Need help with bending tubing for front of exocet

Hey guys and gals of grassroots! I have a dilemma that I hope someone can help me out with. Ever since I purchased and received my exocet ive wanted to connect the two long tubes at the front of the vehicle with some sort of 180 degree pipe. Sounds easy right, just find out the diameter of the pipe (1.75 inch) and the length and contour of the bend you need. Then weld it to the pipes at the front.

Well of course its not that easy, nothing ever is as easy in my head as it is in real life. Every pipe Ive tried to bend myself ends up with kinks in it no matter how much I fill with sand and add heat. Ive researched and researched to find out how to do this and the only way im seeing is to have a mandrel tubing bender of some kind. With prices starting at 2,000 I want to somehow order this online instead of doing it myself.

Ive visited my local exhaust shop and they said it wasnt possible because of the severity of the bend. (aka dont bother us we want to make money off of replacing suzy homeowners catalytic converter)

So now to the part that you guys can help with, does anyone know of a place that will bend tubing to custom specifications, this isnt something I can just buy premade as it isnt a perfect 180. I have the dimensions and measurements of what I need but I cant find a place that can do this.

So anyone got a website or an idea of someone who might be able to do this?

Heres a picture to get an idea of what im talking about. Im talking about a tube that will go in front of the jig.

Does the radius change throughout the bend? That's going to be a real challenge. You might have to weld it up out of chunks and then grind it smooth. Or possibly build an english wheel sort of device that will let you gradually add some curve. Something like this:

Since you're looking for tube and not pipe, see if there's a race fabrication shop nearby. You're dealing with a thick wall material, exhaust shops won't be able to handle it but it will also resist kinking.

The shop that helped me modify my Exocet chassis has a mandrel bender. I can ask them for a rough quote and they could use my car as a mock up to fit the bend? Wouldn't be able to get it over to their shop for a bit though...

Keith, Yeah it does change radius which is why it is so challenging. I never thought about cutting and welding, that could work. The device you have a picture of looks awesome but looks like its expensive. Id try and make it but I have no idea what im doing haha. Ill check for some race fab shops nearby im in dallas so its a major city should be something. Thanks for the advice!

BTD thanks for the heads up, any chance I could have the number of the shop I can call them and get them an idea of what im trying to do.

In the mean time I was thinking of creating a drawing and seeing if a company like this could do it Sharpe Custom Mandrel Bending

Expensive to buy. Not that expensive to build if you're willing to weld.

You could try heating it and bending it around a wooden buck. Never tried it with tube that thick because I have a mandrel bender for roll cage tubing and one of those cheapo bottle jack benders. I have been heating and bending exhaust tubing that way for years to get smooth mandrel bent looking curves. Takes two people, a vice, and a big torch. Put one end in the pipe vice and your assistant on the other end. You heat the pipe all the way around until it glows orange. Assistant pushes down on the pipe and it slowly bends only where the orange is. Slowly chase the orange down the pipe bending as you go. Works great for bending the tight up and over the rear axle tubes. It would probably work on the roll cage tube as well, just haven't tried it. I'm a plumber, so I've bent black gas pipe and PVC pipe that way many times. To get the exact bend you need, you would have to use a form or a buck to do it right, or else one side won't be exactly the same as the other. Try it with a piece of leftover pipe or some cheap gas pipe first. See if it works.

Can you weld? start making slices that almost cut all the way through the tube. Bend to close the gap and weld shut.

If I may poach a picture from our own build threads forum, that is how this was done.

Another option, if yu like the look, is to abandon the tube and go to a I beam construction. Cut out two pieces of flat stock to match the arch of the round tube (these will be the top and bottom of the I, and bend up a third strip to join the two. Put a bunch of speed holes in the piece that is going to be the horizontal part of the I beam and you are good to go.

I would look for a off road fabrication shop. They normally do a lot of tight tube bends for shock mounts etc.. You may even find a pre-made stinger front end bar that would be close.

See this is why I love this site tons of helpful responses quickly.

Keith, I will look into whats required to make one

Tr8, the whole heating and bending is what ive been trying to do , that "jig" in the picture is my attempt at creating a shape for the metal to bend around but no matter how much I try I just cant seem to get it bent without distorting the tube severely.

Nohome, I can "weld" as in I can join two pieces of metal together temporarily with my crappy flux welder then grind down the welds. The thing is that each attempt at this costs me $30 in steel and ive tried 3 times already, each time with a broken or uselessly kinked piece of metal to show for it. Your idea of using cheap steel to practice on is a good one. I am going to try the online place and see what they say when i send them the specs, but i think if they cant do it ill try the cutting and bending way next with welding to fill the gaps.

As far as using I beam, since this is purely for appearance sake (I want it to look pretty dammit!) I would prefer to continue to use the round tube and make it look as if it was made that way.

Papabear Ive tried calling local exhaust shops and roll cage builders but they all say that they cant bend 1.75 diameter they dont have the tooling for it. I am googling off road shops now to see what they say.

Thanks again for all the responses guys they do help!

You have a lot of opportunities to open the creativity envelope if you go to sheet-metal fabrication. An you ARE looking for opportunities to improve your welding skills right?

Sticking with the tube, how thick is the tube you are using? Can I see a front view of your jig to see what you are doing? It should have a saddle in the middle to capture the tube.

Trying to figure out why the sand method and heat is not working, its pretty reliable way to do this job.

jetstar15 wrote: BTD thanks for the heads up, any chance I could have the number of the shop I can call them and get them an idea of what im trying to do.

No problem!

Hanksville Hot Rods (303) 949-3623 http://www.hanksvillehotrods.com/

Hank, the owner is a great guy. Does a lot of work for the local Porsche community (rollcages and the like). Let him know Dan with the weird Exocet kit car sent you and he should have an idea of what you're working with, they did a few rollcage and floorpan modifications for me and the work was superb.

The key in my experience is that with conventional benders there's a point at which the tube deforms and collapses. I do a lot with 1 1/4" schedule 40 pipe, which nets out at about 1 5/8" OD. I can bend around 7 inch radius before things go to heck. To get a tighter radius will require either a mandrel bender which is big bucks, orfilling it with sand and capping the ends which is a PIA. If your radius allows for conventional equipment, there should be plenty of people around who can do it. If you go the mandrel route, a big time race shop may be the way to go.

If you can draw it, I would contact one of these guys to get the part done.

http://www.mandrel-bends.com/catalog/builder-kits-33/

http://www.welderseries.com/blog/store/#!/Chassis-Parts/c/12959479/offset=0&sort=normal

Summit also carries a line of mandrel bent parts that you can put together with your welder to create what you need.

http://www.summitracing.com/int/search/part-type/exhaust-pipes-individual-bends

I have mostly kept to muffler thickness tube as I see this a sacrificial structure in the case of a minor collision. A stiffer tube will transfer the force into the main chassis and you would want to avoid that.

https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/cnc-tubing-bender/100822/page1/

Maybe get a hold of adoyle88. He and his dad built a homemade CNC tubing bender.

You mentioned Dallas -- where are you? Know someone on the west side of the Metromess that may be able to help

I have a 1.75 mandrel bender for roll cages and I'm sure a bunch of other people on this forum do as well. Where are you located. There must be someone within an hours drive that can get you close.

Give Racefab Inc a call south of Dallas. (903) 683-1599 they can bend any tubes you need

That's going to be really hard to do on a "mandrel bender." The technical term for the process is rotary draw bending, where you are essentially grabbing the tube and pulling it around a bend die that defines the radius of the bend. The limitations of the process, as it pertains to this application, are that 1) you must bend a to a constant radius (or several radii, as most machines allow you to stack dies) and 2) you can't practically bend a very large radius, due to the size the bend die would have to be. As far as I can tell, the gradual bends on the sides are not constant radii (maybe they are, and you could probably reasonably approximate them with a constant radius anyways) and, more importantly, the radius would be too large to "mandrel bend" anyways.

What you would need is to roll bend the radii on the sides (basically what Keith Tanner shows in the first reply to the OP), then come back and draw bend the tighter radius in the center. Lots of fancy pants new benders can both roll bend and draw bend and do this all in one setup, but even then it would be tricky with no straight to clamp on between the bends.

What I'm getting at is this isn't the easiest part to bend and going to Joe Blow with a tube bender isn't likely to yield satisfactory results. A racecar fab shop might be able to do it, but you're best/most cost effective bet might honestly be to do it in three sections and weld them together.

Just my $.02 from having worked for and developed parts at a company that does a lot of production-scale tube bending, though I'm far from an expert.

Keep working on your sand bending skills. I have done two full cages that way and once you figure it out it really goes well. It is also free.