HEAT Management Part 2

Hello again guys. It seems that my previous post had numerous verbal feedbacks and it motivated me to continue blogging this time round; EXHAUST WRAPS.

My last post was about reflecting heat, and this post will be on heat insulation of our EXHAUST SYSTEMS to reduce engine bay temperature and increase exhaust velocity.



WHY do we need or want to insulate heat?
Exhaust wraps, or ceramic coating are used to keep heat in the exhaust pipes. We all know that exhaust gasses would be the hottest "object" in our engine. Exhaust gas is produced from our engines and enters into the exhaust manifold, exhaust pipes and exits from the rear end of a car.

Having said the journey of the exhaust gas as per above, it travels through pipes and heats up the exhaust pipes itself. Heat from the exhaust will escape through both conduction and radiation as air in our engine bay is cooler. I once said in my previous post that heat travels to a cooler place from a hotter place.

As the exhaust pipe gets hot from the gasses, it loses velocity as you need to know that heat travels faster than cold air. What we want to do is to keep the exhaust gasses as hot as possible in the pipes so that it travels out of the car(rear muffler) as fast as possible, reducing pressure and increasing exhaust scavenging at the same period of time.

*Tips : Meaning of exhaust scavenging : gas travels through the 4 runners of the exhaust manifold so fast that it is actually SUCKING AIR/EXHAUST GASSES out of the engine cylinders itself!!

When we insulate heat, keeping the gas in our exhaust pipes, less heat escapes through the pipes itself thus reducing heat in the engine bay and exhaust tunnel(undercarriage). This way, the heat form the exhaust pipes will NOT :

- Heat up or harm any electrical components
- Heat up any rubberized or plastic parts in the engine bay
- Heat up our radiator/aircond condenser
- Helps alot if your air filter is located close to your exhaust manifold

Going back to the velocity subject relating to turbo engines, the faster traveling exhaust gas will aid in faster spool up times, resulting in increased torque of a turbo engine. A turbo blanked for the turbine housing can also be used to keep heat in the turbine housing.




Below, are pictures about four different methods of insulating your exhaust system.

TURBO BLANKET

Comes in various sizes to suit different turbos. The below picture shows one being used on a top mounted turbo. God knows what would have happened to his engine bonnet/hood paintjob or exhaust valve seals if one wasn't use. He may have a couple of power steering fluid or aircond gas hose running nearby too!

Exhaust gases can go up to 1200degrees celcius on a turbo engine and trust me, you can light a cigarette up by putting the un-lit end on the turbine housing.














EXHAUST MANIFOLD HEAT SHIELD

This is an OEM one. Comes on most cars.
Does pretty much of a good job if you ask me.









This is an aftermarket one. Can be done DIY. Talking about this picture, notice how close is the cam angle sensor to the exhaust manifold?

EXHAUST WRAPS
There's a variety of qualities for these wraps. The first picture on your right here you see is a normal fibre wrap. You have to soak these in water prior to wrapping for a tight fit. These don't really last over time. They tear. And hey, broken fiber, if touched, it's gonna be real itchy.

We shall call this the "good" exhaust wrap. The most effective way of insulating exhaust heat from your engine bay.keeping gas in. Some say that you can even touch it with your hand when the engine is running.


“The Good” exhaust wrap is a basic fiberglass exhaust wrap that has an operating temp up to the 1,000 degree F mark at best. It can take some intermittent temps higher than that but how often do exhaust temperatures fluctuate? They get to point and stay there. Wear gloves when wrapping to avoid itchy hands and it helps to wet the exhaust wrap first. Final note: wrapping pipes is a difficult job you do not want to have to re-do it any time soon. Take your time and do it right the first time with the proper exhaust wrap for your application. You can buy these at RM70/roll if I'm not mistaken.

If the exhaust wrap is not one of the brand leaders (DEI, Thermotech, Heat Shield) then the exhaust wrap has probably not been treated to increase the insulating capabilities. You will notice that the big companies do not offer a white exhaust wrap. This is because when the exhaust wrap is treated it turns more tan or brown it can also be died black at this time but the color is typically not as vivid black. The black color can be intensified with the use of the silicone spray coating. This exhaust wrap is good to around 1500 degrees F realistically. This exhaust wrap will work for most applications. It is still a fiberglass based product so wear gloves and wet the exhaust wrap. When the exhaust wrap is dry, saturate it with the silicone coating.

 Titanium Wraps. The best. The bomb.

This Titanium exhaust wrap is awesome. They solved a lot of issue that arise from exhaust wraps with this product. It is not a fiberglass based product but rather made from a pumice. Where fiberglass comes from sand this comes from volcanic rock. The Titanium exhaust wrap is easy to wrap, there is no need to wear gloves and you do not need to seal it with the silicone spray…plus it looks sweet! Like carbon fiber. It will handle 2000 degrees all day long and will remain flexible while maintaining its cool looks. Yes, it costs more but the best stuff always does.

This is a sample pic of the titanium wrap used on an evo engine with long runners. It may or may not be close to the radiator and hood. Looks sweet, aye?

Can also be used at the bottom of your car until the exit of your exhaust system. Comes with proper hose clip and no not need soaking in water to wrap.






I will bring a couple of these in to sell and they should cost in a range of RM200-300 for 2inch x 50feet rolls. Kindly keep in mind that anything below RM200 for this particular product(DEI Titanium wraps) with the same length may or may not be a fake. So, beware :).




Cheers!!