Diesel Trucks

[DiamondSCattleCo]

I'm not sure where he got the 8200 pound stuff from. My PS only weighs in at 7700 pounds. Not sure about the Dodge but I suspect it is lighter than the PS.

The 8200 lbs was the curb weight posted for the 2001 Quad Cab on the Dodge website. I honestly don't have a clue what the new ones weigh in at. Its also what Meach's truck weighed the first time he ran 11.98. He likely could have shaved a tenth off if the fool had taken his toolboxes out like I told him to. :lol:

Rod

 

[flaboy+]

I'm not sure where he got the 8200 pound stuff from. My PS only weighs in at 7700 pounds. Not sure about the Dodge but I suspect it is lighter than the PS.

The 8200 lbs was the curb weight posted for the 2001 Quad Cab on the Dodge website. I honestly don't have a clue what the new ones weigh in at. Its also what Meach's truck weighed the first time he ran 11.98. He likely could have shaved a tenth off if the fool had taken his toolboxes out like I told him to. :lol:

Rod

Was he 4x4? The PowerStoke needs to be spooled up to launch very good as you probably already know due to turbo lag. If you spool it up, switch the little switch to 4WH, and launch it, you feel like the guy that tries to follow Dale Jr into the wind tunnel even stock. :lol:

It's pretty funny. Even those old 5 liter Mustang drivers won't look your direction after pulling one of those on them.

 

[DiamondSCattleCo]

Was he 4x4?

Yep. 2WD trucks just couldn't get enough traction. Generally speaking, the hot ticket was spooling up the twins to 8 lbs of boost or so, launching in 4WD, and once 3rd gear was hit, switching to 2wd.

Rod

 

[Saltydawg]

Well Rod I guess a picture might help this guy. 6 liter Ford PowerStroke owned by Gene Feildhans.

Na never mind yanks know it all anyway. :lol:

I'm not sure where he got the 8200 pound stuff from. My PS only weighs in at 7700 pounds. Not sure about the Dodge but I suspect it is lighter than the PS.

I got the 8200lbs from Diamond. He said a truck with 550 hp and weighing 8200lbs could do 11 second quartermiles.
I said no it can't....its too friggin heavy lol.
Has nothing to do with diesel or gas, turbo or not.....simply that 550 horsepower is not enough juice to move 8200lbs down a quartermile in 11 seconds.
Drop about 3000lbs of weight and sure it's possible.

Gene was the ONLY person I could find reasonably believable times for in the 11 second range. He usually wins the events he attends and is normally the only diesel truck into the 11's.
I visited both chevy and dodge race fan sites and all of them mention this guy.

He ran an 11.51 in Houston. His truck is HEAVILY modified and weighs 5300lbs.

Gas powered trucks with similar modifications and running under similar rules are MUCH faster.

This is why Diesels have their own sanctioning body. They havent found a way to keep racing competitive between gas engines and deisel engines without requiring drastically different rulesets.
Gas trucks that are allowed to run turbos, superchargers, nitrous and drag slicks are MUCH faster than comparative diesels.


Why will a large dump truck outpull a light truck even if the light truck has a higher horsepower rating? Its not an anamoly.
The same reason your 100hp tractor will yank your one ton diesel backyards when hooked rear to rear.....gearing and traction.

Why do you think Large trucks and tractors run 10+ speed gearboxes? To make sure their engine is operating in the right rpm range they need to move the load.
You could take your 350 horsepower diesel and bolt it into the dump truck and it would pull the load just fine if you put the right gearing in the tranny to make sure your engine is running where it makes best power.

Your little diesel won't last long doing this but it CAN do it.

A gas engine requires much higher rpm's so they also won't last long....but they can do it too.

 

[DiamondSCattleCo]

Gene was the ONLY person I could find reasonably believable times for in the 11 second range. He usually wins the events he attends and is normally the only diesel truck into the 11's.
I visited both chevy and dodge race fan sites and all of them mention this guy.

I gave you a link with 3 11 second trucks (two of which were drug trucks, which probably puts them over 600 ponies), and I also gave you the names of the drivers of 4 other 11 second trucks, 2 of which I built. Are you calling into question my honesty? I'm not sure why you would, as I have no vested interest in this debate. I could care less what someone wants to drive, and only entered this topic because I saw innaccurate information being posted. Winning a debate is not sufficient excuse for me to compromise my honesty nor my integrity.

Let me toss one last one at you: 1 truck, same gearing, same engine, same peak HP/torque at 2800 RPM (lets say 550HP, 1030 lbft) however through different fuel delivery curves in the computer, we are able to drastically alter the torque curve.

Engine A - Has a torque curve that climbs steady to 1800 RPM. At 1800 RPM, its reading about 1200 lbft of torque. By 2000 RPM, its hit its torque peak of over 1600 lbft. By 2200 RPM, it backs off to about 1300 lbft where it begins to let down fairly quickly. BTW, this is a common torque curve for a VP44 equipped 24 valve Cummins, TST PM3 Comp, Mach 5s, HX40/B2 twin setup, no drugs.

Engine B - Has a torque curve that RAPIDLY peaks to 1200 lbft at 1500 RPM, slowly climbs to a peak of 1400 lbft at 1800 RPM, then begins to let down gradually. BTW, this is a common torque curve for an 03 - 05 Common Rail with a TST CR box, FAST spooling twins, and Flux injectors. No drugs.

Engine C - Has a torque curve that gradually builds to 1030 lbft of torque at 2800 RPM, where it lets down. BTW, this is a typical curve of a 98 12 valve Cummins, with a TST #10 plate, shoved back for drivability, M370 Bosch injectors, and a large, slow spooling B1 turbo. No drugs.

BTW, if you want to verify these curves, these are all on Mustang load dynos (not inertials, as we need a load on a turbo diesel to induce boost and get the computer to start fueling. On the 12 valve, we need some load to convince the AFC to work).

Which of these three engines, when transplanted into the same truck, are going to run a faster 1/4 mile? Since you seem to be all hung up on HP and weight being the only factors in determining ET and trap speed, then you theorize that all three engines would finish at the exact same time?

Rod

 

[wsrutherford]

Torque Wins Races, HP Sales Parts!

 

[Saltydawg]

Which motor will make the truck go fastest in the quartermile?

I need more info.

I can't say without knowing the gearing of the truck. What ring and pinion ratio are you using and what are the ratios of the gears in the tranny?
I also need to know the weight of the truck.

I need to know what kind of torque these engines are making at 1000rpm, 1500, 2000, 2500, 3000, and then of course what rpm the peak torque is seen.
This will give me a better indication of the torque curve.
If there's a significant drop off before 3000rpm (which there probably is) I need to know what rpm it happens and how fast the drop is. Does it take 500 rpm's for the engine to bottom out or does it happen over a 250rpm period.

 

[DiamondSCattleCo]

You missed my point, Salty. You're hung up on weight and HP, calling into doubt 7 different ET & trap speeds, saying they 'weren't believable', yet you didn't have all the information you needed to make that decision.

BTW, if you really want to attempt the actual calculations, I gave you the general shape of the curves, with torque peaks. You can consider the torque fairly linear to the points I gave you. Forget about 3000 RPM, as the shift points are at 2800. 3.55 gearing. 8200 lbs truck. I'm afraid we could never get any accurate information on Engine A as far as genuine torque peak, as the Mustangs didn't read past 1600 lbft. We put one on a SuperFlo load, and it pulled 1800 lbft over 5 pulls, but I doubt that number.

Lets use stock 47RE gearing: 1st - 2.45, 2nd - 1.45, 3rd - 1.00, 4th - .69

Rod

 

[Saltydawg]

Ok I'll explain my fixation on HP and weight and explain why its the two most important figures in getting a vehicle to go fast or do work. This is gonna be a little long winded .

First you need to know and understand Newton's Second Law.

This law states that the acceleration of an object is dependant on its mass and an unbalanced force acting against it.

This is expressed in a formula: Acceleration = force / mass

In our vehicles the force is our engines and the mass is the weight.

The heavier our vehicle is the more force it takes to accelerate it at the same speed.

This is a link to good explanation of Newton's second law with a simple diagram demonstrating it.

http://www.necc.mass.edu/MRVIS/MR3_13/start/htm

Continued in next post .

 

[Saltydawg]

Ok next its important to understand exactly what force, power, work, torque and horsepower are and how they relate to each other.

I thought I was gonna have to type out a long explanation but I found a really cool site that walks through them in everyday language instead of the lingo used in engineering school and by scientists.

http://www.howstuffworks.com/fpte.htm

This site takes you step by step through pretty much all the forces used in figuring out how fast something will move and how much power you need to do it.

There are a few other concerns in drag racing that don't apply to other objects but the basic math is all the same.

Horsepower is a measure of how much work can be done over a given period of time.
An engine makes torque but Torque alone does not express how much work can really be done because it does not adress the speed that work is done.
Horsepower addresses both the ammount of torque that is being applied and how fast its being applied.

Horsepower is a measure of work actually done. It does not measure potential.
A higher horsepower engine will ALWAYS do more work.

It might not always be practical but that is another matter .

 

[Saltydawg]

Diamond based on the information you gave me Engine A in your example has the most potential to get the best speeds out of that truck.

1600lb/ft @ 2000rpm = 609hp

Engine B has dropped to 479hp after you played with it and Engine C stayed at 549hp.

Gearing, traction, aerodynamic drag all influence this but the engine has the most potential. Especially if you say the motor pegged you dyno so could potentially be making more torque.
Higher torque will increase the horsepower the engine is capable of.

If your only goal is to go as fast as possible then you want to make as much torque as you can at the highest rpm possible.

An engine that makes 1000lb/ft of torque @ 4000rpm is MUCH stronger than an engine that makes 1500lb/ft of torque at 1000rpm. The first is 761hp and the second is 285hp.

 

[DiamondSCattleCo]

1600lb/ft @ 2000rpm = 609hp

Screwed up and was giving you results from 2 different dyno runs. Engine A develops 1400 lbft @ 2000 RPM (~530 HP). The other numbers are correct. That 1600 lbft number comes from a 648HP truck.

Even utilizing F=MA, you still can't accurately judge acceleration (or ET) based on peak HP and weight alone. You absolutely need gear ratios because your force is constantly changing. The howstuffworks website is just fine, but it is too dumbed down to get anywhere near what we need, as it doesn't take into account _any_ acceleration. You'd need to analyze based on delta time, to properly calculate F. This is why Patrick Hale developed the formulae he did, and why it is in use by drag racers and engineers everyday. Its just unfortunate that it doesn't apply to turbo or supercharged engines.

So, like I said in an earlier post, you're calling into question my results and the results of others, because you're utilizing the wrong physics formula.

Rod

 

[Saltydawg]

Ok well it must be me and the entire rest of scientific/engineering community using the wrong formula.

I didn't use Patrick Hales..formula. Don't have a clue who the guy is lol.

In fact I didn't even bother doing calculations to see if 550hp is enough to push 8200lbs to 11 seconds quartermiles....cause its so far off from reality, calculations weren't needed.

Newtons Second Law alone says that 550hp is not enough to move 8200lbs of mass that far in that short a time period.

Take a look at this:

http://hpcalc.boostcontroller.com/

Its a basic calculator for Hp if you know a vehicles elapsed time and trap speed in the quarter mile.
Its not perfect but its close enough to demonstrate my point.

Lets take Gene's run from above that Flaboy posted.
11.62et and 119 mph trap speed.
We also know Gene's truck weighs 5300lbs give or take a few.

Amazingly enough this calculator puts Gene's turbocharged and nitroused truck at 668-697hp.

A little research on Gene's truck will show his turbocharged 6.0L Ford dyno's at 600hp +or- a couple without nitrous.
Now add the nitrous and you can see where the other 60-100 hp comes from.

It would seem that calculator is at least in the ball park...close enough for messageboard conversation anyhow.

So now lets plug an 8200lb truck into that thing and use the same et's that Gene ran.

According to that calculator it would take over 1000hp to push 8200lbs to the same speeds that Gene runs with his truck. 11 second quartermiles.

You may well have run trucks at 11 second quartermiles....but they were either about 3000lbs lighter than you say or you were making a whole lot more than 550hp.

If you're telling me Newton's Second Law and Watts definition of horsepower are not applicable then I would expect you know which formula are.

 

[DiamondSCattleCo]

Take a look at this:
http://hpcalc.boostcontroller.com/

<sigh> Didja happen to pay attention to this little piece of code?

function hp(weight,et,speed)
{
var resultet = Math.round(weight/(Math.pow((et/5.825),3)));
var resulttrap = Math.round(weight*(Math.pow((speed/234),3)));
var outputtext = "Trap Speed Method: approx. " + resulttrap + " HP\nET Method: approx. " + resultet + " HP";
document.calculatorform.outputField.value = outputtext;
}

Notice the 5.825? Does it look familiar? How about the 234? Its Patrick Hales formula, and the Patrick HIMSELF says the formula doesn't work properly on turbocharged or supercharged diesel engines and the constant likely needs to be modified down to 5.3 or 5.2. I'm sorry you don't know who Patrick Hale is, but that means you don't have much experience with the racing world, diesel, gasoline or alcohol. If the formula happened to work with Gene's truck, then its a fluke that the 5.825 constant happened to peg it, as those calculators are generally off by at least 4%, even in the normally apirated world.

Rod

 

[Saltydawg]

Alright Diamond I'm not gonna try anymore.

I'm gonna go to a engineering message board and tell them my vette runs 6 second quartermiles with only 450hp.

Then when they tell me its impossible, and use laws that have been around for hundreds of years to prove it, I'll just tell them they are using the wrong formula .