Whats the fastest

ok well me and my dad have been having a argument...

what is the fastest tunner engine in the world

i claimed that the skyline/supra's inline 6 can be the fastest and morst powerful (1300 HP)

he thinks that a V-8 can have more power, though i havent ever seen one with 1300

i might be a total dumass here but whatever what do yall have for imput

i might be a total dumass

Yup.

It depends on what sence your talking about and differnt factors. Street legal stock production cars, modified street legal, not street legal, drag racing, circuit racing.

Turn on your TV and watch NHRA drag racing. All things being equal the one with the most cubic inches wins. If you do all the things to a big block V8 that you do to the Supra 6, well you get the idea.

Top Fuel have over 8000hp to put things in perspective. Halfway down the track, since the fuel is burning so quick and hot, they melt the spark plugs and it essentially diesels the rest of the track.

the fuel is burning so quick and hot, they melt the spark plugs and it essentially diesels the rest of the track.

Cool!
I did not know that. Somehow I don't get to work on any top fuelers under the ole shade tree..

u cant do all the things u can do to a skyline or supra inline 6 to a big block hemi (the most popular high power V-8 right now) the compression on the hemi is to high to put the high shot of nos and REALY high turbo boost... if u did that to a hemi u would drive maby 2 miles hit the nos and that pistons gunna fly strait out bottom... and it definately wouldent be perdy...

Sure you can. Engines are engines. They are big pieces of metal with pistons and cranks and cams. You can put lower compression pistons in a Hemi or use thicker head gaskets to lower compression. The shortblock itself (lower rotating assembly) has almost nothing to do with power output. Power is in the heads, cam, and the design behind the whole thing. A 3.0 liter Skyline engine is no better than a 3.0 liter BMW inline 6, or for that matter a 1973 AMC inline six. The secret is in flow, velocity, and cam technology.

Certain engines present inherent weak points. For instance, I wouldn't build a race engine from a 403 olds since it has a weaker lower end. I wouldn't build a reliable daily driver from a chevy 4-cylinder since they last about as long as one of Brittany Spear's engagements.

If you're going to add nitrous or a turbo to any engine, you tune it the same way; proper ignition timing, compression, and cam events. No brand is better than any other.

If you want to get literal on the subject, the small block chevy -- although cliche' -- is the easiest to modify, turbo, blow, nitrous, cam, and modify. Its the easiest because it IS cliche'. Everybody has one and the aftermarket support is easily a thousand-fold what you can find for any import.

Displacement is displacement. Given the same flow and velocity on the same cam timing events, they'll all do the same.

The other thing that you have to consider is, how long will that skyline 6 last at 1300 hp?

Any engine is a "tuner" engine, its just that the word "tuner" was coined by the sport/import scene. We American Iron folks have been making "tuner" engines since 1915.

Here's a little interesting tidbit. In 1907, "tuners" had engines that make more HP than the sport import "tuners" make today. Hurts doesn't it. :)

yes, top fuel dragsers are V8, but think this whats in the 2000ft-lbs semitrucks we see every day? 90% of them are inline 6s. in my mind the most efficent to least engine designs - H.O., I, V, W. a H.O. engine the downward force of the piston is moving another pistion up. an inline engine the downward force is absorbed by the main caps. in a V engine, the downward force is also absorbed by the main caps, but in two different directions, fighting each other. a W engine is the same as a V, but the force is in four directions, not two.

i would think a inline 6 would beat a V6, and a inline 8 would beat a V8. but i don't know about a inline 6 vs a V8, its about equal to me.

but they couldent go as fast as us :) HP means alot its power to weight ratios and how well u transfer the power from the engine to the wheels... depending on the cars even now can loose 15-20% of the power as it transfers to the wheels think of back when they dident have the tech we have now... 30-40% loss... maby more... so ya i mean the basics of a engine hasent changed in ages... so they can drop just as much power into cars as now... just cant get it to the wheels as effeciently... o ya and curtis can ya get me some more info on those cars i would be interested to see a model T with 1300 horses :) i ur probably meaning 300-400 HP though its a big jump though... the first V-8s made i think 90 HP or something

First of all, no early engines made 1300 HP, that wasn't my intention to imply. But several of the early engines were modified to make well over 300, which is far more than 99.9% of today's "tuners" make.
:) HP means alot its power to weight ratios
HP actually means very little. Torque means everything; how much, when its made in the RPM range, the shape of the curve... HP is torque over time, so without torque, we can't have HP. I don't care if a 2.0 liter Honda makes 3000 hp. If it doesn't make torque in the right places, its a worthless piece of junk.... which is my problem with the automotive market right now. Manufacturers target young buyers with this "horsepower" word, and it means very little. In acceleration, HP has relevance since its a good mathematical illustration of torque vs. weight, but the force you feel between your ass and the seat is torque and nothing else.
I would think a inline 6 would beat a V6, and a inline 8 would beat a V8
Well, it all boils down to a million factors. In general, a V6 of equal parameters would probably make more HP and less torque than an I6. An I6 has 7 main bearings, but a V6 has 4. Therefore, the V6 has about 44% less main bearing friction than the I6. The I6 will have (with the exception of race-style individual throttle-per-cylinder intakes) trouble equally distributing air to each cylinder compared to the V6. Sierra, although your theory has logical value with the main bearing thrusts, the fact is that the journals are riding on oil and the oil takes the forces. It transfers the force to the iron in the mains and since the whole thing is riding on a circle, it doesn't matter which direction the pulses force the crank, provided they effectively apply it at the right time.

Legionofone, if you look over your posts, it appears as though you've already formulated your opinion long before you asked the question. You asked us our opinion saying you knew nothing, now you're defending your viewpoint. The fact is, displacement, volumetric efficiency, and friction are the main factors in power production; not import vs. domestic, not Nissan vs. Chevy, not old vs. new. I could make a 3000 hp Dodge slant-6, but its not practical with the flow from the available heads, the strength of the block, and the availability of suitable pistons and rods.

Stop telling us the right answer and just read what the knowledgeable people here have to say. You might learn something. There is respect in all makes, models, and engines. They all suit different purposes and your skyline 6 is not the pinnacle of engineering, so stop defending it as such.

.... And by the way, I guarantee that if you put a 2000-ft-lb engine in any street car, it would destroy any high-hp skyline you could dream of.

u cant do all the things u can do to a skyline or supra inline 6 to a big block hemi (the most popular high power V-8 right now) the compression on the hemi is to high to put the high shot of nos and REALY high turbo boost... if u did that to a hemi u would drive maby 2 miles hit the nos and that pistons gunna fly strait out bottom... and it definately wouldent be perdy...


Ahh, my neighbor has a pro stock 73 and 69 camaro. 540 merlin block bored out to a 560. I don't know the compression hes running, but I know its high, (12.5:1 sounds familiar). On top of this motor hes running a wieand 8-71 blower pumping in 23psi of boost. On top of that hes running a 500 shot of nitrous. On the dyno, he pumped out 2600 some horse power without the shot....

As curtis said, an engines an engine. It all depends on how you build it or what its weak points are. You say you would blow a rod out of a stock hemi with high boost and a shot of nitrous. I bet you would do the EXACT same thing to any honda, toyota, or any other manufacturers motor. High boost+Big shot of Nitrous= always a dangerous combination.

2600 HP would of eaten the dyno for breakfast... that thing could never handel that much... hell the skyline with 1300 jump off the damned thing and nearly breaks it... with umm... lets see 3 ties in the back 2 on the side and umm 3 people on the car... he must of had like 6 in the back and a bus ontop of that car...

and torque doesent mean everything... there used to be a class of motorcycling that had to be tow started because they were so highly geared that they dident have the torque to start moving and they broke i cant remember eactly like 130-150 mph so no u dont need torque to do anything its the power of the engine torque and HP are 2 different lines on a dyno graph... and the skyline put out 857.5 HP on the day it almost killed the dyno...

Well i look at HP as how long an engine applies its torque...

Although 2000ft/lbs of torque is great how big and heavy is the engine how high is the redline 4000-6000... and how are you gonna manage all that torque? Big heavy Transmission? all this big heavy stuff keeps adding to the drive train power loss...but how much i'm not shure.

with high HP low torque motors...i have the same ability to multiply the torque to the wheels just like the V8 but i can applie that multiplied torque over a longer period of time becase of the high redline so that means i'll still be pulling longer in 1st gear when with the large V8 you need to shift to 2nd gear droping the torque to the wheels.

thats why HP seems to be the final answer i need..if the transmission is geared correctly. even though both engine may be hugely different in the way they applie there torque what matter is how long they do it...if they both have the same HP and the drive trains are matched accordingly they should(in theory) both preform the same.

haha oops i mean 857.5 ft lbs of torque hahaha dumass me

Wow... some of the (mainly one or two) people in this thread amaze me. Ask questions then automaticaly turns around to defend their point of view. Highest hp cars arnt allways going to be the fastest cars, supra and skyline are not the fastest cars in the world- you've been watching too many movies. A 2600hp camaro is hard to believe, but I cant prove you wrong so theres no need for me to argue about it. The torque and hp of a motor does not determine its redline, nor does the weight of the drive train. It does have to do alot with engine design, a motor isnt allways the same as the next, otherwise hp and torque would strictly be based on displacment. As for the fastest motor, do like suggested above and look at NHRA records, you'll find it, and it will be a v8.

Highest hp cars arnt allways going to be the fastest cars, supra and skyline are not the fastest cars in the world.

Reason 1: A car powered by a 1500 hp diesel train engine probably not be a good dragster even with ample torque and hp. Maybe it would win a tractor pull??

Reason 2. I suck at shifting fast enough so I always used an auto tranny. Still did'nt always win :-)

2600 HP would of eaten the dyno for breakfast... that thing could never handel that much... hell the skyline with 1300 jump off the damned thing and nearly breaks it... with umm... lets see 3 ties in the back 2 on the side and umm 3 people on the car... he must of had like 6 in the back and a bus ontop of that car...



In Australia the highest Hp reached is 1400Hp and the car was firmly on the the rollers. How do think prostock teams record their slight increases in power when they change setups in their engines?Dyno, Top Doorslammer reach 2000Hp on the dyno.

2600 HP would of eaten the dyno for breakfast... that thing could never handel that much...

I believe the highest rated engine dyno goes to somewhere around 5000hp... he definately could have had the car dyno'd. Maybe not chassis dyno, but definately engine.

and torque doesent mean everything... there used to be a class of motorcycling that had to be tow started because they were so highly geared that they dident have the torque to start moving and they broke i cant remember eactly like 130-150 mph so no u dont need torque to do anything its the power of the engine torque and HP are 2 different lines on a dyno graph... and the skyline put out 857.5 HP on the day it almost killed the dyno...

You've obviously been fed some misinformation. HP doesn't exist without torque. Its a mathematically calculated physical property of torque as it applies to time. HP is a number we use to demonstrate a physics property, not a property itself. When you put a car on a dyno, it doesn't measure HP, it measures torque and plots HP as a FUNCTION of torque. HP = TQ x RPM/5250. ts always going to be that way and you can't change it. The only way to change HP is to increase torque, or increase the RPM where that torque happens.

The reason those bikes to which you refer need to be tow started is not because they lack torque, its because their gearing reduces the torque made by the engine... or more properly stated, their gearing doesn't provide as much torque multiplication as a lower geared bike. Its no different from a bonneville top speed car. They can achieve incredible speeds, but don't have enough torque making it to the ground to start rolling on their own.

One more little tidbit for you.... Torque is commonly measured in foot-pounds. Common ways of expressing power is in horsepower, kW, and... foot-lbs/second. One HP is equal to 550 ft-lbs/sec. Further proof that HP is a function of torque over a period of time.

so what do they have 1 HP engines? with 0 torque? there has to be a form of power without torque or those engines wouldent do anything...

and the reason they needed to be tow started is BECAYUSE THEY LACKED TORQUE!!! the gear ratios were HUGE making them go hela fast but have no power on the line... u said it urself right there in the post... there has to be another form of power measuremnt if we cant meausure there power in HP/TQ...
quote:
Reason 1: A car powered by a 1500 hp diesel train engine probably not be a good dragster even with ample torque and hp. Maybe it would win a tractor pull??

actualy... if u could fit it in there it probably wouldent be to bad... the reason trains dont have the power is that they have massivly low gear ratios and this CRAZY torque for pulling large loads with little HP

so what do they have 1 HP engines? with 0 torque? there has to be a form of power without torque or those engines wouldent do anything...

and the reason they needed to be tow started is BECAYUSE THEY LACKED TORQUE!!! the gear ratios were HUGE making them go hela fast but have no power on the line... u said it urself right there in the post... there has to be another form of power measuremnt if we cant meausure there power in HP/TQ...
quote:
Reason 1: A car powered by a 1500 hp diesel train engine probably not be a good dragster even with ample torque and hp. Maybe it would win a tractor pull??

actualy... if u could fit it in there it probably wouldent be to bad... the reason trains dont have the power is that they have massivly low gear ratios and this CRAZY torque for pulling large loads with little HP

Perhaps you should read up on some facts before you continue arguing with people that actually know their shyt... :rolleyes:

http://auto.howstuffworks.com/horsepower.htm
http://auto.howstuffworks.com/question381.htm

So Legionofone... have you told your pops that hes right yet? Or is this thread going to have to keep going and going?

so what do they have 1 HP engines? with 0 torque? there has to be a form of power without torque or those engines wouldent do anything...


Those engines DO make torque. Just because they don't advertise it doesn't make it non-existent. I never said that those biked didn't MAKE torque, I said that the gearing reduces it. The gearing can't change what the engine makes.

The honest reason why everything is advertised in HP numbers is because the general american public is too stupid to know any better. People flock to dealerships to buy the "new 230 hp 4-cylinder tuner" and wonder why its dramatically slower than their 5000-lb 1976 Cadillac with only 239 hp. Its torque. That 4-cylinder may only have 190 ft-lbs of it and you have to rev it to 6000 just to get it. The Caddy has nearly 600 ft-lbs and its available to the wheels from idle to almost redline.

Horsepower used to be a great way to advertise back when people understood it, but its become the most misunderstood name in automobiles.

Its much like Watts = volts x amps. Every body knows what to expect from a 100 watt light bulb, but they have no idea how it acheives that amount of light. No one realizes that for every drop in voltage, the light sucks more amperage. That is a pretty good analogy for HP. You can make HP with lots of torque (high voltage) and it doesn't need to work hard (low amperage). Or you can give it not much torque, like with your skyline engine (low voltage) and it will require much more revs to get it (high amperage)

Heres just a small example of what i have seen for myself. 2 identical toyota corollas one with a 1jz twin turbo supra engine imported from japan with an aftermarket management system tuned as best as possible. and the other with a chevrolet stroker. thats a 350 built to a 383 with a 327 crank and long rods for all you import guys out there. never dyno tested but the chevy power car was naturally fueled with carb prolly made around 450 hp. and the other engine to the best of my knowledge made about the same but i would guess a little more hp. I know the outcome of the 5-6 times we ran them side by side in the 1/4 mile any of you have any guess what happened???? It really was an interesting turn out

supra engine probably spanked it ?

Legionofone, I think what people are trying to tell you is to have an open mind. There isn't a specific engine that is the 'holy grail' of all. Listen to other people's replies. There are some knowedgable people that post in this forum. Think of it as free education. Knowing the facts will in turn make you more knowledgable and have better opinions. :)

If you have questions, be honest and you will get honest replies.

So Legionofone... have you told your pops that hes right yet? Or is this thread going to have to keep going and going?

Its never gonna end... I think we'll just have to cut our losses and chalk this one up to 2much 2f/2f.
Supras are not God. Nor are Skylines. Or Ford, Chevy, inline 4s, 6s, v8s, v6s, v4s, 2strokes, 4 strokes etc etc. They're all the same, they're all different, they all serve their purposes; how well is in the opinion of each individual.
But to answer your question, the v8 is always faster :).
The V engine configuration has a bonus that it has fewer main bearings than the inline config. It also has a HUGE bonus in that it is the only allowed engine configuration in the super-powered classes of the NHRA. So naturally, the v8s are going to be the ones putting out the most power, simply because they are the engines required to be built by the best of the best.
So just pay your dad the 20 bucks and stop dreaming of inline sixes. If you like turbos or s/cs or n2o, go buy a car with a big block and throw all three on it. Be assured... there is NO replacement for displacement if your only goal is to make big power numbers. And don't tell me about superchargers and turbos and n2o as a replacement. Because you can do all those things to a bigger displacement motor and get even bigger gains.
There are PLENTY of street legal muscle cars that put down over 1300hp. I mean, you can easily throw a 550+ cubic inch(9 liters) big block into any number of new or old cars, throw a pair of screw superchargers on it pushing 15psi, add a couple of stages of 400hp fogger nitrous to boot, and easily hit 1500 or 2000hp. All the parts you will need can be easily obtained with minimal effort(rather large wallet though, probably cost in the 15,000-20,000 range, depending on what you can do yourself) from any number of major parts suppliers.
Just look at it this way... Top fuel dragsters run low 4s in the 1/4 mile. They're powered by big inch v8s. Lets say they were actually powered by the 1300hp supra engine. The cars would have to weigh in at around 500-600 pounds to make it physically possible run that fast in the quarter with that much power. So if you managed to bolt the supra engine to a pair of axles and threw a seat on top of the valve covers, ignoring all of the complex suspension, chassis, and aerodynamics equipment to cope with that kind of accelleration, you could probably run a low 4 quarter..
That should give you an idea of how much power the v8s make. Considering the top fuel dragsters weigh somewhere in the area of 2600lbs.

ok i guess i give in and have to lose the bet... GRRR!!! i hate that... thanks yall for the info and sorry for being a ass at time... hehe latez!

hum...if HP seems to hold little to no value...why was the formula created for what purpose if there was no purpose then why use it?

And don't gave me anything about advertisers polluting the mind of the buyer into thinking HP is the only thing you need. i wanna know why.

i see HP as equaling work...more HP more work is done. Torque may be the driving force but there is no work behide torque if there isn't any movement...if i push against a walll i may be appling force but i'm getting no work done because the wall isn't moving in the direction that i'm appling my force in.

with the transmission..i can double the torque or half it but HP remains the same...as long as i have HP i can do what i like with the torque given to me. i can make a strung out racing engine look like a big V8 on the output shaft of the transmission, just as long as both engines put out the same HP.

This is an article a friend(Dan Jones) wrote.
Enjoy.


Torque Versus Horsepower - More Than You Really Wanted to Know
by Dan Jones

Every so often, in the car magazines, you see a question to the technical
editor that reads something like "Should I build my engine for torque or
horsepower?" While the tech editors often respond with sound advice, they
rarely (never?) take the time to define their terms. This only serves to
perpetuate the torque versus horsepower myth. Torque is no more a low rpm
phenomenon than horsepower is a high rpm phenomenon. Both concepts apply
over the entire rpm range, as any decent dyno sheet will show and as I will
show below.

Before I begin, I will give the short answer to the torque versus horsepower
debate is that torque is what accelerates a vehicle but it is the torque at
the rear wheels that matters and it is the horsepower of the engine that
determines how much engine RPM can potentially be traded for torque at the
rear wheels via gearing. Gearing is the reason you accelerate harder in 1st
gear than you do in 4th or 5th (there's also an aerodynamic drag effect but
that is relative less important for the purposes of this discussion). Please
understand it is the overall gearing provided by the transmission, rear end,
and tire that is important.

To begin, we'll need several boring, but essential, definitions. Work is a
measurement that describes the effect of a force applied on an object over
some distance. If an object is moved one foot by applying a force of one
pound, one foot-pound of work has been performed. Torque is force applied
over a distance (the moment-arm) so as to produce a rotary motion. A one
pound force on a one foot moment-arm produces one foot-pound of torque.
Note that dimensionally (ft-lbs), work and torque are equivalent. Power
measures the rate at which work is performed. Moving a one pound object
over a one foot distance in one second requires one foot-pound per second of
power. One horsepower is arbitrarily defined as 550 foot-pounds per second,
nominally the power output of one horse (e.g. Mr. Ed).

Since, for an engine, horsepower is the rate of producing torque, we can
convert between these two quantities given the engine rate (RPM):

HP = (TQ*2.0*PI*RPM)/33000.0
TQ = (33000.0*HP)/(2.0*PI*RPM)

where:

TQ = torque in ft-lbs
HP = power in horsepower
RPM = engine speed in revolutions per minute
PI = the mathematical constant PI (approximately 3.141592654)
Note: 33000 = conversion factor (550 ft-lbs/sec * 60 sec/min)

In general, the torque and power peaks do not occur simultaneously (i.e.
they occur at different rpm's). However, since the curves are functions
of each other, the curves will always cross at 5252 RPM when the units
are torque in ft-lb and power in US Horsepower. There's nothing magic
about this number and it will have a different value for different units,
say power in Watts and torque in Newton-meters.

To answer the question "Is it horsepower or torque that accelerates an
automobile?", we need to review some basic physics, specifically Newton's
laws of motion. Newton's Second Law of Motion states that the sum of the
external forces acting on a body is equal to the rate of change of momentum
of the body. This can be written in equation form as:

F = d/dt(M*V)

where:

F = sum of all the external forces acting on a body
M = the mass of the body
V = the velocity of the body
d/dt = time derivative

For a constant mass system, this reduces to the more familiar equation:

F = M*A

where:

F = sum of all the external forces acting on a body
M = the mass of the body
A = the resultant acceleration of the body due to the sum of the forces

A simple rearrangement yields:

A = F/M

For an accelerating automobile, the acceleration is equal to the sum of the
external forces, divided by the mass of the car. The external forces
include the motive force applied by the tires against the ground (via Newton's
Third Law of Motion: For every action there is an equal and opposite re-action
and the resistive forces of tire friction (rolling resistance) and air drag
(skin friction and form drag). One interesting fact to observe from this
equation is that a vehicle will continue to accelerate until the sum of the
motive and resistive forces are zero, so the weight of a vehicle has no bearing
whatsoever on its top speed. Assuming level ground, weight is only a factor
in how quickly a vehicle will accelerate to its top speed.

In our case, an automobile engine provides the necessary motive force for
acceleration in the form of rotary torque at the crankshaft. Given the
transmission and final drive ratios, the flywheel torque can be translated
to the axles. Note that not all of the engine torque gets transmitted to the
rear axles. Along the way, some of it gets absorbed (and converted to heat)
by friction, so we need a value for the frictional losses:

ATQ = FWTQ CEFFGR TRGR * FDGR - DLOSS

where:

ATQ = axle torque
FWTQ = flywheel (or flexplate) torque
CEFFGR = torque converter effective torque multiplication (=1 for manual)
TRGR = transmission gear ratio (e.g. 3 for a 3:1 ratio)
FDGR = final drive gear ratio
DLOSS = drivetrain torque losses (due to friction in transmission, rear
end, wheel bearings, torque converter slippage, etc.)

During our previous aerodynamics discussion, one of the list members mentioned
that aerodynamic drag is the reason cars accelerate slower as speed increases,
implying that, in a vacuum, a car would continue to rapidly accelerate. This
is only true for vehicles like rockets. Unlike rockets, cars have finite rpm
limits and rely upon gearing to provide torque multiplication so gearing plays
a major role. In first gear, TRGR may have a value of 3.35 but in top gear it
may be only 0.70. By the above formula, we can see this has a big effect on
the axle torque generated. So, even in a vacuum, a car will accelerate slower
as speed increases, because you lose torque multiplication as you shift up
through the gears.

The rotary axle torque is converted to a linear motive force by the tires:

LTF = ATQ / TRADIUS

where:

TRADIUS = tire radius (ft)
ATQ = axle torque (ft-lbs)
LTF = linear tire force (lbs)

What this all boils down to is, as far as maximum automobile acceleration is
concerned, all that really matters is the maximum torque imparted to the
ground by the tires (assuming adequate traction). At first glance, it might
seem that, given two engines of different torque output, the engine that
produces the greater torque will be the engine that provides the greatest
acceleration. This is incorrect and it's also where horsepower figures into
the discussion. Earlier, I noted that the torque and horsepower peaks of an
engine do not necessarily occur simultaneously. Considering only the torque
peak neglects the potential torque multiplication offered by the transmission,
final drive ratio, and tire diameter. It's the torque applied by the tires
to the ground that actually accelerates a car, not the torque generated by the
engine. Horsepower, being the rate at which torque is produced, is an
indicator of how much potential torque multiplication is available. In
other words, horsepower describes how much engine rpm can be traded for tire
torque. The word "potential" is important here. If a car is not geared
properly, it will be unable to take full advantage of the engine's horsepower.
Ideally, a continuously variable transmission which holds rpm at an engine's
horsepower peak, would yield the best possible acceleration. Unfortunately,
most cars are forced to live with finitely spaced fixed gearing. Even
assuming fixed transmission ratios, most cars are not equipped with optimal
final drive gearing, because things like durability, noise, and fuel
consumption take precedence to absolute acceleration.

This explains why large displacement, high torque, low horsepower, engines
are better suited to towing heavy loads than smaller displacement engines.
These engines produce large amounts of torque at low rpm and so can pull a
load at a nice, relaxed, low rpm. A 300 hp, 300 ft-lb, 302 cubic inch engine
can out-pull a 220 hp, 375 ft-lb, 460 cubic engine, but only if it is geared
accordingly. Even if it was, you'd have to tow with the engine spinning at
high rpm to realize the potential (tire) torque.

As far as the original question ("Should I build my engine for torque or
horsepower?") goes, it should be rephrased to something like "What rpm
range and gear ratio should I build my car to?". Pick an rpm range that
is consistent with your goals and match your components to this rpm range.

So far I've only mentioned peak values which will provide peak instantaneous
acceleration. Generally, we are concerned about the average acceleration
over some distance. In a drag or road race, the average acceleration between
shifts is most important. This is why gear spacing is important. A peaky
engine (i.e. one that makes its best power over a narrow rpm) needs to be
matched with a gearbox with narrowly spaced ratios to produce its best
acceleration. For instance, some Formula 1 cars (approximately 800 hp from
3 liters, normally aspirated, 18,000+ rpm) use seven speed gearboxes.

Knowing the basic physics outlined above (and realizing that acceleration
can be integrated over time to yield velocity, which can then be integrated
to yield position), it would be relatively easy to write a simulation program
which would output time, speed, and acceleration over a given distance. The
inputs required would include a curve of engine torque (or horsepower)
versus rpm, vehicle weight, transmission gear ratios, final drive ratio, tire
diameter and estimates of rolling resistance and aerodynamic drag. The last
two inputs could be estimated from coast down measurements or taken from
published tests. Optimization loops could be added to minimize elapsed
time, providing optimal shift points, final drive ratio, and/or gear spacing.
Optimal gearing for top speed could be determined. Appropriate delays for
shifts and loss of traction could be added. Parametrics of the effects of
changes in power, drag, weight, gearing ratios, tire diameter, etc. could be
calculated. If you wanted to get fancy, you could take into account the
effects of the rotating and reciprocating inertia (pistons, flywheels,
driveshafts, tires, etc.). Relativistic effects (mass and length variation
as you approach the speed of light) would be easy to account for, as well,
though I don't drive quite that fast.

Later,
Dan Jones

Good post... ^^

Just a reply to whoever said they doubt that 2600hp is capable... several things.

A. It was NOT done on a chassis dyno (even though there ARE chassis dyno's that CAN handle this power)
B. Its a PRO STOCK DRAGSTER, its not a unibody civic. Its a fully roll caged, tubbed out car with a 115 octane burning motor.

I will take pictures for you, its running two demon 1150 carbs on top of a wieand 8-71 blower, pushing in 21-23 lbs of boost. He transfers this all through a TH-400 transmission that is air shifted.

In correspondence to what curtis is saying, there is someone mentioning that HP is always better. First- you say "Oh, I can just change the gearing in the transmission and rear end to compensate, and run the gear longers. Higher HP and running it longer on a specific gear have next to nothing to do with eachother. The powerband of a motor is entirely on how you set it up. You can make a motor with the HP range flat across the board or same with torque. If you ever notice, a lot of european sportscars have high HP numbers. On some reviews you will here them say "This engines are great for racing, but when it comes to daily driving, the lack of lower end TORQUE makes it unbearable"... but im with what curtis is saying, so before you question me, yell at him... :)

Heres just a small example of what i have seen for myself. 2 identical toyota corollas one with a 1jz twin turbo supra engine imported from japan with an aftermarket management system tuned as best as possible. and the other with a chevrolet stroker. thats a 350 built to a 383 with a 327 crank and long rods for all you import guys out there. never dyno tested but the chevy power car was naturally fueled with carb prolly made around 450 hp. and the other engine to the best of my knowledge made about the same but i would guess a little more hp. I know the outcome of the 5-6 times we ran them side by side in the 1/4 mile any of you have any guess what happened???? It really was an interesting turn out

the 383 is actually a bored out 350 with a 400 crank....

i see HP as equaling work...more HP more work is done. Torque may be the driving force but there is no work behide torque if there isn't any movement...if i push against a walll i may be appling force but i'm getting no work done because the wall isn't moving in the direction that i'm appling my force in.

Horsepower is a unit of power, and not an equivalent term. Also power does not represent the amount of work an engine can do unless it is for some given duration of time. Torque is representative of work, but work that causes rotation.

Torque is the amount of work the engine can perform. Torque represents a force at some distance, hence the units “lb-ft” or “Nm”. Power on the other hand is work per unit time, commonly in horsepower (hp) or kilowatts (kW). But since power is simply work divided by time the following equivalent units could be used:

1 hp = 550 lb-ft / s

1 kW = 1 kNm / s

An interesting point that you bring up is that you cannot produce work unless you have force and distance. With linear work you must apply a force to an object and that object must travel some distance. However, since torque involves rotation the outcome is slightly different. When applying a torque to a shaft, the shaft need not rotate for the torque to be non-zero. As long as the force is applied at some distance from (and not through) the centroid of the shaft a torque will be generated. Hence, at 0 RPM one could have X amount of torque with 0 hp.

I don’t think anyone here believes ‘power’ is a valueless performance characteristic. However, I think the point everyone was trying to emphasize is ‘horsepower’ ratings are often misunderstood and their importance exaggerated. Many people just don’t understand the relationship between power and torque.

just found this, good info - http://www.nsxprime.com/FAQ/Miscellaneous/TorqueHPSpeed.htm

i want to copy and paste the whole page, but just this is importent for now:

Power is the rate at which work is performed: Power = Work/Time. We'll measure time in minutes.

Dynamometers can measure torque, in foot-pounds; they can NOTdirectly measure horsepower. To calculate horsepower, we have to combine the torque measurement with a time measurement.

the convertion for horsepower is: horsepower = torque * RPM / 5252

think of HP as a measurement of torque at a certain speed, thats why the peak horsepower range is commonly near the redline

hey RandomTask i was realy talking about actual cars... and not hollowed out tube frames with a fiberglass body put over it...

ok well if we eliminate all the non regular gas burning engines what is the fastest car in the world... i mean there has to be one... and if u can get it the specs on the engine in it :)

hey RandomTask i was realy talking about actual cars... and not hollowed out tube frames with a fiberglass body put over it...

ok well if we eliminate all the non regular gas burning engines what is the fastest car in the world... i mean there has to be one... and if u can get it the specs on the engine in it :)

define "regular gas" you mean 87 octane? or any form of automotive grade gasoline. or do you just mean the fastest production car?

also you want the fastest or the quickest? two very different things.

the last time i checked the land speed record was 763.035 MPH, just over the speed of sound, but it was powered by two jet engines.

87-100ish octaine gas... not meth... ya i know about the jet cars... but thats jet fuel :P and i guess both... fastest quarter fastest top speed...

production car or upgraded car?
Or is the rule they must run on premium and under?

as far as what engine is best there are a lot of other things to consider such as the engines center of gravity (a higher one will hurt handling) the engines weight, flat and v engines weight more than inline because they jsut have more material to them. also consider running duration, a daily driver needs to last a lot longer than a le mans car and an F1 car and especially a drag car. if you want a drag car, everyone will tell you a big block v8 and if they dont they are wrong(save for maybe a few odd exceptions). if you want a sports car your looking at a high reving, light weight engine. big blocks dont work so good for that (although the new ford GT seems to do ok, though it doesnt race).

These are pretty much the fastest street legal cars you'll find, and they do it on 93 octane.


pump gas drags (http://hotrod.com/upcomingevents/113_0401_pump/)

gimme da specs! and does that alow for imports?

ya the fastest that can run on normal everyday premium-unleaded

A fast quarter mile street legal car that runs on premium unleaded, for one runs a fine line. the fastest I can think of here is a street registered Big Block ford Falcon XB, running an nitrious injected 505ci V8. This guy drives it to the strip and back, his car runs 8.90s, but thats an extreme example. Something more practical but very fast to would be be XR6 Turbos. Basically a Ford Falcon(4.0l straight six) with a big aftermarket Turbo and injecters on it car runs flat 11s with only $10,000 spent on upgrades, so for about $60,000 you can get a nice daily driver and a stonking dag car.

$60 000? Holy shit! You can buy a Z06 way less for that and run 11.9 stock with race slicks. Or for about 15 grand you could get a LS1 camaro with heads/cam or 150-shot, and few other minor things, and probably run high 10's on slicks.

And yes, the pump gas drags are open to anyone who can meet the requirements. But you probably won't find any imports there, the only way they can make any power is with huge amounts of boost and race fuel.

I think he's talking Aussie prices, since you can't buy the newer falcons here in the US. 60,000AU is approximately equal to 45,000US.

hum...if HP seems to hold little to no value...why was the formula created for what purpose if there was no purpose then why use it?

And don't gave me anything about advertisers polluting the mind of the buyer into thinking HP is the only thing you need. i wanna know why.

i see HP as equaling work...more HP more work is done. Torque may be the driving force but there is no work behide torque if there isn't any movement...if i push against a walll i may be appling force but i'm getting no work done because the wall isn't moving in the direction that i'm appling my force in.

Yes and no, maybe, one perhaps and a yeah. :) Horsepower is a useful measurement, however it has come to be associated with the wrong parameter of a vehicle's performance. Its like the light bulb analogy. A 100w light bulb is something we understand and we assume that one brand of 100w light bulb will put out the same light as the next, but most people couldn't tell you how many amps it draws or why. They just accept "100w" as gospel truth. In truth, the actual number of lumens (and what color they are) are very different between brands and affect the actual light you get. Horsepower is very similar. The general public hears "150 hp" and assume that it is an indicator of how much "light" they'll get. In truth, they're all different colors and lumens.

If people could really understand the HP/TQ relationship they would see how (although hp is a valuable number) the shape and contour of the torque curve is the real tell tale line. On desktop dyno, I don't even have the simulator plot the HP curve anymore; I have it plot IMEP, BMEP, or VE. When I look at a torque cuve I can guess where the HP is since its just a matematical derivation.

with the transmission..i can double the torque or half it but HP remains the same...as long as i have HP i can do what i like with the torque given to me. i can make a strung out racing engine look like a big V8 on the output shaft of the transmission, just as long as both engines put out the same HP.

True, however, those numbers are based on the ENGINE's RPM. If have a 2:1 first gear ratio, you've now doubled the torque, but halved the RPMs. If you plotted the corrected RPMs to reflect OUTPUT SHAFT RPM on a graph, it would look the same as the original. This is the main reason that chassis dynos are tested with the tranny in what ever gear is 1:1 or closest. Its corrected for a generic rear axle ratio and tire size, but the difference is minimal. Having said that, if you tested your car on a chassis dyno with 3.42 gears, then retested the same car after a 4.10 swap, the curves would be slightly shifted.

You are correct with using gear ratios to make things look good at the output shaft, but they would drive very differently. If you took a high-strung race engine and geared it way down to get the torque multiplied enough at low RPMs, you would have several problems (and these are very fine points, but applicable nonetheless) First, the gearing would have to be very close for the race engine's narrow torque curve peak. Second, you would have to have 15-20 gears to get your top speed RPM below 40,000 :) Third, although the lower gearing would be beneficial to improve the torque on the low end, race engines make tons of torque... way up high in the band. That gearing you chose to make stump pulling torque would let the engine spin through its effective torque band way too fast.

Multiplying the torque isn't as important as keeping the engine in its most effective powerband for the greatest amount of time. If I have time later I'll post some graphs of dyno charts with some gearing options and you'll see that the gearing and engine have to be matched or else it just won't be a useable machine.

Good counter point :)

Curtis is right, many people just talk horsepower btu more important is the shape of the torque curve and where it is in the rpm band.

One thing to add though. On a dyno, torque is usualy measured and horsepower then calculated. On what most of us usually see on a chassis dyno is called an inertia run, where the gigantic drum underneath the floor is accelerated and the computer calculates rate of acceleration and the weight of the drum and some other junk to come up with a hp number the plugs that into the hp-tq formula and comes up with torque. So on an engie dyno when you don't use a transmission, you are actually measureing torque and calculating horsepower. On a Chassis Dyno doing an inertia run, you are calculating hp and then calculating torque, the computer will get the rpm figures from the engine (plug wire) so everything is calculated. So there is no way to fool hp/tq numbers through gearing in the normal chassis dyno inertia run.

Legionofone, How about stock-block and commercially available fuel as regulators? In that case, you should look into pulling tractors. Lots of I-6's there.