1/4 MILE/HORSEPOWER CALCULATOR [Archive] - SR20 Forum

: 1/4 MILE/HORSEPOWER CALCULATOR


04-20-2001, 03:27 PM
go to www.wkdtrbo57.bigstep.com (http://www.wkdtrbo57.bigstep.com) . there i have a link to a hp and 1/4 mile calculator. simply type in your car's weight off u go!!! i am trying to promote my site-please help. there are also 30 or so nissan related links.. thanks

MarC
04-20-2001, 04:24 PM
That HP one is WAY off. It told me I have 158.19 HP at wheels, 205.65 HP at flywheel
I dont think so.

MarC

04-20-2001, 04:44 PM
well MarC, this is not my calculation-just a link. just out of curiousity-how "off" is the HP one? can u shed some light on it? and also - is the 1/4 mile one off? thanks for looking anyway MarC.. :-)

Limited Slip
04-20-2001, 06:11 PM
1hp = 550lb 1ft 1second...

i guess thats assuming 1:1 gear ratio and 15% driveline loss...

http://laf.cioe.com/~benbobbo/NonCGI/confused.gif

Pit_Viper
04-20-2001, 06:13 PM
A quarter-mile calculator should really calculate trap speed, not ET (trap speeds are far more consistent).

The following formula is used for many such calculators:


HP = Weight (lbs) x (Trap Speed (mph) / 234) ^ 3

Scarpa
04-20-2001, 06:25 PM
<font face="Verdana, Arial" size="2">1hp = 550lb 1ft 1second...
i guess thats assuming 1:1 gear ratio and 15% driveline loss...</font>

Actually, horsepower is derived directly from torque. That's why on a dyno chart the HP and Torque curves cross at the exact same point every time. I can dig up a HP vs Torque article if you want, it's sort of a tricky subject and even though I've read a lot about it I don't feel like I know enough to explain it.



------------------
Paul
'92 NX2000 w/ mods

Limited Slip
04-20-2001, 10:49 PM
<font face="Verdana, Arial" size="2">Originally posted by Scarpa:
Actually, horsepower is derived directly from torque. That's why on a dyno chart the HP and Torque curves cross at the exact same point every time. I can dig up a HP vs Torque article if you want, it's sort of a tricky subject and even though I've read a lot about it I don't feel like I know enough to explain it.

</font>

you got me all wrong, i just gave out the definition for the unit horsepower. i mentioned that those trap-speed calculators probably assumes that there is a 15% parasitic loss (through drivetrain) and that all the crank is hooked up to wheels at axles at 1:1 ratio.

hp is a calculated number from torque and engine speed. hp = torque*rpm/5252