Calculating Torque and 1/4 mile top speed

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Can someone help me figure out these two out? I'm just looking for desktop figures.


-Chris
 
What follows is a standard relationship between power , weight, trap speed and 1/4 elaspsed time. Covers weights from 1250 to 5000 pounds, and from 75 hp SAE net to 750 hp SAE net.

Just some notes to you. Torque is really irrelenvent to this excersie. It is true, however, that Power is a torque (twisting force) per cyle of the engine, ie there is a speed factor involved. It doesn't matter if you use a Mazda rotary with next to no torque bellow 4000 rpm, or a 460 Ford with vitrually power and torque everywhere. If both have got 200 hp, it doesn't matter if the Madza has 185 lb-ft and the 460 has 430 lb-ft, and they are both in 2500 pound cars...they will both do 13.5 second quarter mile times potentially. But the Mazda will lag over the first 60 ft and 660 ft areas, and then catch up on the end part.

The chart below is based on a stock 1966 Falcon-size intermediate, with no slicks, full exhast, conservative barometric temperature and bad areodynamics. The following

-Hp verses over all drag factor times the frontal area,

-Low end torque

-Slicks, drive configuration, transmission type and weight tranfer

all change the results slightly, but no more than a couple of seconds at worst.

Formula for Elasped Time
ET = race lb/ net flywheel HP all taken to the 1/3 power, then multiplied by 5.825


Formula for net Horse power at the flywheel
HP= lb race weight divided by the result of (ET /5.825 all taken to the 3rd power).


Formula for Calculating Weight
(ET /5.825 all taken to the 3rd power) times Net flywheel HP


Trap speed in mph
HP/lbs race weight all taken to the 1/3 rd power, and this result multiplied by 234


*Note: These are more conservative than the Moroso "dreamwheel" HP calculator because it is designed to baseline an optimised drag car with no major exhast and slicks and what not, not a real street car with softer springs and more of a compromised set up.

Other options are to check out the tech section via clicking on the FordSix.Com avatar. Grippo & Bowling have a brilliant electronic website there.http://www.bgsoflex.com/auto.html Another good option is http://www.themustangshop.com/index.cfm?nonIE=true



75 hp 1250 lbs 92 mph 14.9 -sec
75 1500 86 15.8
75 1750 82 16.6
75 2000 78 17.4
75 2250 75 18.1
75 2500 73 18.7
75 2750 70 19.4
75 3000 68 19.9
75 3250 67 20.5
75 3500 65 21.0
75 3750 64 21.5
75 4000 62 21.7
75 4250 61 22.4
75 4500 60 22.8
75 4750 59 23.2
75 5000 58 23.6

100 hp 1250 lbs100 mph13.5 -sec
100 1500 95 14.4
100 1750 90 15.1
100 2000 86 15.8
100 2250 83 16.4
100 2500 80 17.0
100 2750 78 17.6
100 3000 75 18.1
100 3250 73 18.6
100 3500 72 19.1
100 3750 70 19.5
100 4000 68 19.9
100 4250 67 20.3
100 4500 66 20.7
100 4750 65 21.1
100 5000 64 21.5

125 hp 1250 lbs 109 mph12.6 sec
125 1500 102 13.3
125 1750 97 14.0
125 2000 93 14.7
125 2250 89 15.3
125 2500 86 15.8
125 2750 84 16.3
125 3000 81 16.8
125 3250 79 17.3
125 3500 77 17.7
125 3750 75 18.1
125 4000 74 18.5
125 4250 72 18.9
125 4500 71 19.2
125 4750 70 19.6
125 5000 68 19.9

150 1250 109 12.6
150 1500 102 13.3
150 1750 97 14.0

150 2000 99 13.8
150 2250 95 14.4
150 2500 92 14.9
150 2750 89 15.4
150 3000 86 15.8
150 3250 84 16.2
150 3500 82 16.6
150 3750 80 17.0
150 4000 78 17.4
150 4250 77 17.8
150 4500 75 18.1
150 4750 74 18.4
150 5000 73 18.7

175 1250 122 11.2
175 1500 114 11.9
175 1750 109 12.6
175 2000 104 13.1
175 2250 100 13.6
175 2500 96 14.1
175 2750 93 14.6
175 3000 91 15.0
175 3250 88 15.4
175 3500 86 15.8
175 3750 84 16.2
175 4000 83 16.5
175 4250 81 16.9
175 4500 79 17.2
175 4750 78 17.5
175 5000 77 17.8

200 1250 127 10.7
200 1500 120 11.4
200 1750 114 12.0
200 2000 109 12.6
200 2250 104 13.1
200 2500 101 13.5
200 2750 98 14.0
200 3000 95 14.4
200 3250 92 14.8
200 3500 90 15.1
200 3750 88 15.5
200 4000 86 15.8
200 4250 85 16.1
200 4500 83 16.4
200 4750 82 16.7
200 5000 80 17.0

225 1250 120 10.3
225 1500 120 11.0
225 1750 120 11.5
225 2000 120 12.1
225 2250 109 12.6
225 2500 105 13.0
225 2750 102 13.4
225 3000 99 13.8
225 3250 96 14.2
225 3500 94 14.5
225 3750 92 14.9
225 4000 90 15.2
225 4250 88 15.5
225 4500 86 15.8
225 4750 85 16.1
225 5000 83 16.4

250 1250 137 10.0
250 1500 129 10.6
250 1750 122 11.1
250 2000 117 11.7
250 2250 113 12.1
250 2500 109 12.6
250 2750 105 13.0
250 3000 102 13.3
250 3250 100 13.7
250 3500 97 14.0
250 3750 95 14.4
250 4000 93 14.7
250 4250 91 15.0
250 4500 89 15.3
250 4750 88 15.5
250 5000 86 15.8

275 1250 141 9.6
275 1500 132 10.3
275 1750 126 10.8
275 2000 121 11.3
275 2250 116 11.7
275 2500 112 12.2
275 2750 109 12.6
275 3000 106 12.9
275 3250 103 13.3
275 3500 100 13.6
275 3750 98 13.9
275 4000 96 14.2
275 4250 94 14.5
275 4500 92 14.8
275 4750 91 15.1
275 5000 89 15.3

300 1250 145 9.4
300 1500 137 10.0
300 1750 130 10.5
300 2000 124 11.0
300 2250 120 11.4
300 2500 115 11.8
300 2750 112 12.2
300 3000 109 12.6
300 3250 106 12.9
300 3500 103 13.2
300 3750 101 13.5
300 4000 99 13.8
300 4250 97 14.1
300 4500 95 14.4
300 4750 93 14.6
300 5000 92 14.9

325 1250 149 9.1
325 1500 141 9.7
325 1750 134 10.2
325 2000 128 10.7
325 2250 123 11.1
325 2500 119 11.5
325 2750 115 11.9
325 3000 112 12.2
325 3250 109 12.6
325 3500 106 12.9
325 3750 104 13.2
325 4000 101 13.4
325 4250 99 13.7
325 4500 97 14.0
325 4750 96 14.2
325 5000 94 14.5

350 1250 153 8.9
350 1500 144 9.5
350 1750 137 10.0
350 2000 131 10.4
350 2250 126 10.8
350 2500 122 11.2
350 2750 118 11.6
350 3000 114 11.9
350 3250 111 12.2
350 3500 109 12.6
350 3750 106 12.8
350 4000 104 13.1
350 4250 102 13.4
350 4500 100 13.6
350 4750 98 13.9
350 5000 96 14.1

375 1250 157 8.7
375 1500 147 9.2
375 1750 140 9.7
375 2000 134 10.2
375 2250 129 10.6
375 2500 124 11.0
375 2750 120 11.3
375 3000 117 11.7
375 3250 114 12.0
375 3500 111 12.3
375 3750 109 12.6
375 4000 106 12.8
375 4250 104 13.1
375 4500 102 13.3
375 4750 100 13.6
375 5000 99 13.8

400 1250 160 8.5
400 1500 151 9.1
400 1750 143 9.5
400 2000 137 10.0
400 2250 132 10.4
400 2500 127 10.7
400 2750 123 11.1
400 3000 120 11.4
400 3250 116 11.7
400 3500 114 12.0
400 3750 111 12.3
400 4000 109 12.6
400 4250 106 12.8
400 4500 104 13.1
400 4750 103 13.3
400 5000 101 13.5

425 1250 163 8.3
425 1500 154 8.9
425 1750 146 9.3
425 2000 140 9.8
425 2250 134 10.2
425 2500 130 10.5
425 2750 126 10.9
425 3000 122 11.2
425 3250 118 11.5
425 3500 116 11.8
425 3750 113 12.0
425 4000 111 12.3
425 4250 109 12.6
425 4500 107 12.8
425 4750 105 13.0
425 5000 103 13.2

450 1250 167 8.2
450 1500 157 8.7
450 1750 149 9.2
450 2000 142 9.6
450 2250 137 10.0
450 2500 132 10.3
450 2750 128 10.7
450 3000 124 11.0
450 3250 121 11.3
450 3500 118 11.5
450 3750 115 11.8
450 4000 113 12.1
450 4250 111 12.3
450 4500 109 12.6
450 4750 107 12.8
450 5000 105 13.0

475 1250 170 8.0
475 1500 160 8.5
475 1750 152 9.0
475 2000 145 9.4
475 2250 139 9.8
475 2500 135 10.1
475 2750 130 10.5
475 3000 127 10.8
475 3250 123 11.1
475 3500 120 11.3
475 3750 118 11.6
475 4000 115 11.9
475 4250 113 12.1
475 4500 111 12.3
475 4750 109 12.6
475 5000 107 12.8

500 1250 172 7.9
500 1500 162 8.4
500 1750 154 8.8
500 2000 147 9.2
500 2250 142 9.6
500 2500 137 10.0
500 2750 133 10.3
500 3000 129 10.6
500 3250 125 10.9
500 3500 122 11.1
500 3750 120 11.4
500 4000 117 11.7
500 4250 115 11.9
500 4500 113 12.1
500 4750 111 12.3
500 5000 109 12.6

525 1250 175 7.8
525 1500 165 8.3
525 1750 157 8.7
525 2000 150 9.1
525 2250 144 9.5
525 2500 139 9.8
525 2750 135 10.1
525 3000 131 10.4
525 3250 127 10.7
525 3500 124 11.0
525 3750 121 11.2
525 4000 119 11.5
525 4250 117 11.7
525 4500 114 11.9
525 4750 112 12.1
525 5000 110 12.3
550 1250 178 7.7
550 1500 168 8.1
550 1750 159 8.6
550 2000 152 9.0
550 2250 146 9.3
550 2500 141 9.7
550 2750 137 10.0
550 3000 133 10.3
550 3250 129 10.5
550 3500 126 10.8
550 3750 123 11.1
550 4000 121 11.3
550 4250 118 11.5
550 4500 116 11.7
550 4750 114 12.0
550 5000 112 12.2

575 1250 181 7.5
575 1500 170 8.0
575 1750 162 8.4
575 2000 154 8.8
575 2250 149 9.2
575 2500 143 9.5
575 2750 139 9.8
575 3000 135 10.1
575 3250 131 10.4
575 3500 128 10.6
575 3750 125 10.9
575 4000 123 11.1
575 4250 120 11.3
575 4500 118 11.6
575 4750 116 11.8
575 5000 114 12.0

600 1250 183 7.4
600 1500 172 7.9
600 1750 164 8.3
600 2000 157 8.7
600 2250 151 9.1
600 2500 145 9.4
600 2750 141 9.7
600 3000 137 10.0
600 3250 133 10.2
600 3500 130 10.4
600 3750 127 10.7
600 4000 124 11.0
600 4250 122 11.1
600 4500 120 11.4
600 4750 117 11.6
600 5000 115 11.8

625 1250 186 7.3
625 1500 175 7.8
625 1750 166 8.2
625 2000 159 8.6
625 2250 153 8.9
625 2500 147 9.3
625 2750 143 9.5
625 3000 139 9.8
625 3250 135 10.1
625 3500 132 10.3
625 3750 129 10.6
625 4000 126 10.8
625 4250 124 11.0
625 4500 121 11.3
625 4750 119 11.5
625 5000 117 11.7

650 1250 188 7.2
650 1500 177 7.7
650 1750 168 8.1
650 2000 161 8.5
650 2250 155 8.8
650 2500 149 9.1
650 2750 145 9.4
650 3000 141 9.7
650 3250 137 10.0
650 3500 134 10.2
650 3750 131 10.4
650 4000 128 10.7
650 4250 125 10.9
650 4500 123 11.1
650 4750 121 11.3
650 5000 119 11.5

675 1250 191 7.1
675 1500 179 7.6
675 1750 170 8.0
675 2000 163 8.4
675 2250 157 8.7
675 2500 151 9.0
675 2750 147 9.3
675 3000 142 9.6
675 3250 139 9.8
675 3500 135 10.1
675 3750 132 10.3
675 4000 129 10.5
675 4250 127 10.8
675 4500 124 11.0
675 4750 122 11.2
675 5000 120 11.4

700 1250 192 7.0
700 1500 182 7.5
700 1750 172 7.9
700 2000 165 8.3
700 2250 159 8.6
700 2500 153 9.0
700 2750 148 9.2
700 3000 144 9.5
700 3250 143 9.7
700 3500 137 10.0
700 3750 134 10.2
700 4000 131 10.4
700 4250 128 10.6
700 4500 126 10.8
700 4750 124 11.0
700 5000 122 11.2

700 1250 195 6.9
700 1500 184 7.4
700 1750 174 7.8
700 2000 167 8.2
700 2250 160 8.5
700 2500 155 8.8
725 2750 150 9.1
725 3000 146 9.4
725 3250 142 9.6
725 3500 139 9.8
725 3750 135 10.0
725 4000 132 10.3
725 4250 130 10.5
725 4500 127 10.7
725 4750 125 10.9
725 5000 123 11.1

750 1250 197 6.9
750 1500 186 7.3
750 1750 176 7.7
750 2000 169 8.1
750 2250 162 8.4
750 2500 157 8.7
750 2750 152 9.0
750 3000 147 9.2
750 3250 144 9.5
750 3500 140 9.7
750 3750 137 10.0
750 4000 134 10.2
750 4250 131 10.4
750 4500 129 10.6
750 4750 127 10.8
750 5000 124 11.0
 
Gee, I guess this means our 1966 Mustangs with an I-6 200, cutting the lights at ~70 mph in an 18 second quarter mile, were putting down a whopping 80 hp.

I WANT MY MONEY BACK!!! :D :roll: :wink:
 
From the table, an 18 second quarter mile would be needing in excess of 100 net flywheel ponies for a car that must weigh in at about 3000 pounds (horse and rider, remember?) 18 secs is about 75 mph trap speed. Don't knock your stead, Stan ma main man! :D (trying to do my best Yosimite Sam voice :wink: )

Choices are:-
75 hp 1250 lbs 92 mph 14.9 -sec
75 1500 86 15.8
75 1750 82 16.6
75 2000 78 17.4
75 2250 75 18.1 a 'Stang Can't be this light
75 2500 73 18.7
75 2750 70 19.4
75 3000 68 19.9

100 hp 1250 lbs100 mph13.5 -sec
100 1500 95 14.4
100 1750 90 15.1
100 2000 86 15.8
100 2250 83 16.4
100 2500 80 17.0
100 2750 78 17.6
100 3000 75 18.1 this is it!
 
Haven't quite worked out the relevance of 60' times, the trap speed, and if it ties into vehicle weight.

Are they at all related? :D
 
60' times will usually give you a good idea of off-the-line traction. ET shows how your chassis (and traction) are doing. MPH shows how much HP you're making (if your gearing is setup correctly). Vehicle weight effects everything.


-=Whittey=-
 
We need a Virtual Spectator Quarter Mile site on this website. You log in your default power/torque curve for your vehicle, and have Bench Racing sesssions like GT2.

Federation Against Rotaries and Turbosstrikes again!


:chill: The quarter mile calculations only need the net flywheel HP and the weight to do calcs. It assumes an optimised chassis, as Whittey says. (If you use the Moroso calculator, there is an extra half a second in it.)

Eg. 1 100 hp Stang, 3000 pounds with discokin6 and his 8" inch knife at the wheel verses Mr Bean in his 50 hp 1500 pound snot green Mini...both 30 pounds per hp cars.

The torque band (how torque is delivered) is of no relevance to a 1320 ft, 402 m, 1/4 mile standing start. Things all even out. The overall drag factor (cd times frontal area all over the total weight: power ) raises or lowers the quarter mile times and speed a little. Using a Mini with 30 lb's per hp, the quarter mile value would be 18.7@73mph, with 0.7 loss due to traction issues of a FWD car, and about 0.1 sec gain to the small frontal area which is like adding HP to the engine. The Stang would be about the 18.1@ 75. The Stang would hook up better because of the higher first gear ratio which transfers torque better, and it has a lack of weight transfer which takes weight off the driven wheels. This is what plagues the Mini and other front drive cars.

At the 60' mark, the Stang would be way ahead. At the 1/8 mile, 660 ft mark, the Mini would be gaining fast.

My friend has a 1973 Firebird with 455, it does 98 mph quarters at a best of 13.6 seconds. It creams all Ricers in his bracket at the start, even 4WD Evo's, VR4'S, Skyline GTS 2.5 R33's, every thing Jap just gets wissed on. But he gets taken to the cleaners at the 660 to 1320 foot mark. The Skylines were wicked at full wick, but didn't have the low end impulse to launch the cars hard. Thats because torque wins on the street. It's a measure of net impulse, which high-winding VTEC's and even Sierra Cosworths just can't touch. Miss a gearchange, and it's all over. His 'stupid' old Poncho just gets shoved in drive, and it cleans up the traffic. :D .

I6's are even better at the 0 to 60 foot mark than V8's if all else is equal. A Ford six doesn't spend a few split seconds trying to speed dead counterbalance weights on a V8 crank from the start line, the engine is instantly pushing a lot of air through smaller ports with less momnets of inertia holding it back. Then the V8 starts to produce power, and it pulls away. A four is always unable to make the lunge at the start like six with a similar weight to power and torque figure can. It's too busy making power through revs, as torque is always less proportionaly.

Now if only I could find the book which estimates 60 foot and 660 feet times. There are net impulse formulas which I have used before, but its a little bit of math to get into. You can take the overall Ist gear ratio, the tire patch and diameter, weight over the wheel, total weight of the car, the peak torque figure at its rpm, and then work it out on a time per 33 ft velocity/ time basis until you've plotted the whole acceleration curve. I did that with my Turbo Cortina, when I was planning to up the boost. But weight tranfer changes, and you end up making calulation stuff ups at the launch because a good six, even turbo'd , will slingshot itself off line even better than the formula suggest.
 
XECUTE":g5x9zh02 said:
From the table, an 18 second quarter mile would be needing in excess of 100 net flywheel ponies for a car that must weigh in at about 3000 pounds (horse and rider, remember?) 18 secs is about 75 mph trap speed. Don't knock your stead, Stan ma main man! :D (trying to do my best Yosimite Sam voice :wink: )

Yeah, you're right, XE. I was trying to make a joke about the low 'real world' power of the early 'Stangs, but I guess I didn't get the 'winkies' right... :wink:
 
XECUTE: How does your buddy manage to pwn off the line? Just for giggles I googled on a car you didn't mention (Talon TSI) and this is what I got:
http://ca.dsm.org/cgi/DSM-chart.cgi?cutoff=100

Take for example:
90. Norm Lachance - 1996 Eagle Talon Tsi AWD (60'=1.829)
13.694 @ 99.967 mph

Your bud can match a 1.829 with a 13 second pancho? I'm assuming fat slicks with chassis work and not much motor, am I close?


-=Whittey=-
 
Pauls 455 is just such a funny thing. Cast pistons, 468 cubes, and a stock HO intake with a 750 cfm 4MV Rochester, water injection, redline is 4800 rpm(!) and diff is 3.31 with 10 bolts 8.2 inch and 265/50 15's.THM 400 with Stage 1 kit. Cam is 6H , as are the heads. Front has no sway bar, headers are dropped, and the axle is stock with the pinion angle changed, some slapper bars, and no fiber glass, battery or body mods. The SD 455 hood scoop is removed on the strip, and a huge velocity stack with two 3 X 10" K&N air cleaners stick up like a mushroom cloud!

I'll e-mail a photo copy of his car at the start line. It's 4080 pounds with him in it, and it launches like a slingshot. 98 mph is his best speed, and we think there is 330 hp net at the flywheel trying to get out. He's the only guy Iknow with a V8 he really uses who isn't broke, and he lives on a modest wage. It never brakes things on it....although the c-clip axle has been close to loosing its axles a couple of times!

He is now working on a fiber glass replica Trans Am 400 to weigh in at 2800 pounds, built on a GM Holden sedan chassis, and a 400 HO V8 with 428 Poncho crank. Has been looking at using three TBI throttle bodies off an EA Falcon. These are 32/36 Weber baseplate, and he has a modified 389 Tri-power manifold to go on. Bl**dy good bloke for a GM man...almost as much fun as
Chevytown
 
:D man this calculator is damm near spot on!!worked out all my old drag racing times and they all worked out neatr right on the mark.my buick with 2400lb's (with me in it) and 255 rear wheel hp 12.6 yeah(best run was 12.68)spot on!! :wink:
 
:D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D :D:D



It's really a lot of cool fun, eh?. Spliced out of a US drag racing book which I hand copied from a mate who had it. The thing is very good for sorting out flywheel HP. So many people can see that there is a lot more ponies lost to the ground than just the 17-26% from a diff and manual or auto trans...there is also drag loss due to the tires. This formua works it all out based on about 32% drive line and tire loss. The net figure is also based on headers and a stricter atmospheric correction than the Moroso. I'm sure there is plenty more there buickroadster...you haven't peaked yet!

Oh an Whittey, Paul says he hasn't cracked the 1.9 second 60' time. I think he has cracked a sub 2 second one though. Virtually no wheelspin on launch, either. The tailgate weighes about 200 pound for a start, so weight transfer is all on the back wheels despite the 650 pound mule at the front. Having tall, wide tires at the back helps.

That Talon is a machine.
 
Well, you can tell Paul "Gratz" for getting that beast hooked up with a motor that puts out that kind of low end.

Yah, those Eclipses are funny beasts. 3200lbs with a stick! @_@


-=Whittey=-
 
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