The Science Behind Thermal Gaskets.
For every 3.3 °C rise in intake temperature, air density drops by 1%. The hotter the air entering your engine, the less fuel the computer injects to compensate for reduced oxygen. Thermal Gaskets reduce air intake temperatures by removing the direct contact between the throttle body and intake manifold surfaces where heat soak usually occurs.
The PTFE thermo plastic has unique thermal resistant properties which standard gaskets simply dont have. An intake temperature drop of around 10 degrees C is expected when using these gaskets on a road driven engine, which is good for around 3 percent power increase. Better results can be expected with track driven applications where heat soak is much more noticeable between pit stops.
- Direct replacements for OEM intake manifold and throttle body gaskets.
- Re-useable with no need for additional gaskets or sealant.
- Protects against heat soak and reduces the incoming air temperature before it reaches the cylinder head.
- Reduces heat transfer into the intake manifold
- High Heat deflection
Thermal conductivity is measured in W/(m K) (watts per metre kelvin) in SI units. This is the amount of energy (heat) a material conducts based on its thickness.
Some common materials and their thermal conductivity properties are listed below:
- Aluminium 237 W/(m K)
- Cast Iron 47-80 W/(m K)
- Steel 36-54 W/(m K)
- Teflon (PTFE) 0.25 W/(m K)
- Phenolic (Tufnol) 0.4 W/(m K)
As you can see, Aluminium is extremly conductive so the intake manifold will absorb a lot of heat from the cylinder head. The use of OEM steel gaskets doesn't elimiante the heat transfer.
The difference between Steel & Teflon (PTFE) is quite significant (14300%). That is why our thermal heat shield gaskets do what we say they do.
Some companies offer Phenolic spacers. This material is more commonly known as Tufnol. This material comprises of layers of paper, cotton or glass fibre mixed with resin. Tufnol, as its name states is extremly tough but is also brittle and does not compress so additional gaskets are required each side. Although the Thermal conductivity is close to Teflon (PTFE), it equates to 60% which means the Phenolic spacer has to be much thicker to offer the same efficiency as Teflon (PTFE), normally between 6mm to 8mm thick so longer bolts are also required. The price is also quite a lot more expensive approx. 100% more.