Horsepower (hp) = torque * RPM / 5500 or something like that. I can't imagine any useful information you can get with this, other than power, which is how much energy per time, meaning it is useful for describing "how fast an engine can be strong."

An s2000 has low torque (160) but a high redline. Looking at the equation, that's how it gets most of its 240 hp from the high 9000 redline. I think the only reason s2000 can accelerate as fast as it does is it can hold a gear longer, not really cuz of the horsepower rating.

109hp Fit is faster than a 110hp civic, b/c throughout most of the RPM, the fits torque curve is flat, and most of the time it's *very* close to its peak @ 105. I think the civic redlines 500-1000RPM higher than a fit, am I right? Two cars can have the same horsepower, same weight, etc, but one car can drive better b/c its torque curve.

In drifting, when they say "the third way of drifting is when a car has a lot of horsepower". Don't they really mean torque?

an electric car tesla has super high torque at 0rpm. Its peak hp is 250 even with a high "redline" of 13,400, but it is still faster than a most ferrarris or cars way above 250hp.

 

You're right. Horsepower is nothing more than a unit in which we measure the power an engine can produce. It's also a very misunderstood property... but given it's complicated nature, I am not surprised people tend to mix it up.

 

horsepower sells cars
torque wins races

=)

 

I don't care for HP. its all about Efficiency and Balance.

I'd rather have a 200 HP car that was efficient, well balanced, and the HP came easily and quickly. than a car that had 1,000 HP but it was a horrible ride.

Sometimes people just like to show off their small penis's by revving their engines at a stop-light and saying "woot! i'm faster than you!" in reality, the best tuned car is a balanced car. I could easily slap a turbo onto any car and crank the boost controller all the way up. that way i'd spank anyone at a stop light. but true tuning isn't about straight line speed, its about suspension, weight reduction, balanced parts, etc.

So the next dude who just spent 5,000 dollars on his engine and NOTHING on his suspension, just laugh at him. cause he may beat you in a straight line, but when it comes to cornering he'll just flip.

 

Just wanted to note (which you hinted at) that Hondas are different from almost all other makes in the sense that they [generally] produce power over a longer powerband than other makes. The curves would be totally different if, for example, my 07 Si had a redline of 6000 vs. the factory 8300 (woohoo!!!!). If Hondas make power in relation to engine speed, than the longer you can hold a specific gear before the shift, the faster you go from point A to point B. The time difference when a human is shifting a manual transmission vs. say, a sequential clutchless transmission, can be astoundingly long. The Volkswagen DSG system shifts at .25 of a second, I believe? That's a lot faster than any human could ever hope to shift.

As far as drifting goes, since torque gets you moving, I would presume you'd rather want higher horsepower than to better-control oversteer. I would think with a ton of torque, you'd increase the chances of encountering too much oversteer, especially in lighterweight vehicles. Just my thoughts though, and I'm not all that familiar with the technical aspects of drifting. But damn is it fun to watch

 

Cosigned .. any retard can drive in a strait line.

 

Gearing also has a lot to do with how fast a car is in relation to it's power and weight. I used to have a MazdaProtege5 that was rated at 130 HP (and i had an intake and catback) and im pretty sure my stock fit is faster, especially between 80-100 mph. Although the gearing wasn't poorly done on the P5, I'm quite sure that the gearing is almost as perfect as it can be in the Fit, to get all it can out of the 109 HP.

 

yea of course gearing is important. Torque is meaningless without a gear ratio. "real" torque = torque * gear ratio * final gear ratio, so even if, say, the s2000 has a low torque of 160, since it has a big redline, it can also up the gear ratio to get that leverage.

 

yes your getting it.

Remember that the S2000 puts out loads of HP due to a large cam profile and a very breathable head ect. The redline DOES NOT give it more power. The high redline let's the engine take advantage of the tall long duration cams that makes power at high RPM.

I also don't put to much weight into HP numbers. For example a ford mustang has 210 hp and 240 lb-ft but is slow.

 

Was that pun intentional? Mustangs are heavy pigs (usually with the power to make up for it). We used to eat them all day in our EG's and EK's. Power-to-weight ratio kicks bootay... lol

 

[quote=Gordio]
109hp Fit is faster than a 110hp civic, b/c throughout most of the RPM, the fits torque curve is flat, and most of the time it's *very* close to its peak @ 105. I think the civic redlines 500-1000RPM higher than a fit, am I right? Two cars can have the same horsepower, same weight, etc, but one car can drive better b/c its torque curve.
quote]

Same HP and same weight is only part of the equation-
Important to consider-
Gearing- closely spaced lower gears help
Traction- which differential?, which tires-soft rubber is better/faster but wears quicker
Lightness of rims/ tires
Presence of electronic traction control- turn it off if possible

 

[quote=MINI-Fit]I think just about everything except the gearing is null when comparing the Civic and Fit. Both have an open diff, there's no traction control on either (Civic Si models being the exception) and to my knowledge they both use the same tires. The difference between these two examples, is primarily down to weight, gearing and rotational mass.

 

ok after reading hte first post i think you guys have a serious misconception on what these two figures are

torque is the force that drives/turns the wheels, horsepower is a measure of power which is the amount of work the engine can do over time

with the final gear ratios at the wheels and the torque figure at that specific rpm you can figure out how fast your car will accelerate, this is called instantaneous acceleration

power is what ultimately decides how fast you can go (your top speed) because it is a measure of how much drag your engine can overcome in a certain amount of time (if you fool around with the equation you'll get what i mean)

anyways, alot of people just look at the peak figures which is almost never a good representation of what the car can do, you never just use your car at 3000 rpm, you use the entire rev range, which is why you need to look at dyno charts

the best way to estimate what performance would be like would be to take the area under the curve, which is representative of what the car would do throughout it's operational capacity

take a look at the mazdaspeed 3 and 6, both have really high peak hp and tq figures but their power curve sucks ass, with the torque falling quickly way before redline effectively rendering the last couple thousand rpm in it's rev range useless

take a look at the civic si and s2000 who's torque curves are flat up until their redlines, letting you use all of the engine all the time

another reason why peak torque at the engine doesnt matter is because of gear ratios, an engine putting out 300lb-ft at 3000 rpm going through a 1:1 gear ratio puts out the same torque at the wheels as an engine putting out 150lb-ft at 3000rpm through a 1:2 ratio

as a personal opinion i prefer high strung engines which have their power and torque peaks occuring high in the rev range as to engines who have lots of grunt at the low range but lose their puff at high rpm

anyways i just realized ive gotten far off topic so il stop here

 

Actually, he makes some very valid points...

 

Probobly the single best wording I've seen. Only thing is how the torque is distributed throughout the rpms. Its much better to have a lower torque peak but flatter than a quick peak that is almost useless until you are in that narrow rpm range. I wish people understood that. At least I got to toss in my 2 cents...

 

couldn't have put it better myself, peak figures are only representative of one point in the rev range

a flat torque curve and lots of space under the curve is what gives real performance and seperates the great from the mediocre

 

i wouldnt know. i drive a honda.

 

People are discussing HP vs torque. I rode in the fastest (read scariest) car of my life. It was a gutted '72 Camaro with a.040" bored over 454 with dual 4 bbl carbs. I was unable to pull my head off of the head wrest during accel. Having said that, it only churned 380 HP. The local shop was never able to measure the torque because the pressure valve would blow before it even reached 2k rpm. Anyway, the 380 HP belittled the amazing power of the car. Here is the simple equation for converting (unable to verify other source) but it is as follows:
HP = (torque x RPM)/5252
So if you know all the numbers ie. RPM and HP torque can be done with some 6th grade algebra.
Hope this helps.

 

read what i said

and btw that formula only works when the units are horsepower and ft-lbs

 

With all due respect, the formula I gave implied horsepower and ft-lbs...not metric or I would have noted that.