Cars produce an immense amount of heat. Temperatures in the combustion chamber can reach well over 2000 degrees Celsius. And adjacent parts like turbines and exhaust manifolds deal with 700+ degrees when you’re working the gas pedal. This is efficiently managed by an extensive cooling system before the engine self-ignites. What is more worrying is the low level of heat protection in auxiliary engine components, electronic parts and wiring and the exhaust tubing. 
Exhaust pipes and parts can easily see 300 degrees, with catalytic converters close to 650. This produces radiant heat in the underbody and nearby parts, with temperatures potentially soaring in the cabin.

The excessive heat can warp, rupture or damage the exhaust piping, wreak havoc on sensors, and burn wire insulation. To deal with a domino effect of issues, exhaust pipe insulations contains the heat of exhaust gases before they can do considerable damage. There are varying products in this respect, but all have the same purpose – to contain heat within the exhaust and prevent it from spreading to other car parts. 

Why the Need For Exhaust Heat Shields?

Heat shield products like exhaust wrap, aluminium sheeting and adhesive tapes can all be used to reduce the effect of too much heat in the exhaust piping. Excessive heat can damage or even melt metal, crack paintwork, confuse sensors and easily cause cracks and fraying in wiring, leading to electrical issues. For instance, oxygen sensors lining the exhaust are exceptionally sensitive to abrupt changes in temperatures, and anything over 300 degrees will lead to accelerated wear and tear and the ECU getting inaccurate readings. What follows are off fuelling and timing, meaning higher fuel use, lower performance and potential damage to the engine internals. 
Elevated heat levels can additionally radiate to other others to the same effect. This is more common in modified or rebuilt cars putting out more power than rated stock numbers. Besides protecting your vehicle, heat shields can also:

• Increase power and torque – used on piping and parts like converters, heat shields help with exhaust scavenging and velocity, sending gases out faster. This has two benefits. It shields sensitive parts and sections with thinner walls and helps the engine breathe by enabling the next combustion cycle. Gases going out faster result in a power and torque increase, with lower heat stress reducing the risk of internal engine damage. 
• Lower fuel consumption – higher combustion efficiency leads to lower fuel use. Wraps, sheets and tapes lower temperatures in the exhaust, and indirectly help air intakes and combustion chambers draw cooler, oxygen-rich air. Engines can produce the same or more power with less fuel. 
• Reduce excessive exhaust noise – when correctly applied, heat shields reduce vibrations and resulting noise. They prevent droning exhausts from ruining driving pleasure or causing discomfort. Combine heat shields with bespoke sound-deadening products for a whisper-quiet cabin, lower temperatures and elevated protection from liquids and chemicals,

Exhaust Heat Shield Products 

Wrap, sheets and tapes are the three form factors that exhaust pipe insulation comes in.  Wraps are the traditional choice. They are easy to install, contain heat at the source, and with different finishes can add more style, such as exposed piping in motorcycles. 
There are several exhaust wraps to choose from, each with varying levels of heat protection. The cheapest is fibreglass wrap, with operating temperatures of up to 500 degrees, suitable for unmodified engines. The wrap benefits from the integrated coating to seal the piping and prevent leaks. 

Next up is a wrap produced from basalt rock fibres, able to deal with temperatures exceeding 700 degrees. This is also non-toxic, recyclable and available in subdued colours to hide stained or discoloured piping. For the best performance, look to titanium exhaust wrap. This can be applied to manifolds and headers where temperatures are the highest. The product can effectively contain heat nearing 1250 degrees, is pliable (so doesn’t require wetting like fibreglass variants) and is simple to install. Regardless of which type you choose, ensure you get enough wrapping to cover the intended portion of the exhaust. Spool lengths come in at 10 or 20 metres, and enough to entirely all piping from the headers to tips in most exhausts. 

Sheets 

While exhaust wrap is applied in overlapping layers, exhaust heat shield sheets are designed to be added to heat sources and prevent radiant heat from reaching other vehicle areas. The 3mm aluminium sheet has high conductivity and low emissivity rates. Sheets need to be pre-formed and cut, then applied at a recommended distance of 10mm from the source. Typical uses are around catalytic converters and mufflers. Installation is relatively simple. Sheets come in different sizes (300 by 500mm, and 500 by 700mm), can be cut with simple tin snips, and have included mounting hardware. 

Adhesive Tapes 

Pressure-sensitive adhesive tape foils, or peel-and-stick shields are another alternative to containing heat in the exhaust system. They perform better at shielding adjacent parts to the piping from radiant heat, with efficiency reaching 250 degrees. Foils have a fibreglass core, and an aluminium outer, are easy to shape and simple to apply. The material moulds to the contours of the vehicle part, and the strong adhesive stays on once applied. A benefit over thicker sheeting is less risk of rattling and noise. Foils and tapes can also replace sheets in low-heat environments. especially around headers, and other heat sources in the vehicle – including airboxes, firewalls, floor pans and the transmission. This heat solution is offered in varying thicknesses, with thicker 0.25mm variants preferred for their puncture resistance.