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Thread: Dyno'd " Project Sucker Punch"

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  1. #1
    Join Date
    Sep 2008
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    Arizona/Utah
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    It has to do with the inherent frictional loss of gear sets. The larger the ratio multipier, ethier up or down, the greater the frictional loss. We always dyno in 4th with a 6 speed because that gear is straight through or 1 to 1. Any other gear would produce lower numbers. Gear set frictional losses are also proportional to the torque being transmitted. The differential gear set is the major part of driveline loss. The same goes for rear gearing as dynoing in different gears only slightly effects the out come. For example going from 3.42s to 4.10s might only change things 5-6%, but the jump to 4.56s might lose you 8%. That might sound small, however 8% of 400rwhp is 32hp lost. This is all a lot of ricer math, but the theory is good.
    ECSB 2kSierra 2wd 4.8L-K&N-HPtuners-Calspeed LT's-Magnaflow-Tahoe20's-HankookRH06

    waiting to go in... 3.90s, 214/220cam

  2. #2
    Join Date
    Nov 2007
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    Pittsburgh, PA
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    FYI you can skew the numbers so easy on a mustang dyno. You can easily make them read 100 hp over actual and 100 hp lower...set the weight wrong watch numbers change, change the weather station...watch numbers change....set smoothing to zero watch numbers change.....set smoothing to 100 and watch numbers change

    now on the DJ the numbers arent as easy to Skew

    on a MD they have a DJ setting so it gives off the same reading as it would on a DJ
    2002 Lightning - GT headed 5.5Litre w/ Twin 7665s
    2002 Silverado - 427Lsx w/ Twin gt4202s
    2010 Silverado crewcab Z71 - 5.3litre w/ procharger
    2000 Wrangler - 5.3litre with some stance
    2014 Xsport- 3.5 Eco boost
    412 Motorsports

    it ain't that I'm too big to listen to the rumors, It's just that I'm too damn big to pay attention to 'em..That's the difference

  3. #3
    Join Date
    Mar 2003
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    San Antonio, TX
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    My dyno has several variables I can change to alter final numbers.
    As well as that DJ correction factor.

    Fwiw. Engine dyno. LQ9 with 224 cam made 460hp a long time ago.

  4. #4
    Power is torque multiplied by angular speed. Lower gearing will lower the angular speed, therefore lowering the recorded power. I'm sure there are many more variables in your case, but this is what I have learned while getting my engineering degree. I don't have the degree yet, so take my words with a grain of salt. Lol

  5. #5
    Join Date
    Mar 2011
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    Quote Originally Posted by fast450ridr View Post
    Power is torque multiplied by angular speed. Lower gearing will lower the angular speed, therefore lowering the recorded power. I'm sure there are many more variables in your case, but this is what I have learned while getting my engineering degree. I don't have the degree yet, so take my words with a grain of salt. Lol

    As I mentioned earlier the tuner had stated that a sime gear change from I.E. 4:10 to 4:56. On a similar setup was roughly 45-55 RWHP, I asked the tuner to " explain " how tha worked but " your " words made more sense lol he stated something similar to that, but I learn better by reading not just listening lol..... Kerrige I think we were spinning it to 6400, 6600 maybe..... I cannot upload the dyno runs from my phone, but I can text them through PM, I took the run of the screen for data purposes, not just watch the trucks me noise going no where, text me your numbers and I will send the vid to anyone that wants to see it

  6. #6
    Join Date
    Oct 2011
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    San Antonio TX
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    A 5x11" magnaflow will do you good. Or as its better known the 22" big body magnaflow. Quiet on cruise and loud at wot.


    4.8, TSP 220, 6L90 swap, 3400 Stall, 4.10s w/30" drag radial and T76 @ 16lbs.
    Best ET 11.54@114 w 1.52 60ft
    Raceweight 4905 lbs.

  7. #7
    Join Date
    Mar 2011
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    Gibbstown, NJ
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    Quote Originally Posted by RS/SS 4.8 View Post
    A 5x11" magnaflow will do you good. Or as its better known the 22" big body magnaflow. Quiet on cruise and loud at wot.

    Do you have one of these mufflers on your truck?? I have been looking into changing my truck over to a magnaflow system.

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