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SI Trans VS. HF

Discussion in 'Civic and CRX - EF' started by Sofast, Sep 19, 2009.

  1. Sofast

    Sofast Member

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    Bought a 90 crx shell with the rest of the body and interior in boxes. I got it all together. Now Im waiting on a clutch to arrive and the motor and trans are going in. Anyhow before I do this I need to know if the HF transmission is a pooch. Will I notice poor performance? If so what are my other options?
     
  2. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    the si is a much shorter geared trans than the hf you will notice a big difference
     
  3. Sofast

    Sofast Member

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    sorry posted in wrong forum
     
  4. Sofast

    Sofast Member

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    Bought a 90 crx] shell with the rest of the body and interior in boxes. I got it all together. Now Im waiting on a clutch to arrive and the motor and trans are going in. Anyhow before I do this I need to know if the HF transmission is a pooch. Will I notice poor performance? If so what are my other options?
     
    Last edited by a moderator: Sep 20, 2009
  5. Jeef

    Jeef NO MA'AM Moderator VIP

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    moved it to the right forum for you
     
  6. INJEN78

    INJEN78 HS LEGEND

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    def. a big differance...almost like driving the slow auto then going to the standard..
     
  7. 4Door89

    4Door89 New Member

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    i drove a customers car yesterday. (SI) mine is a DX, almost felt like it had a diffrent attitude. definatly doing this swap when i have my motor out. i would go SI, better FD.
     
  8. Briansol

    Briansol Admins Admin VIP

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    The gearing on the HF is very long. you will have much less acceleration force with the longer gears.
     
  9. D16SiHatch

    D16SiHatch New Member

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    yep ^

    you will be much happier if you can find yourself an Si tranny. or at the very least a Dx trans.
     
  10. caboose

    caboose USDM to the bone

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    i think that some people combine the si and hf transmissions. usually taking the 5th gear out of the hf and putting it the si for better mileage when crusing, but also giving better acceleration in 1st through 4th
     
  11. CmR333

    CmR333 CANT THINK OF ANYTHING

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    Yeah i agree , i just put a d15b in my girls rex with the stock hf tranny. 1st is ok but 2nd though 4th it falls on its face in the lower rpms, plus the tiny little hf clutch cant really take any power. one plus though is that you can redline at 85 mph in 2nd lol. get the si tranny.
     
  12. D15Beater

    D15Beater HNFTuning

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    Si and Dx have the same gears 1-5, the final drive is the difference.
     
  13. AHHVTEC

    AHHVTEC Well-Known Member VIP

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    this is correct ^ the only one with different gears are the hf and std
     
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