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Project Torque Dyno Numbers.... :( *VIDEO*

Discussion in 'The Garage' started by BranndonC, Jan 14, 2006.

?

Loss (pick more than one if you want)

  1. 20%

    10.3%
  2. 25%

    13.8%
  3. 30%

    20.7%
  4. 35%

    10.3%
  5. Not what i thought the caddy would do

    51.7%
  6. More than i thought it would dyno

    6.9%
Multiple votes are allowed.
  1. BranndonC

    BranndonC 3/4 ton status

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    since 30% seems to be the leader
    with 30% loss 329 Horse Power and 490 Torque

    Video
    http://media.putfile.com/Dyno84

    Run 1
    230.5 Max Power 402.61 Max Torque

    Run 2
    227.95 Max Power(4,000 RPM or so) 342.89 Max Torque (2,750 RPM or so)

    I have my secondaries set to be open all the time temporarly, so when he mashed it on the first run, it bogged a bit, then took off, thats why the spike of torque

    on the second run he eased into it so i could get lower RPM readings.

    So with a doubler and assuming 35% loss, the engine numbers are
    353 and 527
    with 30% loss
    329 and 490

    what do you all think the correct loss for a th400, gear driven 203, to a gear driven 205, 14FF with steel beadlocks (45lbs +/-) and 37 SSR's (50lbs+/-)
     
    Last edited: Jan 16, 2006
  2. blackblazer717

    blackblazer717 1/2 ton status

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    i was glad you had it dynoed finally but i dont know why it didnt do a little better, but will still be real strong.

    LUKE
     
  3. HarryH3

    HarryH3 1 ton status Author

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    You aren't getting maximum airflow efficiency at low RPM's by having the secondaries tied open. Quadrajets use the vacuum door to deliver the air that the engine needs, when it needs it. That really helps keep the intake velocity up.

    IRCC, the Turbo 400 soaks up about 60 HP. A 2WD drivetrain soaks up 20-25% of the flywheel power, so add in two extra transfer cases and that could easily grow into the 25-30% range. :(
     
  4. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    It can be lots of things. Dyno, air quality, tire slippage, tire flex, etc. etc.

    Numbers can differ from dyno to dyno too. I like to think of a dyno as a tuning tool rather than a ruler or concrete measurement.

    Dyno numbers are just that, "numbers". The biggest thing is whether or not you feel the difference and will the motor do what you want it to do. You seem to have no problems smokin' those big meats with a running start (which 95% here can't even come close to doing that).

    Also remember that when you hear or see HP/TQ figures, they are often "inflated" (to sell products or to boost ego's).

    The other possibility is that there is still a portion of untapped potential in your motor. Things like carburation, jetting, timing, component matching, etc. From the way your rig moves though, I would say that you have tapped a large portion of that potential though...
     
  5. 79k20350

    79k20350 3/4 ton status

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    the transfer cases are gear driven, so i would think there is a minimal loss there. what i never understood is shouldnt it be the tranny soaks up x number of horses, not a percent???:confused:
     
  6. BranndonC

    BranndonC 3/4 ton status

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    TTT video up
     
  7. BranndonC

    BranndonC 3/4 ton status

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    ok, after much searching, it seems that 30% or so is what alot of people say a th400 takes, so using 33 percent is what i factored my numbers by for the end of the video. Does anyone have any insight or a site that proves actual loss?
     
  8. hack500

    hack500 1/2 ton status

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    you'd really need to put a torque wrench on the whole drivetrain to see how much it takes to turn everything.
     
  9. 1-ton

    1-ton 1/2 ton status Premium Member

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    Chassis dynos make me nervous because I had a bad experiance on one many years ago.

    Back in (about) 1981 I had this 1969 Plymouth GTX 440, with a 4-speed transmission. I had a friend of mine, who is a mopar expert, put one of his 500 cubic inch stroked 440's out of his Super Comp dragster into it. One day me and my buddy took it to the local Community College, who had one of the few Clayton Chassis Dynamometers in Southern California at that time, to let the instructor there use it to do a dyno demonstration for the students. WHAT A DEMONSTRATION THAT WAS.

    The first run wasn't much because I was too scared to punch it, but the second time the instructor said "don't worry" just go ahead and punch it this time. SO I DID. I got it into third gear and I nailed to the floor. Next thing I know I feel a sudden jerk at the rear, and the rear wheels hopped off the rollers. My cars tires hook concrete and took off. One of the two anchor chains connected to my diff snapped, but luckily the other chain held. My car did almost a complete 360 inside the shop :eek1:.
     
    Last edited: Jan 15, 2006
  10. Greg72

    Greg72 "Might As Well..." Staff Member Super Moderator

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    Brandon,

    Did they have an A/F meter hooked up during the pulls?

    It's important not only from a safety perspective (if it starts going lean on a pull, you'd like to be able to abort the run)...but also to see if you're running too rich or how the transition from the primaries to WOT looks.

    Depending on your budget, you could probably find a lot of HP/TQ with that dyno...it just starts to get expensive to have them messing with timing, jetting, etc. at an hourly rate.

    For what it's worth, my 396 in the K5 put down just over 300 Lb/Ft to the rollers, and my '72 Burb with a 350SB actually put down something like 298 Lb/Ft!!! A little embarrassing for the BBC if you want to know the truth!!! :blush:
     
  11. 89GMCSuburban

    89GMCSuburban 1/2 ton status

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    I know on the big trucks with a manual and the power divider locked in on the dyno, we calculate a 20% loss of power on a semi truck, so I imagine it is in the 30% range.
     
  12. Slapperbar

    Slapperbar Retired Navy NDT Examiner Premium Member

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    At the end of the run, leave your foot on the floor and kill the ignition. The dyno will show the drivetrain loss.
     
  13. BranndonC

    BranndonC 3/4 ton status

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    thats not me, thats the worker doing the runs, but if i go back, i'll suggest that to him
     
  14. Shawn

    Shawn 1/2 ton status Premium Member Author

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    To get a more accurate number, I always run small tires in the back.

    [​IMG]

    I think my best dyno figures were 400rwhp and 450rwtq on my 496. That was with a 465 4 speed, 205, 1350 shaft, 14 bolt.

    I've actually drag raced my 02 Trans Am on a Mustang dyno just like I was at the strip. Kind of freaky when there's a wall 12 feet in front of the car!
    http://www.thecarburetorshop.net/MVC-476W Folder/MVC-476W.MPG
     
  15. JIM88K5

    JIM88K5 1/2 ton status

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    :doah: :haha: :haha: :haha:
     

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