Hardness of Discs

Discussion in 'PSI Superchargers Tech Questions' started by Dragster503, Oct 20, 2004.

  1. Dragster503

    Dragster503 Dragster

    Joined:
    May 22, 2004
    Messages:
    71
    Likes Received:
    0
    Since disc manufacturers will send you all different discs unless you specify. Is there a preffered Rockwell hardness to run?
     
    #1
    Dragster503, Oct 20, 2004
  2. aj481x

    aj481x Member

    Joined:
    Jan 27, 2004
    Messages:
    976
    Likes Received:
    18
    We like 45-50, but hardness is just another tuning tool.
     
    #2
    aj481x, Oct 20, 2004
  3. alkyholic

    alkyholic Jr. Dragster

    Joined:
    Dec 30, 2003
    Messages:
    107
    Likes Received:
    0
    I run a Hays and use 80/90
     
    #3
    alkyholic, Oct 21, 2004
  4. Mike Canter

    Mike Canter Top Dragster
    Staff Member

    Joined:
    Mar 10, 2004
    Messages:
    4,630
    Likes Received:
    189
    OK, so I understand the effect of the 5135 and 5191 compounds and their Coeficient of Friction factor and their aggressiveness when heated BUT how does the Rockwell hardness come into play in a clutch tuneup. I always specifie 50 when I order the disks to keep everything the same but what would happen if I used 40 or used 80? Would I need to change the base on the weights? What if I mixed disks and had some at 40 some at 50 and some at 70?
     
    #4
    Mike Canter, Oct 21, 2004
  5. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
    Staff Member

    Joined:
    May 6, 2003
    Messages:
    6,706
    Likes Received:
    132
    We dont usually rockwell our discs (we just order them from tom..lol). But from our experience as the disc gets thinner it gets harder. We always ground the same discs from the run and put them back in, and when we do have to add a new disc, it usually is the equivalent of 2-3 grams. thats just our car.

    but using that 'barnyard logic' as uncle bob would call it, to a degree, a softer disc seems to bite harder. i'm sure there is 1000 exceptions to this rule, but in our car, that was the case.

    in no way was the above comments meant to be tuning advice or misconstrued as such. the above comments are not necessarily the views of jason cannon racing or insidetopalcohol.com or bonifante clutch discs, but merely observations. all rights reserved, copyright 2004 InsideTopAlcohol.com. The above statements cannot be reproduced without expressed written consent of the office of the Commissioner of Major League Baseball.......
     
    #5
    Will Hanna, Oct 21, 2004
  6. Randy G.

    Randy G. Top Alcohol

    Joined:
    Jun 9, 2003
    Messages:
    1,902
    Likes Received:
    36
    Most of us use a Rockwell tester. I use an Ames model 2 handheld which is recommended by Crower and they cost about $2,000.00 with a 1/2 ball penetrator and anvil (and comes in a nice case). A must for the serious tuner. I have an extra one that's like new that I'd sell for $1,200.00 if anyone is interested.

    Will:

    Don't you think the discs get harder because each run heats them up red hot and then they cool which effects the molecular structure, not because they are getting thinner? I thought you did.

    RG
     
    #6
    Randy G., Oct 21, 2004
  7. Harry Rydbom

    Harry Rydbom Member

    Joined:
    Dec 12, 2003
    Messages:
    129
    Likes Received:
    0
    It get harder because it get closer to the steel center,40 to 55 work the best. ;) ;) ;)
     
    #7
    Harry Rydbom, Oct 21, 2004
  8. Tad117

    Tad117 Member

    Joined:
    Jul 28, 2003
    Messages:
    64
    Likes Received:
    0
    I would have to agree with randy that a rockwell tester is a very important tool to have in the trailer. I did not notice that much of a change in the hardness as they got thinner at the very most all I saw was a change of about ten. As for what works best I would start in the middle and then do some experimenting and see what happens. But let me throw another wrench in the works is also take note at the code stamped on the discs as well because that shows you when the discs were made which also affects how they work because they are not bonded at the same temperature and atmospheric conditions in july as they are in novemeber. Lots of luck and dont be afraid to try mixing and matching from one extreme to the other and seeing how it affects the car you will be surprised at what might work bet for you
     
    #8
    Tad117, Oct 21, 2004
  9. T.Smith

    T.Smith Top Dragster

    Joined:
    May 22, 2003
    Messages:
    167
    Likes Received:
    0
    ALWAYS check your rockwells on the disc you purchase. Your readings could be different from what they got.

    Try to purchase 9-15 disc out of the same batch.

    Try to run the same disc in the same slot until it can no longer be used.

    It may not hurt to rockwell them floaters too.

    [ October 24, 2004, 03:47 PM: Message edited by: T.Smith ]
     
    #9
    T.Smith, Oct 24, 2004

Share This Page





XenPorta 2 PRO © Jason Axelrod from 8WAYRUN.COM