gulzarh

i have Honda civic 2001 dx. i want to know how to calculate hp and what is for my car.
i read online but didn't get it at all. for my car it says''

Engine 1.7L L4 SOHC 16 valves
HP (hp@rpm) = 115 @ 6100
Torque (lb.ft@rpm) = 110 @ 4500

my car engine can make 240KMPH what i see in Dashboard.

i am really confused about that. Thanks to all

xRiCeBoYx

iTrader: (22)

From your post history, is it safe to assume you have an automatic transmission?

If so, a stock d17a1 (the engine in your car) makes 115 max horsepower at the crankshaft. Transmission and drivetrain does incur some power loss as it's transmitted to the wheels. That said, your car is probably putting down 80 wheel horsepower (or, horsepower as measured after the power loss due to tranny and drivetrain).

Torque is just the rotational force the engine is capable of.

The speedometer is no indicative of the top speed of the car. If I remember correctly, the automatic transmission is electrically governed to 110MPH (~180kph).

So, just out of curiosity, what are you confused about?

gulzarh

Yes it is automatic transmission.
Actually what i meant to say by confused is that i dont know what is horse power, torque and how to calculate it. i know a little bit but i cannot explain what i know.
after my research on internet what i understood how to calculate hp is lik that:
1 hp = move 25kg in 1 seconde for 1 foot distance
if my car have 115hp, it mean it can move 2875kg in 1 sec for 1 foot distance. more than this then engine will not able at all. is that right? if so, 2875kg should include car own weight also or car own weight + 2875kg ?

ezone

http://www.web-cars.com/math/horsepower.html

http://www.groschopp.com/blog/what-is-horsepower-hp/

sdaidoji

iTrader: (1)

....

does it matter if you know how to calculate horsepower?

your car have what it have...

xRiCeBoYx

iTrader: (22)

if you really want an accurate reading of your car's horsepower and torque, pay to put it on a dynamometer. Prolly cost you $100

The D17A1 (honda civic dx/lx) engine is rated at 115 horsepower.

Automatic transmission makes the horsepower loss more substantial than a manual transmission.

A manual transmission D17A1 has been dyno'd at about 90 horsepower at the wheels. Estimated automatic transmission D17A1 is about 80 horsepower at the wheels.

For comparison, the D17A2 (USDM ex/Canadian Si) has the following ratings:
127 horsepower (crankshaft - no transmission/drivetrain losses)
110 horsepower (Manual transmission, horsepower measured at the wheels)
90-something horsepower (automatic transmission, horsepower measured at the wheels)

gulzarh

i am just curious to know what is horsepower for general knowledge that s all.

xRiCeBoYx

iTrader: (22)

Just a power rating. Break it down further, work over time.

1 horsepower is the work done at the rate of 550 foot-lbs per second.

Trying to manually calculate your car's horsepower would be about as useful as manually calculating the amount calories in your breakfast. Just saying.

gulzarh

what it doesn mean 550 foot-lbs per second and why 550? why not 500 400 or 600 ?

xRiCeBoYx

iTrader: (22)

because when James Watt used it originally, it was the work produced by a steam engine, as compared to that of a literal horse, hence, horsepower. He calculated that a horse could do the work of 550 ft-lbs per second. The unit of "Watts" is named after the guy.

gulzarh

it mean if i can pickup 550lb and move one foot in one second, it mean i have 1 horsepower?

xRiCeBoYx

iTrader: (22)

Technically yes

gulzarh

reallay??

my car have 115hp
if so, 115 x 550lb = 63250lb
28689,717KG
my car engine so strong it can move 28689 KG. wow...

xRiCeBoYx

iTrader: (22)

I think you're missing the point, but okay.

gulzarh

which one?

xRiCeBoYx

iTrader: (22)

horsepower is simply a power rating. A rating at the rate at which an engine can do work. If you want to move 28689kg, sure, it'll do it. For one second. Theoretically. Then die. If you were to try it, it'd likely not work ever again. Mind you, the work that the engine is producing is rotational work. The transmission and drivetrain convert that to lateral movement.

Materials in construction of your engine further limit the stresses the engine can handle in day to day operations.

Furthermore, there are many variables that make that figure vary quite a bit, including air temperature, available oxygen in the air, road conditions, driving behavior, etc. Perfect conditions, with no power loss at the transmission, drivetrain, and wheels, your car will produce 115 horsepower at 6100RPMs

There's a lot more to engine power than figuring out "my car weighs x, if I can move it for this long, how many horsepower is that?"

This is seriously knowledge you don't need to operate or modify your engine. Use it as a numerical value as opposed to the physics behind it.

pjb3

You have your units all wrong. 500 ft-lbs/sec is not the same as 500 lbs, one is work and the other is weight. So yes, your car engine can move 28689 KG (weight) with the right gearing but you have not specified how fast and how far (work).

You also seem to be confusing mechanical or brake horsepower with drawbar horsepower.

Wankenstein

OP: here's an easy equation to apply to your Civic...D17 engine + base model automatic transmission + weight of car = ball-less

xRiCeBoYx

iTrader: (22)

Good catch. Didn't even realize it. I was too caught up in... explanation.. mode...

ezone

HP and torque ratings are for sales and bench racers LOL
I don't need to know any of those numbers to fix em.