To Mandrel or not.

[Guest Aaron]

OK, there is one of these mobile tool places coming to town, and are advertising pipe benders that go up to 3in pipe for $99 (I think). Obviously, this would not be a mandrel bender, so what are the ramifications to using this bender to make headers/exhaust instead of using pre bent mandrels? Obviously, it would not look as good, but how much difference would it make in flow capacity?

[jeromio]

Pipe bender no equal Tubing bender. Tubing tends to imply thin wall which is more kinkable than pipe which is typically much thicker. Stuff like roll bar tubing is sort of in between, but still quite kinkable.

 

In summation, the $99 tool is more than likely a pipe bender (or tubing ruiner) that simply forces a die (arbor) against the pipe which is kept in place by 2 rollers on either side of the bend. No pulling, all crushing (or kinking). For Pipe this is okay since it's real hard (impossible?) to crush.

 

You're way better off using preformed mandrel bent tubes for your exhaust.

[Guest Anonymous]

I have one of these pipe benders for $49.00 (on sale at Harbour Freight. I used it to bend the stainles steel (heavy wall) pipe that I made nerf bars for the "Fat Boy". The rear nerf bumpers were indented by the benders upper placement rods that the curved hydraulic ram pushed the pipe against to bend. I doubt that this machine could bend without kinking or flattening thin wall material and really cannot make a true 90 degree bend. My Nerf bars came out really good on my second set after I learned to slow down the process and a little heat from a torch may have helped.The "ol Joint Jigger" and preformed bends maybe your solution

[Guest Anonymous]

Its what they I believe call a crush bent system, it crushes the pipe's diameter down where its bent. I've seen both on Z's, crush bent is faster because they can bend a single tube very quickly compared to cutting and welding sections. As far as performance, I'm sure it flows less through the corners, but I'm not sure what it would cost in hp numbers, with dual 2.5's all the way back duals would be cool if possible, but even that into a single 3" all crush bent would probably be ok unless your shooting for big hp numbers. Just an opinion of course. Who knows maybe theres even a sound difference, crush bent might actually be quieter due to some reversion where the bends occur. (if not, isn't that a great PR husle though. ).

Regards,

 

Lone

[Lockjaw]

Mandrel bent is the only way to go.

[Guest Drewz]

Flow capacity is minimal if the engine is a low to mild performer or a turbo car. Carcraft has done tests as Hot Rod mag.s and unless it is a stout or Hot performer it is 10 to 18% range. If headers are being built than mandrel is THE only way to go. If you aren't a 1/4 mile racer or auto crosser etc. than non mandrel is fine. A show car does look sweet with mandrel though IMO'S!!!

[randy 77zt]

i have 3" mandrel bent exhaust on my turbo z and it only took 2 90 degree bends.if you have a chop saw and a mig welder get the bends from summit and do it your self.the muffler shops around my house do so much custom work its cheap so it isnt worth doing it your self even if you can.