Tq vs HP

[krustindumm]

http://vmaxoutlaw.com/tech/torque_hp.htm

[Ricky]

ok...

[DustinsDuster]

i knew this topic was created by Krustin before i even clicked on it...

[DustinsDuster]

also, just because someone posts something up on the internet, that doesnt necessarily make it true.

[black88gt]

lol this again. he just kinda let the last one of these die without a response

[DustinsDuster]

its just funny to me how someone whos mind is so deeply rooted in physics, mathmatics and logic, hes trying to explain to me how important something is that relies solely on what he says doesnt matter at all.

its like arguing the importance of having money if you lived on the moon....

[Stutz]

ZAH BLACK WITH RED FONT BURNS TEH EYES!!!!!

[krustindumm]

I thought people might understand it better explained in a different way than I do.

Also, your right that not everything on the internet is true, but some things are.

[slobalt]

Math what a concept,

manipulation of the numbers to fit your own view, the debate will never end

[DustinsDuster]

I thought people might understand it better explained in a different way than I do.

Also, your right that not everything on the internet is true, but some things are.

i just want to make sure we are all clear on the point you are trying to prove; are you saying that torque doesnt matter, or that torque isnt as important as horse power? because those are two VERY different points...

[Scott]

calculate torque from hp and rpm, calculate hp from torque and rpm, calculate rpm from hp and torque.. is there a point going on here.. so chassis dyno's measure hp and rpm then calculate torque, do engine dyno's measure torque and rpm then calculate hp?? is this an argument or just tyring to be informative??

[lil krumm]

dont even pay attention to what he is saying. he just comes outta no where with random bullshit thinking he is right. and yes he is my brother.

[krustindumm]

calculate torque from hp and rpm, calculate hp from torque and rpm, calculate rpm from hp and torque.. is there a point going on here.. so chassis dyno's measure hp and rpm then calculate torque, do engine dyno's measure torque and rpm then calculate hp?? is this an argument or just tyring to be informative??

It's an ongoing argument. I don't know what engine dyno's measure, the only three I have worked with were relatively small (one sub 1hp, two probably good for 100lb/ft of torque). The electrical type measured HP, the dynojet measured tq and rpm, HP was calculated, I don't know what the third was.

Dustin: HP is, and will always be, more important. Tq, as an integral component of HP, is important, but not nearly as much so. Tq at the wheels is what moves the car, and is caused by gear reduction. My old argument: if you have 10 billion lb/ft of tq at 0 rpm you aint going nowhere. Where you going, nowhere. If you have 10 billion rpm and 0 tq, same thing. Nowhere. If you combine the two, you end up with 10 gazillion hp, and then your really movin.

[DustinsDuster]

Dustin: HP is, and will always be, more important. Tq, as an integral component of HP, is important, but not nearly as much so. Tq at the wheels is what moves the car, and is caused by gear reduction. My old argument: if you have 10 billion lb/ft of tq at 0 rpm you aint going nowhere. Where you going, nowhere. If you have 10 billion rpm and 0 tq, same thing. Nowhere. If you combine the two, you end up with 10 gazillion hp, and then your really movin.

the only reason i bring it up is that i have never told you torque is more important than horsepower. your old argument always used to be "torque doesnt mean anything"; that is all i disputed. i would probably say to a point, horsepower is more important, depending on your application. you can "what if" about your "10,000ft/lbs but no RPM" all you want, but in the end, were never gonna see that example in person, so i really dont see why it matters.

in a performance car application; i would take a 600hp V8 in my car over a 600hp turbo 4cyl any day. a light weight platform matters, but i still think a 600hp/600ft/lb 3000lb rwd car will beat 600hp/350ft/lb 2,200lb FWD car.

just an opinion

[Scott]

definetly is just a matter of opinion here, there is alot of vehicles out there that dont even turn enough rpm to make more hp than torque, like pretty much anything diesel, and lots of electric motors, anything large, etc.. you cant make a general statement saying hp is, and always will be more important than torque, and still want people to think you know what your talking about....

[krustindumm]

definetly is just a matter of opinion here, there is alot of vehicles out there that dont even turn enough rpm to make more hp than torque, like pretty much anything diesel, and lots of electric motors, anything large, etc.. you cant make a general statement saying hp is, and always will be more important than torque, and still want people to think you know what your talking about....

Even on those motors, it is still the HP that does the work, tq can't do shit.

[DustinsDuster]

HP DOES NOT EXIST WITHOUT TORQUE. thats like saying Lincoln's father didnt matter at all because Abraham was the one who freed the slaves....

[Scott]

hp means nothing, its a name given to the answer of an equation no matter how you slice it, even in a chassis dyno, hp is just a measurement of accelerating a set mass compared to time and rpm. horsepower itself is never measured. unlike torque and rpm which can be directly measured, so it sounds to me like torque AND rpm are KING BABY!!

[Scott]

actually the more I think about it, the more stupid this argument is. because every component in the equation we are argueing about IS a very important variable, you cant increase hp without increasing tq or rpm. its just a mute point basically.

[krustindumm]

hp means nothing, its a name given to the answer of an equation no matter how you slice it, even in a chassis dyno, hp is just a measurement of accelerating a set mass compared to time and rpm. horsepower itself is never measured. unlike torque and rpm which can be directly measured, so it sounds to me like torque AND rpm are KING BABY!!

Only crappy dyno's measure the acceleration of a known mass, because that "known mass" isn't really known. Switching to a lighter set of wheels or tires on a dyno like that can increase the HP calculated.

Torque and RPM are independant variables, and yes they are the most important, the combination of which is expressed as HP.

[69gt4speed]

I believe at a given displacement, given rpm range a particular engine design will be found that works the best. Say 250cc 10k rpms probably a 2 cyl. then as we move up in displacement more cylinders are used. We do not see a 4cyl in say a 5000cc motor no it is 8 cyl this guy fails to take into account friction/vib losses/forces due to piston speeds.

His piston area thing is bs in that if it was true we would all run a 289 not a 408 ford, or a 302 not a 383 chevy etc. I'll just tell 9 sec snake he was wasting his time going a 5.4 instead of a 4.6 or the ams evo was a total waste going a 2.4l stroker instead of 2.0l. That proves if we can keep friction/vib down, and stroke it (more displacement) we get more power end of story.

Anyway you can get more air in a engine is the goal and keep vibration friction losses/forces down.

[Nicolaskl]

Torque & RPM = horsepower. That's the entire point of horsepower is that it takes RPM and torque into account. A maximum torque figure by itself is meaningless. It doesn't matter if you're making 1000 lb/ft if you can only make it up to a 100 rpm redline. For a torque figure to be meaningful you have to know what kind of rev range you can make it over, and once you add RPMs into the equation then you are talking about horsepower.

If you've got the choice between a 1000 lb/ft motor and a 1000 hp motor, you take the one with 1000 hp, because the 1000 lb/ft motor could be a waterwheel with a max speed of 12 RPM. Not gonna make a very fast car, which is obvious once you look at the hp figure (like 2 hp I think). The 1000 hp motor, on the other hand, will make a fast car. HP indicates the ability to do work, torque measures the ability to exert force. The ability to do work is what ultimately is important because that's exactly what you're doing when you accelerate a car down a track.



but i still think a 600hp/600ft/lb 3000lb rwd car will beat 600hp/350ft/lb 2,200lb FWD car.


Only because it's RWD. And even then it's iffy. What isn't iffy is if they're both RWD, then the 600 hp/350 ft/lb/2200 lb car will absolutely slaughter the other one.

Ultimately what matters is torque at the wheels, and when you're talking about torque at the wheels you're talking about horsepower. Torque at the crank is basically meaningless. From a purely physical standpoint it doesn't matter if you're making your 500 horsepower from a 4 banger that revs to 10 grand and only makes 200 lb/ft or from a V8 that revs half as high but puts out twice the torque, they're both going to put the same amount of torque to the wheels so they're both going to accelerate the same (all else being equal). From a personal preference standpoint it makes a big difference (to me a torquey V8 is more fun to drive, plus generally has more ultimate power potential).

[Scott]

its kinda funny when you read the thread and everyone is supporting the others arguments just with different words..

[DustinsDuster]

but i still think a 600hp/600ft/lb 3000lb rwd car will beat 600hp/350ft/lb 2,200lb FWD car.


Only because it's RWD. And even then it's iffy. What isn't iffy is if they're both RWD, then the 600 hp/350 ft/lb/2200 lb car will absolutely slaughter the other one.

i know its only because its RWD, because FWD is a terrible platform for dragracing. thats pretty much why i hate hondas. even with the 800lb lighter car, and even if it were on slicks, it will still probably lose to the RWD car. i will admit the car will probably MPH the fuck out of the domestic, but thats where the 800lb handicap comes into play.

what i want someone to explain to me is why a 1,000rwhp Supra will many times run slower than an 800rwhp 03 Cobra....

[Scott]

lol now thats funny, but I think it has something to do with its power band..

[black88gt]

bottom line, torque is required for horsepower. and we live in the real world, where just about any passenger car motor can rev to at least 5k, so the examples of 10 billion ft/lbs at 10 rpm are for naught.

dustin you have yet to respond to these

http://www.crunderground.com/viewtopic. ... 500++honda (http://www.crunderground.com/viewtopic.php?t=9235&highlight=500++honda)

[JJ240]

lol now thats funny, but I think it has something to do with its power band..
the powerband of a 4 digit hp supra still isnt that bad for drag racing. The major issues are weight, traction, and the fact that most supra owners out there are running a 6 speed, no line lock, and no other straight line specific toys that help so much. Check out some of the supras that are actually built for drag...they blow the stereotype out of the water.

[DustinsDuster]

[quote="Scott";p="129516":a4956]lol now thats funny, but I think it has something to do with its power band..
the powerband of a 4 digit hp supra still isnt that bad for drag racing. The major issues are weight, traction, and the fact that most supra owners out there are running a 6 speed, no line lock, and no other straight line specific toys that help so much. Check out some of the supras that are actually built for drag...they blow the stereotype out of the water.[/quote:a4956]

an 03 Cobra weighs 3900lbs without driver, has IRS, and came with 6 speeds.

[DustinsDuster]

http://www.crunderground.com/viewtopic. ... 500++honda (http://www.crunderground.com/viewtopic.php?t=9235&highlight=500++honda)

are you talking to me or Krustin? because we have both responded in that thread.

[black88gt]

haha krustin, sorry i should have specified

[krustindumm]

[quote]
but i still think a 600hp/600ft/lb 3000lb rwd car will beat 600hp/350ft/lb 2,200lb FWD car.


Only because it's RWD. And even then it's iffy. What isn't iffy is if they're both RWD, then the 600 hp/350 ft/lb/2200 lb car will absolutely slaughter the other one.

i know its only because its RWD, because FWD is a terrible platform for dragracing. thats pretty much why i hate hondas. even with the 800lb lighter car, and even if it were on slicks, it will still probably lose to the RWD car. i will admit the car will probably MPH the fuck out of the domestic, but thats where the 800lb handicap comes into play.

what i want someone to explain to me is why a 1,000rwhp Supra will many times run slower than an 800rwhp 03 Cobra....[/quote:c5af6]

I don't know Supra's or Cobra's, but I believe it has something to do with the massive negative rear camber Supra's get during squat that pretty much eliminates their contact patch. There are as many ways to do IRS as there are cars on the road, and some of the ways are probably suited to drag racing. Not nearly as much as a solid axle though.

[DustinsDuster]

the problem doesnt seem to be not being able to hook up in a supra(the high powered ones on ET Streets and ET Drags), it seems to be they hook fine, they just dont make enough torque on the 1st half of the track.

just something really weird about a 9 or 10 second car that cannot pull the front wheels at all

[Nicolaskl]

bottom line, torque is required for horsepower. and we live in the real world, where just about any passenger car motor can rev to at least 5k, so the examples of 10 billion ft/lbs at 10 rpm are for naught.

dustin you have yet to respond to these

http://www.crunderground.com/viewtopic. ... 500++honda (http://www.crunderground.com/viewtopic.php?t=9235&highlight=500++honda)

The real world examples are there as well. Why do you think a 150 lb/ft S2000 is as fast as a 300 lb/ft Mustang? There's a reason that hp/weight ratios are focused on and tq/weight ratios are not.

[krustindumm]

the problem doesnt seem to be not being able to hook up in a supra(the high powered ones on ET Streets and ET Drags), it seems to be they hook fine, they just dont make enough torque on the 1st half of the track.

just something really weird about a 9 or 10 second car that cannot pull the front wheels at all

They are through a couple gears by the 1/8th, so the tq at the wheels has been reduced compared to at the beginning. Your argument makes no sense. I don't know jack shit about supra's but I'm still sticking with the argument that every modified supra owner makes, and that's that they don't hook up for shit. Even if they are running drag specific tires, it's not going to help much when the squat induced camber cuts the contact patch to 1/2 or 1/3 of static.

[DustinsDuster]

in the Scandalous Racing video i watched, they went to a track day for Supras, and those didnt look to have any troubles hooking. one of the cars was running in the low 9's(squatting a LOT), but still not pulling the front wheels. just doesnt seem right to me.

[JJ240]

Its tough to pull the front wheels with a multi link rear suspension. Basically anything other than solid axle its pretty tough. Supra gearing in the factory 6 speed isn't even comparable to a 6 speed cobra gearbox either.

Cobra: 2.66/1.78/1.30/1.00/.80/.62

Supra: 3.83/2.36/1.69/1.31/1/.8

Cobra final drive: 3.55

Supra final drive: 3.13

Even so, I would put down money that with the same tires, same peak hp (in the neighborhood of 500rwhp), and similarly skilled drivers a 6 speed supra, and a 6 speed cobra would run a very similar 1/4. At around 500whp the supra still has a great powerband. Once you start looking at near 1k hp in a 3L motor you have to start turning massive RPM's to make the power. The powerband will still be fine, its just really high. You won't be leaving the line very quick without an auto w/a trans brake, or an ignition retard style spool. Torque is great, its just all about where you make it in my opinion. I would never want peak torque at 3500rpm's, because I don't want to shift at 5 for lack of power. With peak torque around 5 I have a pretty sweet powerband! Furthermore when people talk about torque doing the work and low end power you are still looking at horsepower primarily, but when you are only turning 2k rpms it takes TONS of torque to create any sizeable amount horsepower at all. The real argument shouldn't be torque vs hp, but rather where torque is more useful. Although it gets alot more complicated at that point and you have to have alot of knowlege about gearing as it is an equally contributing factor.

[DustinsDuster]

i got kindof off topic, sorry about that.

in an attempt to end this whole thing, i will offer this comprimise; no matter how much torque you make, with no RPM, no work is being done; so horsepower is important. But, there can be no work done if there is no force pushing, so torque is also important. which of the two is more important is debatable, and depends greatly on application and set up of application.

i am (hopefully) done

[69gt4speed]

I'm done too, all I got to say is look around and find a supra w 500 rwhp and we can find out.

[Scott]

Im done too, find me a supra that makes 375hp to the wheels and we'll see whats more important!!

[krustindumm]

Stock was 320hp, so maybe intake/downpipe/exhaust and some fine tuning?

[Jappbox]

this conversation is gay... TQ when your talking 1/4 mile means nothing, might be able to pull a little better 60ft with more TQ but thats about it. HP pulls the car. I made less than 500Tq more around 450ftlbs yet it killed 550+TQ cars... My new setup maybe MAYBE might hit 600ftlbs and that wont even be in my power band so less than that up top. Give me a 600tq V8 with my new setup and it would be BUS lengths difference. most 4 cyl cars dont make good tq do to turbo leg, less lag (stroker 4cyls) equals more TQ. V8's moslty have instant response witch in turn makes tq. a 600tq 600hp v8 is the same as a 350tq 600hp civic if power/weight ratio is the same. only from a roll the civic would have to break boost to compensate for the more tq on the v8.

[Jappbox]

Im done too, find me a supra that makes 375hp to the wheels and we'll see whats more important!!

scotty you dont make 375whp you make more just cause the dyno said it dont make it true its not posible to make 375whp go 10's inless your less than 1800lbs its simple math. Go to the track run on motor look at your mph, then find a supra with the same or close mph and then race that from a roll and it would be even or close. again Tq on 1/4 is not more important or else AMS would not be going 8.5's at 168+mph with 620 ftlbs of Tq.. :supz:

[Domestic Disturbance]

torque isnt more important that horsepower but its still important. and 620lbs of torque is a lot, even if its way under its hp rating. look at the amount of weight it has to move.

8.5 is pretty impressive still for those number, but u also have to think that they have to compensate a lot 4 that lack. look at the cars running 6s and 7's. it can b done with less torque but u will always have to make up 4 it in some way. the cars with more torque initially always end up with an advantage cuz they have less to compensate 4

[Rollin on Dubs]

[quote="red04evo";p="129641"]this conversation is gay... TQ when your talking 1/4 mile means nothing, might be able to pull a little better 60ft with more TQ but thats about it. quote]

Think about that statement! You have a little to learn about drag racing if you think that a little bit to your 60' isint somthing important. I know what everyone is trying to say that Tq does not mean anything in drag racing, but when you look a being pracital IT DOES. Most of your drag/ street cars Will be automatic trans, and if you stick a GLIDE (2 speed trans with a 1.82 first gear) behind an engine that lacks in tq. IT will kill your ET, And thats why you dont see 4cyl cars running racing ATs/ And as much fun as it is for banging gears, other than that a racing automatic will beat a stick in all catagorys, and in every form of drag racing consistancy is key. and other than lenco's, Libertys and Jerico you just can get the consistancy of an auto.

[69gt4speed]

I said I was done but Jesse ya hi hp on the street can win pretty good and heres why. You can't get traction bottom line with hi tq trust me, esp running less tire than a awd. Ok now with good traction different story, take that evolution gt 500 same exact car, dyno, track, tires etc. etc. except a retune for a 75 shot. Before 596 rwhp and 602 rwtq, with spray on 664 rwhp and 778 rwtq. Et mph without spray 10.4 sec 132 mph, with spray 9.96 sec and 141 mph. Where did 9 mph come from 68hp? Its not all cut and dried, if you can run a havlik setup on the street tq gets the heavy vehicle moving. Look at those 11 sec diesels also. They have tried a old indy engine hi hp before with a heavy vehicle. It doesn't work that good without serious gearing, why those lil s/s sb run like 5.14 gearing. Why to boost tq.

[allgo]

[quote="red04evo";p="129641":bc61e]this conversation is gay... TQ when your talking 1/4 mile means nothing, might be able to pull a little better 60ft with more TQ but thats about it. quote]

Think about that statement! You have a little to learn about drag racing if you think that a little bit to your 60' isint somthing important. I know what everyone is trying to say that Tq does not mean anything in drag racing, but when you look a being pracital IT DOES. Most of your drag/ street cars Will be automatic trans, and if you stick a GLIDE (2 speed trans with a 1.82 first gear) behind an engine that lacks in tq. IT will kill your ET, And thats why you dont see 4cyl cars running racing ATs/ And as much fun as it is for banging gears, other than that a racing automatic will beat a stick in all catagorys, and in every form of drag racing consistancy is key. and other than lenco's, Libertys and Jerico you just can get the consistancy of an auto.
[/quote:bc61e]

Dont argue with jesse he is the super tuner from street psi biatch!!

[69gt4speed]

I was just pointing out some things that don't add up. Ain't starting no sh-t w you or Jesse. I was around kcir for years, it was 8 mi away from my house. I looked at cars, asked questions, got to know regulars. Jesse has done good, I like him, sh-t I raced him plenty of times. Just pointing out that gt500 cause it is well documented, has videos, dyno graphs, et slips. Course we all know that doesn't mean squat on the street. Just street potential. Or take a 03 600 rwhp kb vs a 03 600 rwhp turbo vs 600 rwhp eaton sprayed. Why so much different? 600 is 600 evidently not all I'm saying, plenty of videos out there.

[krustindumm]

I said I was done but Jesse ya hi hp on the street can win pretty good and heres why. You can't get traction bottom line with hi tq trust me, esp running less tire than a awd. Ok now with good traction different story, take that evolution gt 500 same exact car, dyno, track, tires etc. etc. except a retune for a 75 shot. Before 596 rwhp and 602 rwtq, with spray on 664 rwhp and 778 rwtq. Et mph without spray 10.4 sec 132 mph, with spray 9.96 sec and 141 mph. Where did 9 mph come from 68hp? Its not all cut and dried, if you can run a havlik setup on the street tq gets the heavy vehicle moving. Look at those 11 sec diesels also. They have tried a old indy engine hi hp before with a heavy vehicle. It doesn't work that good without serious gearing, why those lil s/s sb run like 5.14 gearing. Why to boost tq.

It's nitrous, that means you didn't get *just 68hp* you got 68hp from the moment you hit the button through redline. That's why the tq number picked up so much, you were on the bottle from way below 5252rpm.

[z28z34man]

Rpm's put more stress on internal engine parts than tq. Rarely dose dose someone snap a rod at 3k rpm even if that is where there max tq is at. They snap them at 6k rpms or higher. That is why I built my engine for tq at about 5k rpms. I still get a decent hp #, but I don't have to rev to the moon to get going and put that extra stress on my engine parts.

[Scott]

Like I always said I dont really believe in dyno's much, I think tuning should be done at the track..but I have had the car on a chassis and the engine on a engine dyno, it made 375 rwhp and 420ft*lbs, and about 540 hp, 530ft*lbs at the flywheel. and given 20-30% drivetrain loss I think this would figure up to be very resonable. and the car has run very consistent mid 10's at 124-125 mph with 3000lb race weight. so unless both of the dyno's I had tested on were broke, I think its very possible to run 10's with 375 hp. and torque in drag racing is huge in my opinion, .1sec in 60' = "approx" .3sec in the quarter. sounds pretty important to me, its just really hard for an import to 60' very good at all so they make up for it the hard way in the mph. I understand that with an import it is very hard to run 10's with that amount of hp because of lack of traction and TORQUE..

[DustinsDuster]

if put in identical cars, which would win a race; a 300hp 4cyl or a 300hp V8?

[69gt4speed]

Here's what a well known engine builder/dyno guy says...

HP= a measure of forced over time, where 1 hp is equal to 550 lbs lifted one foot in one second. Expressed in terms of torque, 1 hp equals 550 ft/lbs per second. Noticed this measurement is time based.

Torque= the measure of instantaneous rotational force an engine can produce. Notice this measurement is not time based.

hp= torque x RPM / 5252
torque= hp x 5252/ RPM


With these two basic equations, you can figure out how much hp or torque you have at a given RPM with either measurement. Notice that because of this equation, an engine can NEVER make as much hp before 5252 RPM as it can torque, and the opposite is true above 5252 RPM. Any dyno chart you ever see where the two plotted curves don't cross at 5252 RPM is a bogus dyno chart.

What's important to understand as this pertains to vehicles is that hp is not a direct determinate to accelerative ability. Horsepower is more a way of easily summarizing the abilities of a car, but not an exact or necessary thing. Horsepower is basically a way of stating torque with gearing already taken into account, which makes the pain of figuring out torque multiplication factors less needed for generalized performance figures. Here's the four most important factors in determining how fast a car can accelerate...

-effective torque at the wheels
-overall vehicle weight
-available traction
-total drag (constituted mainly of aero drag at speeds above 50mph)

Take his 4 overall theories with my experience. You put a higher duration cam in no other changes what happens in a stock auto n/a sb heavy car. It becomes a dog off the line. It will have more peak hp for sure, it can run good if the engine has enough rpms. You stick it on a dynojet and lo and behold it says same or less tq and more hp but shifted to a higher rpm range. Maybe even same area under the curve. But it goes slower down the 1/4. Seen it several times. Wtf!!! To fix it you do 2 things, put in lower gears and higher rpm stall converter. All the higher hp didn't do squat to make the car et quicker or go faster in a 1/4 mi. And it gets worse as the distance becomes shorter if you plotted it out compared to the stock lower hp. Nothing is cut and dried, it is experimentation or copy what works best and claim it as your own. Run a xx motor, cam, gears, heads, tranny, etc. with a a/f of this and timing of that.

[69gt4speed]

Ok Krustin or ? explain to me how a 6 to 7000# 740rwhp can go lower 10's with a turbo diesel. That should be around 1500# of tq. Very narrow powerband 2k or so. I don't really like diesels either yet hard to argue with results. So it's not rpm's, nor piston area theory nor appears area under the curve. Notice it is only 110 mph. So that means it accelerates hard first part of track and either lets off or something. Traction is not a issue. It beats that modded stang off the launch. There is no 5252 rpm crossover, it doesn't exist in that mtr.
http://www.youtube.com/watch?v=-Kfd3A7KFko

[krustindumm]

Ok Krustin or ? explain to me how a 6 to 7000# 740rwhp can go lower 10's with a turbo diesel. That should be around 1500# of tq. Very narrow powerband 2k or so. I don't really like diesels either yet hard to argue with results. So it's not rpm's, nor piston area theory nor appears area under the curve. Notice it is only 110 mph. So that means it accelerates hard first part of track and either lets off or something. Traction is not a issue. It beats that modded stang off the launch. There is no 5252 rpm crossover, it doesn't exist in that mtr.
http://www.youtube.com/watch?v=-Kfd3A7KFko

The piston moves up in the cylinder compressing the air, diesel is injeccted at the proper moment and it self ignites, forcing the piston back down. That pushes the conrod, which turns the crank, which turns gears inside the transmission. The gears turn the output shaft which is connected to the transfer case. The transfer case sends the power through the drive shafts to the axles, which turn the tires.

[DustinsDuster]

Krustin, i think his point was if torque isnt important, how can turbo diesel trucks run in the 10's.

[69gt4speed]

LoL ya I know that one of my first combustion engines was a 2 stroke diesel. I notice you refuse to say engine torque, that is what is measured in a rotating engine/motor gas, diesel, turbine, electric and is converted to hp reading. That's ok I just wanted you to think a bit. And I've said in a street car esp the limiting factor is traction all the tq in the world does nothing if traction isn't there. And I've showed real world example hp isn't a cut and dried answer either. If it was we wouldn't need to regear to multiply tq. as we move the hp curve to higher rpms even though hp was higher.

[69gt4speed]

Krustin, i think his point was if torque isnt important, how can turbo diesel trucks run in the 10's.

Naw that's not it, I just like messing with him. I post random bs to him to confuse him. :biggrin: Hell I even have a honda inline 4 cyl. :bigthumb:

[SpecterGT260]

screw all you guys. tq and hp are both worthless. RPM is where its at!

no, not really, i just thought id pick out a favorite variable and cling to it for no reason.

hp varies directly with torque. more torque=more hp at a given rpm. therefore, the trick would be to design an engine that can continue to make torque at a higher rpm. this is difficult because all engine stop making power (and remember an engine only makes torque) the higher they climb. The engines we have sacrifce low end torque.

to make a valid argument here we have to play a little game i like to call "all things equal". If you want that car to move off the line you now have to take care of your low end power loss. we now have to do things like cut weight (a big thank you to the gentleman who made the 600/600/3500lbs vs 600/350/2100lbs argument... or whatever the numbers were). Now all things are not equal. OR, we can increase the hell out of our traction so that we can get our engine to a point where it is making enough torque to make the proper hp numbers so that we can move the car out of the hole *points a big finger at Jesse* AWD. Again, things arent equal. You guys cannot make the claim that torque isnt important. all you can say is "ive found ways to make a low-torque car fast".

A little more:

the entire argument makes no sense from a physics standpoint to all of you physicists out there. HP is the linear expression of torque. HP is variable by rpm and tq, but tq is variable by rpm across the various platforms, which is really what this argument is about: the platforms. If we really wanna look at this then we have to combine the variability of engine tq #s across rpm against hp and end up with a nifty 3d graph yeilding the geezers theoretical "optimal platform" (just messin :rolleyes: ). But instead we hold rpm as a constant and solve at each rpm. this is what a chassis dyno does. ----recap---- rpm is the independant variable, tq is dependant on rpm, and hp is dependant on both, therefore for u math guys, the laws of physics, nature, Mrs Stephens algebra class, and all things holy dictate that we hold our independant constant for each hp # we look at. just the way it works seriously, what is he talking about anymore? did i miss 4 pages and not realize it? nono you didnt miss anything, the point is that any discussion between tq and hp is meaningless. what the OP is really saying is that low-end torque doesnt matter as much as the ability to continue making torque in high rpms. ex: my old 4.6 mustang would fall flat on its face after about 4500 rpm. no more torque, but thats just about the time some of you honda guys start breathing.

ok, so lets look at this then: low end torque vs high end torque, and remember, all things equal (were still playing).

for comparitive purposes lets look at an engine that makes 500 ft lbs across the spectrum. probably not a gas motor........ but it doesnt matter, because we are only looking at hp, the sheer ability to accelerate. because we are talking low vs high, and because i dont like decimels, Im going to measure this motor at 525.2 rpm and 52,520 rpm. This would seem nuts, but remember our theoretical motor flatlines it tq, so our hp curve is strictly exponential. at the low rpm value our motor makes 50 hp. at the high it makes 5000 hp. sweet. ok, so jimmy tweaks the flux capacitor on our motor and it makes a whopping 501 ft lbs across the board now. At these same numbers, we now make 50.1 hp down low (remember, as defined, the hp is the cars ability to accelerate under ideal conditions). So what about up high? well, 501x52520/5252 = 5010 hp.

so in our theoretical motor down low we gained 50% hp per unit tq added. however, up high we gained 1000% hp for every unit tq we added(for anyone not good with percents, 1 added, 10 yeilded, (10/1)*100%). because we kept all things equal we know that this is a hard fast rule about the relationship between hp and tq and rpm. Im going to have to give it to these guys, in theory, you will be faster with a high revving motor that continues to make torque than a low end torque motor as far as the sheer ability to accelerate goes.

Real world time (not mtv....): no motor makes static tq across the rpm range, and you arent going to race at either 500 rpm or 50k. But the fact remains that your motor torque is of more value to you in the higher rpm ranges. But this theory glorifies the roll race. I said a minute ago that no motor makes static torque across the band. This theory does not take into account a motor's resistance to bogging down (which is basically just torque). Motors which are capable of making high end torque make less torque down low and vice versa (imagine that!). Which is why you then have to do things like cut weight and increase traction in the low tq car. yes, i said it, traction is more of an issue for low torque cars than high tq cars. anyone freaking out? gotta look at what i said. Traction is a bigger issue when racing for a low torque car. however Traction is a bigger issue when racing in a high torque car piloted by a low torque driver. You low tq guys need to rev way up to get out of the hole or u wont move. so really, pick your poison.

can anyone tell that I was bored?

[ZEE]

Really depends on what size washers you use. A little off topic I know. But that's what I think.

[DustinsDuster]

Specter, i appreciate the time you took to type that, but you havent been here long enough to know that the kids arguing here are too bullheaded to accept defeat, no matter what explanation from whatever person you can think of (myself included).

anymore, youre better off just sitting back and enjoying the shit storm.

by the way, no one ever answered my question above. if youre too lazy to scroll back up, here it is again:

"if put in identical cars, which would win a race; a 300hp 4cyl or a 300hp V8?"

[SpecterGT260]

to answer ur question, it depends on the tq!

ive been around awhile, just not so much on this site. but i know alot of the people involved.

[69gt4speed]

Specter, i appreciate the time you took to type that, but you havent been here long enough to know that the kids arguing here are too bullheaded to accept defeat, no matter what explanation from whatever person you can think of (myself included).

anymore, youre better off just sitting back and enjoying the shit storm.

by the way, no one ever answered my question above. if youre too lazy to scroll back up, here it is again:

"if put in identical cars, which would win a race; a 300hp 4cyl or a 300hp V8?"

I would bet money with equal gearing, good traction, 3000#, stock auto a 300hp 350ci would take a 300hp 144ci. Why the tq range will be lower in rpms and more likely a broader curve with n/a enines. In a 5 or 6 speed stick be harder to say. But that will never be anyway. It would take a fairmont, mustang or something, put in a arca 2.3l about 300hp then swap to a 302 300hp. Track testing on each combo. A stang guy is most likely to do this. They do all kinds of bs.

[Domestic Disturbance]

who drives stangs neways honestly

[Rollin on Dubs]

Specter, i appreciate the time you took to type that, but you havent been here long enough to know that the kids arguing here are too bullheaded to accept defeat, no matter what explanation from whatever person you can think of (myself included).

anymore, youre better off just sitting back and enjoying the shit storm.

by the way, no one ever answered my question above. if youre too lazy to scroll back up, here it is again:

"if put in identical cars, which would win a race; a 300hp 4cyl or a 300hp V8?"

300 hp V12! Thats my pick

[SpecterGT260]

weeeeellllllll, is that a acceleration or distance?

[DustinsDuster]

1/4mile drag race. acelleration.

[SpecterGT260]

i know, i was being facetious

[DustinsDuster]

i think youre only like the second person ever to use that word on here. i am pretty sure i did once in a story or something....

[SpecterGT260]

doesnt that get me some sort of a special title or something? http://www.crunderground.com/images/smiles/biggthumpup.gif



btw, i cant get the smilies to work. I had to use the [ img] prompts to get that thumb up there

[amoander]

such cantankerous ppl on here any more!

[SpecterGT260]

dont try adam. i think CRU rule specify only one nifty word per thread. I already got it. GTFO!

[Domestic Disturbance]

the idea of not needing torque is 4 the lugubrious minded