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Thread: OK, so no 4.33' s How about a regular limited slip I can modify?

  1. #1
    Join Date
    Dec 2004
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    122

    Default OK, so no 4.33' s How about a regular limited slip I can modify?

    I can probably get by with the factory limited slip. Any extras out there?

    Steve

  2. #2
    Join Date
    Feb 2004
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    cfr
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    Default

    Steve,
    As you have probably figured out, the 4.33's are pretty rare. If you are looking for a plate type limited slip to use for competition, look for one from an 86-88 GXL. IIRC, they all had ltd slip diff's. The gearing won't be optimal, but neither is the 4.33.

    If you haven't already, check www.rx7club.com. The classifieds there are pretty extensive.
    Jim Cohen
    ITS 66
    CFR

  3. #3
    Join Date
    Jan 2001
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    Default

    The closest you might come to a cheap, available unit might be a 4.10 from an automatic. The next best thing would be a 4.30 from a GTUs. More rare, and more expensive. The manual trans cars came with a 3.90 almost exclusively, I think.
    Chris Wire
    Team Wire Racing ITS #35

    www.themotorsportshour.com
    "Road Racing on the Radio"
    WPRK 91.5 FM
    wprkdj.org

    "Tolerance is the last virtue of a degenerating society" - Unknown


  4. #4
    Join Date
    Jan 2001
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    Floyds Knobs, IN
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    Default

    Quote Originally Posted by Chris Wire View Post
    The closest you might come to a cheap, available unit might be a 4.10 from an automatic. The next best thing would be a 4.30 from a GTUs. More rare, and more expensive. The manual trans cars came with a 3.90 almost exclusively, I think.
    You got that backward Chris. The autos came with the 3.90s. The manuals the 4.10s.
    Chris Ludwig
    GL Lakes Div
    www.ludwigmotorsports.com

  5. #5
    Join Date
    Dec 2004
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    122

    Default Thanks guys, just so you know I'm not nuts,

    I've converted to EP and I'm using a dog ring box with a 1:1 final drive. My 5.12 will not cut it for the longer tracks like Road America. I ended up getting the 4.33 ring and pinion from Mazdaspeed and am calling Mazdatrix for a Kaaz 1.5. I'll use my parts car for the housing.

    Take care and thanks for your help.

    Steve Smyczek

  6. #6
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    Jan 2001
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    Central Florida
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    Quote Originally Posted by C. Ludwig View Post
    You got that backward Chris. The autos came with the 3.90s. The manuals the 4.10s.
    Cool, then I've got two 4.10s sitting in my garage! I wonder if anyone has had any success running the S4-S5 as a 4-speed using a 4.10?
    Chris Wire
    Team Wire Racing ITS #35

    www.themotorsportshour.com
    "Road Racing on the Radio"
    WPRK 91.5 FM
    wprkdj.org

    "Tolerance is the last virtue of a degenerating society" - Unknown


  7. #7
    Join Date
    Dec 2006
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    Dallas, TX
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    564

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    Quote Originally Posted by Chris Wire View Post
    Cool, then I've got two 4.10s sitting in my garage! I wonder if anyone has had any success running the S4-S5 as a 4-speed using a 4.10?
    It will work but not nearly as good as a 5.12. I had a 4.10 LSD before going to 5.12. The difference was night and day, it was the best money I've spent.
    Mark B. - Dallas, TX
    #76 RX-7 2nd Gen
    SCCA EP
    Former ITS, ITE, NASA PT

  8. #8
    Join Date
    Oct 2002
    Location
    Wandering the USA
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    1,341

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    Quote Originally Posted by Chris Wire View Post
    Cool, then I've got two 4.10s sitting in my garage! I wonder if anyone has had any success running the S4-S5 as a 4-speed using a 4.10?
    No performance numbers, since my car went through some other significant mods at the same time as the 4.10 -> 5.12 change. However, it changes your 2-3-4 shifts into 3-4-5 shifts. You need the close ratio transmission with the 5.12. I haven't done the math to decide if 2-3-4 with the 4.10 is better/worse than 3-4-5 with the 5.12. Might be track-dependent. I do know I don't like the shift to/from 5th.
    Marty Doane
    ITS RX-7 #13 (sold)
    2016 Winnebago Journey (home)

  9. #9
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    Dec 2006
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    Dallas, TX
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    Quote Originally Posted by Eagle7 View Post
    I do know I don't like the shift to/from 5th.
    The .756 5th gear is preferred over the standard .697 or .711 - the .756 is only found in the GTUs (not to be confused with the GTU) which are very rare, in most cases you need to get the .756 from Mazdaspeed and have 5th gear replaced when doing the rebuild. Not sure what you have, but this may help the problem.

    Of course there are the Miata tranny gears, but NOT LEGAL for IT.
    Mark B. - Dallas, TX
    #76 RX-7 2nd Gen
    SCCA EP
    Former ITS, ITE, NASA PT

  10. #10
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    May 2001
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    Canal Fulton, OH
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    Default

    Do you still have the 5.13?

    matt

  11. #11
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    Quote Originally Posted by xr4racer View Post
    Do you still have the 5.13?

    matt
    Me? Yes. (in the car, not for sale)
    Marty Doane
    ITS RX-7 #13 (sold)
    2016 Winnebago Journey (home)

  12. #12
    Join Date
    Jan 2001
    Location
    Central Florida
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    Quote Originally Posted by mbuskuhl View Post
    The .756 5th gear is preferred over the standard .697 or .711 - the .756 is only found in the GTUs (not to be confused with the GTU) which are very rare, in most cases you need to get the .756 from Mazdaspeed and have 5th gear replaced when doing the rebuild. Not sure what you have, but this may help the problem.

    Of course there are the Miata tranny gears, but NOT LEGAL for IT.
    I'm already equipped with a 5.12/.756 setup, I was just throwing it out there for discussion. I used to have a gear calculator that would allow the plugging in of ratios and spitting out of speed/rpm tables. Don't remember where I got it though.
    Chris Wire
    Team Wire Racing ITS #35

    www.themotorsportshour.com
    "Road Racing on the Radio"
    WPRK 91.5 FM
    wprkdj.org

    "Tolerance is the last virtue of a degenerating society" - Unknown


  13. #13
    Join Date
    Dec 2006
    Location
    Dallas, TX
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    Quote Originally Posted by Chris Wire View Post
    I used to have a gear calculator that would allow the plugging in of ratios and spitting out of speed/rpm tables. Don't remember where I got it though.
    Lots of really cool and FREE racing calculators here... http://www.wallaceracing.com/Calculators.htm
    Mark B. - Dallas, TX
    #76 RX-7 2nd Gen
    SCCA EP
    Former ITS, ITE, NASA PT

  14. #14
    Join Date
    Jan 2008
    Posts
    115

    Default the best !

    the 5.12 is the best all-around gear for 2nd gen (its) rx-7s. you can find another gear combo for each track , that will help you be quicker . the 5.12 is the best all-around pick!

  15. #15
    Join Date
    May 2001
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    Canal Fulton, OH
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    Default

    Hi Marty, I knew you wouldnot be selling yours, the question was for Steve(newbie)

    matt miller

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