wall thickness and material for turbo header.

[XFlow_Fairlane]

well pricing out materials for building a new header (tube style with a collector and all) and was loking at two options..

1. 1.5" sch 10 304SS. this gives a thinner wall (.109) but roughly a 1 5/8" ID.

2. 2" sch40 1018 mild steel. larger sized ID but thicker walled and larger OD.

pricing looks similar for both (10 els and a 1/2"x4"x36" bar for the flanges)

so is the sch10 too thin for a turbo? I know gauge thickness is a little thin for a turbo with the heat and weight.

 

[StrangeRanger]

The header itself should not be the only support for the weight of the turbo; you want a bracket as well. The sch. 10 should be more than strong enough and the 1.5" size will give higher velocities than the 2".

Even though it will be corrosion resistant, you may want to consider ceramic coating the SS header to reduce heat loss. If you decide to coat it, then the carbon steel version becomes more viable. 1.5" sch. 40 CS pipe is 1.61" ID vs. 1.68" for the sch. 10 SS. I'd tend to go with 1.5" in whichever material.

 

[grocery getter]

The header itself should not be the only support for the weight of the turbo; you want a bracket as well. The sch. 10 should be more than strong enough and the 1.5" size will give higher velocities than the 2".

Even though it will be corrosion resistant, you may want to consider ceramic coating the SS header to reduce heat loss. If you decide to coat it, then the carbon steel version becomes more viable. 1.5" sch. 40 CS pipe is 1.61" ID vs. 1.68" for the sch. 10 SS. I'd tend to go with 1.5" in whichever material.

will the header "grow" as it heats up ? I'm wondering if the bracket should be slotted to allow it to move.

 

[wallaka]

Kind of defeats the purpose of a bracket if it moves, doesn't it?

 

[XFlow_Fairlane]

I was only planning on a bracket if the design I end up with hangs the turbo farther away from the motor than I feel safe with. if it is tucked up close then a bracket shouldn't be needed. I didn't know if sched 40 1.5" would give too small of an ID for mikes new head when it comes out as it will have slightly larger exhaust ports and be flowing more air.

 

[fb71]

I've had issues with sched10 cracking from heat cycling. Same reason most header manufacturers won't warranty a unit that's had header wrap on it. The thinner the mat'l, the more rapidly it heats and cools, so the expansion/contraction is exaggerated, causing fatigue cracks. I like sched 40, 1.5" for the primarys. Keeps the velocity up, retains heat better in stop-and-go (or between passes), and mild steel, since its more fluid, tends to fatigue less quickly than comparatively more brittle stainless.

JM.02

 

[grocery getter]

Kind of defeats the purpose of a bracket if it moves, doesn't it?

No

 

[fb71]

Kind of defeats the purpose of a bracket if it moves, doesn't it?

No

I agree. A bracket supports the weight, not retains location.

one more point about header mat'l. Are you talking tubing or pipe? Tubing specs are OD, pipe specs are ID. So, sched 40 pipe will be slightly larger inside than sched 10 tubing..... I use mild steel pipe.....

 

[StrangeRanger]

"Sch." always implies pipe. Tubing is specified by OD and wall thickness. The diameters for sch 10 and sch 40 1.5" pipe (1.90" OD) are as I specified above.

 

[fb71]

you're absolutely right, sch is for pipe, not tubing. my bad. brain a little fuzzy today.

and, I completely missed the post with your specs!

 

[XFlow_Fairlane]

on pipe sizing the OD is the same for both sch 10 and 40. the ID is different. the 1.5" will just barely squeeze between the exhaust bolts on the 200. 2" will require a sleeve and notch on the tube so it can be bolted through.

so for sch 10 1.5" 304 SS should that be fine? (wall thickness of .109")

I know 321 would be a better pick but I think there should be enough mass in there to cover things. once I figure out my layout (waiting to see the new intakes and such) I will pick any brace points then. The overall design will be a individual runner design with 1-2-3 and 4-5-6 being grouped together at the turbo flange (split inlet style) in the 2.3L crowd I have heard of good gains even if you are just using a single inlet turbo and not a divided scroll.

 

[Anonymous]

I am trying the same thing with 1.5 inch tubing. But going to put them in order of firing order ( my theroy is like a 180 degree header ) Dont know if it will make a diffrence or not but what the hell....


Anybody can design a turd to flush better…. The real challenge is to make it look good and smell pretty

 

[StrangeRanger]

The natural arrangement on an I6 already gives you the balanced pulses in the header. If you collect 1-2-3 and 4-5-6, there will be a pulse every 240° in each collector. No gaps, no uneven pulses and, as an added advantage, very little overlap between successive pulses. It's really an ideal system; there's no point in "improving" it.

 

[Anonymous]

Thanks for the info. Now less work for me.....

Anybody can design a turd to flush better…. The real challenge is to make it look good and smell pretty