Audizine - An Automotive Enthusiast Community

Results 1 to 4 of 4
  1. #1
    Veteran Member Three Rings fstr n u's Avatar
    Join Date
    Jan 20 2015
    AZ Member #
    310403
    Location
    Canada

    Question about pulley ratios: s/c vs crank

    Guest-only advertisement. Register or Log In now!
    So if i understand this correctly, with a stock s/c and crank pulley our ratio is something like: 2.56
    Installing a 57mm s/c pulley only changes that to: 2.84
    A 179mm crank pulley only changes that to: 2.83

    1. So am i correct in understanding that a 180mm crank pulley would match the s/c pulley for ratio?
    2. What ratio would a 187mm crank pulley change the ratio to (if s/c pulley was left stock)?
    3. When you install a Stage 2 tune, what would happen if you were running a 187mm pulley (as it would offer a more aggressive ratio compared to a 179/180mm pulley)? Would a tune run lean?

    Just trying to understand this better.

    I suspect i may start with a crank pulley and tune and enjoy the car before going dual pulley....

    Ryan
    2019 Audi SQ5 Navarro Blue Technik w Black Optics Pkg - stock for now
    2015 Audi S4 6MT Glacier White w Black Int (IE Stg 2, Merc Hx, CTS Turbo CAI & CTS S/C Pulley) - my DD
    2006 Subaru STI Hawkeye Murdered Out - larger turbo 400hp - son's car
    1998 Chev Camaro 6MT, LS2 Rear mount Turbo (710+rwhp/710+rwtq @ 14# boost wheels) - summer hooligan

    http://www.youtube.com/@musclecarfan1
    https://www.instagram.com/ryan_baliski/
    https://www.tiktok.com/@winewithryan

  2. #2

  3. #3
    Senior Member Three Rings Jk79's Avatar
    Join Date
    Sep 20 2018
    AZ Member #
    427217
    Location
    Chicago

    Quote Originally Posted by theweebabyseamus View Post
    ^ this

    Loe’s post to start that thread does a great job explaining everything and the graphs will show what stock vs SC pulley vs stock vs crank pulley sizes (and any other combination) will do to the ratios, max ranges etc

    I’m in the same boat, trying to better understand all of this to make a wise choice on stage 2. I’m going 187 crank pulley with merc racing HX and updated tune.
    2018 RS5
    2014 S4 - EPL Stage 2+ (SOLD)

  4. #4
    Established Member Two Rings btb.tyler09's Avatar
    Join Date
    Apr 04 2018
    AZ Member #
    416606
    Location
    Michigan

    Quote Originally Posted by fstr n u View Post
    So if i understand this correctly, with a stock s/c and crank pulley our ratio is something like: 2.56
    Installing a 57mm s/c pulley only changes that to: 2.84
    A 179mm crank pulley only changes that to: 2.83

    1. So am i correct in understanding that a 180mm crank pulley would match the s/c pulley for ratio?
    2. What ratio would a 187mm crank pulley change the ratio to (if s/c pulley was left stock)?
    3. When you install a Stage 2 tune, what would happen if you were running a 187mm pulley (as it would offer a more aggressive ratio compared to a 179/180mm pulley)? Would a tune run lean?

    Just trying to understand this better.

    I suspect i may start with a crank pulley and tune and enjoy the car before going dual pulley....

    Ryan
    You would be fine to install a 187 mm crank with a stage 2 tune. It may bleed some boost if the tune doesn't want it. If your ultimate goal is dual pully 187/57, and you want to do the crank pulley first it makes more sense to get the 187 instead of getting a 180 then having to uograde both later.

    But do look at the thread others posted for pulley ratios and more details regarding dual pulley setups.

    Sent from my LM-G710 using Audizine mobile app

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


    © 2001-2025 Audizine, Audizine.com, and Driverzines.com
    Audizine is an independently owned and operated automotive enthusiast community and news website.
    Audi and the Audi logo(s) are copyright/trademark Audi AG. Audizine is not endorsed by or affiliated with Audi AG.