What do YOU use to tow your track car?
07-28-2015, 03:48 PM
#401
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click to 14:29 (9m07s, "it went up pretty slow"):
click to 12:32 (7m38s, "we could have gone faster but didn't want to break the speed limit"):
Last edited by Savington; 07-28-2015 at 04:04 PM.
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07-28-2015, 03:51 PM
#402
They are designed to be efficient at high power levels under continuous duty and last a long time doing it, that's where the big rig diesel engines shine. To make 400HP with that level of efficiency requires a big engine, lots of boost, and low REVs, and a lot more.
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07-28-2015, 03:57 PM
#404
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I want to make a super clear point here: Horsepower is what moves vehicles. Torque does not. This is a factual statement that isn't open to interpretation or opinion. When you make lots of torque at a low RPM, you end up with an engine that makes good horsepower at low RPM. This is why they feel "torquey" - the extra power delivered at a lower RPM makes the car accelerate faster than it otherwise would. Marketing doublespeak has trained us to look at torque, but in reality the only reason a high-torque engine accelerates a vehicle faster at low RPM than a low-torque engine does is because the high-torque engine makes more horsepower.
When you look at the semi rig industry, the trend is towards horsepower. 300hp and 400hp engines are giving way to 600 and 700hp engines, and when you look at logging trucks or oversize load trucks, they always have more horsepower. They need huge torque because they don't spin the engine very fast (for longevity/efficiency), and thus the engine has to be huge. You could absolutely pull 80,000lbs up a hill with a 400hp small-displacement gas engine, as long as you gear it appropriately and ensure that it remains at peak power. Getting that load moving from idle would be painful, which is why semi rigs use huge engines with lots of horsepower at idle as well.
When you look at the semi rig industry, the trend is towards horsepower. 300hp and 400hp engines are giving way to 600 and 700hp engines, and when you look at logging trucks or oversize load trucks, they always have more horsepower. They need huge torque because they don't spin the engine very fast (for longevity/efficiency), and thus the engine has to be huge. You could absolutely pull 80,000lbs up a hill with a 400hp small-displacement gas engine, as long as you gear it appropriately and ensure that it remains at peak power. Getting that load moving from idle would be painful, which is why semi rigs use huge engines with lots of horsepower at idle as well.
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07-28-2015, 03:57 PM
#405
It's almost like vehicles are designed with certain goals in mind when they are built, with priority to certain aspects?
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07-28-2015, 03:57 PM
#406
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Do explain. When I tow it's not a contest of how fast I can get somewhere, it's of how comfortably I can maintain a speed and how safely I can control the load. So I set the cruise on the 6.7L diesel and it very very rarely leaves overdrive.
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07-28-2015, 04:00 PM
#407
I want to make a super clear point here: Horsepower is what moves vehicles. Torque does not. This is a factual statement that isn't open to interpretation or opinion. When you make lots of torque at a low RPM, you end up with an engine that makes good horsepower at low RPM. This is why they feel "torquey" - the extra power delivered at a lower RPM makes the car accelerate faster than it otherwise would. Marketing doublespeak has trained us to look at torque, but in reality the only reason a high-torque engine accelerates a vehicle faster at low RPM than a low-torque engine does is because the high-torque engine makes more horsepower.
When you look at the semi rig industry, the trend is towards horsepower. 300hp and 400hp engines are giving way to 600 and 700hp engines, and when you look at logging trucks or oversize load trucks, they always have more horsepower. They need huge torque because they don't spin the engine very fast (for longevity/efficiency), and thus the engine has to be huge. You could absolutely pull 80,000lbs up a hill with a 400hp small-displacement gas engine, as long as you gear it appropriately and ensure that it remains at peak power. Getting that load moving from idle would be painful, which is why semi rigs use huge engines with lots of horsepower at idle as well.
When you look at the semi rig industry, the trend is towards horsepower. 300hp and 400hp engines are giving way to 600 and 700hp engines, and when you look at logging trucks or oversize load trucks, they always have more horsepower. They need huge torque because they don't spin the engine very fast (for longevity/efficiency), and thus the engine has to be huge. You could absolutely pull 80,000lbs up a hill with a 400hp small-displacement gas engine, as long as you gear it appropriately and ensure that it remains at peak power. Getting that load moving from idle would be painful, which is why semi rigs use huge engines with lots of horsepower at idle as well.
I still think it's crazy how people don't understand the difference between HP and Torque but claim they do. Makes for a great read.
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07-28-2015, 04:01 PM
#408
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<p>He means that the reason you don't have to leave overdrive is because you have a lot of horsepower at 2k. Horsepower is a direct relationship to torque.</p>
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07-28-2015, 04:03 PM
#410
You should look up the HP of that motor at the RPM you tow at in overdrive. That HP level is enough to move your rig. It takes a certain amount of power to move your truck. Wind resistance, rolling drag, geartrain losses, all of this for the trailer too. Add it up and it might be 30HP or it might be 250HP when going up a hill. If you motor can make the required HP at that RPM, then it won't downshift. If it can't, it will downshift.
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07-28-2015, 04:10 PM
#412
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<p>I hate the guy in the passenger seat with a ******* passion. I used to watch a lot more fast lane truck stuff and he just pisses me off so much I can't do it anymore.</p>
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07-28-2015, 04:13 PM
#413
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I hate them both, and there's a huge amount of false technical interpretation in every single one of those videos, but Ed asked for a Ram and an F150 towing 10k up a hill, and that's exactly what TFL does with pretty much every truck on the market.
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07-28-2015, 04:16 PM
#414
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<p></p><p>Also how are they accurate when there are other people on the road.</p><p><img src="http://cimg3.ibsrv.net/gimg/www.miataturbo.net-vbulletin/1220x924/80-grinds_my_gears_ccd0ab0520137425eef7ecb66d70e4658a fdd08b.png" title="" /><br /><br /> </p>
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07-28-2015, 06:45 PM
#416
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<p>Isn't the argument between whether it's HP or Torque moving the load really just semantics? I mean, A vehicle that makes a lot of low RPM torque has low RPM horsepower, and a vehicle that makes a lot of high RPM horsepower also shows torque at those high RPMs. What's the difference, and the point of arguing the difference?</p><p>And indeed, good thing I didn't bet real money cuz I'd have lost some of it.</p><p>That being said, that rock guard would absolutely affect the way it tows at high speeds. It's not an apples to apples comparison. But the Ram does seem a bit disappointing.</p>
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07-28-2015, 06:48 PM
#417
<p>Isn't the argument between whether it's HP or Torque moving the load really just semantics? I mean, A vehicle that makes a lot of low RPM torque has low RPM horsepower, and a vehicle that makes a lot of high RPM horsepower also shows torque at those high RPMs. What's the difference, and the point of arguing the difference?</p><p>And indeed, good thing I didn't bet real money cuz I'd have lost some of it.</p><p>That being said, that rock guard would absolutely affect the way it tows at high speeds. But the Ram does seem a bit disappointing.</p>
Torque is not.
They are two different things. Torque is a force, HP is a force multiplied by a distance. That's what has been pointed out, as saying things like "HP doesn't matter" is wrong.
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07-28-2015, 07:10 PM
#418
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No. It's an important distinction. 2000ft.lbs of torque at 1200rpm moves lots of things. 1000ft.lbs of torque at 2400rpm (or 500ft.lbs at 4800rpm, or 250ft.lbs at 9600rpm) moves the exact same quantity of things at the exact same velocity. Half the torque (or 25% or 12.5%), but the exact same power, and thus the exact same work being done.
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07-28-2015, 07:28 PM
#420
I want to make a super clear point here: Horsepower is what moves vehicles. Torque does not. This is a factual statement that isn't open to interpretation or opinion. When you make lots of torque at a low RPM, you end up with an engine that makes good horsepower at low RPM. This is why they feel "torquey" - the extra power delivered at a lower RPM makes the car accelerate faster than it otherwise would. Marketing doublespeak has trained us to look at torque, but in reality the only reason a high-torque engine accelerates a vehicle faster at low RPM than a low-torque engine does is because the high-torque engine makes more horsepower.
When you look at the semi rig industry, the trend is towards horsepower. 300hp and 400hp engines are giving way to 600 and 700hp engines, and when you look at logging trucks or oversize load trucks, they always have more horsepower. They need huge torque because they don't spin the engine very fast (for longevity/efficiency), and thus the engine has to be huge. You could absolutely pull 80,000lbs up a hill with a 400hp small-displacement gas engine, as long as you gear it appropriately and ensure that it remains at peak power. Getting that load moving from idle would be painful, which is why semi rigs use huge engines with lots of horsepower at idle as well.
When you look at the semi rig industry, the trend is towards horsepower. 300hp and 400hp engines are giving way to 600 and 700hp engines, and when you look at logging trucks or oversize load trucks, they always have more horsepower. They need huge torque because they don't spin the engine very fast (for longevity/efficiency), and thus the engine has to be huge. You could absolutely pull 80,000lbs up a hill with a 400hp small-displacement gas engine, as long as you gear it appropriately and ensure that it remains at peak power. Getting that load moving from idle would be painful, which is why semi rigs use huge engines with lots of horsepower at idle as well.
Horsepower is measure of torque applied over time. HP = Torque x RPM ÷ 5252 .
If you took a little RC plane motor and asked it to move a 80,000lb vehicle wheel it is possible to do with astronomical, no loss gearing. In so doing, you have massively increased the torque applied to the wheels.
If you took a 80,000lb vehicle motor and asked it to move an RC plane prop, it is possible to do with gearing. In so doing, you have decreased the torque applied to the prop. The RC plane won't fly however.
So, you make design choices appropriate to your vehicle and needs. Horsepower is the more relevant factor to move most road vehicles quickly. Increasing the horsepower, as is the trend today, allows more work to be done in the same or similar packaging. This is allowed by advanced materials and engineering practices used today. I would change this though and say the trend today is combustion efficiency.
Trying to simplify the argument into "Torque wins bra" vs "Horepower is badass bra" eschews a fundamental understanding of applied torque at the wheel, work, gearing, & horsepower pervasive on forums.
Here is one website that goes over some details.
Power and Torque: Understanding the Relationship Between the Two, by EPI Inc.
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