This procedure was performed on a MY04 STi with some modifications which may or may not be relevant for the purposes of this How-To. This procedure is only ONE way of removing the transmission and is not meant to be the be-all method. This is a DIY on your driveway process only. If you have access to a lift, this would be the preferred and safest method.
Perform this procedure AT YOUR OWN RISK.
This procedure allows you to remove the transmission from a Subaru STI for the purpose of gaining access to the clutch and flywheel system for inspection and or replacement.
This procedure allows you to remove the transmission without the benefit of a lift and is meant as a DIY for the weekend warrior. This is by no means a simple or easy procedure and it requires a good deal of strength. IT IS RECOMMENDED YOU HAVE A FRIEND THERE TO HELP. You will need a second pair of hands at times.
How does a lightweight flywheel improve performance? A transmission can be thought of as a fulcrum and lever in a car. First gear has a really long lever; second gear has a shorter lever, etc. The lever represents the mechanical advantage that gears give your vehicle. When your car is moving, you have two factors that are present during acceleration, one is driveline losses, which are constant and the variable, which is vehicle weight and the mechanical advantage supplied by each gear.
While changing to a lighter flywheel will give the user little to no changes on a dyno, the apparent changes are quite dramatic due to the greater mechanical advantage. Consider these made up figures for consideration: Drive line losses, 45 pounds and vehicle mass (weight) at the driveline (remember your gear’s mechanical advantage reduces your actual car weight). We know that within reason, vehicle mass is a constant.
Now imagine if you reduced the driveline loss from 45 to 35 with the use of a lightweight flywheel. Since the engine has less drivetrain losses to compensate for, this means the “gained” horsepower can be applied to moving the vehicle mass. Using mathematics, one can realize that the higher you go up in gears, the less effect that a lightened flywheel will have to the overall equation.
Are there any downsides to a lightweight flywheel? While the performance characteristics of a lightweight flywheel seem to be the perfect solution, there are compromises:
a. Low end performance is affected. This usually means that higher revs are necessary for smooth starts due to the reduced rotational mass. For drag racers, this can be a BIG issue.
b. Possible missfire check engine light.
c. Possible chatter, like missfire this affects some users and not others.
We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. By clicking “Accept”, you consent to the use of ALL the cookies.
This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. We also use third-party cookies that help us analyze and understand how you use this website. These cookies will be stored in your browser only with your consent. You also have the option to opt-out of these cookies. But opting out of some of these cookies may affect your browsing experience.
Necessary cookies are absolutely essential for the website to function properly. These cookies ensure basic functionalities and security features of the website, anonymously.
Cookie
Duration
Description
cookielawinfo-checkbox-analytics
11 months
This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Analytics".
cookielawinfo-checkbox-functional
11 months
The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional".
cookielawinfo-checkbox-necessary
11 months
This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
cookielawinfo-checkbox-others
11 months
This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other.
cookielawinfo-checkbox-performance
11 months
This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Performance".
viewed_cookie_policy
11 months
The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. It does not store any personal data.
Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features.
Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors.
Analytical cookies are used to understand how visitors interact with the website. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc.
Advertisement cookies are used to provide visitors with relevant ads and marketing campaigns. These cookies track visitors across websites and collect information to provide customized ads.