Torque?

[NitrousG35]

A good way to really feel the difference is to accelerate hard up a steep hill. Torque will give you a bigger "push" while horsepower will be felt when a car is nearing redline on a flatter surface. The only time I ever played with an Si was when the G35 I own in addition to a FA5, was at a stoplight on a steep hill. The '06 FG2 nailed it, I nailed and I totally wasted the guy. BTW, my car was pure stock.

I have noticed that going up hills, my G35 is much stronger, but on a flat road surface, my Si in VTEC seems to pull harder at higher rpm's.

[TJ213]

torque = Nascars
hp + revs = F1 Cars


F1 cars are faster, HP > TQ, end of story


IMO the reason that the Si, and many other Hondas, don't have torque is that tq usually requires more displacement, which usually means lower fuel economy, and a lower redline.

S/C are another option, but Honda doesn't like that either

btw, In japan there is a tax increase for motors over 2.0l, which may be a reason why Honda likes 2.0l I4s so much

[Sirbelch]

Originally Posted by TJ213

torque = Nascars
hp + revs = F1 Cars


F1 cars are faster, HP > TQ, end of story


IMO the reason that the Si, and many other Hondas, don't have torque is that tq usually requires more displacement, which usually means lower fuel economy, and a lower redline.

S/C are another option, but Honda doesn't like that either

btw, In japan there is a tax increase for motors over 2.0l, which may be a reason why Honda likes 2.0l I4s so much

An F1 car is 2150 lbs lighter than a Cup car is. That is why an F1 car accelerates faster than a cup car. They both produce about 800 hp. An F1 car does it at 19000 rpm where a Cup car does it at 9000 rpm. With that said, and F1 car is making 221 lbs/ft of tq at 19000 rpm and a cup car makes 466 lbs/ft of tq at 9000 rpm. 466 lbs/ft of tq isn't that much when you consider that a Ford F-350 make 500+ lbs/ft of tq.


Honda uses the "less torque over more rpm" philosphy in order to make their cars go fast. This has been known about honda for decades. If you wanted torque, why did you by a honda for performance (Si)? You should have gotten a Cobalt SS/Redline or a Mini Cooper S or a MS3 or a SRT-4 or WRX or even a Mustang GT all of which are in the same pice range as an Si.

When i got in my Si after my GSR, the first thing i though was, man, this Si really has a lot more low end torque than my old GSR did.

Honda built our engines to rev so wind that bitch up and watch her fly.

[atruhondagrl]

Originally Posted by sheek360

ummm the "getting pushed back in the seat instantly" thing is the tq.

Dammit. You stole my thought.

[Jardiniboy]

Originally Posted by atruhondagrl

Dammit. You stole my thought.

Haha I was gonna say the samething too. Because couple days ago my brother let me drive his g35 (Was the D2 that night) while driving it I loved the torque. That push back to the seat feeling is great.

[Tom1222]

Torque is really what you feel and Horsepower is a number on a sheet of paper. Sure they are related but when it comes down to it torque is more important because that is what you feel when you accellerate. BTW, there are a lot of small displacement engines that have nearly as much or more torque as they have Horsepower.
Volkswagon GTI comes to mind which has a good balance of torque and horsepower and when you ever test drive one you will know that it feels a lot stronger than the Si. I just wish it wouldn't be so damn ugly then I would have bought the GTI over the Si in a heartbeat.

But overall I am pretty happy with the Si and with my mods I think I do have a nice push back in your seats feeling especially when the Nitrous kicks in :

[asndragonboii]

thanks for those in-depth explainations.

I dont have an SI though, i have an LX

[Tom1222]

Originally Posted by asndragonboii

thanks for those in-depth explainations.

I dont have an SI though, i have an LX

Even worse. It has no torque at all.
I almost settled for an EX or LX with manual transmission and when I test drove one it felt sooo sloooww that my old Geo Metro could probably have beaten it. Then I test drove the Si and it was like night and day. Much better rev range and torque curve available almost at any rpm range.

My suggestion to you is save your money and in a couple of years get something with a little bit of pep.

[SiViC06]

Originally Posted by Tom1222

Even worse. It has no torque at all.
I almost settled for an EX or LX with manual transmission and when I test drove one it felt sooo sloooww that my old Geo Metro could probably have beaten it. Then I test drove the Si and it was like night and day. Much better rev range and torque curve available almost at any rpm range.

My suggestion to you is save your money and in a couple of years get something with a little bit of pep.

[Slow_si]

See Also: Installing a V8

[SternoBoy]

Originally Posted by Blainestang

I have to disagree with a LOT of that explanation...

If you DO read that, you really should read THIS POST as a follow-up.

It's a post of mine from the last time someone pointed out that vettenet explanation.

I have to agree more with vettenet than you. For the moment, forget torque and horsepower and recall from high-school physics a = m / f. Any force applied to the mass of your car is derived entirely from torque. Consider a car weighing 2000 lbs and is generating 100 ft/lbs of peak torque at 4000rpm. Let us also assume a 4:1 total drive ratio (let's say a 4:1 final drive ration and 1:1 transmission gear ratio). This means that without any losses we're generating 400 ft/lbs of torque to the drive wheels with a drive wheel speed of 1000 rpm.

(To keep everything else simple, let us also assume no frictional losses, no wind resistance, a perfectly flat surface, no wheel slipage etc. etc. You know, the usual though experiment assumptions.)

But to determine the force applied to the car, we also need to know the diameter of the wheel. Let's say the diameter of tire is 26", that makes the radius 13" so the force transmitted to the pavement is 400lbs * 12 / 13 = 369lbs. More specifically, the thrust is 369 lbs.

Back to our weight of 2000 lbs, treating this as mass with an applied force of 369lbs we get an acceleration of 369 / 2000 = ~0.18G

Now let's change one thing: we have a car of the same weight but now we're generating our 100 ft/lbs of torque at 8000rpm. So to be at the same drive wheel speed of 1000 rpm, we'd have to downshift a gear of a 2:1 ratio thus doubling the torque with a total drive ratio of 8:1. It shouldn't be any surprise that our thrust has now doubled to 738 lbs as does our acceleration to ~0.36G

Hence vettenet's statement that it's better to make torque at high rpm than at low.

But what about peak horsepower? Again, it's a matter of taking advantage of gearing to maximize torque applied to the wheels. Our car makes 100 ft lbs of torque at 8000rpm which translates to (100 ft/lbs * 8000 rpm) / 5252 = 152 hp. But let's say at 9000 rpm our horsepower peaks at 163hp which means our torque has dropped to 95 ft/lbs. This means, that for the same drive wheel speed of 1000rpm we were doing with the 8:1 total reduction ratio, we now need a 9:1 ratio. This increases our 95 ft/lbs to 855 ft/lbs and has increased our thrust to 789 lbs and our acceleration is now ~0.39G

But what if we hadn't changed our total drive ratio to 9:1 and left it at 8:1? Our drive wheel speed would have increased from 1000rpm to 1125rpm but the torque to drive wheels would have dropped from 800 ft/lbs to 760 ft/lbs, thrust would have dropped from 738 lbs to 701 lbs, and acceleration dropped from ~0.36G to ~0.35G

So in summation: the only thing that causes acceleration is force. Torque is force. Horspower is an expression of torque over time. Acceleration is what you feel and you feel the most at peak torque.

- Mike

[asndragonboii]

Originally Posted by Tom1222

Even worse. It has no torque at all.
I almost settled for an EX or LX with manual transmission and when I test drove one it felt sooo sloooww that my old Geo Metro could probably have beaten it. Then I test drove the Si and it was like night and day. Much better rev range and torque curve available almost at any rpm range.

My suggestion to you is save your money and in a couple of years get something with a little bit of pep.

lol thanks =]

But i wasnt wondering if i could beat another car. Just wondering about torque and horsepower in general

I checked howstuffworks.com. THey got some good stuff

[Blainestang]

Originally Posted by Tom1222

Torque is really what you feel and Horsepower is a number on a sheet of paper. Sure they are related but when it comes down to it torque is more important because that is what you feel when you accellerate.

Like I said before, while technically all you "feel" is torque, the torque number on it's own means nothing. If you're making 300 ft*lb of tq, but you're making it at only 2000 rpm, and even though the torque number is REALLY high compared to, say, an Si, guess which car is going to "Feel" faster if the Si is making just 100 ft*lb of torque @ 7000 rpm?

Surprise... it's the Civic!

Know why? Because Torque*RPM is HIGHER for the Civic.

Civic = 100*7000 = 700,000
Other = 300*2000 = 600,000

So, let's figure out the ratio here:

Civic/Other = 700,000/600,000 = 1.16666666 (You'll see the importance of this later)


So, despite the other car's torque advantage, the Civic still FEELS and IS faster at those given points in the powerband, because it is making less torque, but at a much higher rate, so it is faster and feels that way as well.

And guess what? That "Torque*RPM" number, guess what that is equivalent to? HORSEPOWER! The only difference is that Horsepower is arbitrarily THAT number divided by 5252. Why? That's what the person who invented the unit decided, but if you divide both numbers by the same number, they are, for all intents and purposes, the same. So, let's change those to horsepower...

Civic = 700,000/5252 = 133.28256 hp = ~133 hp
Other = 600,000/5252 = 114.2422 hp = ~114 hp

Let's figure out the ratio again... I think most of you probably see where this is going now.

Civic/Other = 133.28256/114.2422 = ~1.1666666


Unsurprisingly, it's the same ratio as before, because we simply divided both numbers by the same number.

So, I'll reitterate what I said above. While TORQUE is the only FORCE actually acting here, it means nothing unless you include RPM, the number of times (or rate) at which you apply that torque number... aka Torque*RPM... essentially, Horsepower.


Think about it like a Flintstones car.

Let's say you've got 2 guys racing their Flintstones cars. One guy "pedals" with 200lb of force (compare to torque), but he can only do it 1 time per second (rpm)... Essentially 200lb/s (horsepower).

The other guy "pedals with only 150lb of force (torque), but he can pedal 2 times per second (rpm)... essentially, 300lb/s (horsepower).

So, despite not PUSHING quite as hard (not as much Torque, persay), the second guy pushes twice as often (double the RPM), so when you multiply the Torque time the Rate (Tq*RPM, aka Horsepower) you get a higher number, so the second guy is going to have the higher average acceleration and is going to win the race... and feel faster, on average, as well.


Again, sorry for the novel, but it's a difficult topic... mostly because of the arbitrary nature of the unit of "Horsepower". I think a lot of the confusion would be eliminated if it we just used Torque*RPM or "Ft*lb*RPMs" or something simple like that

[Blainestang]

Originally Posted by SternoBoy

So in summation: the only thing that causes acceleration is force. Torque is force. Horspower is an expression of torque over time. Acceleration is what you feel and you feel the most at peak torque.

- Mike

I think the real answer here is a mix of both your explanation and mine. In the end, yes, maximum acceleration IS at Max Torque, BUT, not necessarily Max ENGINE torque... Max acceleration is at Max APPLIED torque, which, if geared properly, is at Max Engine HORSEPOWER, not max Engine Torque.

[KingMarineM16a4]

In the low rpms it will put you back into your seat.

[mO 64 StAnG 06]

Wow.... Rep for all you guys that just explained everything.

[KingMarineM16a4]

Originally Posted by mO 64 StAnG 06

Wow.... Rep for all you guys that just explained everything.

If you want I can explain torque and horsepower down to the letter according to the Automotive Service Excellance board.

[mO 64 StAnG 06]

Originally Posted by KingMarineM16a4

If you want I can explain torque and horsepower down to the letter according to the Automotive Service Excellance board.

You just want rep don't you..... Well ya got it!

[Tastycakes]

Originally Posted by Blainestang

All you EVER feel is torque, actually, but that's a little deceiving, because how hard it FEELS like you're accelerating is based on HP, not torque. That's because the torque number, on it's own, means NOTHING. In order to really know anything, you have to know the RPM at which that Tq is being produced because that tells you basically how often you are producing that tq... essentially, Horsepower.

The reason a Torquey car feels faster at low RPM is because it's making more Horsepower. Let's say your Si is making 100 ft-lb of tq @ 2000rpm. Well, all else being equal, a car making 200 ft-lb of tq @ 2000rpm is going to feel roughly TWICE as fast. Why? Because it's making that torque at the same rate, but it's making TWICE as much as you each time. Make sense? Let's put it into the HP equation...

HP = (TQ*RPM)/5252

HP (Civic) = (100*2000)/5252 = 38 hp
HP (Other) = (200*2000)/5252 = 72 hp

Surprise... it's DOUBLE!


Now, let's say you're still making that 100 ft-lb of torque, but now you're @ 6000rpm, and the other guy is still @ 2000rpm. He's STILL making TWICE as much torque, but you're making your tq 3 times as often as he is... so let's see what happens.

HP (Civic) = (100*6000)/5252 = 114 hp
HP (Other) = (200*2000)/5252 = 72 hp

All else being equal, guess who's faster? I'll give you a hint... NOT the guy making more Torque. Know why? He's not making it nearly as often as you are. I have to explain this to people who think "Torque is EVERYTHING" all the time. Fact is, Torque means NOTHING without knowing how often you're making that torque... aka RPM. On the other hand, people with high RPM engines like to think that RPM means everything. Sorry, it doesn't, either. RPM means NOTHING without knowing how much Torque you're producing every time. So, to make it easy on everyone, we've got a special unit that combines BOTH Torque and RPM... Horsepower.

So, all you TECHNICALLY "feel" is torque, but just as important as the torque number is how many times you "feel" it.

TONS of torque even with low RPM = good HP = "Feels Fast"
TONS of RPM even with low torque = good HP = "Feels Fast"

And you know what both of these "Fast feelings" have in common? Lots of HP.


Sorry for the novel... Hope that helps

This has got to be the most informative post i'v ever read here. +1

[KingMarineM16a4]

Tq is the rotating power of the engine and horsepower is the rate a at which tq does work. Basically.