First gear question.

Discussion in 'Manton Push Rods Top Alcohol Tech Questions' started by dragster156, Nov 16, 2017.

  1. dragster156

    dragster156 Member

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    combo is a blown hemi with psi 14-71 in a dragster weighing 2350lbs. I am looking to take weight out of the car. Currently has 4.56 in the rear with a 36" tire. I'm getting rid of that tire and most likely going to run a big bubba or Hoosier equivalent.
    I was thinking of changing to a 4.10 gear with the smaller tire and continue with the 3 speed. 1.64 first 1.31 second.
    My question is if I leave the 4.56 can I run the 1.31 as the first gear or is that to much of a drop. Getting rid of the second section and taking 35lbs out of the car. The "numbers" say it's not that much of a diff. Currently the car is set up to pull 10 degrees and it ramps back in over 2.25 seconds. So I can put more power to it if needed to help.
    Any thoughts would be appreciated.
     
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  2. KZ5 Blown SBC

    KZ5 Blown SBC Member

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    I wouldn't change anything other than the tires. Put the Mickey big bubba on it I wasn't a fan of the Hoosiers bubba. Can you take out weight anywhere else . Making it a two speed what you gain out of making it lighter you will lose in performance
     
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  3. dragster156

    dragster156 Member

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    Why do you think it will slow down?? It's a TD car and not something turning 10,000 rpm that needs to be kept inside a certain rpm window at all times.
    The 4.56 gear is way to aggressive the way it is now. Hence all the timing pulled. To me it makes sense to kill ratio and if needed add timing for more power. It's easier to change the trans than the rear and at the same time as mentioned lose the 35 lbs.
    Just seeing if people run something like this. 4.56 and a mid 1.30 first gear.
    As mentioned the ratio is in the ballpark. The 1.66 and the 4.56 is way to,high and running it I,know it's much to aggressive..
     
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  4. KZ5 Blown SBC

    KZ5 Blown SBC Member

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    I'm not saying you will slow down you just won't see any gain from that 35 lbs an taking a gear from it but if just wanting too bracket race ya for sure make it a 2 speed with that 1.31first gear an should work great
     
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  5. dragster156

    dragster156 Member

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    I guess I will just have to try it out to know for sure. Not a big deal to make it 1.40, 1.50 or whatever is needed. Or like you said the 1.3 might work out great??
     
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  6. rb0804

    rb0804 Member

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    I assume this is a converter car by what your describing. Switching to a two speed won’t kill the car as bad through the mid range like it would if it was a clutch car. I also don’t know what type of surfaces you race on, if it’s prepped really good or if it’s all over the place from one round to another. If you Race all over at different tracks, different elevations, differing preps (some good, some not so good) then it’s a good idea to be able keep some timing out of it so you can hit your driveshaft numbers and ultimately your et numbers under those varying conditions.
     
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  7. dragster156

    dragster156 Member

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    Yes converter car. I guess that would have been a key factor to include in the post - lol. Tracks are usually very good. Some so so I guess.
     
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  8. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    My biggest problem with a 4.56, unless you are running in altitude, is your trap rpm for a Top Dragster.

    With the Kruse Missile TD we cross the traps a little over 9000 on a 235 mph run with a 4.29. Granted that is with a 34.5.

    Depending on what tire you go with, you can make the 1.31 deal work with the 4.56, but you will lose MORE than what the 35 lbs will gain in my opinion. A 3 speed is nice in Top Dragster as it lets you go faster and it's easier on parts since you aren't lugging the motor as hard.

    I think the optimum combo would be a 4.29 with that 1.64 and a standard 'alcohol' 34.5/17 Hoosier. You will still have to retard timing, but it's better to have more than you need and control it than just have to stand on it.

    The Kruse Missile is very easy on parts, and we don't really start the ramp from 10 degrees until 3.5 seconds or so.
     
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  9. dragster156

    dragster156 Member

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    I agree 100% with the 4.56. And yes the tire will either be a 34.5 or the big bubbas. I am most likely putting a 4.10 in because it's what I have.
    I have thought of keeping the 3 speed and see how it runs with the gear and tire change. Very easy to just take it out later if wanted.
     
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  10. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    I would definitely stick with the 3 speed with a 4.10. That's not a bad combo
     
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