Performance Benefits of Phenolic Intake Gaskets
Many people look to gain extra performance out of their cars with bolt-on modifications like aftermarket cold air intakes and larger intercoolers, but one simple modification with a similar boost in performance is often overlooked. Upgrading to a phenolic intake gasket on your car can significantly improve performance.
The performance gains provided by phenolic intake gaskets is a result of colder intake air. Just like a cold air intake, the gasket helps keep the air flowing into your engine cooler. Colder air is more dense and packs more oxygen molecules. This ultimately allows your car to combust a larger mixture of air and fuel, increasing the mass flow rate of an engine. Consequently, modifications such as cold air intakes and phenolic intake gaskets allow your car to make more power.
This colder air can also add a factor of safety to modified engines by decreasing the risk of predetonation. Higher air inlet temperatures are particularly of concern in forced induction applications because off the additional heat created during the compression of a fluid. However, phenolic intake gaskets benefit both naturally aspirated and turbocharged/supercharged engines.
Intake Gasket Location
What Is a Phenolic Intake Gasket?
Your intake gasket sits between your air intake manifold and the engine block. Think of the intake gasket as a seal between these two components, keeping precious intake air from leaking out.
A phenolic intake gasket is different from your typical rubber composite gasket in that it is made of a phenolic material. They are made of a plastic created by layers of material laminated with a phenol/aldehyde resin. The result is a thermally insulating intake gasket just as durable as the OEM gasket. This thermal insulation is the property of these gaskets that allows your engine to make more power.
Expected Power Gain
The rule of thumb for most hobby mechanics is that a 10 degree decrease in air inlet temperature results in a 1% increase in horsepower. As you can imagine, this is by no means a very accurate way of predicting horsepower gains, but it does show that the gains produced by colder intake air is significant. Power increases from switching to a phenolic intake gasket are going to vary between make and model, but most people can expect a gain between 5 and 10 horsepower. An interesting article from AutoSpeed investigated the real performance gains from phenolic manifold insulation on a Mazda K series V6 engine. During the article, a phenolic intake gasket was created and installed on the author's vehicle. He then ran various tests to verify the performance gains of the modification. As seen in the graph below, while operating his car continuously at around 60mph, the vehicle saw a 30 degree F drop. After other various tests the author wrote, "According to my dyno plots, I gained up to 7 horsepower and 11 ft-lbs of torque over the major portion of the power curve."
How to Install
Installing intake gaskets is a fairly straightforward job for the weekend mechanic and typically only takes a couple hours. There are plenty of articles discussing how to install intake gaskets and general tips for the job on the web, but each vehicle is going to be a bit different. If you really have any questions about installation try contacting the manufacturer.
Where to Find Phenolic Intake Gaskets
A few different companies produce phenolic intake gaskets. Gizzmo is a well-known manufacturer of these intakes for Japanese imports: Honda, Nissan, Mazda, Mitsubishi, and Toyota. Being acquainted with the distributor for Gizzmo products in the USA, I might be biased here, but the performance and quality of Gizzmo’s products seems to be top notch. Other manufacturers of phenolic intake gaskets include BBK Performance and Grimmspeed but I personally have no experience with these companies.