Jump to content
SAU Community
  • Welcome to SAU Community

    Welcome to SAU Community, like most online communities you must register to view or post in our community, but don't worry this is a simple free process that requires minimal information for you to signup. Be apart of SAU Community by signing in or creating an account.

    • Start new topics and reply to others
    • Subscribe to topics and forums to get email updates
    • Get your own profile page, build reputation and make new friends
    • Send personal messages to other members.
    • See fewer ads!

    Consider joining our newsletter for the latest content updates

    Click here to register


Piggaz

Borg Warner EFR Series Turbo's V 2.0

Recommended Posts

Posted (edited)

you're overthinking it and your gut feel is way off. Its primarily an oil drainage concern. 

the axial thrust forces on a compressor/turbine assembly are huge when operating at high mass flows. force on the thrust surfaces due to gravity will be orders of magnitude less. the compressor its trying to suck itself out the front of the turbo and the turbine is trying to blow itself out the exhaust. yes, these forces are in opposite directions but do not cancel completely which is why journal bearing turbos require a thrust bearing as they have no inherent axial stability otherwise.

from your chart the most appropriate bearing for a CHRA would either be a pair of identical 7s or a pair of 6s in a mirrored arrangement.

main concern is oil drainage and oil pooling at the back of the CHRA if the angle is excessive, for the same reason a maximum of 20degrees of rotation about the shaft axis is recommended.

remember, accelerating and braking the car at ~1g is going to impart more force on the rotating assembly than inclining it by even 45 degrees, let alone 10 or 20.

 

 

this is a question that should be directed at BW.

Edited by burn4005
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now




×
×
  • Create New...