1/4 Mile Issues

Discussion in '1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-' started by sharp2377, Oct 27, 2013.


  1. clement

    clement Founding Member

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    i wasn't trying to insult you with the world is flat comment. so im sorry about that.
    #41
  2. A5literMan

    A5literMan Mustang Master

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    Very interesting discussion.:chin
    #42
  3. NIKwoaC

    NIKwoaC 中國製造

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    336 to the tire and I've barely cracked 12s.

    Because street car...?

    [​IMG]
    #43
  4. clement

    clement Founding Member

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    with your car I would expect to see 115+ mph with that kind of power assuming its 3200lbs or so. could be something as simple as how the valvesprings are setup. a couple little simple things can kill an NA car. its tough to shake it down away from the track. 110mph is good for 12.20s though.
    Last edited: Nov 18, 2013
    #44
  5. John Dirks Jr

    John Dirks Jr Active Member

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    I took the "world is flat" comment as playful banter. There is no need to apologize. It's all good.
    #45
  6. NIKwoaC

    NIKwoaC 中國製造

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    Yea, I think there is a lot that I’m leaving on the table with the car. The car should be getting a new transmission this winter that will better handle the power, and if money permits, new lightweight wheels to replace the 28 lb replica Mach 1s. Then I’m going to track the crap out of the car next season and see if I can’t post some better times/speeds.
    #46
  7. 84Ttop

    84Ttop They make new pistons every day, so why worry? SN Certified Technician Mod Dude

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    :pop: No useful input, Just going to eat my popcorn and watch the show :p
    #47
  8. A5literMan

    A5literMan Mustang Master

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    Looking forward to seeing that!! You definitely have the power for better times.
    #48
  9. sharp2377

    sharp2377 Member

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    I think a vic jr I
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  10. sharp2377

    sharp2377 Member

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    I think a vic jr is a bit much on a mild 351w, don't you think? I actually just ordered a rpm air gap and worried about that being too much. I was told by summit that a 600cfm carb was more than enough for my setup and that a 750 could actually make less power for me and should only be used on big hp motors. I haven't tried other brands of carbs on this motor but I really like the summit carb. I just touch the ignition and it fires right up, no hesitation, plugs read perfectly, and idles good. I eould hate to switch gor a couple of HPs and then have nothing but problems. Thank you all for the input!
    #50
  11. Bullitt347

    Bullitt347 man bewbs please...

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    You can never have too big of a carb. If adjusted correctly you could put a 1100 cfm Dominator on that 351 with no issues. It is like saying you can't put a 90mm throttle body on a 90' 5.0 and get it to run right. Hell diesel engines do not even have a throttle body, just a big open plenum, and they typically do not spin over 4,000 rpm, and spend most of the time under 2,500 rpm. I can get a stock 302 to idle and drive great with a 1bbl carb, or with a 1100 cfm Dominator, it is all about proper adjustments, and BTW the 1100 cfm equipped engine adjusted correctly will ALWAYS make more power over any other smaller carb, period. Personally I would get a Quick Fuel 780 SS series carb and watch that thing fly. Dominators cost to much for this application.
    #51
  12. John Dirks Jr

    John Dirks Jr Active Member

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    Fuel atomization begins at the point where the air enters the throttle bore on the carbureted engines. That's why velocity is important. On the diesel and fuel injected examples you give, the atomization happens way down in the intake where the runners neck down and there is increased velocity at that point. Comparing carburetors to your examples is apples to oranges.

    I disagree that a bigger carb will always make more power. It's about getting the fuel mixture correct. If a carb is big enough to pass the amount of air an engine can pull in, it's big enough. From that point, it's a matter of getting the fuel mixture correct.

    Again, a larger opening will not enable an engine to increase it's fixed ability. So long as a bore is big enough, putting a larger one on will not bring in more air volume. No way, no how.
    #52
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  13. mikestang63

    mikestang63 Mustang Master

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    Doesn't matter IMO how big a carb or TB on a motor. It's only going to flow as much as the intake/heads are going to allow it. You can slap on a dominator carb on a stock 302 with E7s and it is not going to make more power than a 600 holley, just as if you put a 90MM tb vs. a 65MM.
    #53
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  14. A5literMan

    A5literMan Mustang Master

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    And I thought this debate was over:dead:
    #54
  15. NIKwoaC

    NIKwoaC 中國製造

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    Agreed, but there is also flawed logic in "good enough" parts sizing. Some stuff, like TBs, there is no harm on being a little on the big side. If you set out to make 300 RWHP and you buy a "400 RWHP" TB and you end up making 310 RWHP, are you or anyone else going to complain?

    Carbs on the other hand... I have no idea about those caveman things. That's voodoo magic to me.
    #55
  16. John Dirks Jr

    John Dirks Jr Active Member

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    It's not complicated really. Its basic physics. It all comes down to air / fuel mixture. Remember, the thread was started about a carburated naturally aspirated engine. The engine is a basic air pump. It can pump in a certain amount of air. The amount is limited by the engine displacement and the max rpm the engine is expected to run. The CFM requirement can be calculated and a carburetor size selected. If the equation says x cubic inches at x rpm will draw 550CFM, then a 600CFM carb is a good choice. From that point, tailoring the amount of fuel delivered can optimize the package.

    Adjusting A/F mixture can affect any setup with any size carb. But to believe that a larger carb will always make more power is misguided in my opinion.

    I'm sure there has been cases where a 600CFM was not properly adjusted, although it was actually big enough. Then, a 750CFM was slapped on that was closer to the mark in overall adjustment and an improvement was noticed. The conclusion then might be made that the 750 was better. In reality, the 600 was never properly adjusted or jetted and not given a chance to show what it can do.

    Remember, stupid air pump. Fixed amount of air required. Add the correct amount of fuel......done.
    #56

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