The Dyno Thread
06-15-2016, 10:45 AM
#31
Yes it is corrected to Engine Power as Pete explains. It says so right on the plots. The Mustang software has a curve that can be applied to add the drive train losses that are expected, back into the plots. It says "Eng" at the top of those plots, because that curve has been applied. If it was wheel power, it would say "whp" on those plots.
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06-15-2016, 10:50 AM
#32
Yes it is corrected to Engine Power as Pete explains. It says so right on the plots. The Mustang software has a curve that can be applied to add the drive train losses that are expected, back into the plots. It says "Eng" at the top of those plots, because that curve has been applied. If it was wheel power, it would say "whp" on those plots.
This is a setting that the Dyno operator can choose which gives the engine the flywheel power rating projection, even though the power is gathered at the wheels.
I have spent thousands of hours of my life using dynamometers. I have 3 under my roof.
This is a setting that the Dyno operator can choose which gives the engine the flywheel power rating projection, even though the power is gathered at the wheels.
I have spent thousands of hours of my life using dynamometers. I have 3 under my roof.
06-15-2016, 11:16 AM
#33
Former Vendor
People look at dyno graphs for the wrong reasons, 99.9% of the time. Their eyes only wander to the peak output power plot, and they don;t pay attention to anything else. These people are looking at the graph in a totally *** backwards manner, because all they want is bragging rights.
This is why the Mustang dyno has the curve for converting the figures from WHP to ENG numbers.
When I send owners their dyno plots, I hear over and over "My engine made xxx from the factory, why is it only 15-20HP stronger than that now?". They do not realize they are comparing the Porsche stated flywheel power figures, to our figures that are not converted (and never will be) to flywheel figures. When we are only 15-20HP higher, that figure is really 20%+ the 15-20HP higher.
Wheel power, is wheel power, and should never use a generic curve to correct it to flywheel (Eng) power, as every car is different, and the numbers will lose accuracy, and comparability. Each car is different due to rear wheel alignment, tires, brake condition, CV point condition, transaxle wear, gear oil temperature, and type, etc, etc, on, and on.
Too often, people just want one big number, they don't look at whats really important, and what truly explains how the engine is performing. I judge engines less by peak numbers, and more by average outputs, and power figures at less than 5,251 RPM, the point where TQ and HP must always cross. To me, I am shooting for efficiency, so my BSFC, AFR, and ignition maps are most important, I want to overlay these..
If I want flywheel power figures, the engine goes on my engine dyno. Since it takes two days to set an engine up in the test cell, we reserve the engine dyno only for product and engine combination development. Its easy to change cams, heads, and etc on the engine dyno, and attain back to back figures with no drivetrain losses. Its also easier to make the changes of components.
06-15-2016, 11:26 AM
#34
You're preaching to the choir and I agree. I used to tune motors awhile back on both dynojet and mustang dyno's. Most guys wanted to sacrifice the low end(or area under the curve) so they can bump up the high end. The scary thing is some of these guys were really greedy and wanted me to tune their motors to the ragged edge where there is very little to no room for any cushion. Some of the new cars were a bit more forgiving with their knock sensors and sophisticaed ecu's but regardless, I would tell them to go to another tuner. For forced induction motors, I requested an EGT bung be available or welded to their system if they wanted to stretch it, in addition to my own homemade knock sensing system.
06-15-2016, 11:30 AM
#35
Former Vendor
Absolutely, EGT is another thing that I watch, nothing aids in dialing in the proper ignition timing more than EGT.
I've had guys get pissed off and throw a dyno graph on the ground when they didn't make the power that they were promised by suppliers of components, and bolt ons. They think that XX part gives 15 HP, and YY part gives 30 HP, and that you can add all those up and make some big number. In my experience, a lot of that JUNK makes the engine lose power, when the two items don't work together, or when the part is some over- advertised piece of crap.
Thats why I don't rent my dyno time anymore, and the only engines that we test, are our own. We don't have time to deal with it anyway :-)
When I see those eyes wander straight to peak HP, I instantly get pissed off.
I've had guys get pissed off and throw a dyno graph on the ground when they didn't make the power that they were promised by suppliers of components, and bolt ons. They think that XX part gives 15 HP, and YY part gives 30 HP, and that you can add all those up and make some big number. In my experience, a lot of that JUNK makes the engine lose power, when the two items don't work together, or when the part is some over- advertised piece of crap.
Thats why I don't rent my dyno time anymore, and the only engines that we test, are our own. We don't have time to deal with it anyway :-)
When I see those eyes wander straight to peak HP, I instantly get pissed off.
06-15-2016, 04:15 PM
#36
2nd Gear
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Sneaky Pete caught it first.
People look at dyno graphs for the wrong reasons, 99.9% of the time. Their eyes only wander to the peak output power plot, and they don;t pay attention to anything else. These people are looking at the graph in a totally *** backwards manner, because all they want is bragging rights.
This is why the Mustang dyno has the curve for converting the figures from WHP to ENG numbers.
When I send owners their dyno plots, I hear over and over "My engine made xxx from the factory, why is it only 15-20HP stronger than that now?". They do not realize they are comparing the Porsche stated flywheel power figures, to our figures that are not converted (and never will be) to flywheel figures. When we are only 15-20HP higher, that figure is really 20%+ the 15-20HP higher.
Wheel power, is wheel power, and should never use a generic curve to correct it to flywheel (Eng) power, as every car is different, and the numbers will lose accuracy, and comparability. Each car is different due to rear wheel alignment, tires, brake condition, CV point condition, transaxle wear, gear oil temperature, and type, etc, etc, on, and on.
Too often, people just want one big number, they don't look at whats really important, and what truly explains how the engine is performing. I judge engines less by peak numbers, and more by average outputs, and power figures at less than 5,251 RPM, the point where TQ and HP must always cross. To me, I am shooting for efficiency, so my BSFC, AFR, and ignition maps are most important, I want to overlay these..
If I want flywheel power figures, the engine goes on my engine dyno. Since it takes two days to set an engine up in the test cell, we reserve the engine dyno only for product and engine combination development. Its easy to change cams, heads, and etc on the engine dyno, and attain back to back figures with no drivetrain losses. Its also easier to make the changes of components.
People look at dyno graphs for the wrong reasons, 99.9% of the time. Their eyes only wander to the peak output power plot, and they don;t pay attention to anything else. These people are looking at the graph in a totally *** backwards manner, because all they want is bragging rights.
This is why the Mustang dyno has the curve for converting the figures from WHP to ENG numbers.
When I send owners their dyno plots, I hear over and over "My engine made xxx from the factory, why is it only 15-20HP stronger than that now?". They do not realize they are comparing the Porsche stated flywheel power figures, to our figures that are not converted (and never will be) to flywheel figures. When we are only 15-20HP higher, that figure is really 20%+ the 15-20HP higher.
Wheel power, is wheel power, and should never use a generic curve to correct it to flywheel (Eng) power, as every car is different, and the numbers will lose accuracy, and comparability. Each car is different due to rear wheel alignment, tires, brake condition, CV point condition, transaxle wear, gear oil temperature, and type, etc, etc, on, and on.
Too often, people just want one big number, they don't look at whats really important, and what truly explains how the engine is performing. I judge engines less by peak numbers, and more by average outputs, and power figures at less than 5,251 RPM, the point where TQ and HP must always cross. To me, I am shooting for efficiency, so my BSFC, AFR, and ignition maps are most important, I want to overlay these..
If I want flywheel power figures, the engine goes on my engine dyno. Since it takes two days to set an engine up in the test cell, we reserve the engine dyno only for product and engine combination development. Its easy to change cams, heads, and etc on the engine dyno, and attain back to back figures with no drivetrain losses. Its also easier to make the changes of components.
Our dyno has notoriously been called the "heartbreaker" for years. We read exactly 10% lower than multiple dynojets in our area, and 3% to 10% lower than other local mustang dynos. 440 hp crate engines put down 300 hp on our dyno.
Not sure why tdream1's numbers are higher than what you would expect, but i will guarantee you its NOT a high reading dyno at the source.
You may actually be the first person in about 11 years to say the numbers here are higher than other dynos
06-15-2016, 04:24 PM
#37
Former Vendor
The numbers tdream1 has posted are our dyno numbers at the wheels and not calculated at the flywheel. They are the same numbers we have been using here since 2005 when the dyno was installed. The eng has no correlation to engine power. All drivetrain losses are different and one equation for calculating this would not work.
Our dyno has notoriously been called the "heartbreaker" for years. We read exactly 10% lower than multiple dynojets in our area, and 3% to 10% lower than other local mustang dynos. 440 hp crate engines put down 300 hp on our dyno.
Not sure why tdream1's numbers are higher than what you would expect, but i will guarantee you its NOT a high reading dyno at the source.
You may actually be the first person in about 11 years to say the numbers here are higher than other dynos
Our dyno has notoriously been called the "heartbreaker" for years. We read exactly 10% lower than multiple dynojets in our area, and 3% to 10% lower than other local mustang dynos. 440 hp crate engines put down 300 hp on our dyno.
Not sure why tdream1's numbers are higher than what you would expect, but i will guarantee you its NOT a high reading dyno at the source.
You may actually be the first person in about 11 years to say the numbers here are higher than other dynos
This plot is not the one that had me most confused, it was the other Mustang plot, from the 3.4 engine which were off the hook on the high side.
06-15-2016, 04:33 PM
#38
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Yes, these are values taken at the wheel and NOT corrected for the flywheel.
I have no idea why Mustang designated the term "eng power" and "eng torque" for these measurements, but if you own a couple dynos then you know they all do some really weird things
Mustang also likes to designate the lock for the front rollers as "rear lift" and the back rollers as "front lift" just to confuse the hell out of anyone trying to learn the machine...
I have no idea why Mustang designated the term "eng power" and "eng torque" for these measurements, but if you own a couple dynos then you know they all do some really weird things
Mustang also likes to designate the lock for the front rollers as "rear lift" and the back rollers as "front lift" just to confuse the hell out of anyone trying to learn the machine...