spetz99

Hello all,

Does 15lbs of more torque than the old VQ engine makes really any difference the 3rd generation 190 hp se and the 4th generation 190 se.
Old one produces 190 hp at 5600 rpm and 190 lbs at 4000 rpm.
New one produces 190 hp at 5600 but 205 lbs at 4000 rpm.
That is only 15lbs more, but does 15lbs make any difference?
Does the 4th generation maxima considered as a low end or high end power vehicle. Last but least either in auto or stick where does the engine at what rpm produces the most torque. Sorry for the long winded question.

Thanks.

MaxedOut97SE

Yes, it should make somewhat of a difference. I've never thouroughly (sp?) driven a 3rd gen SE engine w/ 190HP, but I can tell you that the 4th gen engine has forever been praised for its torque. I'm sure the 3rd gen engine has sufficient pull, but not quite that of the 4th gen. engine. One amazing attribute of the 4th gen. VQ is the fact that it has so much grunt but still flies in the top end. However I would say that the torque is more impressive overall. And for your last question, the VQ produces 95% of its torque between 1500RPM and 4500RPM. (not sure if thats 100% accurate, but its close) I drive a 5spd, and I very rarely find myself having to downshift for more power in everyday traffic, hell, I can power it up from 30 in 5th gear (about 1500RPM) with absolutely NO problem. Hope this answers your questions, if not let me know.

I30CeFiRo

The more torque you have the better your acceleration is. 15 ft/lbs of torque can make a noticable difference

BobMax

>The more torque you have the better your acceleration is.

An automatic can use the additional torque when starting out because the RPM's are so low and there's a lot of waste in the auto tranny. It's much more noticable (in general) in an auto.

Bob

BrianV

iTrader: (9)

horsepower is derived from torque even

HP = (torque * RPM) / 5252

I think the 4th gen Vq is a mid-range power engine

Not good low end or high end, but killer middle. My car dies down at about 5500 and it needs to be at about 3500 to really start moving.

brubenstein

If your run the 4000 RPM torque values through the HP equation, you'll see that there is a 12 HP difference at 4000 RPM. Since the torque specs are at 4000 RPM, it's pretty safe to assume that that is where the torque peak is.

Pervis Anathema

iTrader: (8)

In simple terms, torque is a measure of how much work an engine can do. Horsepower is a meausure of how fast an engine can do the work. That is one of the reasons why a tractor trailor with ~1300 lbs-ft of torque but only 250 hp moves slowly.

More torque usually means better low end acceleration while more horsepower means a higher top end.

brubenstein

Torque is NOT work, it is a force (twisting). HP is the ability to do work. This is why acceleration is dependent on torque (a = f/m). Top speed is dependent on HP, because of the WORK of moving through a fluid (air).

edward079

Actually its the other way around. At high (max)speeds, 100%
of the cars torqque us used to maintain counter-drag (such as wind, friction,etc.) Torque is a component of hp so it is part of the equation of deriving hp. If you want quick acceleration, it doesnt matter where the torque is as much as how high hp is (cars w/ low end torque tend to have lower rpm peak hps compared so they reach the optimum hp sooner (Truck engines that require heavy towing loads, american musclecar engines, the 4th gen max, etc.)than say, variable valve timing engines with high breathing high revving engines (hondas VTECs, etc.) So, acceleration depends more on level of hp, and how free revving your engine is (how quickly you reach that peak, and maintain it)
You notice why the max has weaker top end vs. low end? stroke in the max is shorter, this is one of the main factors /displacement being held the same.

Daniel B. Martin

Check with a physics major or textbook.

As I remember it, work is defined as force times distance. Torque is work, by definition.

Horsepower is work per unit time. One horsepower is the work done at the rate of 550 foot-pounds per second, by definition.

edward079

Sorry about the confusing post. I confusedm myself reading it. To clarify, more Torque does not necesarily = more acceleration

however, HP DOES.

Sonic

More torque AND more HP = better acceleration. More is ALWAYS better, but it depends where it comes from. Low end torque helps off the line, but since the torque peak is relatively low, acceleration slows as you pass the torque peak. The point of continuing after reaching the torque peak is so that when you shift to the next gear the engine isn't lobbing around at too low a RPM. To go back to the original question, yes it makes a small difference(~7%), along with the 150 pounds that the car lost in curb rate between the 3rd and 4th gens.

brubenstein

Torque is a force, it is not work.
tau (symbol for torque) = force x moment arm (Modern Technical Physics, 3rd Edition)
There is no requirement for distance moved, hence no work. If a 100lb person stands on the end of a 2ft long breaker bar a torque of 200 lb-ft are applied. It doesn't matter if the bolt on the other end turns.

Daniel B. Martin

I stand corrected.

brubenstein

Daniel, you are a gentleman and a scholar. I have no idea how you have the patience to keep answering some of the questions you do without "shouting".

GNGXE

I think Carroll Shelby said. HP sells cars,torque wins races. I'll take torque anyday. How about those vtechs needing rpms to make power, pathetic torque

edward079

High RPM's for acceleration is better for drag racing off the line. Less wheel spin on those engines (result of higher end torque) make for more controlled takeoffs during low rpms! Plus, VTECs are just arguably more advanced than the max engine. They rev freer so they reach high rpm quicker than VQ's. Dont diss the Vtec, the only reason max AT kills accord 6's is they dont come manual! Max auto vs. acord v6 is a prety even match off the line. Why do you think the 5th gen have torque bands more like VTECS and VVTi's? b/c nissan finally joined teh bandwagon
(but I have to say, ya cant beat the sound of wheelspin!!)

edward079

P.S.
HP makes acceleration, torque placement just determines where most of acceleration occurs (at low speeds or high)

MaxedOut97SE

I'm sorry but VTECH isn't all everyone thinks it is. And I don't believe it's a Honda V6 (VTECH) that has been on the 10 best engines list for seven straight years; it is the VQ. Also, Road & Track didn't say that a Honda VTECH V6 "Revs like no other engine this side of a V8 Ferrari.", they said that about the Maxima V6! And the reason Maxima's kill Accords is because the engine is better, sorry. In case you didn't know, the Nissan VQ has been hailed as possibly the finest V6 ever produced. Nissan, not Honda!! I'm sorry it just gets on my nerves how people think VTECH is a substitute for twin turbos or something. I can't even to begin to list all of the VTECH's I've smoked!!!

Sonic

Hate to correct you , but its VTEC, not VTECH. Also, Honda's engines get great HP for their displacement, but the downside is that they have horrible torque figures.

GNGXE

Engines that make hp up high in the range is better for acceleration? They will have less wheelspin if accelerating from low rpms,but when you drag race,dont you bring rpms up to where the hp is?

Daniel B. Martin

I agree with that, but cannot reconcile it with the forumula HP = (torque * RPM) / 5252. There must be more to the story.

brubenstein

It comes from the RPM part of the formula. Design the engine to have a narrow, high RPM torque curve, and you get a engine with a high HP, but over a narrow band at high RPM's.
Honda has been doing this for decades, and well before they made cars. They established themselves for making high performance motorcycles in the mid 60's by competing in GP racing. They had a 50cc twin that spun to over 20,000 RPM, a five cylinder 125cc engine that spun almost as high and a 6 cylinder 250cc engine that spun in the high teens. Their engine technology was fantastic. Their chassis weren't in the same league, but (as I recall) they won the Mfg.'s GP titles in the 50cc, 125cc, 250cc, 350cc and 500cc. (Does anyone here, besides me, remember Mike the Bike Hailwood?)

Keven97SE

It's late and I'm sure this is all going to read like jibberish, but here are my thoughts on the subject:

I think some of you are too focused on one thing or the other..."torque is best"..."HP is best". The fact is that BOTH are important factors, although if you had to choose one number as "king" in determining how fast a car accelerates over a wide range of speed, it would have to be HP.

In general, the more HP a car has, the faster it will accelerate. The profile of the torque curve also impacts acceleration, but I'll suggest here that peak torque is not all that important. Peaks/valleys in the torque curve will affect how quickly that car accelerates at any given moment in time, but because every car you will ever drive uses a transmission, peak torque doesn't do much for you.

Here's an example: Turbocharged cars with low compression ratios and moderate to high boost levels typically make little torque at lower rpms, then have a surge of torque at a mid-range rpm, with torque tapering off towards redline. This non-linear torque curve will ultimately make the car slower 0-XX than, say, an identical car of the same weight but with a big V8 that has a nice, flat torque curve. Although the peak torque of the big V8 and the smaller-displacement turbocharged motor may be equal, the fact that the V8 has maybe 90% of it's peak torque available over the majority of it's torque curve allow the car to accelerate at 90% of peak acceleration over most of the used rpm range. The T/C'd car has a severe "dead spot" at lower rpms before coming to life to ultimately pull as hard as the V8. It's average torque across the useable rpm range may only be 60% of peak.

To prove that the peak torque itself is not important as to how fast the car accelerated 0-XX, take this example: Take the same car as above, and compare a V6 version of that car (VQ35DE maybe?) vs the big V8'd one...again, the weight of both cars is the same, and the torque curves of both cars are the sane shape (pretty flat...90% of max torque over most of the rpm range), but the V8 curve is shifted to a higher peak torque values with torque falloff at a lower rpm, and both engines have the same peak HP. Both cars will accelerate 0-XX in the same amount of time. Even though the V8 has more torque? Yes. Why? Gearing. The big V8 cannot run with the same gearing as the V6, because it will not rev to as high an rpm, and it simply runs out of steam at a lower rpm. The gear ratios for the V8 will be lower than the V6, which will reduce it's torque-at-the-wheels to the same level as the V6. Torque at the wheels will determine

There are, however, a few times where a high peak torque value is an advantage. One is if you're "pullin' stuff" at the farm, driving with a heavy load or uphill, and accelerating from.

For pullin stuff: Since torque represents the brute force available in an engine, more torque allows the car to lurch forward with more force. However, to prove that these "stump puller" engines are not really an advantage to accelerating a car on the street, consider that to be able to translate that massive torque to the wheels where it'll be usefull, you'll have to use transmission ratios wither fairly high values. (A transmission is nothing more than a device that lets you "trade" speed for acceleration. In lower gears, accel is highest but highest speed is limited, which is why you "trade up" to higher gears to give up accel in lieu of higher mph.) The high gear ratios allow you to pull like mad over a limited mph range. However, by say, 10 mph, you have no more rpms to go in your stump puller engine, and are forced to upshift, reducing the amount of torque at the wheels. If second gear is geared similarly aggressively, you'll find yourself having to shift again at 20/25 mph. You spend more time shifting than accelerating, and with every shift, reducing the amount of torque at the wheels. Only if the engine can rev to extended rpms and still make torque could you take advantage of the large gearing...and of course, if you could still make torque at an extended rpm, the engine would, by definition, make more HP. Once again, HP rules.

Another situation where peak torque would help acceleration is if the car weighed more than usual, or was driving up a steep hill. The increased weight (load) seen by the engine is the same irregardless of whether the engine is a high-rpm/low-torque motor or low-rpm/high-torque motor. If the load translated to the engine equates to a 25 ftlb load and the engine only makes 100 ftlbs, the car is obviously going to be significantly slowed. It will now only accelerate at 75% of it's unloaded capability. However, if the engine makes 300 ftlbs, the affect is far lower, and the car will accelerate still at (300-25)/300=~90% of it's unloaded capability.

Finally, higher peak torque will also mean faster acceleration when you stay within gear. I think most people here are familiar with the frustration of having to downshift a small motor'd car to get enough torque to accelerate sufficiently. This is due to low peak torque.

chris j vurnis

The magnitude of acceleration at a given RPM is dependent on the torque at a given RPM --

Torque is what makes acceleration --

For example, an engine that makes 200HP at 5000RPM and 240HP at 6000RPM will have the exact same acceleration potential both of those speeds -- at both of those speeds, the equation for torque works out the same with the above HP numbers

When you look at a dyno chart, the shape of the torque curve will determine the shape of the acceleration curve --

So why are horsepower numbers important -- because that is a measure of how high a speed torque can be maintained --

Keven97SE

If all we were interested in doing was driving between 0 and 5 mph, then peak torque WOULD rule. HOWEVER, engine torque alone is NOT sufficient to accelerate a car. Consider how weak accel is in 4th gear, at which the overall gear ratio is approx 1:1, where the car is being accelerated by engine torque alone without any gearing to add torque multilication. We DO need gearing, at which point HP really becomes the most important figure.

Yes, physics dictates that torque determines acceleration, but in the real world with torque multiplication from transmissions and speed consideration, HP is what ultimately defines acceleration.

brubenstein

The difference between low and high speed acceleration is air drag. Acceleration is due to the application of force, and only torque is a force. (The whole concept of gearing is to keep the engine in it's power band, for the greatest amount of torque at the driving wheel(s) in relation to the car's road speed.) Moving a car through air is work. The amount of work needed, to just maintain speed, increases at the square of the velocity. So at speeds below 50 mph, where drag is minimal, almost all the torque can accelerate the car. When the amount of available torque is greater than the amount of power needed for overcoming air resistance the car accelerates. As speed increases, the amount of torque, in excess of that needed to overcome air resistance rapidly decreases, so the rate of acceleration decreases. Eventually the acceleration drops to zero, this is know as top speed.

So, the two basic principles are:
1) Acceleration is due to a force. The only force here is torque.
2) Moving a car through air, and overcoming the other resistances, is work, and that is measured in HP.

If you can't keep these two things straight, it's just jibberish.

Keven97SE

Okay, I still haven't made my point I guess.

EVEN considering that below 50/60 mph aerodynamic drag is minimal, HP is STILL going to dictate how fast a car accelerates to, say, 60 mph.

If torque was the only important figure, then let's take that thought to an extreme level. Say you have an engine with 1000 ftlbs and 50 HP peak. To make those sort of numbers, the engine would have peak HP at ~250 rpm. If torque was "all that", then you would expect 0-60 times on that car (say it weighed 3000 lbs) to be very low, say well under 5 sec. Nope. Why? If, using generic, common gear ratios of say ~8:1 average (gear ratio x final drive) for gears 1+2, the motor would have to turn at 5000ish rpm at the top of 2nd gear. Impossible. The engine peaks (HP) at only 250 rpm, and would most likely not be able to run past 350 rpm. You would have to OVERDRIVE the gearing so much to be able to get acceptable speeds with that engine. The gear ratios you'd have to go with would be on the order of (250/5000)x8:1 = ~0.4:1 for 1+2 gears (average). This would drop the torque available at the wheels to literally 5% (0.4/8) of what would be available with the "standard" transmission. You have to go with that low gear ratio just to be able to get the motor to be in an acceptable rpm range to get to 60 mph.

Now what you have is a motor that, although makes LOADS of torque at the engine, due to it's very low comparitive HP, is required to run such "weak" gear ratios that the torque is "diluted" at the wheels. Due to this gearing, the torque multiplication is only 5% (!) of a car with a "standard" transmission (standard because the engine can run in a more typical rpm range, 0-6000 rpm or thereabouts). Although the monster motor makes 1000 ftlbs at the wheels, the average 1/2 gear (average 0.4:1 ratio) torque is only 1000x0.4=400 ftlbs. Compare this now to the typical engine (say, 150 ftlbs at the engine) with the 8:1 average 1/2 gear ratio. It has 150x8=1200 ftlbs available at the wheels...3 times MORE torque at the wheels than the monster.

And why does the smaller engine have more torque at the wheels than the monster? HP. It has more HP so it can use higher gear ratios. Transmissions are the ultimate equalizer.

HP rules. Peak torque really does not matter for acceleration. Shape of the torque curve does affect acceleration at a particular instant in time.

brubenstein

The only point you have made is that you don't know physics.

f=ma
torque = force
HP does not = force, it has nothing to do with acceleration.
What you have to keep in mind is that force, in real world calculations, is net force. When accelerating from 0 mph the net force is the (engine torque x gear ratio) - driveline loses. At speeds greater than 0 mph, one has to remember the deffinition of acceleration: (Vf - Vo)/(T2 - T1). If you are accelerating from 50 mph, then the amount of work necessary to be done to maintain Vo has to be subtracted from the gross available torque (force) to yeild the net available torque (force).

Keven97SE

Last post on this subjec...

Torque at the engine is meaningless. Torque at the wheels is what determines acceleration. Torque at the wheels is determined in large part by gearing.

torque at wheels = torque at crank x overall gear ratio

Overall gear ratio is determined in large part by peak HP and the rpm where it occurs.

Hence, the overall conclusion is that HP, in the end, effectively dictates acceleration, NOT peak engine torque.

Since you obviously haven't read anything within my previous posts, hopefully you'll read this condensed version and it will entice you to read the other bazillion words I've written on the subject.

Jeff92se

iTrader: (82)

Dunno. What about the those semis that have MASSIVE torque but low relative hp?? I mean they even have what, 16 gears. Even from a standstill, they can't accerate very fast(even w/o their trailers)? If torque is everything, then why can trailerless semis to 0-60 in 3.0 sec?

Keven97SE

Thank you, Jeff. I know I said I wouldn't post on the subject again, but you are absolutely correct. There IS a reason why those semis are slow...weight/power ratio is atrocious. It seems that some of us have forgotten that all-important indicator of a car's potential to accelerate. Weight/HP ratio is THE best indicator of a car's acceleration capability. Note that it's NOT weight/torque. Those semis are slow even without a trailer because they are very heavy and, in spite of having massive peak torque, have relatively low HP. The engines in those trucks are designed to simply have sufficient HP to tote along a loaded trailer at 80 mph or so. Slow acceleration is acceptable. High torque is required to move the massive load. Read my first post in this thread (the loooong one) about torque being important for pullin stuff.

I guess everyone's argument about torque being the force that accelerates an object is correct, albeit short-sighted. In the real world, where you have to worry not only about pure accelerative force but also being able to get up to a certain speed, HP is ultimately what dictates how quickly a car accelerates.

Now I'm really done. Last post.

Daniel B. Martin

The comparison between Maximas and Semi tractors isn't really valid. Those big diesels have such a narrow powerband that they have 13-speed transmissions. The Semi driver has to do about 10 double-clutched shifts to reach 60 mph.

Jeff92se

iTrader: (82)

Well Daniel, it seems using formulas doesn't work too well for visualation so thus the semi example. Yes, semis have a narrow powerband. It's because they have such low relative hp. 13 gears are needed to get ANY accerlation not the other way around. We are trying to prove a point that if torque is everything, why can't a torque monstered semi w/ the benefit of gear multiplication still can't get out of it's own way?

brubenstein

Until you demonstrate some basic comprehension of the laws of physics, you will post nothing but nonsense. I am not interested in what you think, because it is obvious that you don't know much.
People used to think that the Earth was the center of the universe; that never made it so. What Keven thinks doesn't change the laws, and definitions of physics.

edward079

Max's dont "kill" accord 6's. They beat them modestly if the race is won in honor and fairness (AT vs AT that is). And the reason maxs beat accords is b/c they have MT, accords dont.
And all that Wards crap, c'mon, How credible are they? Wouldnt be surprised if Nissan was the only factor that kept Wards afloat! You cant say an engine is 100% best! It depends on engineering philosophy!

MaxedOut97SE

Whatever, all I know is that it is the VQ that has been on the 10 best list for seven years straight, not the Honda VTEC V6, or any Honda engine for that matter. I believe they said "Taking the VQ to it's 6600 RPM redline is one of the world's greatest automotive pleasures." Try to discredit Ward's all you want, but it's not just them who praise the VQ. Virtually every respected name in the Automotive editorial business has said nothing but great things about it. Road & Track, Car & Driver, MotorTrend, Autoweek, etc., etc.... I could go on for another half a page listing quotes, but I really don't wanna waste my time. There may be great things in an Accord, but I'm sorry, the Maxima's engine is better, and that's all there is to it.

MaxC1Get!

Different definition:

Torque: the ability to Launch.
Horsepower: the strength of an engine.

Therefore, torque is for acceleration, and HP is for TOP SPEED. Two cars that are compareable in weight, but CAR 1 has more torque, while CAR 2 has more HP. CAR 1 will pull ahead in the start, but eventually and without a doubt, CAR 1 will be overtaken by CAR 2 due to it's advantage in HP.

brubenstein

There is one technically correct definition for torque and horsepower. Any other definitions that you make up are meaningless to someone else. You might as well say the sky is red, grass is purple and water is orange.
The example you give doesn't have enough information for you to draw your conclusion. Just saying that a car has more torque doesn't mean much without specifing RPM (even if you mean peak torque). You have to have a good idea of the torque curve: lb-ft vs. RPM. You also have to know something about the gearing, since engines don't turn at a single RPM. (If a transmission has ratios badly matched to an engine's torque curve, it won't accelerate very well, or reach its maximum, theoretical speed.
As far as top speed (or any high speed above 70-80 mph) is concerened, the important thing is power to drag (Cd) ratio.
You need a more substantial understanding of things than gutter physics to make meaningful sense out of things.

edward079

Dont get me wrong. R&T, C&D arecredible, but they dont have a "10 best "lisst. They didnt say it was the best. Only Wards did. I never said the VQ was bad! Its a great engine! But to say its number such and such best... cmon, thats baseless! Theres no way to say it is number 3 or 8 or top ten, that would be totally subjective. I just think that accords, cl's 3.2, bmw 330's engines are just as comparable and not "killed" by the max just beaten. The differences are so minute taht the main factor in most casese should be the driver. I mean if u look for praises for the accord engine, or whatever else, I bet ull find a lot too. I just have a hard time w/ Ward's thats all. W/out Nissan's advertising, etc. I prob still wouldve never heard of em. If you love the max, great, I do too! But I also appreciate the other guys out there!