Homemade Bypass

Cat bypass

If you go to his e-bay site, he has a current auction and ships to the USA. It's $462.00 and if you include shipping, I believe it's quite a bit higher than the OEM issue. Besides, If it don't fit, how do you return it? I too have a tube bender (Baileigh) and mig/tig welders in my shop. Maybe this winter....

I'm bent.

Looking closely at both the Staintune and the UK bypass, I see that in both cases the pipes were bent or should I say formed on a standard radius bender. It's especially apparent in the UK model. A standard radius bender will actually collapse the diameter in a tight radius draw as the metal actually elongates to make the bend or radius. If the pipes were bent on a radial draw bender, the diameter would stay constant and would flow better than the conventional bend. To maintain a constant diameter, a radial draw bender or a mandrel bender must be used. I believe most all muffler shops use a standard radius bender where the tubing is actually bent around a stationary die. That will cause the decreased diameter in the radius.

Sidecar Flip said:

Looking closely at both the Staintune and the UK bypass, I see that in both cases the pipes were bent or should I say formed on a standard radius bender. It's especially apparent in the UK model. A standard radius bender will actually collapse the diameter in a tight radius draw as the metal actually elongates to make the bend or radius. If the pipes were bent on a radial draw bender, the diameter would stay constant and would flow better than the conventional bend. To maintain a constant diameter, a radial draw bender or a mandrel bender must be used. I believe most all muffler shops use a standard radius bender where the tubing is actually bent around a stationary die. That will cause the decreased diameter in the radius.

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The standard radius bender must be cheaper to buy than a radius draw bender or more common. I see what you mean from the two photo's.

One selling point of many aftermarket exhaust systems for autos is that they are mandrel bent.

Pig9r said:

One selling point of many aftermarket exhaust systems for autos is that they are mandrel bent.

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I wanted a custom pipe on my tractor that blew horizontal for indoor work. My local muffler shop bent one for me but it looked terrible all squished and distorted. But it was cheap so I use it,.....but it still bugs me.

Bender over!!

I know that's not PG13, but I couldn't resist.

Pigger and Hondax:

My Baliegh is a radial draw bender. While a mandrel bender is ultimate so is the cost. For every i.d. of tube or pipe to be bent, a different mandrel has to be employed as well as a different set of dies. In addition, a mandrel bender takes a lot of room and costs about what 5 R3's would cost without any tooling. Mandrel benders have die sets just like radial draw and hydraulic forming machines. They are mostly computer controlled and used in a production environment. The "mandrel" is actually a flexible insert that goes inside the tubing to be formed and keeps the walls of the tube at a constant diameter. Second in the pecking order is the radial draw bender that I have. A radial draw forms the tube or pipe around a fixed die employing a sliding shoe that is the same o.d. as the material being bent (formed). Radial draw benders are mostly used for fabbing roll cages and frames and some high performance exhaust work. The last one on the tree is the standard pipe bender like your muffler shop uses. That bender uses a hydraulic cylinder and a female die to force the material around another female die. That's why you get the decrease in diameter in the radius. It has to do with the cold flow characteristics of the metal. Even a radial draw bender will decrease the radius when asked to make a sharp bend on material with a high Rockwell and there are limitations as to how tight a bend you can actually make without fracturing the material.

When it gets cold here and I'm in my shop and not farming, I'll draw some different tube with different chem's and post them so you can see what happens to different compositions.

That's your shop lesson for today.:bch:

When it gets cold here and I'm in my shop and not farming, I'll draw some different tube with different chem's and post them so you can see what happens to different compositions.

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Sounds kewl and thanks for the info on bending pipe.:gp:

wonder if they would be willing to sell just the by pass ?

the e bay by pass is now carried by : http://www.newr3.com/html/performance_pipe.html

New Bonneville

Brent at NewBonneville.com has some nice acessories for the Rocket, but you can buy the Rivco stuff direct. www.newbonneville.com

I've bought a few items from Brent for my T100 and also from Mike Sellman at www.bellacorse.com.

I prefer buying from Mike as I just happen to ride with him ocassionally, but Mike isn't really into R3 stuff but can get about anything you want.

Brent isn't any cheaper, actually I believe he's a little more than what the item is selling on E-Bay for.