Hi guys, Will be attempting to build my own exhaust in a few weeks and am after a few helpfull hints on settings and techniques to help speed up the learning process I will be welding 3inch mild steel with a mig welder. Cheers, Steve
For it to look any good you'll want to tight it up otherwise its going to look shit ay. Are you going from dumps back or cats back. Your better off getting someone e with a mandrel bender to bend it all up for you then just weld all the flanges and brackets on.
Dumps back, no flanges other than at the dumps and I'm looking at Mendel bent sections 45's and 90 degree. I've got cats, dumps, x pipe and mufflers already from summit racing
Mandrel bends are good, but more expensive, if you have access to a tube bender, then you'd have almost no need for the welder. A quick eyeball of the pipe 'run' will give you an idea of how many bends you will need, but keep in mind to keep bends to a minimum for better exhaust flow- the more bends you have, the more backpressure the system will have. Not sure what welder you have, or what gas you are using, but watch your feed rates and amperage so you don't blow the ass out of that steel tube. Gasless mig wire might work OK but the spatter can be pretty full-on and the fumes are known carcinogens. As for welder settings mess around on some scrap steel first, tack weld the sections together under the car, then zap it up on the bench if you can.
No pipe bender unfortunately and will be hiring a gas mig, will be practicing on a some offcuts first, yeah that's one good thing about our cars, the exhaust doesn't wind all over everything...
That's about the only way you can weld tube with a MIG. If you try and do continuous beads you have to have too low a voltage which doesn't penetrate, and then it gets too hot and you start blowing holes. Welding exhuasts is a PITA. The Zed is a bad one to learn on too. When I pulled the V8 out and but a TT in I just took it to the local exhaust shop to join all the mufflers back up and it didn't cost much. It was way better than trying to lay on my back under the car tacking bits of pipe together when you can't see and you get hot slag falling all over you.
How are you going to do it then?? You can't just guess it by eye. It's especially hard with twin exit mufflers as you have to get the distance, angle and height just so compared to the rear bar.
Im soon to do our zeds exhaust. Stainless steel and lobster tail angles. Im going to have so much fun with that... Beauty is i have my own gear so im not rushed to have it done asap. I thought about going a step further an making a full length jig to mimic the current exhaust. That way i have all the angles and lengths pre determined and i can then play with fitment of the new cats and mufflers, etc. Plus i could do a few for people with the jig. haha. OP have you done welding before? Easiest method is to get your straight tubing and mandrel bends and just go from there. Start at the front and work backwards. You'll have to do a heap of climbing in under the car to check your lengths and cuts, even tack weld it. Then remove it and then do your complete weld. Ive made a few over time, its not hard work, just fiddly if its your first attempt. Once you've made your first pipe the second you'll do in half the time. But for a pretty job. Get some practice time in first before cutting anything. Also practice burning holes in the steel and then mending it. Mild steel is forgiving so thats handy. With your cuts try to get them as close to perfect as you can. Also the gap between the joints. Too large of a gap and youll try to fill the gap with too much weld and it will either drip or burn a hole. So again, practice your gap filling. Lastly, if it pisses you off. Walk away and try again later. Welding and tube work can get tiresome. So be patient with your work. AND HAVE FUN.
Yep, this is probably the hardest part. I have a pretty big Makita metal drop saw and I still have trouble getting straight cuts.
Ok so the car will be up on jack stands and I will be working from the dumps back, I have a mitre drop saw for cutting the tubing and bends, I will be working on one side only and then mimicking it for the other side till I get to the x pipe then it will be mounted while I repeat the process from the xpipe back to the mufflers, then I will remove and joint he left and rights to the x pipe and finish mounting it all. This is the plan... I'm sure it will change, lol As for the tacking and welding under the car I have purchased a joiner that you clamp the two ends together under the car to get the angles right and the joint flush it has 3 cutouts around it which u can tack through then take off the clamp and continue the weld. I have arc welded before and done some silver soldering and ally welding but that was a long time ago...
Haha dude hats off to ya for being so keen but with little to no experience with making an exhaust I think you will give up before the x pipe. Its not a guessing game it has to be quiet precice.
Regardless of it being a precise instrument, the exhaust. Give it a shot. In the end if you get it done and am not happy with the outcome. It's only time and experience, for you to give it another shot later. No point giving the bloke a kick in the guts before he's even began :/ Just saying.
thanks guys, yeah i was top of the class for arc welding, its just been a really long time, same for the old man he was an fitter and turner but he hasnt done any of that in at least 25 years but hopefully it will all come back to us..
why dont you get a pro to do it mate? if youv got all the bits n pieces you wont be paying a pro much more for welding and fitting the exhaust than the cost of hiring a mig welder i reckon.
