Diesel PU compared to Big Rig sled pulling HP

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Moretorque

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I have a ? here for those who have like 4 to 5 hundred HP modified diesel pickups pulling or those who know. How does the power compare in a pull compared to a Rig that has 4 or 5 hundred horse but much more torque.

Just curious as to weather the PU lower torque engines can stay in the power groove under as much load as the BB Rig. Thanks and enjoy the coming new year.
 
Big rig weighs 20,000 lbs. Sled setting is way different and a pickup will stop instantly. Hp and torque don't matter when the weight is so much different

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What I am after is can a 4 or 500 HP PU diesel engine pull 40 or 50 tons like it's bigger displacement longer stroke big brother. I think they can but would need more gears to stay in the power groove under such load.
 
If it were somehow possible to get the two motors in the same weight class the big rig motor would easily out pull the pickup motor because it has double the torque. The extra torque would let the big rig motor run a higher gear and keep it moving when the weight hit. You may have seen the meme floating around the Internet that says Horsepower is how fast you hit the wall, Torque is how far you take the wall with you. Same basic principle would apply in this pulling situation.
 
It would be intresting to see a SS diesel truck pull the same setting against a hot rod semi. Semi would probobly win, but I wonder what the diffrence would be

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Thanks for the last 2 posts, this is what I am after. Yes the engine with more torque has the ability to pull a gear longer and harder.

This is the debate, some top builders have said your HP is your MPH and your torque is your ability to achieve that MPH under load and another group says no HP is HP and you can gear around lack of torque.

Top motor builders have told me your torque engine is the more powerful engine but when I look at 1/4 mile times I am like it should get down there faster with double the torque as in the John Robinson diesel drag car.
 
ParkerFly said:
If it were somehow possible to get the two motors in the same weight class the big rig motor would easily out pull the pickup motor because it has double the torque. The extra torque would let the big rig motor run a higher gear and keep it moving when the weight hit. You may have seen the meme floating around the Internet that says Horsepower is how fast you hit the wall, Torque is how far you take the wall with you. Same basic principle would apply in this pulling situation.
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This is what I am after, is it because the rig engine makes it's power over a broader % of the RPM of it's narrow RPM power band or because twisting force = making more power through more torque which is really more powerful than turning more RPM to make it even though math looks the same.

So you have one engine let's say a Mack Maxidyne 237 RWHP, I use the Mack because it truly shows what having the torque of a Pro Stock car can achieve in a low HP app.

The Mack Maxidyne was reported to be able to swing from 35 to 60 MPH in 5th gear, in one gear no shift. We are a talking a Tractor able to move 40 tons with a 5 speed and no split. It can only go 60 under that load which is peak HP = MPH.

Lets say the Mack makes 137 hp to 237 hp from 1000 to 2000 RPM and another engine does the exact same from 2000 to 4000 RPM. On paper they look the same and make HP over identical % of respective RPM range and you just cut the gear ratio in half for the engine that needs more RPM to achieve same goal.

Or is there something in the laws of physics that makes the motor that turns more RPM less powerful even though they are the same on paper. To me this is a huge ? in being able to truly understand HP and how to read a dyno.
 
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Horsepower is not a good number to compare when talking diesels. In the gas world your horsepower and torque are nearly the same. Diesels vary vastly across the board. Horsepower is a calculated value based on torque.

HP = Torque x RPM ÷ 5252

Notice one of the multipliers int he equation...RPM. Make torque down low and you will have less horsepower than if you made it up high in the RPM range. Big rigs work in extremely low RPM ranges. Hints why a 400hp big rig has twice the torque of a 400hp pickup truck.

Here is some reading that will help you understand why a 400hp pickup truck cannot do the same amount of work that a 400hp big rig can:

http://www.epi-eng.com/piston_engine_technology/power_and_torque.htm
 
zfaylor said:
Horsepower is not a good number to compare when talking diesels. In the gas world your horsepower and torque are nearly the same. Diesels vary vastly across the board. Horsepower is a calculated value based on torque.

HP = Torque x RPM ÷ 5252

Notice one of the multipliers int he equation...RPM. Make torque down low and you will have less horsepower than if you made it up high in the RPM range. Big rigs work in extremely low RPM ranges. Hints why a 400hp big rig has twice the torque of a 400hp pickup truck.

Here is some reading that will help you understand why a 400hp pickup truck cannot do the same amount of work that a 400hp big rig can:

http://www.epi-eng.com/piston_engine_technology/power_and_torque.htm
Click to expand...

^ This is pretty much, exactly what I was going to say.

Not to mention, a big rig (11, 13, 15L) is going to have up to 1850ftlbs of torque in stock form. That's at ~1250-1500 RPM as well.

You're going to have a hard time building a pickup that can stay cool hauling that much weight, and your chassis will likely be pretty unhappy with you as well.
 
Sarafin said:
It would be intresting to see a SS diesel truck pull the same setting against a hot rod semi. Semi would probobly win, but I wonder what the diffrence would be

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If the hot rod semi pulled the same weight as a SSD, the sled wouldn't be able to stop the semi.... Sleds have a tough time stopping some of the hot rod semis with everything they have on the sled... I wouldn't be surprised is my sub-600 hp, 16,000 lb semi could out pull a 2.6 truck.

In a sled pulling application you have to factor in ground speed. Even if you could gear a pickup to have the torque at the wheels a semi does, it would never be able to run as fast. Ground speed is a major factor in sled pulling.
 
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Talked to a guy, used to run a multi-engine mod tractor, pulls a super semi now.
He gets a bigger rush from the semi, and it faster down the track too.
 
zfaylor said:
Horsepower is not a good number to compare when talking diesels. In the gas world your horsepower and torque are nearly the same. Diesels vary vastly across the board. Horsepower is a calculated value based on torque.

HP = Torque x RPM ÷ 5252

Notice one of the multipliers int he equation...RPM. Make torque down low and you will have less horsepower than if you made it up high in the RPM range. Big rigs work in extremely low RPM ranges. Hints why a 400hp big rig has twice the torque of a 400hp pickup truck.

Here is some reading that will help you understand why a 400hp pickup truck cannot do the same amount of work that a 400hp big rig can:

http://www.epi-eng.com/piston_engine_technology/power_and_torque.htm
Click to expand...

Thank you all a lot,

What it comes down to is a lot of people I believe misinterpret HP. Hp is just how much work is being done at a certain RPM and how you get there under load is determined by your torque, peak HP which is just peak work or peak MPH.

Some people think you can put a small block 400 HP 302 in a Semi and with proper gearing in a 10 speed configuration it will pull it and the people who built race engines for a living laugh and said it would need like a 30 or 50 speed gearbox air shifted if it had any chance to move 40 tons reasonably.

I poised the ? to Reher Morrison what would happen if you put a 2300 HP ship motor spinning at the end of the track and geared it correctly with a cable and dropped the boom on a Pro Stock chasses. The engine in ? made 2300 HP at 270 RPM and 40,000 foot pounds of torque.

They said it would probably leave your head at the starting line and go over 300 in a snap and Tony Shumacher would be going where'd he go.
 
OP ya lost me. Are you just starting ridiculous theoretical threads to get your post count up? Your first few posts indicate you believed a 400hp pickup truck engine could hang with a 400hp semi engine. Now you are on to ocean going ship engines and winches and such? dafuq?
 
zfaylor said:
OP ya lost me. Are you just starting ridiculous theoretical threads to get your post count up? Your first few posts indicate you believed a 400hp pickup truck engine could hang with a 400hp semi engine. Now you are on to ocean going ship engines and winches and such? dafuq?
Click to expand...


Kinda my thinking....


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zfaylor said:
OP ya lost me. Are you just starting ridiculous theoretical threads to get your post count up? Your first few posts indicate you believed a 400hp pickup truck engine could hang with a 400hp semi engine. Now you are on to ocean going ship engines and winches and such? dafuq?
Click to expand...
I lol'd hard at this.

OP ... What is the information you're looking for? Is it gear reduction, torque, horsepower, displacement or what?

#lyfe
 
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ImageUploadedByTapatalk1451585126.507011.jpg

What if you strapped this roughly 10,000 hp to the sled with an anchor point and snatch block end of track , with a cable set up , wired in its own small sub station to power it . Would it pull the sled fast than a Saturn era rocket motor would ? You'd have to factor in the added weight of roughly 100,000lbs though .

This thread like the other is pretty confusing not sure where comparing apples to sky scrapers to ocean going freighters is gonna take you and for what end result . There's 1000 ways to drag a sled down some dirt but it's done a particular way for a reason .
 
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