The cooling system of your car is one of the most important parts; without one, your engine would be useless in minutes. Many people change their caps for aesthetic reasons alone, and while we like things to look good, there has to be a more important reason. What does the radiator cap do? Besides the most apparent reason, allowing you to fill your radiator, the radiator cap is an essential part of the system. As the coolant gets hot, it expands creating pressure inside of the system, and when it reaches a certain point, this pressure is then released through the radiator cap plunger into an overflow tank. Once the pressure drops below the desired level, the plunger inside the cap closes.
So why should you upgrade your radiator cap? Increased pressure in your cooling system can increase the boiling temperature. By upgrading to a stronger cap, you can effectively raise the boiling temperature of your system, reducing the risk of having your coolant turn into steam which then will cause cavitation. Cavitation, or air pockets, will prevent the coolant from actually cooling the engine which can result in extreme wear and damage vital engine parts. The OEM cap is rated at 1.1 bar and the Hybrid Racing cap is rated at 1.3 bar!
Type-F Caps typically fit most aftermarket radiators, while Type-D caps are most commonly used on OEM Honda radiators. This, however, depends on the year/make/model as the newer Honda Civic Type-R (FK8 use the Type-F cap on its expansion tank.)
Fitment:
Type D works with the following chassis- 2007-2008 Honda Fit
- 2000-2009 Honda S2000
- 1992-2015 Honda Civic
- 1990-1994 Honda Accord
- 2003-2008 Honda Element
- 1993-1997 Honda Civic del Sol
- 2002-2006 Acura RSX
- 2004-2008 Acura TSX
- 1994-2001 Acura Integra
- 2022+ Honda Civic Si/Sport/EX
- 2023+ Acura Integra Base/ASpec
- 1988-1991 Honda Civic
- 1992-2001 Honda Prelude
- 1988-1991 Honda CRX
- 1990-1993 Acura Integra
- 2016-2021 Honda Civic
- 2023+ Honda Civic Type R
- 2024+ Acura Integra Type S
Detailed Fitment:
- Integra 1990-1993
- Integra 1994-2001
- Integra Base 2023-2024
- Type S 2024+
- Integra Type S DE5
- ILX 2013-2015
- RSX 2002-2006
- RSX Type S 2002-2006
- TL 2004-2008
- TSX 2004-2008
- TSX 2009-2014
- Accord 1990-1993
- Accord 1994-1997
- Accord 1998-2002
- Civic 1988-1991
- Civic Hatchback 1988-1991
- Civic 1992-1995
- Civic 1996-2000
- Civic SI 1999-2000
- Civic 2001-2005
- Civic Si 2002-2005
- Civic 2006-2011
- Civic Si 2006-2011
- Civic 2012-2015
- Civic Si 2012-2015
- Civic 2016-2020
- Type R 2017-2021
- Civic Si 2017-2021
- Civic 2022+
- Civic Si 2022+
- Civic Type R FL5
- Del Sol 1993-1997
- CR-V 1997-2001
- CR-V 2002-2006
- CRX 1988-1991
- CRZ 2011-2016
- Fit 2007-2008
- Fit 2009-2014
- Fit 2015-2020
- Prelude 1992-1996
- Prelude 1997-2001
- S2000 2000-2005
- S2000 2006-2009