Hmm, interesting idea. I was too lazy to tear the manifold back off. I attacked it with a big cross cut file before I installed it so the leaking was at a minimum to begin with. As I've driven it, I've just gone back and retightened the head studs a couple times and all of the little exhaust leaks are gone now.

 

Perhaps as the manifold got hot during use to the point that it relaxed a little and took the shape of the head?
I like the idea if puting a bead arownd each port!

 

DIY 1.6L manifold for Mazdaspeed IHI turbo installed on Mazdaspeed OEM brackets.

Equal length runners, of course. Target is to use all OEM parts (ducting, intake box, oil & water lines etc.), so the maifold appears very compact

 

did you weld in the studs?

 

Looks like it.

The poor collector.

 

And I thought I spent a ton of time building a DIY manifold to use a cheap tiny oem turbo. I've been outdone on all counts.

 

The ones which goes into turbo housing are actually welded. It's definitely not the best solution in terms of thermal expansion, I agree.

Do you feel that is REALLY critical (even if I compensate by increasing the diameter of 3 holes on the turbo housing)?
I'm still in time for changing this item... and you have far more experience than me!

 

anyone know if the "3d" flange that has the taper and step for the 1.5" SCH40 pipe exists for the 1.6L?

 

Is there any downside to using mild weld els i know most use SS because there cheaper however I can get mild els for 6 bucks a piece. I've used mild with success for a log but this time i am planing more of a tubular design.

 

I only went with SS manifold because I did not want to deal with rust. When I build my first DIY manifold I am planning on going with mild steal the first time.

 

Just ordered a Wiertech flange/weld el package for bottom mount goodness for the SAAB.

 

I really want BMC race to get back to me. I added a t25 flange to my order and they're literally telling me a price away from having my money. If I dont hear back from them by the middle of next week I'm taking my cad model copy of their premium flange, this piece of 1/2" 304 stainless I have kicking around and just making one myself.

 

I got my flanges from weir already, \ after reading on various other forums and a thread here with a mild SCH40 absurdflow mani. I realize there are no downsides really for this on a street car, other than rust which can be solved by having it coated. Thanks

 

Mild steel elbows may have a tighter radius than ss ones which could be a downside/upside depending on what you want to fab.
6$ sounds too many middlemen expensive for mild steel. (Locally 5/4 s235 elbows are about 1$ Pavol Mará)

 

90s are made in both short or long radius.

 

Even 1.25" 304L, but the tight radiuses in that size are about $85 each, long radius ~6.

 

that pic is of a short and long. 6 bucks is cheaper than ace stainless so I don't thinks its a bad price.

on the left is a long radius SCH10 SS from Weir on the right is a long radius SCH40 mild from my local place(sand blasted)

 

In any case short radius bends would significantly restrict flow?

Incidentally, the picture posted shows 2 long radius bends all be it to different standards.
In SK/EU for whatever reason, stainless pipes are supplied in metric sizes to DIN 2506 and mild steel pipes are supplied in inches according to ASME.
DIN 2506 uses R=1.5d which is > than ASME long radius equivalent.

 

McMaster has short radius $42 and about $10 for the long radius in dual grade 304/304L. A234 elbows are $12 for long radius and $20 for short radius.

 

a 90 is a 90.

Radius doesnt really matter that much as compared to the friction caused by the length of the pipe and the surface of the ID of the pipe.

Generally fabricators will use all long radius though to keep costs down when they can.

I know that I use only long radius and I havent had an instance where i needed a tight radius yet.

Im sure something like a BMW turbo manifold or something similar in a VERY tight space may need a few of them.