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Discussion Starter · #1 ·
As crazy as this might sound, Im thinking about crafting my own exhaust out of inconel (nickel chromium) tubing. I know its going to take some time getting used to welding new alloy and there are a sheet load of bends in the exhaust system. My questions if there are any experts out there doing this, I assume you need to have all the bends for the correct back pressure, but just wanted to make sure theres no way of escaping this. Does the system need an X pipe (do you need to balance out exhaust flow) or can I get away without? Also what size is best for a stock 748? 50.8mm, or 54mm? Thanks!

On a side note, if anyones got a set of R cams or know where to find them, let me know. Thanks-
 

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jfoo13 said:
Does the system need an X pipe (do you need to balance out exhaust flow) or can I get away without?
You could get away with it but at the detriment of what you are trying to acheive, the X over/balance point should be as close to the cyl head end as I understand it.

The further back the balance point the increase in low end, the closer to the cyl end increase in HP, all to do with pulses and purging with optimal lenghts.

Alex Ortner is the man to talk to on it, he knows the ins and outs very well.
 

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Doesn't welding inconel require a barrier gas setup similar to titanium? That would make the traditional cut/fit/tack process of building an exhaust more than slightly difficult.
 

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inconel can be welded using conventional stainless steel tig welding techniques. inconel filler metal 625 rod can be used to weld inconel to inconel as well as to dissimilar metals including stainless steel.
 

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Man,you guys' are gettin' deep with this one.WHY inconel????????WHY??? It seems just last year Confederate Motorcycles' had "exhaust through the swingarm" with an Inconel flex hose connecting the "swing" to the hard mounted part of the exhaust.They claimed it ( the inconel part) could stress for many thousands of cycles without stress failure. Why not fab out of regular steel tube and nickel plate? What is the desired effect of using Inconel?? That you can have bragging rights to exotic exhaust material? Or maybe you're an expert welder with a pet project?:confused:
 

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I'm gonna be using lightweight stainless steel for my custom exhaust - check www.burnsstainless.com for all the X-overs, cones, tubes you could want - and for those nice lightweight straightthrough mufflers without fiberglass sound cladding to blow out....

PS - they will even design it for you, if you complete their specs sheet!
 

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Discussion Starter · #9 ·
Thanks old baldy - Yea I'm thinking about maybe going with the stainless myself depending on what the cost is between the two, inconel/stainless. What kind of diameter bends are you requesting for your modification? They said I needed to tell them exactly the diameter before they could quote me on a price. This is for my superbike so I was going to say a couple 6", couple 8" U bends should cover it. Post some pics and let me know how it turns out!

As far as going with inconel, well it seems to be the choice cut of the top fab places out there including ARC at BCM in Laconia. And ofcourse the exotic welding brag rights!
 

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Ask Doug Cook @ ARC Fabircation/BCM Motorsports. I believe he's the one that built Alex Ortner's exhaust systems.

From my limited discussions with Doug while he was fabbing my spaghetti's, it's a lot harder than you think (and I'm not talking about the welding).

Would be fun though.
 

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jfoo13 said:
Thanks old baldy - Yea I'm thinking about maybe going with the stainless myself depending on what the cost is between the two, inconel/stainless. What kind of diameter bends are you requesting for your modification? They said I needed to tell them exactly the diameter before they could quote me on a price. This is for my superbike so I was going to say a couple 6", couple 8" U bends should cover it. Post some pics and let me know how it turns out!
It's part of this winter's project....I'll post pics on the progress (or lack thereof! ;) )

BTW - I spent a lot of time measuring the stock pipes, and found that the two headers are WAY different in overall length, despite thinking that they looked like equal length headers. I intend to try to make them equal length, to the tuned-length spec appropriate for my cams and RPM. None of the fancy **9 different-diameter, different-length stuff ;)
 
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