Horsepower sells cars, torque wins races.

[chiplee]

Nice charts and all, but it's just kind of understood that the area under the curve matters.

 

This is really all there is too it. Acceleration is proportional to power. Power is calculated using force (tq) and engine speed (RPM). It's true that it's always better to make more TQ, but if two engines happen to make EQUAL TQ output (have identically shaped torque curves), then the one that makes that TQ at the HIGHEST RPM will be the engine that is able to produce the faster acceleration. This is because it will be the one with higher HP. All of these examples that include multiple variables are really quite useless. TQ is the only thing an engine actually makes, but for comparing engines to each other, and for understanding how our tuning efforts are effecting the "ability" of our own engine to get our car moving, it is useful to have a measure of an engine's ability to make torque at high RPM, since that's where all the real "work" gets done. The thing we've "come up with" to represent an engine's ability to make TQ at high RPM is called HP. Comparing honda civics to cummins turbo diesels doesn't really settle anything about the whether TQ or HP "matters" more in a race. They both matter, but they're also both very closely related, and all else being equal, it's better to make your TQ at higher RPM so you can take advantage of gearing to overcome your lack of low end TQ, and still benefit from the ability to make TQ at high RPM.

Edited February 4, 2011 by chiplee

[Maxzillian]

I didn't get the impression that everyone understood that the area under the curve matters. I don't doubt that yourself, Chad, or a number of other members understand this, but we surely have a handful of members who hadn't considered this or knew any better.

 

 

I saw a lot of talk about torque being king, horsepower being king, peak this, peak that. They're certainly not numbers to ignore, but they're not all there is to consider. I realize most of my discussion has been generically aimed at Chad, and that's not quite right as I know he understands it all. Regardless, the information is useful and pretty relevant to the discussion at hand.

 

Lending off your point about making use of torque at higher RPM, I think my discussion about shift points greatly supports that as was shown in the 1st to 2nd gear shift. Despite the engine producing much less torque than it's peak, it still produced more torque at the wheels than peak wheel torque in the next gear. That just lends that often times a little torque is often more useful at a high rpm than a lot of torque at a low rpm.

 

I don't know, maybe I'm reading beyond the lines and hijacking the thread a little. As long as someone finds the information useful I don't regret it.

[chiplee]

I didn't get the impression that everyone understood that the area under the curve matters. I don't doubt that yourself, Chad, or a number of other members understand this, but we surely have a handful of members who hadn't considered this or knew any better.

 

 

I saw a lot of talk about torque being king, horsepower being king, peak this, peak that. They're certainly not numbers to ignore, but they're not all there is to consider. I realize most of my discussion has been generically aimed at Chad, and that's not quite right as I know he understands it all. Regardless, the information is useful and pretty relevant to the discussion at hand.

 

Lending off your point about making use of torque at higher RPM, I think my discussion about shift points greatly supports that as was shown in the 1st to 2nd gear shift. Despite the engine producing much less torque than it's peak, it still produced more torque at the wheels than peak wheel torque in the next gear. That just lends that often times a little torque is often more useful at a high rpm than a lot of torque at a low rpm.

 

I don't know, maybe I'm reading beyond the lines and hijacking the thread a little. As long as someone finds the information useful I don't regret it.

 

Good point, there is evidence in this thread to suggest that everyone wasn't considering the area under the curve.

[Chad]

Indeed, it's like looking at a compressor map. Few times if ever do we reach the maximum rated CFM on any given turbo, that line to the right is just the hypothetical limit of a given compressor.

 

While the dyno graph does represent the limits of a engine under a static load, driving that engine in a dynamic environment is very different, add a turbos responce curve and it becomes almost meaningless unless you are just looking at WOT performance.

 

Building a motor for maximum torque peak will not increase the acceleartion charactersitics anywhere near as much as building that motor for maximum RPM's of that torque (which means building it for horsepower instead).

 

 

I guess my summary:

 

Bragging about torque is cool,

 

Bragging about Horsepower is cooler, cause it means more and it still has torque in it. You can't take the torque out of horsepower, but there is no horsepower in torque.

[Maxzillian]

Indeed, it's like looking at a compressor map. Few times if ever do we reach the maximum rated CFM on any given turbo, that line to the right is just the hypothetical limit of a given compressor.

 

While the dyno graph does represent the limits of a engine under a static load, driving that engine in a dynamic environment is very different, add a turbos responce curve and it becomes almost meaningless unless you are just looking at WOT performance.

 

Building a motor for maximum torque peak will not increase the acceleartion charactersitics anywhere near as much as building that motor for maximum RPM's of that torque (which means building it for horsepower instead).

 

 

I guess my summary:

 

Bragging about torque is cool,

 

Bragging about Horsepower is cooler, cause it means more and it still has torque in it. You can't take the torque out of horsepower, but there is no horsepower in torque.

 

I think that's a good way to sum it up! Personally, I'm done thinking for now.

[jinx]

So you don't acknowledge that the 350 ft/lb honda motor at 8000 RPM has twice the axle torque as the 700 ft/lb 2000 RPM cummins?

 

It's all about torque, so there is your torque. the honda wins

No. I don't care what your "formulas" say. I'd have to be pretty stupid to adopt your "philosopys" over real world results, I've regularly SEEN with my own two eyes.

 

How many quick 54 powered LOW hp corolla and starlet swaps we've seen here ? Classic example;

Rolla guys proven their beloved low hp 1.8L 3TC pushrod motors, into low 10/hi 9 street cars with 5speed boxes. Gets NO better than that.

And what are they doing now? Replacing them with RZs. This is FACT, not formulas.

520hp "built" 3TC 1.8 goes 10.4, 5 speed street car.

RZ with bone stock head and cam, @26psi and ~470ish gone 9.8 no spray, 37mpg!!! Same car!

Once again what do these clowns know ? I'm sure your "axle tq" formulas prove they don't.

 

Lets' interject some common sense here

I know a few moded diesel owners. Normally clever business men, who use their truck as a boat tow rig/plaything. Look what some of them they go thru; 50+psi, meth injection, 2,3,400 shots of nitros, etc to move those heavy monsters. ONLY tq can do so

mild example;

6780 pounds, 542hp 6.6L duramax goes 12.50

What you're tellin us, is that he can SIMPLY replace that 6.6 with a DX 1.6 honda, a cam, a SC61 @~30psi, hondata tuned =542hp.... adapt it to a tranny of choice, to 'optimize' gearing, and it will accelerate that big truck to 12.50 ET

As Captain Kirk said to Spock, "are you out of your vulcan mind" ? heheh

 

That is as silly as your Banks/Ligenfelter "driveability" remark... or shift at 2500rpm.... or..

You really are misguied by peak hp numbers imo.

Stick to those formulas, if thats what works for you. I'll carry on with the real world, mang.

[Chad]

No. I don't care what your "formulas" say. I'd have to be pretty stupid to adopt your "philosopys" over real world results, I've regularly SEEN with my own two eyes.

 

 

But do you really know what you are "seeing"? Do you know the power curves of any of these cars? have you seen the dyno results on any of them. Do you know where their torque peaks are? what is their power peak? Where do they shift. All you know is you hear numbers and see results, but you don't put any effort into understanding those numbers. Have you noticed that every example with known results you have given to prove your torque theory has been rated in horsepower? don't you find that rather odd? I sure do.

 

So you don't believe the higher HP honda motor will out torque a cummins if geared correclty, or is it that you don't care that it's true? There is a very distinct difference between the two.

 

Do you believe a starquest will accelerate more quickly in 1st (at 3.369:1) than it will in 4th (1:1)? Cause if you believe that, than you belive the scinece and simple math to my axle torque claims.

 

You do realize most of your "real world" examples suffer from gearing inefficenys right? I doubt most of the higher HP motor setups spent the propper time and attention to gearing. Throw a car transmisson behing a diesel and watch it's " acceleration performance" drop. Same torque, less "performance". Same will happen if you put a diesel thansmission on a honda motor.

[Chad]

So let's demonstrate for you other real worls examples Jinx:

 

MK4 supra:

1/4 mile 13.3 seconds at 109 mph

Curb wieght 3,417 lb

320 hp at 5600 rpm and 315 ft·lb at 4000 rpm

 

Gen 1 Viper:

1/4 mile 13.1 seconds at 112 mph

curb weight 3,284 lb

400 bhp at 4600 rpm and 465 lb·ft at 3600 rpm

 

Woa, whats up with that? the supra is 4% heavier, has 20% less HP, 33% less torque, but it's 1/4 mile time is only 2% slower.

 

how do you rationalize that Jinx? Seems there is more to it than torque too . The viper has way more torque than the supra. Yes their performance is almost identical, we are takling 1/5 of a second difference in their 1/4 mile times.

 

Since it is often accepted that 100 pounds = 1/10 of a second in a 1/4 mile, if you equaized the weight of these 2 cars by throwing ~150 pounds in the back of the viper, they would be virtualy dead even at 13.3 in the 1/4, despite the HUGE 150 ft/lb torque advantage of the viper. I bet if we analysed the power curves, transmission ratios and final axle tourque, we would find the reason but I realize you hate analysis.

[jinx]

what you should realize is that I'm result oriented.

I personally, need nothing more. I should hate analysis, if they lead me to your conclusions.

If I wanna build a quick car, I do exactly what the quick cars have done. Analyze that.

 

Viper vs mk4, you're comparing boosted vs n.a, at who knows what "rated" flywheel hp.

Additinally, from viewing road testing, they never could seem to get the vipers to hook. Wanna bet... slicks on both cars, the pictures changes significantly ? Drivers. Variables?

"HP sells cars". Remember that ? Insurance companys sit on the fence and pick 'em off. Think.

Rolla example is whp, both boosted, same dyno, same driver. Nullifies "variables".

 

Yes, gearing can make a difference.

rolla example I gave played around with gearing on the 3T, but not with the RZ. Wrong again!

Stop assuming rolla guys are dummys. They don't swap in torquey RZ truck motors for "driveability". They KNOW what it takes to go quick. Proven.

As do the G54 powered ones.... or ANY bigger displacement swap = age old practice.

"Over analyze", make excuses and argue against results all u like, guy

 

I posted an Izusu gemini, full weight, streetable, 2 valve 1.8.... 9.1sec no spray.

Hondas waaayyyy more peak hp. I see 8 sec 1.8L 2300# streetable hondas everywhere. Do you ?

 

You need an abundance of tq to accelerate a greyhound bus with 60 passengers. That's why they have the torquey monsters they do.

You can't convince me that a honda 1.6 of equal peak hp will match that duramax acceleration.

Now, when I see folks start going backwards, swapping in smaller motors and ET quicker ...that's another story

I really hope those dumb diesel truck owners read this thread, and do that honda 1.6 conversion. I can see that as the next fad, instead of V10 to cummins. Wait for it

Edited February 6, 2011 by jinx

[Tim_C.]

I've been reading everyone's posts on this for years. Jinx, Chad and many others. All with good points. I figure that without enough torque, you can't get off the line from zero or low speed off of a corner. Without enough HP, you can't continue to accellerate beyond where the torque falls off. So if you are building a torque oriented race car, you need to do whatever you plan to do, at low to mid range RPM (compared to a similar class car that is built for hi-RPM racing). In other words, the Audis, and diesel cars built for torque, can rev too, but not nearly as high as the cars with gasoline / alternative fuels, built with more horsepower.

 

The real world is when you go to race your car, there will be improvements you want to make, and it depends on what will gain you most, as to what you will do. The track layout itself can change the way the car is set-up. Race teams vary their torque and HP for what track they are running. If there are long straights and less sharp turns,they want hp so they can take that RPM run-out higher. If there are many turns and few short stretches, they will increase torque in the build.

 

So, if we run our quest on a road track, and can't come out of a corner as fast as we would like, you might want to increase your torque by modifying to increase power at lower RPM. Whereas if you can come off fine from corners, but tend to nose over with people passing you before the next corner, you may want to increase power at a higher RPM. Our cars are somewhat limited because we don't have variable cam timing, and other fancy new technology items to give us the best of both worlds.

 

To me, it is all about RPM and where you want the power, because you can't really have both with our cars. I know, it isn't that simple, but that is a good starting point.

 

Instead of trying to make our points in this discussion, we should maybe turn our focus to real world help for others. Like, make a list of things to do in the build to increase torque, and another list of things to increase HP. And maybe a list of things that are common to both. Then guys can build their cars accordingly to get the results they are looking for without havng to build it over and over and learn the hard way. It sounds to me that Chad could start a list for a good HP build, and Jinx a list for a good torque build. I know we have said do this and do that many times, but a single list for each would be very helpful. Then we could have discussion about what is good to do for each direction of build, and Jinx can update his list for a torque build if he feels something discussed should go there, and Chad can do the same for HP.

 

I think a thread started by Chad and another by Jinx could open up discussion about how to build in that direction, and help us all to choose what we want to do.

 

My personal thoughts at that the StarQuest drivetrain is not built for a lot of torque in front of it. If you build too much in that direction, you may need to find ways to beef up the drivetrain. Of course, an HP build has its initial cost increase too, but at least that is mostly engine parts that are readily available in most cases.

 

We have just proven that we can argue both sides for decades, but it would be nice if the discussion could yield a list of real world improvements for both types of builds.

[Chad]

 

 

Viper vs mk4, you're comparing boosted vs n.a, at who knows what "rated" flywheel hp.

 

I gave you rated flywheel HP.

 

All a turbo does is change the shape of the torque curve, so I don't see how that turbo does anything to make the supra better than the Viper, the viper still has 150 more ft/lb, regardless of where the peak is at.

 

My point was not to show that HP trumps torque, it was to show that your method of "results oriented analysis" is flawed because you use it to draw universal conclusions that are not univerally true. Your stated conclusion is that broad high torque curves yield superior results in an acceleration contest, univerally. It was also to show your approach is flawed because it ignores other factors such as HP, transmission gearing, and axle torque cause they are for "bench racers".

 

 

 

Additinally, from viewing road testing, they never could seem to get the vipers to hook. Wanna bet... slicks on both cars, the pictures changes significantly ?

 

If I were to use your methodology of observation analysis, I'd condlude the viper has too much low end torque and would benifit from having it's power further up in the RPM band. But if we did that, it's horsepower would increase. See the corelation between higher HP and more usable torque? Seems too much low end torque is actualy a disadvantage in a real race. Again, that is using your "observe and conclude" approach.

 

So lets observe and conclude on JUST the viper then:

 

Gen 1 Viper:

1/4 mile 13.1 seconds at 112 mph

curb weight 3,284 lb

400 bhp at 4600 rpm and 465 lb·ft at 3600 rpm

 

Gen 2 Viper:

1/4 mile 12.3 seconds at 128 mph

curb weight 3,224 lb

450 bhp at ???? rpm and ??? lb·ft at ???? rpm

 

Gen 3 Viper:

quarter mile: 11.77 sec @ 123.68 mph (199.04 km/h)

curb weight 3,388 lb

500 bhp at 5600 rpm and 535 lb·ft at 4200 rpm

 

 

Gen 4 Viper:

quickest quarter mile: 10.92 sec @ 127.79 mph

curb weight 3,460 lb

600 bhp at 6000 rpm and 560 lb·ft at 5600 rpm

 

 

Notice the Torque peak goes up a full 2000 RPM from gen 1 to 4? That's a pretty fundimental change in power curves don't you think? Why did they do that? Notice the 1/4 mile times grealty improve despite the cars getting progressivly heavier (almost 200 pounds no less). the torque went up only 95 ft/lb, but the car gained a lot of weight, yet the 1/4 mile times got faster by over 2 full seconds. Surely that extra 95 ft/lb and ~200 additional pounds didn't do it. This was done on the same basic chassis, same basic aerodynamic shape, same basic weight distribution, same basic motor, same gearing, same rear tires. how to you explain this?

 

Personaly, I explain it as the car picked up 200 HP and the torque curve was moved up a lot higher into the RPM band where it's more usable in a race. The first gen 465 lb·ft at 3600 rpm is only good for puling stumps or breaking the tires loose on the street. the 4th gens 560 lb·ft at 5600 rpm (which creates 200 more HP) is for winning races.

 

If I wanna build a quick car, I do exactly what the quick cars have done. Analyze that.

 

the quick vipers added horse power by moving the torque a LOT higher up the RPM band, yielding a lot more HP. If you focus on the horse power, the torque argument becomes moot because horsepower is torque.

[Chad]

1994 Viper with a few bolt-ons

http://www.dragtimes.com/images_dyno/14451-1994-Dodge-Viper-Dyno.jpg

 

 

 

2008 bone stock viper (red line):

http://www.dragtimes.com/images_dyno/14116-2008-Dodge-Viper-Dyno.jpg'

 

Lets assume these 2 cars are in a race, they both shift at a conservitive 5500 RPM, the 2008 one with the higher HP has 500 ft/lb at 5500 (the red bone stock line). the 1994 one only has 360 ft/lb or torque at 5500 RPM.

 

Their torque peaks are only 47 ft/lb apart, but the one with more HP has a butt-load more torque at the RPM the two cars would actually race at. Does it really make sense to build a motor arrond it's torque peak now?

 

By building for horse power, you are by it's very nature building for torque, you are merely considering where that torque is in the RPM band, which is the whole logic behind my statements that building for horsepower will yield superior performance vs. the maximum torque method.

 

Also please note how the 2 dynos have ~470 ft/lb at 3600, but the one with more HP has a lot more torque and power higher in the RM band, there is no arguement here that the higher HP viper is at a disadvantage in the LOW RPM range where normal people drive their cars, there they are identical. Even at a cruise RPM of 2500 they are the same. Dodge didn't sacrifice torque, they added horse power.

[UlrichWolf]

Boy, you guys can sure over-complicate something.

 

Here's all you have to know.

 

Torque gets you OFF the line.

 

Horsepower gets you ACROSS the line.

 

See how simple that is?

 

Tim

[Chad]

 

 

Torque gets you OFF the line.

 

Horsepower gets you ACROSS the line.

 

See how simple that is?

 

Tim

 

So Tim, is that axle torque or engine torque that gets the car off the line?

[UlrichWolf]

So Tim, is that axle torque or engine torque that gets the car off the line?

 

See, there you go again, over-complicating it. That's actually a loaded question, depending on what sort of car we're discussing, because if it something with an automatic, the torque converter is multiplying engine torque.

 

However, looking at the brochure in the showroom, you don't have the technical material available to work the equation.

 

So, simply put......

 

Got a car with a monstrous torque figure? Expect a car that will do burnouts that will set off fire alarms.

 

Got a car with a goodly horsepower figure, and a somewhat equal torque figure? That's going start perking up after the 60 foot, with a rush towards the end.

 

Tim

[Chad]

"Torque gets you off the line" is an over simplification because it leads to the conclusion that making more torque is ideal for acceleration and that HP is meaningless. Take our 2 sample motors discussed earlier:

 

So you have 2000 RPM = 700 ft/lb at the crank with the cummins, though a 3.0 : 1 diff, that's 2100 ft/lb of axle torque.

 

Using the same transmission, if you put in the 4:1 diff gear change and run the honda motor out to 8000 RPM you will have 8000 RPM = 350 TQ though a 12.0 : 1 diff = 4200 ft/lb of axle torque. Due to the 4:1 honda:cummins engine RPM ratio, the axle speed will still be the same but is has more axle torque.

 

The lower torque motor can make a lot more axle torque if geared correctly, and do it at the same tire speed.

 

If we hooked up the axle to the motor with no transmisson, and if the differentiial was a 1:1 ratio, the honda will never have a chance. Since we all use transmissions and differentials on our cars so we can take advantave of this feature.

 

Torque is just one varraible, Horsepower is 3 (torque, time, and distance).

[Chad]

So Tim, is that axle torque or engine torque that gets the car off the line?

 

See, there you go again, over-complicating it. That's actually a loaded question, depending on what sort of car we're discussing, because if it something with an automatic, the torque converter is multiplying engine torque.

 

Tim

How is that overcomplicated? it's a very simple question about torque actually getting to the pavement.

 

The transmisson and differential are your torque multipliers, the converter is a coupling device. the converter is not a multiplier. the transmission is a torque devider when in Overdrive.

 

 

Got a car with a monstrous torque figure? Expect a car that will do burnouts that will set off fire alarms.

 

Got a car with a goodly horsepower figure, and a somewhat equal torque figure? That's going start perking up after the 60 foot, with a rush towards the end.

 

That assumes equal transmission/differential gearing. Most "torque" motors use numericaly low gears, while most high HP motors have numericaly high gearing. This is done to equalize the scenenrio. Take 2 motors with equal HP but different torque, if you equalized their gearing ratios arround thier horsepower peaks, they would have the same tire speed/torque at that peak.

 

Ever see a formula-1 car do a smokey burnout? they have about the same torque at a stock v-6 mustang, but they can easily cook the rubber off a super stickey track tire, and lay that stickey rubber for hundereds of feet. That's not engine torque, it's gearing and horsepower, which creates axle torque. A current F-1 engine makes about 980 HP at 18,000 RPM but that is only 286 ft/lb.

 

Go to a dodge dealership and pull out the brochures. Say they have ae gen-1 and gen-4 viper. Almost the same torque, but one has 200 More HP. The one with more 95 ft/lb more torque weighs almost 200 pounds more. They have the same gearing and are almost identical in all other ways. Which one is going to excite you more in the delaership? By your measure, they should be the same, but the one with 200 more HP kicks the other ones butt in real life. horsepower on the borochure tells you something that torque can't.

 

It is very simple, no over-complication at all.

[UlrichWolf]

How is that overcomplicated? it's a very simple question about torque actually getting to the pavement.

 

The transmisson and differential are your torque multipliers, the converter is a coupling device. the converter is not a multiplier. the transmission is a torque devider when in Overdrive.

 

I'd look up torque converter basics, amigo. While it is true that a torque converter is a fancy fluid coupling, due to the design, it can multiply torque when there is a substantial difference between input and output rotational speed, thus providing the equivalent of a reduction gear. The one in the 4R70W in my Vic will do about 2.2 times...this is why the transmission is rated for 700 ft-lbs of torque, and a slightly modded engine will burn it up.

 

 

 

 

That assumes equal transmission/differential gearing. Most "torque" motors use numericaly low gears, while most high HP motors have numericaly high gearing. This is done to equalize the scenenrio. Take 2 motors with equal HP but different torque, if you equalized their gearing ratios arround thier horsepower peaks, they would have the same tire speed/torque at that peak.

 

Ever see a formula-1 car do a smokey burnout? they have about the same torque at a stock honda civic, but they can easily cook the rubber off a super stickey track tire, and lay that stickey rubber for hundereds of feet. That's not engine torque, it's gearing and horsepower, which creates axle torque.

 

Go to a dodge dealership and pull out the brochures. Say they have ae gen-1 and gen-4 viper. Almost the same torque, but one has 200 More HP. The one with more 95 ft/lb more torque weighs almost 200 pounds more. They have the same gearing and are almost identical in all other ways. Which one is going to excite you more in the delaership? By your measure, they should be the same, the one with 200 more HP kicks the other ones butt in real life. horsepower on the borochure tells you something that torque can't.

 

It is very simple, no over-complication at all.

 

Yes, I agree, with you. The gearing makes a fantastic difference on how a car will feel. However, I think your Dodge Viper considerations are somewhat flawed. First off, 95 ft/lb more torque is NOT almost the same, and just as I said earlier, the higher horsepower will cross the finish line first, even if it does feel a little soft off the line.

 

I think we're saying almost the same thing here.

 

Tim

[Chad]

But the torque converter does not "create torque", it "converts" it. If the converter increases torque, it does so by reducing gear speed, not unlike a CTV transmission. It is in effect addign a fluid "gear" between the engine and transmission. What it is doing is idealizing ratios at the time.

 

The torque difference between the 2 vipers is ~17%, but the performance difference is more like 35%. Keep in mind it takes more than 17% more torque to go from a 13+ second 1/4 mile to sub 11 seconds. acceleration is a square equasion.

[lmwii]

the math that chad is presenting is unarguably right. in a perfect world, the greater hp motor wins every time. if you can't wrap your mind around the figures, read the example below. it takes the torque argument to its logical conclusion, and kills it.

 

http://vettenet.org/torquehp.html

 

The Case For Horsepower

 

OK. If torque is so all-fired important, why do we care about horsepower?

Because (to quote a friend), "It is better to make torque at high rpm than at low rpm, because you can take advantage of *gearing*.

 

For an extreme example of this, I'll leave carland for a moment, and describe a waterwheel I got to watch awhile ago. This was a pretty massive wheel (built a couple of hundred years ago), rotating lazily on a shaft which was connected to the works inside a flour mill. Working some things out from what the people in the mill said, I was able to determine that the wheel typically generated about 2600(!) foot pounds of torque. I had clocked its speed, and determined that it was rotating at about 12 rpm. If we hooked that wheel to, say, the drivewheels of a car, that car would go from zero to twelve rpm in a flash, and the waterwheel would hardly notice :-).

 

On the other hand, twelve rpm of the drivewheels is around one mph for the average car, and, in order to go faster, we'd need to gear it up. To get to 60 mph would require gearing the wheel up enough so that it would be effectively making a little over 43 foot pounds of torque at the output, which is not only a relatively small amount, it's less than what the average car would need in order to actually get to 60. Applying the conversion formula gives us the facts on this. Twelve times twenty six hundred, over five thousand two hundred fifty two gives us:

 

6 HP.

 

Oops. Now we see the rest of the story. While it's clearly true that the water wheel can exert a *bunch* of force, its *power* (ability to do work over time) is severely limited.

[Chad]

Despite its 2-ton curb weight, the Crown Victoria was reasonably quick thanks to a 4.6-liter V8 engine with 224 horsepower and 272 pound-feet of torque; LX models equipped with the upgraded performance package were a bit swifter, with 239 horses and 287 lb-ft of torque. A four-speed automatic was the only transmission available, although Crown Vics equipped with the sport package also had an upgraded torque converter and shorter rear-axle gearing that made for quicker initial acceleration off the line

 

So assuming you have that 287 ft/lb LX version and a 2.2:1 torque multiplying converter, you still have just 239 horsepower reaching the pavement, no matter what. It's going to have more torque on it, but the axle speed will be less. It will make the car a lot more responsive, and subsequently the "initial acceleration" will be better, but the car will not reach the end of a track any quicker. While it's busy "torquing" that rear axle, it has ginven up it's axle speed. Makes the car "feel" faster, but it's not actually faster.

 

I get what you are saying Tim, I just think you are doing a dis-service to the learning of others to make general statements witout addressing the mechanics and physics behind them. Yes, the crown vic is probably faster than the viper from 25-30 MPH, but is it faster than the viper from 25-60? I really doubt it. That is the difference you and I are talking about.

[Chad]

Thanks Imwii, I knew that one was out there, but I didn't find it. That one has been on the net for quite a while, and it is the article that was the catalist for my own journey to understanding.

[UlrichWolf]

So assuming you have that 287 ft/lb LX version and a 2.2:1 torque multiplying converter, you still have just 239 horsepower reaching the pavement, no matter what. It's going to have more torque on it, but the axle speed will be less. It will make the car a lot more responsive, and subsequently the "initial acceleration" will be better, but the car will not reach the end of a track any quicker. While it's busy "torquing" that rear axle, it has ginven up it's axle speed. Makes the car "feel" faster, but it's not actually faster.

 

I get what you are saying Tim, I just think you are doing a dis-service to the learning of others to make general statements witout addressing the physics behind them. Yes, the crown vic is probably faster than the viper from 25-30 MPH, but it it faster than the viper from 25-60? That is the difference you and I are talking about.

 

I would like the opportunity to discuss this more, however, I have an appointment to keep at the moment......so don't think I am abandoning the conversation.

 

I will be back later to further this.

 

Tim

[jinx]

I have already typed more than it's worth, and showed enough examples to prove that HP will NOT trump torque everytime.

Izusu gemini, full weight, streetable, 2 valve 1.8.... 9.1sec no spray.

Hondas waaayyyy more peak hp.

and 100 times more higher hp 1.8 hondas out there. Show me these 8 sec 1.8L 2300# streetable hondas then. Should be lots of them

 

as Tim C summed it up, you can get a torque curve to do as good an acceleration job as any, without making the tq higher in the rev band(i.e. peak hp). End of story

[chiplee]

I have already typed more than it's worth, and showed enough examples to prove that HP will NOT trump torque everytime.

 

and 100 times more higher hp 1.8 hondas out there. Show me these 8 sec 1.8L 2300# streetable hondas then. Should be lots of them

 

as Tim C summed it up, you can get a torque curve to do as good an acceleration job as any, without making the tq higher in the rev band(i.e. peak hp). End of story

 

Absolute nonsense.