How to Make Your Own Custom Exhaust

Installing a custom exhaust is the first modification a lot of custom car and truck owners perform. Although it's simpler to take the vehicle to a shop for the work, if you're handy with a welder and have patience, you, too, can perform the job. Be forewarned, this isn't an easy task. Properly cutting and marking bent tubing can try your patience.

Things You'll Need

  • Metal cutting chop saw
  • Steel exhaust tubing
  • Steel exhaust tubing U-bends
  • Permanent marker
  • MIG Welder
  • Welding helmet
  • 1/8-inch round steel dowels
  • Oxy-Aceteline torch
  • Bench vise
  • Reciprocating saw with metal cutting blades
  • Jack
  • Jack stands
  • 24-inch pry bar
  • Tape measure
  • WD-40 or other spray lubricant
  • Pliers
  • Lift the vehicle using the jack and support it on jack stands. Be sure the vehicle is fully secure on the stands before you crawl underneath. Make sure the vehicle is high enough in the air that you can work underneath it safely. You'll need to work the reciprocating saw, so keep that in mind.

  • Locate the part of the exhaust where you want to start the new part and mark it with the permanent marker. Cut into the stock exhaust and use the same diameter tubing or step up to a larger diameter if you're looking for performance gains. If that's the case, buy steel tubing that transitions from the stock size to the larger size, which is available at Magnaflow (see "References").

  • Cut the exhaust using the reciprocating saw on the mark you just made. If the exhaust goes over the rear suspension or another area that would make it difficult to remove, cut it there as well to make removal easier.

  • Pry the stock exhaust out of the exhaust hangers using the pry bar. If you have difficulty getting it out of the hangers, lubricate the mounts using WD-40 or a similar lubricant.

  • Lay out your new exhaust visually. Note areas where you'll have to avoid objects such as the gas tank and rear suspension and consider muffler placement. All of these things can be laid out exactly as the factory did it, or any way you create.

  • Take the straight sections of exhaust tubing and cut it to fit the first attachment point at the engine using the chop saw. Leave enough room for a bend.

  • Tack-weld the old exhaust to the new tubing using the MIG welder. A tack weld is designed to hold the parts in place, but is easily removable if things aren't placed perfectly. This way, if you have a problem with your layout, you can pull apart the exhaust easily and reuse the parts.

  • Hold a piece of U-bend tubing up to the section you just tack-welded to the stock exhaust. Place the tubing such that the bottom of the U shape is aligned with the new tubing and one of the top portions points in the direction the exhaust is going. This is going to allow you to just cut a section of tubing for the new exhaust, while reusing the other half for another section.

  • Mark the U-bend where the bend and the stock tubing intersect with the permanent marker. This is going to be the joint where the two pieces connect, so make sure that your marks are as accurate as possible.

  • Place the U-bend in the bench vise lightly so you don't distort the tubing.

  • Cut the U-bend using the reciprocating saw. Make sure that your angles are correct, because you want these two sections of tubing to match precisely.

  • Tack weld the newly cut U-bend to the other piece of tubing.

  • Continue this process along the length of the exhaust until you reach the area where you want to attach the muffler.

  • Cut the 1/8-inch steel dowel into 6-inch lengths. These parts will be used for exhaust hangers and will support the exhaust.

  • Mark the steel dowel so there are a 4-inch section and a 2-inch section using the permanent marker.

  • Place 2 inches of the dowel in the bench vise and heat up the mark to a rosy red, then bend it to a 90-degree angle using a pair of pliers. Make the bend more than 90 degrees if you want more of a hook shape to your hangers. Allow the part to cool before handling it. Repeat this process for each exhaust hanger needed.

  • Weld the new exhaust hangers onto the exhaust, then hook them into the rubber mounts, using the pry bar if necessary.

  • Locate the muffler in the vehicle. Weld exhaust hangers to the muffler for support; by doing that first, it will help you support the muffler while the exhaust is in the air.

  • Tack weld the muffler to the exhaust tubing. Install a muffler tip on the muffler or just run the pipes wherever you like.

  • Fully weld the exhaust once you're happy with the placement. Make sure there are no gaps in the steel and welds; otherwise, you'll have exhaust leaks.

  • Start the vehicle and test for leaks. If you hear an exhaust leak or can feel it around the welds, then you need to weld up that spot or patch it appropriately.

  • Jack up the vehicle and remove the jack stands.