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ITB's, 38mm big enough?

Discussion in 'Engine Building' started by 5speed4life, Apr 18, 2006.

  1. 5speed4life

    5speed4life Senior Member

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    Ok, ive really been looking into ITB's for my ls/v crx. My buddy has a set of 38mm ITBs off of a yamaha. I know about all the work involved with setup and tuning... Im not scurred of that. I was just wondering if that is big enough to support atleast 300whp.

    Thanks.
     
  2. K2e2vin

    K2e2vin Senior Member

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    Probably not; most of the guys that are around 260-300hp are using around 50mm ITBs and larger. I myself am using 42mm GSXR ITBs on my D15B, and CRXmotorsports is or was using 44mm CBR ones on his non-vtec D15(race car).
     
  3. SlushboxTeggy

    SlushboxTeggy It's only stupid if it doesn't work VIP

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    use honda ITBs, it already has a TPS and they are the right size anyway.
     
  4. phunky.buddha

    phunky.buddha Admin with a big stick Admin VIP

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    38mm should be large enough to make decent power without killing your low end, but maybe not all motor. If you do the math, 4x 38mm pipes have the same cross section as one 76mm pipe.
     
  5. MikeBergy

    MikeBergy Blah blah blah....

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    :werd: it's all about airflow. 38mm ITBs should do MUCH better than the stock or even overbored throttle body. I'm certain the ports are going to choke well before 38mm ITB's will. If that's the case 38mm should be more than big enough, but do the calcs to check and make sure that your engine isn't sucking in more than the crit flow rate of that size ITB.
     
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