Wrapping things is mainly done when you want to give someone a gift so it’s not obvious what they’re getting. Well, while wrapping exhaust components is also a thing, it is not done to surprise someone. In fact, it’s quite the opposite. What is used to wrap a header may look much out of a star wars movie but it does a simple, yet important task.
Also known as header wrap, exhaust wraps are usually a piece of fibreglass that helps reduce heat and thus extend the lifespan of the component it’s used on. An exhaust header wrap can also extend the lifespan of components surrounding the part that is being wrapped. Since heat doesn’t radiate onto nearby parts, they are not affected by it. As there are multiple reasons to invest in a performance exhaust, there are also reasons to invest in an exhaust header wrap. But how effective can this simple solution be?
How Much Heat Does Exhaust Wrap Reduce?
While various factors affect how well an exhaust header wrap will reduce heat, one thing is for sure – in the majority of cases when using a proper exhaust wrap you’re able to reduce temperatures down by as much as 50%. As a result, exhaust gasses flow through the exhaust system more easily which makes your vehicle run more efficiently.
How to Heat Wrap Exhaust
What You’ll Need
While there isn’t a lot of gear or equipment for this task, it’s important to have gloves, safety glasses, and a dust mask. You also need a lot of patience to wrap your exhaust header as you need to go slow and give your best with each wrap around the header. Before you start wrapping though, make sure to soak your wrap in a bucket of water.
1. The first wrap around the pipe needs to be done flush with the flange. Then, you need to wrap around 3 more times at an angle. This initial wrap-around needs to be secured with a stainless steel tie clamp or a hose clamp.
2. Once you’ve secured the initial wrap continue wrapping around with each pass overlapping the previews one by about 5mm. You’ll want to keep tension on the wrap and tighten the wrap with your hands every two to three passes so it stays tight.
3. If you encounter pipes that are close together and are too close together to wrap them separately you’ll need to wrap them as one. Do the same 5mm overlapping technique and proceed with wrapping until you reach the end.
4. At the end of the exhaust system or component, do the same thing you did with the initial wrap. Except here you will fold over about 1.9cm of the wrap and then tuck it under itself. Secure the last coil of wrap using a hose-clamp, a regular or a thermal wire.
Heat Wrap Solutions
When it comes to wraps that act as insulators you are getting a product that retains heat in whatever they are placed on. This can seem like a bad idea, but it is not, since it prevents the heat from a certain component having a negative effect on other parts. With an insulator, you can prevent temperatures as high as 530°C from affecting other components. Fibreglass wraps are the most common ones used as they can withstand extremely high temperatures.
Fibreglass insulator wraps can come with graphite or vermiculite coating which increases its temperature resistance up to around 640°C. If a fibreglass wrap comes with a 1090°C rating it means it can only withstand this level of heat for a short period of time. When exposed to these temperatures for an extended period, fibreglass melts. This is why you’ll see that fibreglass comes with different types of coatings on it.
Barriers, on the other hand, act as a preventative solution since they prevent heat from affecting a certain component. Rather than retaining heat, a wrap barrier keeps it out of the way of a component. This can be beneficial when you don’t necessarily want to increase performance but want to prolong the life expectancy of a certain component. An exhaust wrap barrier is typically placed 2.5cm away from the heat source, with the most common barrier being made from aluminium in combination with silica, fibreglass, and ceramic insulation.
Barrier wraps can withstand temperatures of somewhere up to 1090°C. This is their known limit, with more common barriers being able to withstand temperatures of up to 640°C and others that can withstand temperatures up to just 260°C. Yes, engine bay temperatures can go really high up and a wrap with a high-temperature rating is going to be a better solution. But if your vehicle has an extremely high engine bay temperature there might be something else that’s gone wrong and a wrap might do more harm than good.