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Old 04-09-2005, 11:48 PM   #16
Wally
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Regulator generally sits on the return line.
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Old 04-09-2005, 11:52 PM   #17
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Originally Posted by Wally
Regulator generally sits on the return line.

On my sisters integra B18b1, the regulator is on the right side of the engine looking into it from the front, so does it mean the fuel go from the left side of the rail to the right side?
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Old 04-16-2005, 07:59 PM   #18
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When your looking at a car to go fast, would you want to see the torque curve or the horsepower curve.

Why do people always say horsepower and a cars performance usually say horsepower when horsepower is not what makes a car accelerate. ChrisV said that torque is what you feel on your back. Isnt this what counts when drag racing?
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Old 04-16-2005, 11:56 PM   #19
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Quote:
Originally Posted by CarEXPERT
When your looking at a car to go fast, would you want to see the torque curve or the horsepower curve.

Why do people always say horsepower and a cars performance usually say horsepower when horsepower is not what makes a car accelerate. ChrisV said that torque is what you feel on your back. Isnt this what counts when drag racing?

Lez see, you generally want a flat torque curve (I believe the ford GT is supercharged to try to level out the torque line)

Torque and horsepower is a sketchy area. Horsepower is a number derived from RPMs and Torque. So, the horsepower curve you see, is actually the torque curve. Is torque required to go fast? Yes, but you don't need as much as some muscle car owners might tell you. There's engines out there that put out 500+ ft-lbs, but they do 60 in 5.5, while the Enzo has 483 and hits 60 in 3.3.

Formula one cars (whilest I don't take the weight into effect) have less than 350 ft-lbs, and are still incredibly fast, as they get their power from RPMs.

So, take those into effect, and I'll let ChrisV, or inygknok, or wally, etc. etc. handle the horsepower vs. torque argument.
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Old 04-17-2005, 03:25 AM   #20
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Quote:
Originally Posted by Godlaus
Lez see, you generally want a flat torque curve (I believe the ford GT is supercharged to try to level out the torque line)

Torque and horsepower is a sketchy area. Horsepower is a number derived from RPMs and Torque. So, the horsepower curve you see, is actually the torque curve. Is torque required to go fast? Yes, but you don't need as much as some muscle car owners might tell you. There's engines out there that put out 500+ ft-lbs, but they do 60 in 5.5, while the Enzo has 483 and hits 60 in 3.3.

Formula one cars (whilest I don't take the weight into effect) have less than 350 ft-lbs, and are still incredibly fast, as they get their power from RPMs.

So, take those into effect, and I'll let ChrisV, or inygknok, or wally, etc. etc. handle the horsepower vs. torque argument.

Let me tell you something,
Pretend there is a car A that makes 200 torque at 4000RPM(peak torque), and car B makes 200 torque at 2000RPM(peak torque). When car A gets to 4000RPM it pull(accelerate) the same as car B that is going at 2000RPM (assume THE CARS ARE THE SAME WEIGHT AND EVERYTHING THE SAME).
But when you put in the forumula for horsepower, Car A would make twice as much horsepower as car B at their peak torque, but they will have the same torque therefore same acceleration.

SO horsepower is nothing to do with how strong the car pulls (force of your back to the seat).
Can anyone tell why horespower is so freaking important and why everyone says it.
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Old 04-17-2005, 03:30 AM   #21
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Hold up, is horsepower determain when you should shift gears. Usually the torque peak hapens before the power peak but you dont shift at the torque peak, you shift at the horsepower peak right? Is this why?
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Old 04-17-2005, 12:49 PM   #22
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Interesting seeing as the acceleration curve follows the torque curve, which is only logical.

Without the horse there is no movement and therefore no torque = simple
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Old 04-18-2005, 04:13 PM   #23
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Did a little research, carexpert, and these golden rules always apply.

In a RWD car, torque at the REAR wheels is the only thing that matters.
In a FWD car, torque at the FRONT wheels is the only thing that matters.
In a AWD car, torque at all wheels is the only thing that matters.

RPMs are just as important as torque is, and it's how the gearbox manages it. In a formula one car, the engine only puts out 350 ft-lbs at the flywheel, but at the rear wheels, it's more like 1000. that's because the car's crankshaft turns at insane speed, and the gearbox utilises that, and turns it into torque at the rear-wheels. With the right gearbox, YOU can turn out over 10000 ft-lbs by turning a crank. That's why horsepower matters; it's RPMs X Torque divided by 5252. RPMs are just as important as torque is (at the flywheel). At the wheels, it's all torque.

Hope this helps.
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Old 04-18-2005, 04:24 PM   #24
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Your car accellerates at a rate that exactly matches the torque curve. But you shift at the power peak to maximize torque in the next gear up, due to gear ratios. AND, due to those same gear ratios, keeping it in gear to the power peak will make sure there is more torque to the wheels in that gear than there will be in the next gear up.

Explained here: http://www.allpar.com/eek/hp-vs-torque.html
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Old 04-18-2005, 11:34 PM   #25
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Doesn't he advocate changing gears at redline?

"(note: peak torque is at 5500 RPM, peak horsepower is at 6500 RPM)

Without graphing, there's something immediately apparent: in any gear, at 7000 RPM, the transmission torque output is always higher than at any RPM in the next gear up. What this means is, for this car:

Shift at the redline, not at the torque peak! "
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Old 04-19-2005, 12:46 AM   #26
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Quote:
Originally Posted by Godlaus
Did a little research, carexpert, and these golden rules always apply.

In a RWD car, torque at the REAR wheels is the only thing that matters.
In a FWD car, torque at the FRONT wheels is the only thing that matters.
In a AWD car, torque at all wheels is the only thing that matters.

This is simply because torque is the force that drives the wheels. As we all know, engine force is delivered to the rear wheels in a RWD and the front wheels can spin freely (brakes and car rigidity excluded) .... similarly for front and all wheel drive.

Quote:
Originally Posted by Godlaus
RPMs are just as important as torque is, and it's how the gearbox manages it. In a formula one car, the engine only puts out 350 ft-lbs at the flywheel, but at the rear wheels, it's more like 1000. that's because the car's crankshaft turns at insane speed, and the gearbox utilises that, and turns it into torque at the rear-wheels. With the right gearbox, YOU can turn out over 10000 ft-lbs by turning a crank. That's why horsepower matters; it's RPMs X Torque divided by 5252. RPMs are just as important as torque is (at the flywheel). At the wheels, it's all torque.

Hope this helps.

The way torque works through a gearbox is like this (assuming no losses):
The input shaft has a certain torque being put through it. If the gearbox has a 1:1 ratio, then the output shaft has the same speed and therefore the same torque. This is the same as just having a straight shaft through the gearbox.

If you ratio the gears so that the output speed is half the input speed, then the torque is doubled. If you ratio the gears so that the output speed is double the input speed, then you halve the torque.

HERE's AN EXAMPLE WITH MADE UP NUMBERS THAT DON'T MAKE A LOT OF SENSE IN THE REAL WORLD, BUT THEY ARE EASY TO WORK WITH
Based on the whole Torque/power argument, Torque x speed = power.
Let's assume we have an engine that puts out 150kW at 1000rpm
This means that the input shaft to the gearbox is always getting 1000rpm
And that we have a gearbox with 3 gears (2:1, 1:1, and 1:2) That means that in 1st gear, the output speed from the gearbox (to the wheels/diff) is 500rpm, in 2nd gear it's 1000rpm, and in 3rd gear it's 2000rpm.

So power = 150kW = Torque x speed
1st gear: 150 = T1 x 500
2nd gear: 150 = T2 x 1000
3rd gear: 150 = T3 x 2000

Simple algebra gives us: T1 = 2xT2 = 4xT3

Therefore Torque output from the gearbox is 4 times as much in first gear as it is in 3rd ..... but the speed is 4 times as much in 3rd. .... this is at the same engine power and speed (revs)..... So it shows how a gearbox can increase the torque by decreasing the output speed.

SO ACCELERATION IS FASTER IN 1ST GEAR - MORE TORQUE!
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Old 04-28-2005, 07:04 PM   #27
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okay, in case you guys haven't noticed, I changed up the thread title, now to "stupid question thread" for any meaningless questions that don't deserve a new thread. So here's my first one;

Does WHP measure the RPMs of the wheel or the crank? Because, it it's at the crank, then can't you setup the gearbox to make the rear wheels turn at 1 RPM, and get insane torque? let's say that Car A has a redline at 1000, with 200ft-lbs at that redline. If there'sa gear ratio of 1000:1, then it's putting out 200,000 ft-lbs, but the wheel si only turning at 1 rpm. But, if the RPMs are measured at the crank, we're getting a HP number of 38 thousand. Where are the ROMs measured?
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Old 04-28-2005, 10:37 PM   #28
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It's engine revs versus output at the wheels. With a bit of thought you can figure out that an old trick to make the car owner feel like he has a supa dupa engine is to tie down the car to reduce the rolling radius and apply an inflated transmission loss %.
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Old 04-29-2005, 12:20 AM   #29
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But you are right .... if you gear the car down insanely low, you will get vast amount of torque at the wheels, of course it'll be pointless because it won't make the car go faster because at high rpm's you'll still be going way slow.

Think of a block and tackle - by gearing the speed down, you can lift a heavy engine with just your arm strength.
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Old 04-30-2005, 12:30 AM   #30
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Okay me and my friend were talking and he knows about this site and wanted me to ask a question (which probly belongs here, i'll let you be the judges of that). What really is the difference between a Dodge Srt-4 and a regular Dodge/Plymouth Neon? Other then then engine and some body modifications and that, they pretty much look and seem like the same car. Is the Srt-4 just a Neon in 'sheeps clothing' i guess you could say or is there much more to it? I myself am not really into Neons, Cavaliers, and cars of that sort but i'm not saying they are bad. Any opinions/facts and whatever else will be helpful and appreciated. Thanx in advance. I hope you understand what i'm asking lol.
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