Sprocket/Belt compatibility

Discussion in 'PSI Superchargers Tech Questions' started by James2, May 7, 2004.

  1. James2

    James2 Member

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    Can I use 13.9mm sprockets with a 14mm GT belts? Is it advisable? Why or why not? I've heard some people run this type of setup, and this is what I've got to work with for now.

    Thanks for any help you can provide.
     
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  2. Randy G.

    Randy G. Top Alcohol

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    FYI:

    In case you haven't seen the difference between the two configurations, here's a great link courtesy Steve Leach. Notice the difference between the HTD and GT2 belts:

    http://www.rcdengineering.com./belt1.html

    I'm not a big fan of mix and match if it's not necessary. You must have a reason, though.
     
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  3. James2

    James2 Member

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    Thanks Randy.

    I have seen the sectional views of the different belts, and noted the different profiles. I also subscribe to the theory of sticking with matched parts, but I had heard that people have tried the 13.9 sprocket/14 belt combination - and I was wondering whether or not that worked out, or if it was a problem. I was also interested in the rationale behind such a combination. If after further research I do not find a compelling reason to try this combination, I'll just go buy some 14mm GT sprockets.

    Thanks again.
     
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  4. Scott Misus

    Scott Misus New Member

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    But, you can't find a compelling reason NOT TO, either.

    14mm and 13.9mm HTD profiles are ONE millimeter apart...

    Do some research into why two almost identical profiles exist in the same marketplace, and I'm sure you'll decide that you CAN mix the two.
     
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  5. James2

    James2 Member

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    Scott,

    Thanks for the input. Can you elaborate on your ideas? I'm not sure what you're leading me toward, or what information you have found that you believe would be useful in this case.

    One theory could be that one manufacturer makes only 13.9mm and another makes only 14mm, and they want you to only buy their product - but that doesn't appear to be the case, since one of them sells both.

    I've got 13.9mm sprockets, which I believe are HTD profile, and 14mm belts of the GT variety. It appears that the tooth height on the belts are the same, although the shape looks slightly different, and the tooth spacing is .004" wider on the 14mm GT belt. Looks like the 14mm GT belts are .016" thicker on the backing.

    Maybe this would work?!?
     
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  6. Randy G.

    Randy G. Top Alcohol

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    Scott:

    The difference isn't just 1 mm. It's the design of the teeth and the way the pulleys are cut (depth, etc.). GT pulleys won't let HDT belts ride correctly.

    Call JR at RCD or Mert at Littlefield's before relying on keyboard advice. You'll save yourself a lot of grief.
     
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  7. Ken Sitko

    Ken Sitko Super Comp

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    For what it's worth, I am running the 14 mm GT belts on 13.9 pulleys on my TAD, and have had no problems. We only run to about 9400 rpm though, so I'm not sure if the belts would last if you tried to go fast.
     
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  8. Randy G.

    Randy G. Top Alcohol

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    Ken:

    From what I know, using 14MM GT belts with 13.9 HTD pulleys will work, but you can't run 13.9 HTD belts with 14MM GT pulleys.
     
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  9. James2

    James2 Member

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    Thanks for the input. This gives me a point of reference, and some food for thought. The 13.9 sprockets came with some stuff I got, and I wasn't sure if they were running it this way, or if they were just giving me their junk. The RPM will be much lower than 9400. I might want to put a little more blower in it, so I'll have to get some new sprockets anyway. Thanks again.
     
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  10. Gary Mangiafico

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    I agree, thru experience, I do NOT recommend mixing the two. It is either one or the other. When you mix the two you consideribly shorten your belt life.

    Sincerely,

    Gary Mangiafico
     
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