Dyno results in!

Discussion in 'Race 400/430/455' started by wormwood, May 13, 2008.

  1. wormwood

    wormwood Dare to be different

    these numbers dont seem to compute. Keep in mind that these are rear wheel numbers and we weren't comfortable reving the motor past 5,500 rpm so we actually stopped at 5,300 and it was still making power. what is confusing me is, how could my torque be so much lower then the famously advertised 510 ft lbs? is it hopefully because this is through the drive train?

    407 HP peaked @ 5,300 rpm
    405 ft lbs torque peaked @ 4,800 rpm
     

    Attached Files:

  2. flynbuick

    flynbuick Guest

    There is reason to believe that factory had a finger on the scale when they rated the max torque on the 455. JW has never tested a stock 455 that made as much as 510 ft lbs. This could also be accounted for based on a dyno calibration difference.
     
  3. whamo

    whamo 454 71 skylark custom

    What kind of loss should you expect on HP and Torque to the wheels? I believe 15-20% loss of hp through the drivetrain is normal. I have never heard the factor for torque loss.
     
  4. wormwood

    wormwood Dare to be different

    crap, that attachment came out horrible, i cant read a thing.
     
  5. sean Buick 76

    sean Buick 76 Buick Nut

    Those are good numbers! You are over 500 hp and neer 500 ft/tq at the crank, I bet it pulls hard!
     
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Jim,
    There was a musclecar magazine that did a complete stock rebuild on a 455 Stage1 motor, and they did get to 510 ft lbs of torque, and something like 380 HP. They had to use about 38* of timing though. Wish I could find that magazine.
     
  7. flynbuick

    flynbuick Guest

    I think Jw's conclusion is also based on his interview with the chief engineer at the time , Cliff Studaker.
     
  8. sootie007

    sootie007 65 Skylark -455 - T350

    I think I read on here once Jims normal number he reads was 470 ft lbs on 70 existing builds hes dynod ...if your at 405 ftlb * 1.20 (for 20%) driveline losses your crank torque would be ~ 486 ftlbs and ~ 488hp - no slouch ! J
     
  9. 19Skylark68 455

    19Skylark68 455 Neighborhood Nuisance

    Just curious as I'll be throwing mine on a chassis dyno soon: what are the specs of your motor build?

    Thanks,

    Jon
     
  10. whamo

    whamo 454 71 skylark custom

    I poked around on the net a little and it seems 20% loss of horsepower is on the high side, probably closer to 16% or 17%. Im not sure if that factor applies to torque as well. Does anyone know for certain?
     
  11. wormwood

    wormwood Dare to be different

    i'll do my best , i'll work from the top down.

    1) 1050 cfm proform (4150 holley style) carb
    2) TA SP1 intake very mild gasket match porting
    3) TA 1.6 roller rockers
    4) TA stage 2 SE heads with Gessler level 2 porting
    5) stage 2 headders with 3' exhaust out
    6) TA's "The Gibson" cam
    7) JE 11:1 pistons .030 over
    stock crank, rods
     
  12. flynbuick

    flynbuick Guest

    Those chassis dynos are all over the place relative to one another. So I would not try too many conclusions about chassis dyno numbers except to see if a change improves output that day.
     
  13. GRIMM

    GRIMM Well-Known Member

    Horsepower is a factor of torque. This makes me think the loss is comparable.
     
  14. whamo

    whamo 454 71 skylark custom

    Hey Dan, your build is pretty close to mine. What did you say you ran at the track in the 1/4 mile? Also what gears and converter?
     
  15. whamo

    whamo 454 71 skylark custom

    Also, what does your car weigh with driver and fuel?
     
  16. wormwood

    wormwood Dare to be different

    steve, our combination's arent that close, you have the TE heads with a better port job (i think), a bigger cam, and now 1.65 roller rocker, making your cam even bigger,

    i think that the total weight of the car with driver and a half a tank of gas is 3,250. 373 gears in a chevy 10 bolt 8.5.

    the converter stalls at 3200 rpm and by the dyno numbers dosent seem to lock up until about 4,200 rpm (thats what the dyno tech told me, not sure what that means). if thats the case, seems to me like im making power a little too late in my power band.
     
  17. whamo

    whamo 454 71 skylark custom

    Wow! your car is way lighter than mine, I think Im sitting at about 3800lbs. Your 10 bolt is more efficient than my ford 9" as well. Here is an et calculator that I input info from your previous ET...... I think I remember you saying you ran a 11.7 in the past. It comes very close to the RWHP number that you saw on the chassis dyno.


    <FORM><CENTER><TABLE cellSpacing=0 cellPadding=0 width=520 border=3><TBODY><TR><TD align=left bgColor=#c0c0c0 colSpan=2><CENTER>Estimated 1/4 Mile Horse Power Calculator</CENTER></TD></TR><TR><TD align=middle bgColor=#a8c7a7><CENTER><TABLE cellSpacing=0 cellPadding=3 width="100%" border=0><TBODY><TR><TD>
    1/4 Mile ET: <INPUT size=10 value=11.70 name=qtret>

    </TD><TD>[SIZE=+0]1/4 Mile MPH: [/SIZE]<INPUT size=10 name=qtrmph>
    </TD></TR><TR><TD>Vehicle Weight: <INPUT size=10 value=3250 name=wgt>
    </TD><TD>[SIZE=+0]60' ET: [/SIZE]<INPUT size=10 name=sxtyet>
    </TD></TR></TBODY></TABLE></CENTER></TD></TR><TR><TD align=middle bgColor=#a8c7a7><CENTER><TABLE cellSpacing=0 cellPadding=3 width="100%" border=0><TBODY><TR><TD>[SIZE=+0]RWHP from ET: [/SIZE]<INPUT size=10 value=401.06 name=rwhpet>
    </TD><TD>[SIZE=+0]Break HP from ET: [/SIZE]<INPUT size=10 value=481.272 name=brkhpet>
    </TD></TR><TR><TD>[SIZE=+0]RWHP from MPH: [/SIZE]<INPUT size=10 value=0 name=rwhpmph>
    </TD><TD>[SIZE=+0]Break HP from MPH: [/SIZE]<INPUT size=10 value=0 name=brkhpmph>
    </TD></TR><TR><TD>[SIZE=+0]Max G's Acceleration:[/SIZE]<INPUT size=10 value=Infinity name=sxtyg>
    </TD><TD>Hook Factor: <INPUT size=10 value=0 name=hook>

    </TD></TR></TBODY></TABLE></CENTER></TD></TR></TBODY></TABLE></CENTER><CENTER><INPUT onclick=HPcalc(this.form) type=button value=Calculate name=compute> <INPUT onclick=clear(this.form) type=reset value=Reset> <INPUT onclick='window.open("HPCalc-help.htm","Help","toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=yes,resizable=yes,width=450,height=450")' type=button value=" ? " name=help></FORM>[SIZE=-2]Copy write 1999 by Kenneth R. Zink II (S-Series.Org)[/SIZE]
    </CENTER>
     
  18. 19Skylark68 455

    19Skylark68 455 Neighborhood Nuisance

    Wow. With that build, those numbers seem pretty low. I am planning on dyno'ing mine soon and have been doing some reading. I know that chassis dynos can vary a lot, but how much?

    Jon

    P.S. ( I'm gonna start a new thread to see what I can expect at the rear wheels based on my build. I think I've been getting a little over zealous.):cool:
     
  19. wormwood

    wormwood Dare to be different

    whammo. unfortunatly, i ran a 11.9, but that was before my head work and cam change, and that was with the 850 carb, not the 1050. if that calculator is right i will be prety upset that i spent about 2,500 between porting heads and cam/carb upgrades (almost 3,500 if you include the TA front timing chain cover) for .2 tenths.:mad:
     
  20. whamo

    whamo 454 71 skylark custom

    Dan, what is your target ET? Did they do any tuning on the chassis dyno? To take advantage of your engine combo you may need to fine tune timing and mixture as well and possible gearing or converter set up?
     

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