Re: wheel horsepower vs. ET
[Re: mcat4321]
#2005345
02/04/16 09:48 AM
02/04/16 09:48 AM
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Joined: Nov 2003
Posts: 1,969 Chandler, AZ
Duner
top fuel
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top fuel
Joined: Nov 2003
Posts: 1,969
Chandler, AZ
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I have dyno charts showing RWHP - but the numbers are overly optimistic / false when compared to actual timeslips. Since all dynos are different, I assume the one I was on would be considered "happy" or "not stingy". LOL It worked well for a tuning tool, but that's about it.
With that said: 705rwhp only produced 10.51 @ 130.13 mph at 4190# in my truck.
Last edited by Duner; 02/04/16 09:49 AM.
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Re: wheel horsepower vs. ET
[Re: Duner]
#2005351
02/04/16 10:16 AM
02/04/16 10:16 AM
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Joined: Jan 2003
Posts: 5,762 Hot Rod Ridge
FastmOp
master
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master
Joined: Jan 2003
Posts: 5,762
Hot Rod Ridge
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I have dyno charts showing RWHP - but the numbers are overly optimistic / false when compared to actual timeslips. Since all dynos are different, I assume the one I was on would be considered "happy" or "not stingy". LOL It worked well for a tuning tool, but that's about it.
With that said: 705rwhp only produced 10.51 @ 130.13 mph at 4190# in my truck. Wallace racing calculators say you make 711 HP at 130mph and 4200 pounds
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Re: wheel horsepower vs. ET
[Re: mcat4321]
#2005353
02/04/16 10:29 AM
02/04/16 10:29 AM
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Joined: Oct 2015
Posts: 570 UK
rb446
mopar
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mopar
Joined: Oct 2015
Posts: 570
UK
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This one says something different http://www.wallaceracing.com/hpcalculatorquarter.phpYour HP computed from your vehicle ET is 643.53 rear wheel HP and 715.04 flywheel HP. Your HP computed from your vehicle MPH is 665.06 rear wheel HP and 738.95 flywheel HP. I always used this one for all my calcs for the race cars I ran, always came out spot on but was fly HP... http://www.wallaceracing.com/accel-calc.php
1969 'Cuda 446ci, best 9.96@133.9 in 1990 1971 340 'Cuda, best 11.01@122.8 in 1987
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Re: wheel horsepower vs. ET
[Re: mcat4321]
#2005366
02/04/16 11:11 AM
02/04/16 11:11 AM
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Joined: Oct 2015
Posts: 570 UK
rb446
mopar
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mopar
Joined: Oct 2015
Posts: 570
UK
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Yes I know that thanks, thats why I always used the 2nd Wallace link I gave and just input weight and change hp figs till you get the ET/mph you actually ran, but that is fly hp. Its only a guide but as said it came out spot on with actual numbers I ran and fellow racers cars I knew ran even on the short times.
example> '69 Cuda in sig. 3000lbs/600hp/32" tyre/4.88's> 60 Foot E.T. : 1.38 1/8 Mile E.T. : 6.28 1/8 Mile Trap Speed : 108.15 1/4 Mile E.T. : 9.96 1/4 Mile Trap Speed : 135 1/4 Mile Trap RPM : 6,899
my 60 was 1.388 and trap rpm was 7200 with vert slip
Last edited by rb446; 02/04/16 11:23 AM.
1969 'Cuda 446ci, best 9.96@133.9 in 1990 1971 340 'Cuda, best 11.01@122.8 in 1987
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Re: wheel horsepower vs. ET
[Re: FastmOp]
#2005370
02/04/16 11:42 AM
02/04/16 11:42 AM
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Joined: Jun 2008
Posts: 3,916 usa
lewtot184
master
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master
Joined: Jun 2008
Posts: 3,916
usa
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ET has little to do with HP and everything to do with putting the power to the ground.
this. if your looking at horsepower then look for mph.
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Re: wheel horsepower vs. ET
[Re: mcat4321]
#2005372
02/04/16 11:46 AM
02/04/16 11:46 AM
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Joined: Oct 2015
Posts: 570 UK
rb446
mopar
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mopar
Joined: Oct 2015
Posts: 570
UK
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thats exactly what I just said wasn't it.
1969 'Cuda 446ci, best 9.96@133.9 in 1990 1971 340 'Cuda, best 11.01@122.8 in 1987
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Re: wheel horsepower vs. ET
[Re: lewtot184]
#2005377
02/04/16 11:53 AM
02/04/16 11:53 AM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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if your looking at horsepower then look for mph. +1. The Moroso HP calculator is supposedly based on RWHP... Then again, the results it gives aren't far off from the crankshaft HP #s seen from the Superflow engine dyno that Porter Racing Heads uses. I did one chassis dyno session years ago w/ my 4-spd A12 RR and the results were around 290 HP for a 3800#(+?) car & driver combination that ran about 110 MPH at the same event. On the other hand, the engine HP for my Challenger on PRH's engine dyno was about 610 for a combination that ran 10.5s at 126 MPH at 3755#, after the full exhaust and engine accessories were bolted on. Let me know if you can make sense of it all.
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Re: wheel horsepower vs. ET
[Re: mcat4321]
#2005379
02/04/16 11:57 AM
02/04/16 11:57 AM
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Joined: Oct 2015
Posts: 570 UK
rb446
mopar
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mopar
Joined: Oct 2015
Posts: 570
UK
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610fly hp@3755lbs = 10.67@126 according to my numbers 60 Foot E.T. : 1.48 1/8 Mile E.T. : 6.74 1/8 Mile Trap Speed : 100.91 1/4 Mile E.T. : 10.67 1/4 Mile Trap Speed : 126 just use this link, input your weight, if you know what the car ran change the hp numbers till you get as close as you can to those numbers and there's your fly HP http://www.wallaceracing.com/accel-calc.php
Last edited by rb446; 02/04/16 12:03 PM.
1969 'Cuda 446ci, best 9.96@133.9 in 1990 1971 340 'Cuda, best 11.01@122.8 in 1987
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Re: wheel horsepower vs. ET
[Re: rb446]
#2005381
02/04/16 12:02 PM
02/04/16 12:02 PM
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Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
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Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
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610fly hp@3755lbs = 10.67@126 according to my numbers
60 Foot E.T. : 1.48 1/8 Mile E.T. : 6.74 1/8 Mile Trap Speed : 100.91 1/4 Mile E.T. : 10.67 1/4 Mile Trap Speed : 126 Pretty close... my 60-fts were in the 1.45s and my 1/8 mile MPHs was a tad higher, which helped chisel the 1/4 mile ET down about a tenth from your #s.
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Re: wheel horsepower vs. ET
[Re: mcat4321]
#2005382
02/04/16 12:08 PM
02/04/16 12:08 PM
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Joined: Oct 2015
Posts: 570 UK
rb446
mopar
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mopar
Joined: Oct 2015
Posts: 570
UK
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Yeah, I've been using this method for ages and it always gives the right numbers, on all my cars and and all others I've tried, but really its a way of finding the HP your making against your weight if you have your timeslips, the gearing tyre part is useful as well....quite simple really.
However this doesn't answer the ops question re RWHP.........
Last edited by rb446; 02/04/16 12:37 PM.
1969 'Cuda 446ci, best 9.96@133.9 in 1990 1971 340 'Cuda, best 11.01@122.8 in 1987
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Re: wheel horsepower vs. ET
[Re: mcat4321]
#2005563
02/04/16 05:55 PM
02/04/16 05:55 PM
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Joined: Oct 2015
Posts: 570 UK
rb446
mopar
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mopar
Joined: Oct 2015
Posts: 570
UK
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Yep thats 694Flyhp to get your numbers which is an 18% loss at 588....sounds about right, losses differ from car to car of course.
Last edited by rb446; 02/04/16 05:58 PM.
1969 'Cuda 446ci, best 9.96@133.9 in 1990 1971 340 'Cuda, best 11.01@122.8 in 1987
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Re: wheel horsepower vs. ET
[Re: rb446]
#2005610
02/04/16 07:30 PM
02/04/16 07:30 PM
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Joined: Jan 2003
Posts: 9,876 Weddington, N.C.
Streetwize
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master
Joined: Jan 2003
Posts: 9,876
Weddington, N.C.
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The only thing about the 1/4 mile equation (if I remember right) is it's also based on a 'fixed' (assumed 'constant') .50 drag coefficient...(and, interestingly enough .50 c/d seems to be more or less average for a mid size late 60's early 70's car)
So, a theoretical 1968 and a 2002 Camaro at the same weight running the same ET and MPH (lets say 3000 pounds and 11 flat at 120 mph) might have the same "theoretical" RWHP and FWHP, but since the 68 Camaro has a c/d of ~.50 and the 2002 is only about .29, the 68 likely needs another 35 or so HP to push through the wind on the big end.
There is a frontal area 'compensation i.e. (< or >.50)factor' I found once on the internet, it may even be in the Wallace charts.
Last edited by Streetwize; 02/04/16 07:32 PM.
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Re: wheel horsepower vs. ET
[Re: mcat4321]
#2005726
02/04/16 10:36 PM
02/04/16 10:36 PM
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Joined: Aug 2011
Posts: 2,864 Pattison Texas
CSK
master
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master
Joined: Aug 2011
Posts: 2,864
Pattison Texas
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this has a mph vs drag & hp RB racing
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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Re: wheel horsepower vs. ET
[Re: mcat4321]
#2005741
02/04/16 10:49 PM
02/04/16 10:49 PM
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Joined: Feb 2011
Posts: 4,302 Nebraska
72Swinger
master
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master
Joined: Feb 2011
Posts: 4,302
Nebraska
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Is there one that calculates for elevation?
Mopar to the bone!!!
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