I should be hopping on the dyno this weekend (As long as my brother doesn't blow up his 05 first)

Couple of questions: Anyone have any thoughts on which level for a smarty only run? Any thoughts on which level for a smarty + TST run? 

 

And for the fun part! Guessing

Give your guess for: Smarty only and smarty + TST   My sig is up to date!

uggg. 

 

Acceleration comes  from   applying  more torque to the rear wheels  than  the  total resistance  from  gravity,   road  and  wind resistance,  and  vehicle/load  mass    are trying to   hold the vehicle  back.

 

 

I  see what you are saying about  rolling over the hill starting  at  2500 rpm..   I  too    have    experienced this  with a lot of  heavy hauling  over the years!          I don't  lug  on  purpose either,        any engine  that  does not  respond to  additional  throttle  is  considered  lugging  in my  camp.    Doesn't have to be a lot of  response,  but   some..   we call it   'free to accelerate'.    If  I'm  running   half throttle @  1700,  and  desire more rpm,  I  mash down a little  harder..  if  I can't see or hear a fairly immediate   response in the   tach...  I   downshift..     

Please  don't lecture me  on  how to  handle a load.   I've  certainly paid my dues.    pickup trucks  and  small    20k  loads  are not  exactly   a   trip down   extremist  path for me.

Please  consider this:    lets  take a load,  one that will certainly tax our engines.   Start up  a    4% grade,  say  2 miles long.   First  pull will be started    at   1600, (which I've never  pulled down into in the first place)   1800  I'm more comfortable with anyways.(only from a  bearing and  piston  longevity standpoint)     Then  do it again  starting @ 2500.       In  5th (straight through)    MY  trucks  will all  be in   4th by the time I'm at the top of the hill anyways.      Soon as  I burn off  the momentum  from   hitting the bottom of the hill  @2500,   I'll be  in 5th,   then in  4th.  

After you burn off the momentum  from  the  original  speed  the   2500 rpm  gave you for  'free'... that is  when the true test  should start.   You are comparing  apples and oranges.

 

I'm all ears  and  eyes  for this  mysterious  'horse-o-meter'   Please    post.

Torque is static, by definition.  Horsepower is dynamic.  Torque at an RPM will move you... Torque at 0 rpm won't move you and torque at an RPM is, by definition, power.  

This subject is kind of like all the liquid pressure versus flow debates.

 

Does a Vacuum cleaner suck or blow?....................depends on which end you are on.

I don't view it as apples to oranges at all. It's only apples and orages if you assume the engine will slow from 2500 rpms. If it hold 2500 rpms with 555-610 ft/lbs, but doesn't hold 1600 rpms with 610 ft/lbs (which it won't if the load is maxed out on the 2500 rpm run) then horsepower is what keeps you moving, not the torque.

 

I don't pull grades at 1600 either, just simply using the ratings. The Cummins 600 (04.5-07) has a peak torque of  610 ft/lbs at 1600 rpms. It makes at least 555 from 1400-2900. So torque at 1600 rpms is at least equal to, if not greater than, torque at 2500 rpms. I am talking about a fixed load, gearing, tire size, etc... That's apples to apples, the torque output is basically the same. The variable is rpms, which given a flat torque curve means more horsepower. More horsepower, the faster the work is done.

 

In my truck if I hit that grade at 1600 rpms in 5th I will be in 4th by the top. 41 mph in 5th is 1600, which is 2200 in 4th. But if I hit the same hill in 5th at 2500 rpms, 64 mph, I will make the top in 5th.. even on a 7-8% grade at 20K GCW on a 75° day at 7K feet.

 

There are ways to measure horsepower. Think about the original horsepower calculation. It's the ability to move 550 lbs 1' vertically in 1 second. If it takes 2 seconds you measured at 1/2 horsepower, or if it take 1/2 a second you have 2 horsepower. The torque is the same in both of them, so you are not measuring torque... heck it could take an hour and the torque is the same. That's how a chassis dyno works. To rotate the drum 1 time takes the same torque, whether you are at 1 rpm or 1000 rpms of the drum. The difference is horsepower, that's why they cannot tell you the torque output of your engine only the horsepower output. A water-brake, or other engine dyno's are the opposite. They measure the work being done, not the rate at which they are done.. they needs rpms to calculate hp. A chassis dyno needs rpms to calculate torque.

Apples to oranges on both sides.

 

Engine specs are done at flywheel on a water brake dyno in controlled and specific environments with probably a large amount of engines to get a large pool to average from.  All else is as varied as our individual finger prints and DNA...............................................No amount of calculations and banter will change that. Change the humidity and temp by just a few digits and things change very quickly even if everything else remains equal.  Plus no matter what any specs are every hunk of iron is a very different animal even if they come off the same assembly line and are finished by the same person or robot on the same same day ect.

Ya know, I just thought of something.

who in their right mind hits a hill at 1600 rpm, and floors it all the way to the top? NOBODY. It's suicide to expect this engine to produce it's max torque value for any length of time. What is MAX torque value anyway?? answer; the absolute end of any rpm gain. finito, the end. Do this on a daily commute, and it's lites out for even the baddest cummins ever screwed together.

life on the gerbil wheel is easy compared to a 3 mile long run. Why> because it's short. very short. Our engines are rated at wot balls out max production. Sure, the max numbers are quite neat to brag about, but when that 3 mile hill lures me up to the summit, I use the transmission, not the over fueled engine. for torque multiplication to the tires. I say overfueled, because that's exactly what any engine is considered that should only do it for a few measly seconds.

Ah, can you tell me just how bad your truck falls on it's face @ 1600? I'll tell you right now. my bone stocker when loaded with a 20k load will quickly lose it's 2500 on a grade, (forcing a wot situation.. which I will not tolerate) What I am saying, is I can keep throttle in mid fuel AND maintain 1600-1700. It'd be painfully slow, what? 45 mph?

Those max torque readings are from full fuel, wot. The difference is we are not driving a load wot.. any distance. Lets face it, going up hill, @ 2500, you are a lot closer to that point already. Tach numbers say nothing about how much fuel is being injected.. and as everyone knows, the more fuel and air, the more TORQUE will be sent to the rear wheels.

I don't know what mods you've done to your truck.. maybe you are well above the stock torque @2500, which is fine and dandy. But your 1600 level may not be linear to your performance @ 2500. Instead of the huge jump at your 2500, you are only gaining a little at 1600? Possible the wider gap is what you are feeling/complaining about?

Again, my truck at it's peak torque curve of 1700-1800 is a rock for holding rpm constant. At less than full fuel to boot. I can't say that at 2500. I'd have to bury the throttle, and this is not how a diesel should be operated.

This is all when loaded. I'm doing this exact scenario tomorrow morning. I'm headed out to Valentine Ne to pick up some cows. I'll make notes of me rolling through the Sandhills on the way home! (experiment, if you will call it that)

I don't view it as apples to oranges at all. It's only apples and orages if you assume the engine will slow from 2500 rpms. If it hold 2500 rpms with 555-610 ft/lbs, but doesn't hold 1600 rpms with 610 ft/lbs (which it won't if the load is maxed out on the 2500 rpm run) then horsepower is what keeps you moving, not the torque.

 

I don't pull grades at 1600 either, just simply using the ratings. The Cummins 600 (04.5-07) has a peak torque of  610 ft/lbs at 1600 rpms. It makes at least 555 from 1400-2900. So torque at 1600 rpms is at least equal to, if not greater than, torque at 2500 rpms. I am talking about a fixed load, gearing, tire size, etc... That's apples to apples, the torque output is basically the same. The variable is rpms, which given a flat torque curve means more horsepower. More horsepower, the faster the work is done.

 

In my truck if I hit that grade at 1600 rpms in 5th I will be in 4th by the top. 41 mph in 5th is 1600, which is 2200 in 4th. But if I hit the same hill in 5th at 2500 rpms, 64 mph, I will make the top in 5th.. even on a 7-8% grade at 20K GCW on a 75° day at 7K feet.

 

There are ways to measure horsepower. Think about the original horsepower calculation. It's the ability to move 550 lbs 1' vertically in 1 second. If it takes 2 seconds you measured at 1/2 horsepower, or if it take 1/2 a second you have 2 horsepower. The torque is the same in both of them, so you are not measuring torque... heck it could take an hour and the torque is the same. That's how a chassis dyno works. To rotate the drum 1 time takes the same torque, whether you are at 1 rpm or 1000 rpms of the drum. The difference is horsepower, that's why they cannot tell you the torque output of your engine only the horsepower output. A water-brake, or other engine dyno's are the opposite. They measure the work being done, not the rate at which they are done.. they needs rpms to calculate hp. A chassis dyno needs rpms to calculate torque.

Again, no.

If your example engine is 2 horsepower, which can move the weight in half the time(which it certainly can)or double the original weight @ normal speed.... the torque MUST double.

Your example is impossible to achieve. why?? this theoretical engine doing the work is maxed out. there is no more rpm because it's at the end of it's rope. So, the only way to double the HP, is to DOUBLE THE TORQUE.

Why not just double the original motor speed to do the same you ask? well, sure! that would double the HP! unfortunately the original motor has nothing left to give! *this is how max values are based.. otherwise it surely wouldn't be a true test.

Now, lets take a simple electric motor. lets say one is 1750 rpm, and 1 horsepower.

lets also take another similar frame motor that is brushed for 3500 rpm and is rated at 2 horsepower.

now attach both of them to our test mule! guess what? The poor 2 hp motor will never spin up to speed.. it'll smoke it's way all the way up. why? The torque load will prevent the weight from going up any faster than 1 foot per second.. (jus working the formula backwards here too)

This is figured on the original motor being able to do 2 things! Maintain it's rated rpm of 1750, AND maintain 1 foot per second. if we were to add ONE more pound of weight to the test mule, rpms would suffer. and the weight would no longer make the voyage in one second. It's at the end of it's rope!

So now we throw the 2 hp motor on the mule.

lets even give it a chance to spin up to full speed before we engage the pulley! guess what'll happen!

The 550 lb weight will drag that motor down so it's buzzing away at half speed.. Why? because 550 lbs will slow this motor to 1 foot per second.. because it's got just enough torque to move the weight 1 foot per second. If it had double the torque, and the same rpm, it could be geared up and move the weight at 2 foot per second.. as long as the gear box was 100 percent efficient.

This example is based solely on 2 parameters! The ability to maintain speed of 1 foot per second, *means the motor cannot deviate from it's rated rpm and exactly 550 lbs. Even one tenth of a second off the pace is a failure.

Edited February 28, 201510 yr by rancherman

another thing..

back in my caveman days of running a prehistoric water brake..

We'd for fun 'see' what the max was. We'd crank her down until there was zero throttle response. (maxed out so to speak) we'd throttle back say 100 rpm from max, crank down the brake, and see if it would spool back up.

typically, there was about 35-40 percent difference in torque from rated.. to max.

So, what does the gerbil wheel do here, that 'maxes' out our engines? This doesn't necessarily mean it needs to stall rpm progression, I'm sure they have algorithms that can figure amount of torque to accelerate a loaded drum to speed... This is probably where the 'calibration' part comes in.. to build a certain amount of load for each particular vehicle.. Can't really figure the same load for my Toyota.. It might not even get the wheel turning! (hell, It probably couldn't climb the ramp up to it!) with it's pounding 140 ft. lbs of torque!

I have results!

Smarty on 7 TST off: 372.66hp  801.88 Torque

 

Smarty on 7 TST on 9:  

Run 1: 499.80hp   1032.17 Torque

Run 2: 502.39hp   1038.48 Torque

 

I'll upload the graphs asap, but the smarty did NOT fall on it's face. I was rather impressed!

 

EDIT: Oh and the CR made 724.xx hp and 12xx torque... Guess I'm not too bad at tuning haha

That is amazing. The 24v made twice the rated power without porting, polishing, intake manifolds etc. Like a gas motor would need. That's more power than class 8 tractor trailers made until the late 90's!

Cool!

I would put you in the 450 hp 800 tq range with the stack and smarty alone I would guess 375-400 ish.

 

 

I have results!

Smarty on 7 TST off: 372.66hp  801.88 Torque

 

Smarty on 7 TST on 9:  

Run 1: 499.80hp   1032.17 Torque

Run 2: 502.39hp   1038.48 Torque

 

I'll upload the graphs asap, but the smarty did NOT fall on it's face. I was rather impressed!

 

EDIT: Oh and the CR made 724.xx hp and 12xx torque... Guess I'm not too bad at tuning haha

I was pretty close hp wise but fell short on the torque a bit, did you do the runs in 4th or 5th?. Good numbers. What is all done and added to the 3rd gen?

As far as the smarty they have made so many updates they probably got it tuned in from the early days.

I am particular interested in your REVO settings and the smarty only curve if you get a chance to post it. 

I was pretty close hp wise but fell short on the torque a bit, did you do the runs in 4th or 5th?. Good numbers. What is all done and added to the 3rd gen?

As far as the smarty they have made so many updates they probably got it tuned in from the early days.

Exergy 100hp over tips on original bodies (@170k miles) Industrial 85% over cp3 South bend dual disk, stock 5600, phatshaft 62/65/14 over an s475/96/1.32, second gen 3 piece manifold, 5in straight pipe exhaust, fass 150 titannium, fass sump with draw straw, UDC tuned by me, custom traction bars, and I think that's it.

All runs were made in 5th gear. It was funny to see the dyno operator's face when I flipped the TST on for the second run He whipped around "DID YOU CHANGE SOMETHING??"

As you can see the smarty held up pretty well all the way to 2750 or maybe a little higher. The TST holds strong all the way past 3K though.

With the smarty I was right around 35psi of boost.

With the Comp my wastegate opened up at 45psi and egts hit 1300 or a little higher.

Those are some great numbers!   

Nice run TFaoro. Did you double your timing with the Smarty and tst?

TST doesn't do any timing... it's just a fueling box, so no. and thanks!

Smarty handle the timing nd TST handles the fuel.

how is the miss now?

That is amazing. The 24v made twice the rated power without porting, polishing, intake manifolds etc. Like a gas motor would need. That's more power than class 8 tractor trailers made until the late 90's!

Cool!

If they would've been overfueled the same rate as this, No contest.

They were set up to chug all day, day after day at that ancient rate capacity.

10 seconds of burst is a completely different story. Semi trucks would rarely have the throttle pushed to the rubber mat.

I got a 903 cummins that was typically set up for anywhere from 275 up to 375 horsepower.. mine is on 320, Continuous duty..

When they were stuck in Coast Guard pursuit vessel, they were fueled for 1500 HP, 2880 ft. lbs, and 3000 rpm momentary duty. 45 minutes was what the limit was at this rate. (kinda weird, shoot... after 45 minutes, what's the difference?) LOL< probably out of fuel then!!

'overfueling' isn't necessarily just the level of what an engine can withstand before damage to the engine occurs... It's just any amount of fuel over and above the rated capacity.

vehicle manufactures ( semi truck, ag tractor etc) look at the total package too. driveline,transmissions,clutches, frame.. everything must be able to handle the torque coming out of the engine... day after day..

Engine manufacturers know exactly what level an engine will self destruct at any level, over a certain time frame...

... and keep us (joe public) well away from it...

Edited March 2, 201510 yr by rancherman