mustang ** dynapac ** dynojet dynos
07-08-2011, 01:55 PM
#1
mustang ** dynapac ** dynojet dynos
Can anyone explain or help with the differences or what dyno is better to tune off of? Getting ready to tune my car and I'm just tryin to get some facts on these dyno's. Thanks guys!!!!!!!!!!!!!!!!
07-08-2011, 02:39 PM
#2
You left off the best one to tune on... the load based Dyno Dynamics.
Dynos are tools... period. Comparing one to another is basically nonsense. You can compare two dynos, but only after getting runs made on doth on days with very similar atmospheric conditions. Shops will tell you they read low, or adjust for a Dynojet number, or adjust for elevation or atmospheric pressure ... its all crap to a degree.
Bench racing or chasing numbers is FAIL, like I said, its a tool that gives a number.. nothing more, nothing less. If you really want to use they dyno for what its good for, get a reading prior to mods being installed, then a tune and another reading after on the same dyno on the same day.
Dynos are tools... period. Comparing one to another is basically nonsense. You can compare two dynos, but only after getting runs made on doth on days with very similar atmospheric conditions. Shops will tell you they read low, or adjust for a Dynojet number, or adjust for elevation or atmospheric pressure ... its all crap to a degree.
Bench racing or chasing numbers is FAIL, like I said, its a tool that gives a number.. nothing more, nothing less. If you really want to use they dyno for what its good for, get a reading prior to mods being installed, then a tune and another reading after on the same dyno on the same day.
07-08-2011, 02:54 PM
#3
Thanks man. This tuning thing is somthing that I'm trying to learn or atleast understand somewhat.. Just got done doin my motor so this will be the third tune I have had. The first 2 were on my other motorand I was running a SC. now I have a fully built TT set up, alot of money tied up and just want to start understanding everything so I know whats goin on. Thanks for the help. 
07-08-2011, 03:26 PM
#5
quick one guys, A few people say dynapac's read high numbers like dynojet etc... My car did 459whp and ran 119.60mph 1/4 mile on **** road tires. Does that sound like a 460whp trap speed?
07-08-2011, 04:12 PM
#9
Heres my personal take on this.... but I would gladly stand corrected if anything has changed over the last few years of which i havent been operating a dyno or in the big horsepower race.
Inertial dynojets (248c, non-load-based), are the only dynos that you can really compare graphs created on one versus another. These dynos only offer like 5 or so difference standard correction values that are based STRICTLY on environmental conditions. All you need to know is STD reads a little higher than SAE (not a TON, maybe 20hp on a 500 hp car or something like that). The graph should say which was used on it. Ive noticed over the years that tuners usually use SAE, and people trying to sell you something use STD.
Now, its been debated that dynojets read higher than real proper horsepower. OK, i cant argue one way or the other on that... if its true its true, whatever. I still say at least you know what you are looking at with their graphs.
Other dynos, be it a mustang, dyno dynamics, dynapac, etc... its all up in the air. You never really know exactly what you have. The reason for this is, regardless of any environmental correction factors they have to choose from... they (VERY VERY UNFORTUNATELY) have a operator defined correction factor. This means they can simply just STACK ON 10% if they want.
This creates a lot of problems. Because instead of just being able to say MUSTANG READS LOWER THAN DYNOJET, DYNO DYNAMICS READ LOWER THAN DYNOJET... you cannot say that. Because while it MAY read lower than dynojet without an operator defined correction factor being set... many dyno operators CHOOSE to add a STATIC percentage to what they believe will equal a dynojet number.
Even much much more unfortunate than that, these other brands of dynos do not display the operator defined correction on the actual graph so that people know what they are looking at.
So now what we end up with is, every single friggin guy to ever use a dyno that is not a dynojet, posts his graph and absolutely positively MUST include a caption about how much more they think it would be on a dynojet, or they will at least say "on this LOW READING DYNO", or at the very bare minimum they have to throw in the phase "heartbreaker".
But when they say that, its has no value. Not because there is anything about those people that makes their statements worth less than others... but just because there is no telling what operator defined factors that graph was filtered through, and for all we know its actually much higher than a dynojet.
as for dynapac all i can say is that every car that i ever personally knew to dyno on a dynapac, the dynapac was quite optimistic (i believe quite a bit more so than a dynojet). But then again, thats probably after the operator stacked on some ******** 25% or something thinking that there is actually a static value that will create a dynojet number out of a xxxxx number.
its the same thing with the guys who use altitude correction factors. dont ever buy it. I know that the guys up at the top of the rockies suffer a lot of power loss due to air density. Sure... but those guys are hilarious they use the most rediculous and exageratted "corrections" on their timeslips and dyno graphs, and when they bring their car down to altitude is when they experience the real heartbreaker.
Lastly, I do not want to discredit other dynos at ALL. I believe that the load based dynos are all better tuning tools than the old dynojet 248c, for sure. I just personally dont ever take a graph to heart if it didnt come from a dynojet.. i honestly usually dont even look at them anymore. because I just cant base it off anything at all when I do not know how much the operator decided to stick on top. im sure plenty of shops dont add anything at all.... but until these other brand dynos display ON THE GRAPH, ALL APPLIED CORRECTION VALUES, then i just dont care to read them.
Inertial dynojets (248c, non-load-based), are the only dynos that you can really compare graphs created on one versus another. These dynos only offer like 5 or so difference standard correction values that are based STRICTLY on environmental conditions. All you need to know is STD reads a little higher than SAE (not a TON, maybe 20hp on a 500 hp car or something like that). The graph should say which was used on it. Ive noticed over the years that tuners usually use SAE, and people trying to sell you something use STD.
Now, its been debated that dynojets read higher than real proper horsepower. OK, i cant argue one way or the other on that... if its true its true, whatever. I still say at least you know what you are looking at with their graphs.
Other dynos, be it a mustang, dyno dynamics, dynapac, etc... its all up in the air. You never really know exactly what you have. The reason for this is, regardless of any environmental correction factors they have to choose from... they (VERY VERY UNFORTUNATELY) have a operator defined correction factor. This means they can simply just STACK ON 10% if they want.
This creates a lot of problems. Because instead of just being able to say MUSTANG READS LOWER THAN DYNOJET, DYNO DYNAMICS READ LOWER THAN DYNOJET... you cannot say that. Because while it MAY read lower than dynojet without an operator defined correction factor being set... many dyno operators CHOOSE to add a STATIC percentage to what they believe will equal a dynojet number.
Even much much more unfortunate than that, these other brands of dynos do not display the operator defined correction on the actual graph so that people know what they are looking at.
So now what we end up with is, every single friggin guy to ever use a dyno that is not a dynojet, posts his graph and absolutely positively MUST include a caption about how much more they think it would be on a dynojet, or they will at least say "on this LOW READING DYNO", or at the very bare minimum they have to throw in the phase "heartbreaker".
But when they say that, its has no value. Not because there is anything about those people that makes their statements worth less than others... but just because there is no telling what operator defined factors that graph was filtered through, and for all we know its actually much higher than a dynojet.
as for dynapac all i can say is that every car that i ever personally knew to dyno on a dynapac, the dynapac was quite optimistic (i believe quite a bit more so than a dynojet). But then again, thats probably after the operator stacked on some ******** 25% or something thinking that there is actually a static value that will create a dynojet number out of a xxxxx number.
its the same thing with the guys who use altitude correction factors. dont ever buy it. I know that the guys up at the top of the rockies suffer a lot of power loss due to air density. Sure... but those guys are hilarious they use the most rediculous and exageratted "corrections" on their timeslips and dyno graphs, and when they bring their car down to altitude is when they experience the real heartbreaker.
Lastly, I do not want to discredit other dynos at ALL. I believe that the load based dynos are all better tuning tools than the old dynojet 248c, for sure. I just personally dont ever take a graph to heart if it didnt come from a dynojet.. i honestly usually dont even look at them anymore. because I just cant base it off anything at all when I do not know how much the operator decided to stick on top. im sure plenty of shops dont add anything at all.... but until these other brand dynos display ON THE GRAPH, ALL APPLIED CORRECTION VALUES, then i just dont care to read them.
Last edited by phunk; 07-08-2011 at 04:17 PM.
07-08-2011, 10:20 PM
#13
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Dynapaks not having all the inertia of a roller from what I have read and heard makes it one of the best to tune on. If this gives any comparison, I made 330 whp on the dyno dynamics at Forged with my 3.12 pulley and a stock exhaust on about a 85 degree day. Later I changed out to the 2.87 and a dual exhaust and made 418 whp on a 50 degree day on a dynapak. I have always assumed about a 10% correction factor on that dynopak and about a 20% correction on the dyno dynamics at Forged. There is really no way to know. I have read where dynopaks read lower that dynojets and I have read the exact opposite, too bad there isn't some set standard out there and all dyno could just read the same, but in the end it only matters how fast you trap across the finish line.
07-09-2011, 05:16 AM
#14
Dynojet is the only inertia based dyno in the conversation here. The rest are brake dynos.
Dynapak adjusts brake load with hydraulics (like an auto tranny) and mustang/dynodynamics use eddy currents. Most others are brake based as well, e.g. you can adjust the loading/braking which aids in tuning. But the drawback of a brake dyno is the numbers don't mean much unless compared to the same dyno on the same day. A tuner can make a brake dyno read whatever they want...
Dynojet is inertial (no braking) which makes it the only 'popular' dyno you can truly compare numbers with -- it's always the same and there's no calibration or fudge factors a tuner can apply. The weighted drum IS the load and is a known mass... that weight/load never changes between dynos, so calculating power is simple and _highly_ accurate. Dynojets and other inertial dynos also require no calibration. My car dynos within 1whp between two completely different dynojets... pretty cool
So... for tuning you want a brake dyno (mustang, dynodynamics, dynapak), and for final numbers you want an inertial dyno, specifically Dynojet... very simple.
Dynapak adjusts brake load with hydraulics (like an auto tranny) and mustang/dynodynamics use eddy currents. Most others are brake based as well, e.g. you can adjust the loading/braking which aids in tuning. But the drawback of a brake dyno is the numbers don't mean much unless compared to the same dyno on the same day. A tuner can make a brake dyno read whatever they want...
Dynojet is inertial (no braking) which makes it the only 'popular' dyno you can truly compare numbers with -- it's always the same and there's no calibration or fudge factors a tuner can apply. The weighted drum IS the load and is a known mass... that weight/load never changes between dynos, so calculating power is simple and _highly_ accurate. Dynojets and other inertial dynos also require no calibration. My car dynos within 1whp between two completely different dynojets... pretty cool
So... for tuning you want a brake dyno (mustang, dynodynamics, dynapak), and for final numbers you want an inertial dyno, specifically Dynojet... very simple.
Last edited by djamps; 07-09-2011 at 05:27 AM.
07-09-2011, 08:10 AM
#16
Dynojet is the only inertia based dyno in the conversation here. The rest are brake dynos.
Dynapak adjusts brake load with hydraulics (like an auto tranny) and mustang/dynodynamics use eddy currents. Most others are brake based as well, e.g. you can adjust the loading/braking which aids in tuning. But the drawback of a brake dyno is the numbers don't mean much unless compared to the same dyno on the same day. A tuner can make a brake dyno read whatever they want...
Dynojet is inertial (no braking) which makes it the only 'popular' dyno you can truly compare numbers with -- it's always the same and there's no calibration or fudge factors a tuner can apply. The weighted drum IS the load and is a known mass... that weight/load never changes between dynos, so calculating power is simple and _highly_ accurate. Dynojets and other inertial dynos also require no calibration. My car dynos within 1whp between two completely different dynojets... pretty cool
So... for tuning you want a brake dyno (mustang, dynodynamics, dynapak), and for final numbers you want an inertial dyno, specifically Dynojet... very simple.
Dynapak adjusts brake load with hydraulics (like an auto tranny) and mustang/dynodynamics use eddy currents. Most others are brake based as well, e.g. you can adjust the loading/braking which aids in tuning. But the drawback of a brake dyno is the numbers don't mean much unless compared to the same dyno on the same day. A tuner can make a brake dyno read whatever they want...
Dynojet is inertial (no braking) which makes it the only 'popular' dyno you can truly compare numbers with -- it's always the same and there's no calibration or fudge factors a tuner can apply. The weighted drum IS the load and is a known mass... that weight/load never changes between dynos, so calculating power is simple and _highly_ accurate. Dynojets and other inertial dynos also require no calibration. My car dynos within 1whp between two completely different dynojets... pretty cool
So... for tuning you want a brake dyno (mustang, dynodynamics, dynapak), and for final numbers you want an inertial dyno, specifically Dynojet... very simple.
However, I'm
Not sure how the numbers compare between inertia and load control dynojets.
Ross
07-09-2011, 12:15 PM
#17
This doesnt directly answer the OP question but this was a post i made on another forum when people were asking about dyno #'s, so I thought i would copy and paste it...
The Main difference from a numbers standpoint between Mustang and dynojet, is that with Mustang you can change a Value to either make it read higher or lower. Mustang has this power/coast down procedure that u perform several times thats gives you a value. You take those values and then average them out and thats the value you are suppose to use in the Mustang software. Now if you maunually make that value higher or perfrom the power/coastdown procedure wrong and it gives you higher numbers...the dyno will read higher. Same is true with lower values
Now with a dynojet, that number isn't adjustable, that's why its the industry standard and everybody compares them. Now we have both, and they both work great for what they do. If we are talking about a accurate numbers and repeatability stand point, its no doubt that the dynojet is more accurate. If we are talking about a load control and variable tuning tool, no doubt the mustang is better.
Quick story, we used to do alot of Porsche product testing. Specifically on the 997 Carrera 4. Company was making intakes and exhaust on a already pretty well engineered N/A 3.6 liter. Long story short, is that no matter what this company did they couldn't make any more power with there products. They got everybody involved including current and previous Porsche engineers. Through this process with them being here they had brought all the factory calculated drivetrain loss figures (from Porsche R&D), stating that there was a 13% drivetrain loss on that vehicle. Well with 340BHP, we consistently got 293-296 WHP on over a half dozen Carrera 4's.
So that is one specific instance of the accuracy of dynojets numbers. When you compile that with the 100's if not 1000's of stock NA cars that we have done with the information that is out there, dynojet numbers always seem to be on par with what is expected to see HP at the wheels....
The Main difference from a numbers standpoint between Mustang and dynojet, is that with Mustang you can change a Value to either make it read higher or lower. Mustang has this power/coast down procedure that u perform several times thats gives you a value. You take those values and then average them out and thats the value you are suppose to use in the Mustang software. Now if you maunually make that value higher or perfrom the power/coastdown procedure wrong and it gives you higher numbers...the dyno will read higher. Same is true with lower values
Now with a dynojet, that number isn't adjustable, that's why its the industry standard and everybody compares them. Now we have both, and they both work great for what they do. If we are talking about a accurate numbers and repeatability stand point, its no doubt that the dynojet is more accurate. If we are talking about a load control and variable tuning tool, no doubt the mustang is better.
Quick story, we used to do alot of Porsche product testing. Specifically on the 997 Carrera 4. Company was making intakes and exhaust on a already pretty well engineered N/A 3.6 liter. Long story short, is that no matter what this company did they couldn't make any more power with there products. They got everybody involved including current and previous Porsche engineers. Through this process with them being here they had brought all the factory calculated drivetrain loss figures (from Porsche R&D), stating that there was a 13% drivetrain loss on that vehicle. Well with 340BHP, we consistently got 293-296 WHP on over a half dozen Carrera 4's.
So that is one specific instance of the accuracy of dynojets numbers. When you compile that with the 100's if not 1000's of stock NA cars that we have done with the information that is out there, dynojet numbers always seem to be on par with what is expected to see HP at the wheels....
07-09-2011, 12:34 PM
#18
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Tuning
This doesnt directly answer the OP question but this was a post i made on another forum when people were asking about dyno #'s, so I thought i would copy and paste it...
The Main difference from a numbers standpoint between Mustang and dynojet, is that with Mustang you can change a Value to either make it read higher or lower. Mustang has this power/coast down procedure that u perform several times thats gives you a value. You take those values and then average them out and thats the value you are suppose to use in the Mustang software. Now if you maunually make that value higher or perfrom the power/coastdown procedure wrong and it gives you higher numbers...the dyno will read higher. Same is true with lower values
Now with a dynojet, that number isn't adjustable, that's why its the industry standard and everybody compares them. Now we have both, and they both work great for what they do. If we are talking about a accurate numbers and repeatability stand point, its no doubt that the dynojet is more accurate. If we are talking about a load control and variable tuning tool, no doubt the mustang is better.
Quick story, we used to do alot of Porsche product testing. Specifically on the 997 Carrera 4. Company was making intakes and exhaust on a already pretty well engineered N/A 3.6 liter. Long story short, is that no matter what this company did they couldn't make any more power with there products. They got everybody involved including current and previous Porsche engineers. Through this process with them being here they had brought all the factory calculated drivetrain loss figures (from Porsche R&D), stating that there was a 13% drivetrain loss on that vehicle. Well with 340BHP, we consistently got 293-296 WHP on over a half dozen Carrera 4's.
So that is one specific instance of the accuracy of dynojets numbers. When you compile that with the 100's if not 1000's of stock NA cars that we have done with the information that is out there, dynojet numbers always seem to be on par with what is expected to see HP at the wheels....
The Main difference from a numbers standpoint between Mustang and dynojet, is that with Mustang you can change a Value to either make it read higher or lower. Mustang has this power/coast down procedure that u perform several times thats gives you a value. You take those values and then average them out and thats the value you are suppose to use in the Mustang software. Now if you maunually make that value higher or perfrom the power/coastdown procedure wrong and it gives you higher numbers...the dyno will read higher. Same is true with lower values
Now with a dynojet, that number isn't adjustable, that's why its the industry standard and everybody compares them. Now we have both, and they both work great for what they do. If we are talking about a accurate numbers and repeatability stand point, its no doubt that the dynojet is more accurate. If we are talking about a load control and variable tuning tool, no doubt the mustang is better.
Quick story, we used to do alot of Porsche product testing. Specifically on the 997 Carrera 4. Company was making intakes and exhaust on a already pretty well engineered N/A 3.6 liter. Long story short, is that no matter what this company did they couldn't make any more power with there products. They got everybody involved including current and previous Porsche engineers. Through this process with them being here they had brought all the factory calculated drivetrain loss figures (from Porsche R&D), stating that there was a 13% drivetrain loss on that vehicle. Well with 340BHP, we consistently got 293-296 WHP on over a half dozen Carrera 4's.
So that is one specific instance of the accuracy of dynojets numbers. When you compile that with the 100's if not 1000's of stock NA cars that we have done with the information that is out there, dynojet numbers always seem to be on par with what is expected to see HP at the wheels....
07-10-2011, 05:43 AM
#20
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while i agree with Zivman i will add that i would never choose a tuner based on which dyno they use and if tuning your self i would recommened which ever dyno you think you are happy to be able operate correctly.