About 2 years ago we were searching the market to see what kind of custom-made exhausts we can find for Ducati Panigale 959. And whatever we found had 2 major problems: the sound was not good, and it had some standard looks. As only a small part of the exhaust is visible on this model it’s quite a challenge to attain something that will look cool. We had 2016 959 in our hands and this was the start. We were looking for a way to make this work and what we found the best way to achieve it was the pie cutting. It’s not cheap, if you’re looking for the most affordable option, but it’s definitely worth it.
We use this technology in our Ducati pie cut exhausts because it allows us to create any kind of bends and achieve all kinds of angles and complex curves. This is essential for manufacturing something unusual and extraordinary. And the result is very precise as well. Using pie cutting, we get no shrinkage as you may with other methods. That means if our tube diameter is 7 cm it’s gonna be 7 cm all the way through. It’s strong and durable. And, well, it looks good.
You surely can use other methods like crush bending or mandrel bending, for instance. The method that you’ll choose mostly depends on what you expect to get as your final product and the money you are ready to spend.
Crush bending is the cheapest and the simplest way to bend a tube. You fix a tube in place and add pressure to each end. In case you need an additional bend just reposition the tube and repeat the whole process. This is quick and easy, but it has some flaws. Due to the pressure the tube is losing shape and it can get wrinkles which will cause hot spots. This can affect performance. There might be occasions when you can use this method, of course, but this is not our case.
Another commonly used way of bending tubes is mandrel bending. But it requires a special toolset. A mandrel is placed inside the tube to prevent it from deformation, formation of wrinkles or flattening. After that you add pressure to rotate the tube around a bend die. This method is apparently much more effective than the crush bending and still can be cheaper than the pie cut. You can bend the tubes in different directions and most of the time this might be a perfect fit for your work unless you need a complex shape with different angles and curves.
To get a complex curve you might need to cut the bend. And that’s where the shoe pinches. If the tube wasn’t bent properly, which is a common issue, you might find that the bend ovals out to a point where the more you slice it the harder it is to get a proper fit-up to weld. There might be significant gaps which you will have to scrape and clean to make a perfect fit and still you’ll most probably have hard times calculating the angles and bringing it all together. It’s harder to control.
Though pie cutting might be a bit more expensive and requires much more welding it gives you freedom to move, rotate and create what you want. So how does this work? To make a pie cut exhaust you take a straight tube, cut it in pie-shaped sections and then weld them to get the required design. It’s usually a 9 or an 18-degree piece. To achieve this pie-shape you cut the sections at 4.5 or 9 degrees from each side of the pie center, according to the chosen pie size. But this is not a must. The degrees can vary depending on what you need. We use 15-degree pieces, which means we cut them at 7.5 degrees from the center. You have to mark the exact half of the tube prior to cutting it so it can later be aligned with other pieces to get a perfect bend. The pies are linked together using TIG welding.
TIG welding is one of the most common arc welding processes. A tungsten electrode is used here. It has an extremely high melting point and is considered not consumable which means it doesn’t melt to become a part of the weld. Argon or helium gas is used as well. It protects the weld from oxygen and water contamination which can cause lower quality of the welds. TIG welding produces strong, high-quality welds that can be done with or without the use of filler materials. We don’t use any filler materials in our Ducati pie cut exhausts..
This is why we use it!
Before we start to make the actual exhaust, we need to have some kind of a design in mind, but the final product is a pure inspiration. Pie cutting gives a lot of freedom for that and helps getting creative solutions. This technology allows us to build lighter and stronger exhausts which beside this all, let us admit, look quite cool and stylish.
If you’re still not sure you can check our Ducati pie cut exhausts below. Tell us this is not what you’re looking for!