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  1. #1

    Machined 1300 throttle bodies

    Ok, hope i did this right with the pic uploads.
    Here are the throttle bodies i bought from Ronn25 with the tops machined, compared to stock throttle bodies.
    Machined with carbide cutters.. First a 60 degree cut down it the throat of the body, then topped with a 45 degree cut, finished with a 30 degree cut on the top, then old school (hand massaged) with sand paper and then polishing compound.. The 3 angle cut creates a perfect radiused edge similar to what the novi carbs have.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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  2. #2
    One day at a time..... N8R's Avatar
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    cant wait to see the results. i can see that your ski will be picking up alot more speed.

  3. #3
    Moderator RX951's Avatar
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    2000 GPRXP 4tec shooter98xpl's Avatar
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    I am curious as well. I have heard that there is no results to be gained from this. Lets see what happens here with your results.
    SHOOTER

  5. #5
    You may be right, i may get nothing from this... If anything it will be small.. Also machined off the throttle blade screws on the back side where they protrude. Just old school tried and true basic stuff being done here for max airflow..Porting of the throttle body if you will...
    Wont be able to test till the middle of december... Will give results....

  6. #6
    txgp1300r's Avatar
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    while you had them on the mill you could have bored them to 44mm and installed new butterflys...that definatly will give you more air flo.....has anyone tried this ? would we need bigger injectors or just turn up the efi controller? your throttle body's look good...hurry up and test.

  7. #7
    One day at a time..... N8R's Avatar
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    that is why iam waiting for the Macboost or Advent. easier to dial in.......bigger injectors,,, tripples etc.........

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    philip_gpr's Avatar
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    "while you had them on the mill you could have bored them to 44mm"

    unfortunately there is very little material to work with so simply boring to 44 wouldn't work

  9. #9
    Boring to 44 would leave the neck of the throttle body paper thin, dont think it would work.. 42 may be possible, but may do more harm than good. Since these are throttle bodies and not carbs they have no booster to get in the way of airflow, so a 40 TB will flow much more than a 40 carb.

    Also boring the TB will slow velocity of airflow going through them at any given rpm and could do the opposite of what we hope, especially in the midrange rpms.

  10. #10
    txgp1300r's Avatar
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    Quote Originally Posted by rossnemo View Post
    Boring to 44 would leave the neck of the throttle body paper thin, dont think it would work.. 42 may be possible, but may do more harm than good. Since these are throttle bodies and not carbs they have no booster to get in the way of airflow, so a 40 TB will flow much more than a 40 carb.

    Also boring the TB will slow velocity of airflow going through them at any given rpm and could do the opposite of what we hope, especially in the midrange rpms.
    yes you are correct on the velocity...unless the engine can take more....if i had a spare set of throttle body's i could see how far i could bore them....does anybody know the cfm of our 1300's at 7100 rpm??

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