time and money and help bring what you think will work and what actually will work into a final result. It will also give you a nice schedule for what bends/straights will be needed so if you plan to use the best material (besides inconel), 321 stainless steel which is VERY expensive, you will not over buy and will be able to determine if the cost of self construction will be worth it or if you may decide to go with mild steel and opt to have it coated once complete. Both of these will work well, just a matter of how long the coating stays on as to how long the mild steel will hold up.

a few other notes,

be sure to use solar flux on the interior of the pipes when welding so the push through of the welding wire/rod is minimized to a clean smooth weld bead rather then a pourous oxidized glob. although the outside looks great they would never pass an X-ray test and will not have the same strength as a weld which is purged with argon or was coated with solar flux a chemical oxidizing inhibitor. Also as mentioned, be sure to price all components before starting.. it can add up quickly and unless you are setup in a shop to do this kind of fabrication or have no other choice such as my situation where no company offers a turbo system for your car, you WILL come out cheaper in the end with ALOT less headache by purchasing a proven available kit. It is a very long and frustrating process and is why it requires alot of turbo kit fabricators a very long time to complete the R&D and why the price tag is usually higher then what you would expect by adding up the sum of the cost of parts alone. Just a few words of warning before you start a project and end up kicking yourself half way into it and too far to turn back.

Chris

i have all the pieces including the collector, i also have a 500 amp tig welder which makes a good enough weld that i dont have to worry about blow throu.. i am not planing on weldidng these with a stick welder. i have no problems fabing these up.... these are going to be made from 16ga crs with 1/2" crs flange, and will be coated. i looked into s/s and it would of blew the bank and not offered any benifit over coated crs. Even if i did go s/s i would of still coated them to reduce temps. also i am going to do my best to make them equill lenth but i am not going to loose any sleep over it. it will probably end up close.

the only question i need answered is if it is benifical to have the primaries go into the collector in any order????

lets say this is the head (1) (2)(3) (4)

and this is the collector

(1)(2)
(3)(4)

so when the engine is running the exhaust enters the collecor in a circular pattern

or does this even matter ????

i have all the pieces including the collector, i also have a 500 amp tig welder which makes a good enough weld that i dont have to worry about blow throu.. i am not planing on weldidng these with a stick welder. i have no problems fabing these up.... these are going to be made from 16ga crs with 1/2" crs flange, and will be coated. i looked into s/s and it would of blew the bank and not offered any benifit over coated crs. Even if i did go s/s i would of still coated them to reduce temps. also i am going to do my best to make them equill lenth but i am not going to loose any sleep over it. it will probably end up close.

the only question i need answered is if it is benifical to have the primaries go into the collector in any order????

lets say this is the head (1) (2)(3) (4)

and this is the collector

(1)(2)
(3)(4)

so when the engine is running the exhaust enters the collecor in a circular pattern

or does this even matter ????

I am actually building these as we speak as well. I am doing it in this order
(4)(3)
(2)(1)

Matt

For the swirl effect, it's different from driver's side to passenger side on SBC/LT1 engines:

passenger side:
(8)(4)
(2)(6)

Driver's side:
(1)(3)
(7)(5)

They can be rotated clockwise or counterclockwise, but should remain in that order for the swirl effect.

thanks this is what i was looking for