dyno results for my "bombed" 01.5

[Todd T]

Joe I dont disagree with what you stated, and my definition of "meager pronouncments" would be "laymens terms". the principle that the dynojet is based on is called Rotational Inertia. and it, is based on the fact, that at any given time a computers software can precisely calculate using pure maths, the power. by the simple input of the drum speed and engine RPM's.



but you still kinda danced around the fact that the dyno jet because it cant load the engine up correctly. it is friction control only, and that is not exacting and cannot be duplicated. and/or the operators ability to do so, result in the readings being scewed.



the operators have to carefully time the run and know when to time the run, thus making outcomes, not consistent across different machines, trucks and operators. it also helps to have an understanding of the vehicle that is on it and its behavioral habits.



IE. "the sweet spot"



this is why if you compare a mustang dyno (which can simulate different loads through an eddy current system, which is easily duplicated, after the dyno is calibrated) and Dyno Jet (drum weighting is the only fluctuation) the mustang can produce a more easily obtained continuity. between machines and operators. if the load is set the same, and the truck is the same, the second guessing of where the sweet spot is, is eliminated as long as the operator selects the same gear and starting point(RPM). the outcome should be the most the engine is capable of, using the "brake", and can be measured at any point in the run, or held for infinity if desired. or the operator can pull the engine down and let it go and more accurately measure torque and HP. Not just look at what it was doing at that moment in time of the run, like a dyno jet.



just my 2 cents worth. I'm sure you will disagree, but thats what makes up our little world we live in.

 

[Joseph Donnelly]

I feel I should answer some of Todd T's comments to help bring out some valuable points regarding dyno testing.



"but you still kinda danced around the fact that the dyno jet because it cant load the engine up correctly. it is friction control only, and that is not exacting and cannot be duplicated. and/or the operators ability to do so, result in the readings being scewed. "



The Dynojet loads the engine by simulating a truck weight, usually abou 5000 lb, depending on the model of Dynojet. There is no friction control. It is inertia loading, a simple and reproducible principle of physics. The correctness or incorrectness would only relate to what truck weight is being simulated. At that, if the Ram is a very high hp one, readings would tend to be low since full power might not be achieved in the few seconds involved for the run. There is no reason the raw hp measurement itself would be high. Corrected measurements, SAE or other, could be "wrong" if the correction factors were not geared to the intended purpose of the run. These errors typically would be very small, around 1-2% or lower.



True, this setup can't load the engine with as much as the truck can on the road, but during testing, as long as the load is repeatable, so shall be the hp/tq figures. Since (a) the load is ONLY the weight of the drums, which cannot be altered or adjusted by the operators, (b) the inertia principle is simple, reproducible, and virtually nonvariant with environmental conditions, and (c) there are no difficult to reproduce frictional contributors such as tire slippage or braking, this is the only dyno that is truly reproducible. Any load dyno that uses water or electricity is obviously influenced by heat, and as its usage time goes up per session, it's efficiency goes down. This has to be compensated for on other dynos... not on a Dynojet.



"the operators have to carefully time the run and know when to time the run, thus making outcomes, not consistent across different machines, trucks and operators. it also helps to have an understanding of the vehicle that is on it and its behavioral habits. "



Time the run? There is no timing on the Dynojet. The engine just accelerates and the Dynojet measures the time elapsed. Obviously to measure horsepower, other variables such as torque converter efficiency should be excluded (lock up the converter!) However, that is true for other dynos also.



"this is why if you compare a mustang dyno (which can simulate different loads through an eddy current system, which is easily duplicated, after the dyno is calibrated) and Dyno Jet (drum weighting is the only fluctuation) the mustang can produce a more easily obtained continuity. between machines and operators. if the load is set the same, and the truck is the same, the second guessing of where the sweet spot is, is eliminated as long as the operator selects the same gear and starting point(RPM). the outcome should be the most the engine is capable of, using the "brake", and can be measured at any point in the run, or held for infinity if desired. or the operator can pull the engine down and let it go and more accurately measure torque and HP. Not just look at what it was doing at that moment in time of the run, like a dyno jet. "



Drum weighting (inertia) does NOT fluctuate, which is what makes the Dynojet so repeatable and consistent. Most commonly, the Mustang has trouble getting reproducibility within 10hp from run to run. There is no simpler way to have consistency than if there are no variable, friction related or heat related, factors, and no user adjustments to be made, as in the case with the Dynojet. The sweet spot you mention would be the same for either dyno. Once discovered, (gear and RPM point), consistency and repeatability on a Dynojet is +/- 0. 1hp How much closer does it need to get?



With the Dynojet there is no reason to hold rpm constant for a period of time. The only improvement would be a higher slug dyno (more inertia) to force the Cummins to achieve full boost and power earlier (i. e. at lower rpm). Lawrence Bolton of Diesel Dynamics has experimented with such things, but the standard Dynojet is adequate for almost all purposes, is very reproducible, and is comparable across the country.

 

[joesoot]

Maybe this is a stupid question, maybe it isn't... but if you can only simulate a truck's weight or "load" of 5000 #s and your truck weighs close to 7000, won't the outcome of the calculation be affected???

 

[KatDiesel]

Originally posted by Joseph Donnelly

Most commonly, the Mustang has trouble getting reproducibility within 10hp from run to run.

I have to disagree on this statement, 8 runs over a 2 hour period. Biggest "gap" was . 7 hp.



I'll be on the same one tommorrow with the "Addtional" mods on. I'll prolly make 4 passes, I'll report the findings tommorrow.

 

[Todd T]

if you cant simulate enough of a load to work the engine to its capacity then you dont really know whats it is capable of, do you, Joe.



THAT, is the problem with a Dyno Jet. period.



I cannot contest your presentation on the parisitic and efficientcy of the others.



unlike yourself, most of the folks on here are interested in finding out what the maximum output of thier truck is. not using the dyno to make repeated runs to test and tune with.

 

[drawson]

I'm with Kat on this also I have seen the Edges Mustang dyno be very repeatable on more than a few trucks.



I have talked to alot of guys that get alot higher numbers on the Dyno-jet (40-50 HP).



The tires losing traction doesn happen on the Mustang dyno but I think this would be easy to overcome.

 

[Hammer]

Being one of the few valve-limited trucks at the dyno the day ICEMAN pulled somehow I missed all this hoopla,,ICEMAN when you get everything back Ernie will pull your truck for the same deal as he will all MD-TDR members,,Let me know when its going to happen and I'll come over,,First thing I'd like to address here is Todd T,,I can not figure out how you can make such an assumption on the DYNOJET as far as being a waste and if without looking back will not load control,,You have shown here the reason that you need to research before you hit the submit key,,Kauffman's dyno jet WILL LOAD CONTROL and was the day it was pulled upon,,He was inconversation with them on what it should be set at and they gave him the numbers that MOST ALL DYNOJET owners use when pulling these trucks (level playing field),,So there was no chance of "idling" syndrome,,He also then pull the dyno apart to showw all that were in attendence at the end the drums and their locomotive brake that provides the load control,,Can't believe the whole gang of us were blind and did not see what we saw,,I agree with the 12 valve master Joe D in the statement that,after seeing a few of these days and pulling on them I'd say the Dynojet is most accurate as all 3 of my pulls from 3 different places are within a few numbers of each other,,And last but not least to Katdiesel,,Seems the computer scootered overvalved electronic diesels got bushwacked by me,,Seems my under-valved non-eletronic truck that waited till near the end to pull put one on them,,They were nipping at my heels though,,324. 5hp and 812. 8 ft lbs of torque,,We all learned some lessons that day and our gracious host said it the best"You can not hide anything from the HUMBLER,it tells all",,I also in closing will say this,,After an exhaustive conservation with the Kauffman group afterwards in the week new the dyno was going to be in question from those non-believers,,Since DYNOJET was just in earlier in the week making sure his jet was updated with ALL the latest equipment due to testing for some Winston Cup teams and also testing for Holley,inc there is NO QUESTION in my mind its up to the task and has proven itself time and time again,,The people who run the operation are as solid as anyone and WILL NOT fabricate any numbers that are bogus and for anyone to question their equipment and their integrity without meeting them OR being there to pull their own truck is a shame to say the least,,ICEMAN and those going to Capital,pm me the date and we will go to,,Better place to thrash them would be Mason-Dixon in Hagertown,MD can be done during a regular bracket race on a Sunday and we can run as many time as we want,,Either is good drop me a note. .

 

[Todd T]

your right Hammer

I didnt realize this place you went to was using a FRICTION brake. LOL



its amazing the reaction you get, when you rub someone's, pets hair, the wrong way.



tell me, did he use the brake during your runs?