Horsepower is horsepower?

wilber1 wrote:
What test and why are you tryng to make this a competition? The OP wanted to know why an engine with less peak HP out pulled one with more peak HP. Some of us have been trying to explain why.

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Well in that case, it should be explained correctly. The tundra was down on power at altitude. End of story.

Well some mathematicians are right, but missing the point.
Using my "300hp" truck as an example. It just so happens tha HP peak is at 6500 Rpm's. In 2n gear, that equals 65 mph. Perfect for climbing the steepest interstate grade right? In theory, yes. In practice its a noisy experience. I find if I ignore the noise, I can maintain 65 up just about any highway grade. Practically speaking, I would prefer a gear like the rams 8spd has for 3rd. So ideal gearing, is perhaps not always ideal. And an 8 speed while towing is a trump card.

wilber1 wrote:
What test and why are you tryng to make this a competition? The OP wanted to know why an engine with less peak HP out pulled one with more peak HP. Some of us have been trying to explain why.

transamz9 wrote:

The same test that the OP linked........You, me the OP and the people that do the tests make it a competition?

For me it's about learning and understanding. I'm not interested in a competition. If that's what this thread is about, I'll bow out.

-- Rob

wilber1 wrote:

transamz9 wrote:

wilber1 wrote:

transamz9 wrote:

bimbert84 wrote:

transamz9 wrote:

Why would I need to make peak power in OD? Third already runs faster than the speed limit and I personally have yet found a time needed full power in third.

I think you're agreeing with wilber's point. You don't need full power in third. And you're not getting it, either. But yet you're still happy with how it pulls.

What that means is you could get away with an engine that had less peak power, if it were able to put that peak power to the ground when you needed it. That's what gearing will do for you.

Consider two engines:

1. 400HP @ 4000RPM
2. 300HP @ 4000RPM

Assume both are travelling at a speed such that engine 1 is spinning at 3000RPM. At that speed, engine 1 is generating about 300HP. If engine 2 is coupled to the same gear ratio, it will generate only 225HP or so. But if engine 2 is coupled to a lower gear such that it can spin at 4000RPM, it will generate its peak of 300HP.

So both engines are now generating 300HP, although engine 2 is spinning faster. But that will happen only if engine 2 can be mated to that lower gear. Having more gears to choose from makes it more likely that it can.

-- Rob

You and wilber don't seem to be getting what I'm saying either. Life out on the road is never the same as in a test or mathematics. No I don't need full power in third but if I wanted it then I could put it there because I chose the have an engine with enough power to do the task that I ask to do. It don't matter what you drive, gas diesel, big or small, it takes X amount of power to pull Y up a certain grade at a certain speed.

Will 240 hp do it? Certainly it will. It's just going to be slower.

Will it do it faster than 240 hp with a 4 speed? Probably a little but that will depend on a thing or two.

Will it keep up with a 300 hp engine with a six speed? I'm going to say no way, especially if in fact it keeps the TC locked because then at some point it won't be able to make full power.

I appreciate that you feel you have enought power for your needs but this isn't a test in mathematics, it's a test of an engine transmission combination's ability to put power to the ground in different situations.

Just because you are running peak power RPM, doesn't mean you are making peak power unless the engine is also at full throttle. Each gear is capable of doing that at just one vehicle speed. No more, no less. The more gears, the greater the range of speeds where it possible for the engine to run at or near peak power under load.

None of these vehicles are capable of reaching full power RPM in any OD ratio, so for practical purposes the 4 speed is really a 3 speed, 6 speed is really a 4 speed and the 8 speed is really a 6 speed, so the 8 speed has 100% more gears than the 4 speed and 50% more gears than the 6 speed in order to find a ratio that is closer to ideal for its engine to make maximum power under whatever load it is trying to move.

Gears are what enable the engine to get the job done, whether the engine is a diesel in a truck pulling a trailer, or a human on a bicycle peddling up a hill.

I guess we will just have to wait for the test. ;)

What test and why are you tryng to make this a competition? The OP wanted to know why an engine with less peak HP out pulled one with more peak HP. Some of us have been trying to explain why.

The same test that the OP linked........You, me the OP and the people that do the tests make it a competition?

I wrote:
the only way you can put full power there is to 1) downshift or 2) speed up.

transamz9 wrote:

What I'm saying is that my motor has the power to accelerate to peak power with my load in 3rd on every hill that I have pulled.

That's what I said, you have to speed up to get to peak power. So we're in agreement there. But if you have to accelerate to get peak power, can we agree you're not getting peak power right now?

-- Rob

what exactly was the comment about the 7.3 about? Oh I forgot you drive a Ram. LOL

transamz9 wrote:

wilber1 wrote:

transamz9 wrote:

bimbert84 wrote:

transamz9 wrote:

Why would I need to make peak power in OD? Third already runs faster than the speed limit and I personally have yet found a time needed full power in third.

I think you're agreeing with wilber's point. You don't need full power in third. And you're not getting it, either. But yet you're still happy with how it pulls.

What that means is you could get away with an engine that had less peak power, if it were able to put that peak power to the ground when you needed it. That's what gearing will do for you.

Consider two engines:

1. 400HP @ 4000RPM
2. 300HP @ 4000RPM

Assume both are travelling at a speed such that engine 1 is spinning at 3000RPM. At that speed, engine 1 is generating about 300HP. If engine 2 is coupled to the same gear ratio, it will generate only 225HP or so. But if engine 2 is coupled to a lower gear such that it can spin at 4000RPM, it will generate its peak of 300HP.

So both engines are now generating 300HP, although engine 2 is spinning faster. But that will happen only if engine 2 can be mated to that lower gear. Having more gears to choose from makes it more likely that it can.

-- Rob

You and wilber don't seem to be getting what I'm saying either. Life out on the road is never the same as in a test or mathematics. No I don't need full power in third but if I wanted it then I could put it there because I chose the have an engine with enough power to do the task that I ask to do. It don't matter what you drive, gas diesel, big or small, it takes X amount of power to pull Y up a certain grade at a certain speed.

Will 240 hp do it? Certainly it will. It's just going to be slower.

Will it do it faster than 240 hp with a 4 speed? Probably a little but that will depend on a thing or two.

Will it keep up with a 300 hp engine with a six speed? I'm going to say no way, especially if in fact it keeps the TC locked because then at some point it won't be able to make full power.

I appreciate that you feel you have enought power for your needs but this isn't a test in mathematics, it's a test of an engine transmission combination's ability to put power to the ground in different situations.

Just because you are running peak power RPM, doesn't mean you are making peak power unless the engine is also at full throttle. Each gear is capable of doing that at just one vehicle speed. No more, no less. The more gears, the greater the range of speeds where it possible for the engine to run at or near peak power under load.

None of these vehicles are capable of reaching full power RPM in any OD ratio, so for practical purposes the 4 speed is really a 3 speed, 6 speed is really a 4 speed and the 8 speed is really a 6 speed, so the 8 speed has 100% more gears than the 4 speed and 50% more gears than the 6 speed in order to find a ratio that is closer to ideal for its engine to make maximum power under whatever load it is trying to move.

Gears are what enable the engine to get the job done, whether the engine is a diesel in a truck pulling a trailer, or a human on a bicycle peddling up a hill.

I guess we will just have to wait for the test. ;)

What test and why are you tryng to make this a competition? The OP wanted to know why an engine with less peak HP out pulled one with more peak HP. Some of us have been trying to explain why.

wilber1 wrote:

transamz9 wrote:

bimbert84 wrote:

transamz9 wrote:

Why would I need to make peak power in OD? Third already runs faster than the speed limit and I personally have yet found a time needed full power in third.

I think you're agreeing with wilber's point. You don't need full power in third. And you're not getting it, either. But yet you're still happy with how it pulls.

What that means is you could get away with an engine that had less peak power, if it were able to put that peak power to the ground when you needed it. That's what gearing will do for you.

Consider two engines:

1. 400HP @ 4000RPM
2. 300HP @ 4000RPM

Assume both are travelling at a speed such that engine 1 is spinning at 3000RPM. At that speed, engine 1 is generating about 300HP. If engine 2 is coupled to the same gear ratio, it will generate only 225HP or so. But if engine 2 is coupled to a lower gear such that it can spin at 4000RPM, it will generate its peak of 300HP.

So both engines are now generating 300HP, although engine 2 is spinning faster. But that will happen only if engine 2 can be mated to that lower gear. Having more gears to choose from makes it more likely that it can.

-- Rob

You and wilber don't seem to be getting what I'm saying either. Life out on the road is never the same as in a test or mathematics. No I don't need full power in third but if I wanted it then I could put it there because I chose the have an engine with enough power to do the task that I ask to do. It don't matter what you drive, gas diesel, big or small, it takes X amount of power to pull Y up a certain grade at a certain speed.

Will 240 hp do it? Certainly it will. It's just going to be slower.

Will it do it faster than 240 hp with a 4 speed? Probably a little but that will depend on a thing or two.

Will it keep up with a 300 hp engine with a six speed? I'm going to say no way, especially if in fact it keeps the TC locked because then at some point it won't be able to make full power.

I appreciate that you feel you have enought power for your needs but this isn't a test in mathematics, it's a test of an engine transmission combination's ability to put power to the ground in different situations.

Just because you are running peak power RPM, doesn't mean you are making peak power unless the engine is also at full throttle. Each gear is capable of doing that at just one vehicle speed. No more, no less. The more gears, the greater the range of speeds where it possible for the engine to run at or near peak power under load.

None of these vehicles are capable of reaching full power RPM in any OD ratio, so for practical purposes the 4 speed is really a 3 speed, 6 speed is really a 4 speed and the 8 speed is really a 6 speed, so the 8 speed has 100% more gears than the 4 speed and 50% more gears than the 6 speed in order to find a ratio that is closer to ideal for its engine to make maximum power under whatever load it is trying to move.

Gears are what enable the engine to get the job done, whether the engine is a diesel in a truck pulling a trailer, or a human on a bicycle peddling up a hill.

I guess we will just have to wait for the test. ;)

I think you're missing our point, which is that the only way you can put full power there is to 1) downshift or 2) speed up. Simply put, if the engine is not spinning at peak HP RPM, it's not putting out peak HP. I don't care if your engine can produce 8000 HP, if you're not turning peak HP RPM, you're not getting peak HP.

What I'm saying is that my motor has the power to accelerate to peak power with my load in 3rd on every hill that I have pulled. I choose not to run it that hard because the cooling system is my weakest link at this point.

I know someone is going to say "come out west". I don't want to come out west. I have pulled Monteagle in both directions. I know it's not the steepest but it's pretty steep and long.

transamz9 wrote:

bimbert84 wrote:

transamz9 wrote:

Why would I need to make peak power in OD? Third already runs faster than the speed limit and I personally have yet found a time needed full power in third.

I think you're agreeing with wilber's point. You don't need full power in third. And you're not getting it, either. But yet you're still happy with how it pulls.

What that means is you could get away with an engine that had less peak power, if it were able to put that peak power to the ground when you needed it. That's what gearing will do for you.

Consider two engines:

1. 400HP @ 4000RPM
2. 300HP @ 4000RPM

Assume both are travelling at a speed such that engine 1 is spinning at 3000RPM. At that speed, engine 1 is generating about 300HP. If engine 2 is coupled to the same gear ratio, it will generate only 225HP or so. But if engine 2 is coupled to a lower gear such that it can spin at 4000RPM, it will generate its peak of 300HP.

So both engines are now generating 300HP, although engine 2 is spinning faster. But that will happen only if engine 2 can be mated to that lower gear. Having more gears to choose from makes it more likely that it can.

-- Rob

You and wilber don't seem to be getting what I'm saying either. Life out on the road is never the same as in a test or mathematics. No I don't need full power in third but if I wanted it then I could put it there because I chose the have an engine with enough power to do the task that I ask to do. It don't matter what you drive, gas diesel, big or small, it takes X amount of power to pull Y up a certain grade at a certain speed.

Will 240 hp do it? Certainly it will. It's just going to be slower.

Will it do it faster than 240 hp with a 4 speed? Probably a little but that will depend on a thing or two.

Will it keep up with a 300 hp engine with a six speed? I'm going to say no way, especially if in fact it keeps the TC locked because then at some point it won't be able to make full power.

I appreciate that you feel you have enought power for your needs but this isn't a test in mathematics, it's a test of an engine transmission combination's ability to put power to the ground in different situations.

Just because you are running peak power RPM, doesn't mean you are making peak power unless the engine is also at full throttle. Each gear is capable of doing that at just one vehicle speed. No more, no less. The more gears, the greater the range of speeds where it possible for the engine to run at or near peak power under load.

None of these vehicles are capable of reaching full power RPM in any OD ratio, so for practical purposes the 4 speed is really a 3 speed, 6 speed is really a 4 speed and the 8 speed is really a 6 speed, so the 8 speed has 100% more gears than the 4 speed and 50% more gears than the 6 speed in order to find a ratio that is closer to ideal for its engine to make maximum power under whatever load it is trying to move.

Gears are what enable the engine to get the job done, whether the engine is a diesel in a truck pulling a trailer, or a human on a bicycle peddling up a hill.