Why is everyone picking more TQ over max HP?
#41
Originally Posted by fordslowcus
How much torque for how much hp is sacrificed from the 300hp?
The wikipedia articles are right on.
Originally Posted by wikipedia
Mathematically, the equation may be rearranged to compute torque for a given power output. However in practice there is no direct way to measure power whereas torque and angular speed can be measured directly.
287 hp @ 6,200 rpm to 300 hp @ 6,400 rpm
remove a little torque from here, give a little more torque there.
Bottom line is tho, you can't get something from nothing. From the same engine, you might be a little quicker at earlier but you'll be slower later. In the end I think it will equal out.
#42
Originally Posted by bailey bill
Well, yes, it was missing a factor, so I edited it in.
But with or without the 5252 divisor, HP rises in direct proportion to torque.More torque, more HP.
And since peak HP occurs at the point where the torque curve is declining faster thatn RPM increases, the only way to increase peak HP is to increase torque.
bill
But with or without the 5252 divisor, HP rises in direct proportion to torque.More torque, more HP.
And since peak HP occurs at the point where the torque curve is declining faster thatn RPM increases, the only way to increase peak HP is to increase torque.
bill
power = torque x angluar momentum
power does increase when torque increases, BUT it is possible to LOWER the PEAK power while at the same time INCREASING PEAK torque and vice versa. This is because the area under the curves is the same and that is the true measure of overall power and torque.
I can't belive i'm saying this but ROAST is RIGHT () when he says (paraphrasing) peak power or torque is sort of meaningless without looking at the whole curve.
edit: i love these discussions we've been having about physics lately. let's keep it up
#44
Originally Posted by roast
You mean "relational" and "proportional".
I'll simply repeat the significant fact:
"At any point along the RPM axis, an increase of 5% in torque will yeild a 5% increase in HP, an increase of 10% will yeild an increase of 10% in HP, etc."
]You are obviously referring to just one point on the axis.
"At any point along the RPM axis ...
If you want to demonstrate the effect of changin one variable (torque), you MUST hold the other (RPM) constant.
I don't know many people who look at a powerband in terms of a single RPM.
To be sure, neither of these data points (for any car) gives a real indication of overall performance. The best indicator is "area under the curve". Unfortuantely there is no quick shorthand like "300@6400" to describe "area under the curve".
So my lawnmower engine won't compete with the vq?
Last edited by bailey bill; 08-18-2006 at 05:37 PM.
#45
Mike-
If you read my post about the perfromance of my MR2 turbo, and my post just above, it should be apparent that I understand the concept of "area under the curve". The MR2 reached peak torque (200) at 3200 RPM, and the curve was nearly flat to about 5200. That makes for a big area under the curve. And it makes for a lot more real perfromance than you would normally expect from a car with "just" 200 HP and 200 ft/lbs. That's real world example of why the 2 data points (HP@X RPM, torque@Y RPM) don't accurately describe performance capability.
But the relationship between torque and horsepower is clearly defined by the formula. At any given RPM, 1) You cannot increase HP with out increasing torque, and 2) the percentage change in HP will be the same as percentage change in torque. (When I got my mechanical engineering degree, that was called a proportional relationship. But that was back in the 60's. Maybe its changed?)
The formula, HP = (Torque X HP)/5252. You can only substitute one value for torque, and one value for RPM. Each point on the RPM axis must be associated with a corresponding value on the torque curve. You can only calculate HP by referencing a specific point on the RPM axis.
bill
If you read my post about the perfromance of my MR2 turbo, and my post just above, it should be apparent that I understand the concept of "area under the curve". The MR2 reached peak torque (200) at 3200 RPM, and the curve was nearly flat to about 5200. That makes for a big area under the curve. And it makes for a lot more real perfromance than you would normally expect from a car with "just" 200 HP and 200 ft/lbs. That's real world example of why the 2 data points (HP@X RPM, torque@Y RPM) don't accurately describe performance capability.
But the relationship between torque and horsepower is clearly defined by the formula. At any given RPM, 1) You cannot increase HP with out increasing torque, and 2) the percentage change in HP will be the same as percentage change in torque. (When I got my mechanical engineering degree, that was called a proportional relationship. But that was back in the 60's. Maybe its changed?)
The formula, HP = (Torque X HP)/5252. You can only substitute one value for torque, and one value for RPM. Each point on the RPM axis must be associated with a corresponding value on the torque curve. You can only calculate HP by referencing a specific point on the RPM axis.
bill
Last edited by bailey bill; 08-18-2006 at 06:35 PM.
#46
Torque is king on the street, horsepower is king on the track. I'll take as much as I can get of both, but a torque monster is easier to drive and takes fewer shifts to cover the ground.
That said there isn't a huge difference between the two Z engines. Somebody drop a Chevy 502 into one and we'll compare notes.
That said there isn't a huge difference between the two Z engines. Somebody drop a Chevy 502 into one and we'll compare notes.
#49
Originally Posted by bailey bill
Mike-
If you read my post about the perfromance of my MR2 turbo, and my post just above, it should be apparent that I understand the concept of "area under the curve". The MR2 reached peak torque (200) at 3200 RPM, and the curve was nearly flat to about 5200. That makes for a big area under the curve. And it makes for a lot more real perfromance than you would normally expect from a car with "just" 200 HP and 200 ft/lbs. That's real world example of why the 2 data points (HP@X RPM, torque@Y RPM) don't accurately describe performance capability.
But the relationship between torque and horsepower is clearly defined by the formula. At any given RPM, 1) You cannot increase HP with out increasing torque, and 2) the percentage change in HP will be the same as percentage change in torque. (When I got my mechanical engineering degree, that was called a proportional relationship. But that was back in the 60's. Maybe its changed?)
The formula, HP = (Torque X HP)/5252. You can only substitute one value for torque, and one value for RPM. Each point on the RPM axis must be associated with a corresponding value on the torque curve. You can only calculate HP by referencing a specific point on the RPM axis.
bill
If you read my post about the perfromance of my MR2 turbo, and my post just above, it should be apparent that I understand the concept of "area under the curve". The MR2 reached peak torque (200) at 3200 RPM, and the curve was nearly flat to about 5200. That makes for a big area under the curve. And it makes for a lot more real perfromance than you would normally expect from a car with "just" 200 HP and 200 ft/lbs. That's real world example of why the 2 data points (HP@X RPM, torque@Y RPM) don't accurately describe performance capability.
But the relationship between torque and horsepower is clearly defined by the formula. At any given RPM, 1) You cannot increase HP with out increasing torque, and 2) the percentage change in HP will be the same as percentage change in torque. (When I got my mechanical engineering degree, that was called a proportional relationship. But that was back in the 60's. Maybe its changed?)
The formula, HP = (Torque X HP)/5252. You can only substitute one value for torque, and one value for RPM. Each point on the RPM axis must be associated with a corresponding value on the torque curve. You can only calculate HP by referencing a specific point on the RPM axis.
bill
not sure where you got: hp = (torque x hp) / 5252.
Anyway, I think, as is often the case, the issue comes from a misunderstanding. And your right, for some reason I missed your MR2 post, I apologize for that.
That being said, I was commenting on an earlier post, in which hp is always proportional to torque. Which is true ONLY at the same RPM (which you later clarified). And in fact they are directly proportional as you say. a 1% increase in torque would equal 1% increase in hp. At varying RPMs though, torque can fall while hp rises, which is often the case when you look at a dyno chart. But I have a feeling you already know that so I'm not going to argue with you about it, we're on the same page. Like I said, I think it was just a misunderstanding. No harm, no foul
And you are right, the most important thing is do you have the torque when you need it.
#50
Originally Posted by deluzrider
i would rather have hp. i have the 06 and i wouldnt trade an 05 on any day
That's what would make the Z better, 18 foward speeds and 6 reverse speeds and max torque at 1800 RPM
#51
Originally Posted by mikeg8r
not sure where you got: hp = (torque x hp) / 5252.
Or by googling "horsepower torque "
Its the standard formula for (mechanical) horsepower
http://vettenet.org/torquehp.html
http://auto.howstuffworks.com/question622.htm
http://www.largiader.com/articles/torque.html
http://www.innovatemotorsports.com/f...hp/t-3350.html
http://en.wikipedia.org/wiki/Horsepower
#53
Originally Posted by fordslowcus
Or at least thats what i am to understand. The new REVUP engines give you more hp but people here talk about downgrading to the old components because it gives you more torque. How much torque for how much hp is sacrificed from the 300hp? I had a 95 v6 stang and the thing had good tq(215) but lame hp(145) and that thing was slowwwwwwwwwwwwwww.
in racing though, you want as much hp as you can, under the power curve.
#54
In a recent track event at Pahrump (just outside of Las Vegas) I did some data logging of engine vitals using the Cipher data logger.
The purpose of the test was (predominantly) to data log throttle position and engine RPM while on the track. Knowing this information would give insight on the real world effect of MREV2 while on the track.
The first thing to find is the average RPM while on the track.
The second thing to find is the throttle position so all RPM data could be sorted based on throttle position.
By sorting to throttle position it was possible to find the average RPM at a range of throttle positions. All RPM’s at a throttle position less than 95% were discarded from the data set to help focus on average RPM while at very high engine loads.
There is no point in analyzing or comparing performance data at less than 95% of full throttle because stock or modified engines are both equally capable of the same power output at less than 95% of full throttle.
Any difference of “modified Vs stock” is revealed at full throttle or very close to full throttle.
When the data was sorted to 95+% of full throttle, I found the “average” track RPM to be ~5600 RPM.
There is of course WOT RPM’s above and below 5600 RPM but the average is the best unit of measure to compare by.
Since the average track RPM is ~5600, you will be able to find an average HP utilized on the track based on your power level on your dyno plot power curve.
Every dyno machine has different absolute numbers but if you look at the pre/post dyno installations of MREV2 and spacer, you can see how much of a power change is seen on the track by comparing the modified and stock plots.
There is approximatly a 12HP gain at 5600 RPM with the MREV2 and spacer. So this means you have 12 more average HP while tracking.
Although this is a technical analysis demonstrating the MREV2 and spacer provides more power on the track, it doesn’t take a rocket scientist to see which power curve will make more power on the track, auto X or street.
You only need to see the independant dyno plots below for an obvious answer.
These dyno plots are two recent independent REVUP pre/post dyno tests of MREV2 and spacer Vs baseline.
Tony
The purpose of the test was (predominantly) to data log throttle position and engine RPM while on the track. Knowing this information would give insight on the real world effect of MREV2 while on the track.
The first thing to find is the average RPM while on the track.
The second thing to find is the throttle position so all RPM data could be sorted based on throttle position.
By sorting to throttle position it was possible to find the average RPM at a range of throttle positions. All RPM’s at a throttle position less than 95% were discarded from the data set to help focus on average RPM while at very high engine loads.
There is no point in analyzing or comparing performance data at less than 95% of full throttle because stock or modified engines are both equally capable of the same power output at less than 95% of full throttle.
Any difference of “modified Vs stock” is revealed at full throttle or very close to full throttle.
When the data was sorted to 95+% of full throttle, I found the “average” track RPM to be ~5600 RPM.
There is of course WOT RPM’s above and below 5600 RPM but the average is the best unit of measure to compare by.
Since the average track RPM is ~5600, you will be able to find an average HP utilized on the track based on your power level on your dyno plot power curve.
Every dyno machine has different absolute numbers but if you look at the pre/post dyno installations of MREV2 and spacer, you can see how much of a power change is seen on the track by comparing the modified and stock plots.
There is approximatly a 12HP gain at 5600 RPM with the MREV2 and spacer. So this means you have 12 more average HP while tracking.
Although this is a technical analysis demonstrating the MREV2 and spacer provides more power on the track, it doesn’t take a rocket scientist to see which power curve will make more power on the track, auto X or street.
You only need to see the independant dyno plots below for an obvious answer.
These dyno plots are two recent independent REVUP pre/post dyno tests of MREV2 and spacer Vs baseline.
Tony
#57
Guest
Posts: n/a
TQ moves mass.
HP makes mass travel at determined velocities.
Bottom line here is that TQ get's you going and evetually HP takes over to maintian velocity.
Theoretically you want to have an equal amount of both and a nice linear exchange of both. I honestly don't think that 15 loss of TQ and 15 HP gain on the 06' model is all that much of a difference. The difference that is important to me is the extended rev range.
HP makes mass travel at determined velocities.
Bottom line here is that TQ get's you going and evetually HP takes over to maintian velocity.
Theoretically you want to have an equal amount of both and a nice linear exchange of both. I honestly don't think that 15 loss of TQ and 15 HP gain on the 06' model is all that much of a difference. The difference that is important to me is the extended rev range.
Originally Posted by fordslowcus
Or at least thats what i am to understand. The new REVUP engines give you more hp but people here talk about downgrading to the old components because it gives you more torque. How much torque for how much hp is sacrificed from the 300hp? I had a 95 v6 stang and the thing had good tq(215) but lame hp(145) and that thing was slowwwwwwwwwwwwwww.