Thread: What is the diameter?

Results 1 to 11 of 11

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1 What is the diameter? 
    GXP Level Member
    Join Date
    Mar 2015
    Location
    Tomball
    Posts
    2,633
    Thanks (Received)
    0
    Likes (Received)
    3
    Dislikes (Received)
    0
    What is the supercharger crank pulley that drives the supercharger. Looking for the closest to the exact diameter to do some calculations.

    Thanks,

    Jeff
    Reply With Quote  
     

  2. #2 Re: What is the diameter? 
    Turbo is the way to go. Fivefingerdeathpunch's Avatar
    Join Date
    Sep 2009
    Location
    Rogers, MN
    Posts
    21,022
    Thanks (Received)
    21
    Likes (Received)
    45
    Dislikes (Received)
    0
    The pulley on the supercharger shaft is the same size as the motor, best way to remember.

    So 3.8 inches. If stock motor.

    SMGPFC Member #1
    Reply With Quote  
     

  3. #3 Re: What is the diameter? 
    GXP Level Member
    Join Date
    Mar 2015
    Location
    Tomball
    Posts
    2,633
    Thanks (Received)
    0
    Likes (Received)
    3
    Dislikes (Received)
    0
    Crankshaft pulley diameter.

    Jeff
    Reply With Quote  
     

  4. #4 Re: What is the diameter? 
    GTP Level Member wowitsfast's Avatar
    Join Date
    Oct 2014
    Location
    portland oregon
    Posts
    955
    Thanks (Received)
    6
    Likes (Received)
    34
    Dislikes (Received)
    0
    the balancer?
    Reply With Quote  
     

  5. #5 Re: What is the diameter? 
    Turbo is the way to go. Fivefingerdeathpunch's Avatar
    Join Date
    Sep 2009
    Location
    Rogers, MN
    Posts
    21,022
    Thanks (Received)
    21
    Likes (Received)
    45
    Dislikes (Received)
    0
    I found somewhere that says 7-5/32nd.

    SMGPFC Member #1
    Reply With Quote  
     

  6. #6 Re: What is the diameter? 
    GXP Level Member
    Join Date
    Mar 2015
    Location
    Tomball
    Posts
    2,633
    Thanks (Received)
    0
    Likes (Received)
    3
    Dislikes (Received)
    0
    The diameter of the dampener where it drives the supercharger. I want to know the drive ratio.

    Thanks Fivefingerdeathpunch, I'll use that for now.

    Jeff
    Reply With Quote  
     

  7. #7 Re: What is the diameter? 
    GXP Level Member
    Join Date
    Mar 2015
    Location
    Tomball
    Posts
    2,633
    Thanks (Received)
    0
    Likes (Received)
    3
    Dislikes (Received)
    0
    I'm not sure that's right according to my calculations the boost would be too low.
    Reply With Quote  
     

  8. #8 Re: What is the diameter? 
    Turbo is the way to go. Fivefingerdeathpunch's Avatar
    Join Date
    Sep 2009
    Location
    Rogers, MN
    Posts
    21,022
    Thanks (Received)
    21
    Likes (Received)
    45
    Dislikes (Received)
    0
    Then look up any parts store that sell them. They should all provide details on the product.

    Length and width are given.

    SMGPFC Member #1
    Reply With Quote  
     

  9. #9 Re: What is the diameter? 
    GXP Level Member
    Join Date
    Mar 2015
    Location
    Tomball
    Posts
    2,633
    Thanks (Received)
    0
    Likes (Received)
    3
    Dislikes (Received)
    0
    I tried that couldn't find a listing for the supercharged unit. I removed my belt and measured the circumference and came up with 22.75" so right at 7.25" diameter, just about what you said.


    Here re are the numbers I came up with for blower drive ratio based on the previous to Gen V blower.

    3.8" pulley DR 1.908:1= 7.49 psi
    3.6" pulley DR 2.014:1= 8.72 psi
    3.4" pulley DR 2.133:1= 9.88 psi

    does this sound about right?

    Jeff
    Reply With Quote  
     

  10. #10 Re: What is the diameter? 
    Turbo is the way to go. Fivefingerdeathpunch's Avatar
    Join Date
    Sep 2009
    Location
    Rogers, MN
    Posts
    21,022
    Thanks (Received)
    21
    Likes (Received)
    45
    Dislikes (Received)
    0
    The way I see it, there are too many variables.

    Ambient temps, heat from the supercharger, exhaust flow and intake air flow are just some.

    Just the stock numbers seem to be right in the ball park, they normally make right around 7-8ish psi with stock everything.

    I wouldnt doubt that if someone tossed a 3.4 on a gen v blower with stock everything else it would make nearly 11-12 psi of boost, enough to kill that motor quickly.

    SMGPFC Member #1
    Reply With Quote  
     

  11. #11 Re: What is the diameter? 
    GXP Level Member
    Join Date
    Mar 2015
    Location
    Tomball
    Posts
    2,633
    Thanks (Received)
    0
    Likes (Received)
    3
    Dislikes (Received)
    0
    Well there aren't really that many variables, and all of them combined will only account for a +/- .5 psi difference based on experience with other supercharged cars using the M90 and M112. These readings are typical of a car with stock type cam moderate exhaust and free flowing intake. Ported heads, headers and cams with lower than 112* LSA tend to have lower boost pressures, since boost is really nothing more than the inabality to pass the air from the supercharger through the engine.

    one of the parameters I use in the calculation is barometric pressure and that makes the highest difference. I just wanted to see ihow well the formula I used works for the 3.8l SC'd engine too.



    Jeff
    Reply With Quote  
     

Similar Threads

  1. Down pipe diameter
    By traildog in forum General Tech Discussion
    Replies: 11
    Last Post: 02-05-2014, 06:25 PM
  2. Diameter of the fog lights?
    By bradical in forum General Tech Discussion
    Replies: 4
    Last Post: 12-15-2012, 06:53 AM
  3. Tire Diameter
    By gpgt04 in forum Tires & Wheels
    Replies: 4
    Last Post: 10-01-2009, 08:41 PM
  4. 4" outside diameter
    By GP2003GT in forum 3.8L V6 Naturally Aspirated (L36)(L26)
    Replies: 7
    Last Post: 06-28-2008, 03:38 PM
  5. Radiator Hose Diameter
    By 03GPScottyd in forum General Tech Discussion
    Replies: 4
    Last Post: 05-20-2008, 03:01 PM
Bookmarks
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
  •