Yes this topic has been beaten to death. Really I have a question regarding the topic. i need a little understanding. I thought i read sometime in the past that an engine that makes more HP will eventually dominate one that makes more torque but less HP. I also read some where that an engine that can breathe well(good flowing head) will shine in the higher rev range(with supporting mods of course)

This was posted in another forum and it doesnt sound quite right:

"a stock RSX-S on a typical dyno makes roughly 121ft/lbs of usable torque (i know there can be a lot of variables), with all of the good "bolt on" mods and a tune on the same dyno you could be making as much as 144ft/lbs of torque at 3500rpm producing 96hp. at 6500rpm if you're still making 144ft/lbs you're now producing 178hp. almost twice the hp but your car isn't accelerating any "harder" at 6500rpm than it was at 3500rpm in the same gear, because you're making the same amount of torque at both engine speeds. the K20A2 typically peaks in torque around 6000-6500rpm and that's where "all the power" is and where it accelerates your car "hardest". by 7600rpm it's trailed off some to say 137ft/lbs and now you're producing 201hp. if you look at dyno figures, by 8600rpm you're only generating about 87% of available torque which in this example would be 126ft/lbs, meaning your car is now accelerating at a lower rate, but you're still generating MORE hp @206! alright that's awesome! now you're cool and way faster bouncing off the rev limiter, with those extra 5 ponies that aren't doing as much you'll surely be able to leave that 350Z in the dust."


Also this:

"what you have to realize is that with good intake and exhaust mods and a reflash you're reaching the limits of the engine's torque and hp capabilities, without boosting of course (boosting adds TORQUE, not revs btw). you can drop thousands more dollars on "high performance" cams valves intake manifolds k-pro injectors pulleys spark plugs and stickers to squeeze out the last 8 or so ft/lbs of torque from this engine, it still won't be much faster....."

 

That is total BS.

Think of running up a flight of stairs. Your leg can produce the work (torque) required to move your body mass to the next step, but it's how rapidly you can perform that work (horsepower) that gets you up the flight of stairs faster.

A Formula One engine isn't turning nearly 20,000 RPM to make more torque. Its so that they can make the most torque at a higher RPM and acheive more horsepower.

 

Thought so.

 

thats a great anology.

stratton.

 

no it's not BS, it's physics.

force=mass*acceleration

the force is your measured torque, the mass is the weight of the car. if in fact the torque is the same at 3500 and 6500 and the mass of the car hasn't changed... acceleration must also be the same at both RPM. needless to say you must control for gear ratio and external friction like wind resistance...

 

in terms of distance covered (and if you are interested in time required) you should look at Horsepower because that is a measure of work (force over distance)

rate of acceleration is what you feel and is a function of weight, drag, and wheel torque.

the history of the term "horsepower" is actually halarious. oringally used to compare mines if im not mistaken and it was originally pony power but ponies are the twinks of the horse world so they said 2 pony power = 1 horse power to be more macho lol

 

How many of you really aspire to rev at 20,000 rpm to find the sweet spot in a motor that's 2.0-2,4 liters? When the light goes green on your way to work are you willing to launch at 7K-7.5K just to get to the motors sweet spot and accelerate past a Pinto? HP and torque are both necessary in a performance motor. Not trying to be a peehnuss head.

 

you've got it all there but i think because of your wording it seems like you're saying work is measured in Hp. to do a "measure of work" in some "time required" is power. [i think you know that, i can just imagine someone reading that misunderstanding and then misquoting it like wild fire...]

the work, commonly expressed in Joules or also Newton-meters... which converts to ft-lbs is known as torque.

 

So you have little experience with a Honda 4 banger, is that what you are saying??

 

h2b for the win

 

This may just be a random comment but I have always thought of torque as a turning force (work) and horsepower as simply a measure of the rate torque is being produced over time (rpm). Don't know if that makes sense...

That may be more random than my comment lol

 

that's similar to how i think of it. the wording that makes the most sense to me... at the point of contact with the road it becomes a linear force like thrust. so i think of torque as effective thrust. and horsepower; how hard/fast it can "fight" to overcome opposing forces. things like wind resistance, friction, gravity (uphill).

another way...
a lack of Hp is where i can't maintain some speed on the interstate uphill, into the wind. a lack of torque is where it takes too long to reach some speed from some lower speed (technically "area under the torque curve" or average torque for the given range). we know this is why torque is always related to accel. and horsepower to max speed.

...and I'm rambling.

 

After reading the comments here from Jean-Bernard-Léon Foucault and Einstein, I just wanna throw away the B20 on my car...

 

b20's are garb. B-series in general are garb. Take way to much bullshit just to crack passed 200whp

 

I think I might swap back to a B16 with some stupid add ons and leave the car mostly original. Everybody's gonna give a different opinion anyway. The thing with the B20s is that I read everywhere about the freaking sleeves, "don't make it turbo, the sleeves crack", "it won't handle the Vtec head, eventually will crack the sleeves"... I have it just bcuz I bought the car with it... My personal opinion I'd like the ability to go with HP vs TQ... and I know this B20 will limit that big time...

 

This isn't 1999. There's been plenty of times stock b20s are able to handle tons of abuse. There are piston and rod combo b20s making 400+ on stock sleeves. B16s are even bigger turds, no torque whats so ever. You look like your trying to turbo your turd though so it wouldn't make a difference.

 

Not garbage. Just past their prime. They are still fun motors, but technologically out dated is all.

 

H's are also "outdated" and h2b's out torque and power most b-series with just bolt on's and built b-series for that matter aswell.

 

if hp is a product of torque then why is there even a discusion? Without toque you dont have hp right? so the question becomes," Is it better to make peak torque at a higher or lower rpm? and what gearing is best for the rpm range?" Plus you have to consider the design of the motor and wheither or not it will permit better efficieancy at lower or highwer rpm range. eg: rod stroke ratio, rotating mass, head port design... I mean arent certain motors designed for different aplications? So in my opinion I could care less how much hp i make and how much torque but wheither or not all my parts work together to achieve my goal. Oh yeah for the record more torque and proper gearing always, repeat always wins the race.

 

 

First off, discussing peak numbers (whether we're talking hp or torque) is rather meaningless in determining performance. Area under the curve has far more value than the peak numbers.

That aside, make HP with the engine, make torque with gearing.

My GSR makes over 1,175 ft-lbs in second gear.

 

thats alot of torque, imagine if your motor made 20 more foot pounds of torque at the motor so if you put a shorter final drive in you will make even more power. ft-lbs is a measure of force we call torque, torque rates and hp rates are linear because hp is a PRODUCT of applied torque. The rate of increase in torque is identical to the rate of increase hp becaus the are the same thing, power. the question again is at what time or rpm does your motor make the most power, force torque. not hp. and how do you harness that time frame with selecting the proper gearing and shift points.

here's an example instead of rpm imagine revolution per sec, or better yet degrees of rotation per half a second. your crankshaft travels a certain distance or degrees maintaning a certain amount of force or ft-lb of torque, ther is no hp going on there. there is inertia because an object in motion wants to stay in motion but no hp. Horsepower doesnt exist, it is made up to give you an idea of the amount of ft-lb of torque your motor is producing.

maybe im misunderstanding the original question cause I've had too much caffine but hp is always relevant to applied ft-lbs of torque

my bad i see what hes asking. hes asking if its better to make power at a high rate vs a lower rate. that question answers itself?

 

TORQUE

 

 

great info