My Experience with the Difference of Road Tunes vs Dyno
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Joined: Jun 2003
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From: Orlando, FL
My Experience with the Difference of Road Tunes vs Dyno
I did an interesting comparison this weekend with my laptop hooked up to my car, while strapped on a mustang dyno. I tune fairly extensively on my own car, as well as my other buddy's Evos. My car will produce anywhere between 415-445hp using Data Log Lab software, depending on weather. At a local shop's mustang dyno, it made 373hp, which is understandable, given the reputation that mustang dynos read lower.
To give a frame of reference, before I switched to using E85 fuel, my car was producing 380hp on DLL, and it trapped 120mph in the quarter mile.
I tune my car on the road, and one data that I will monitor is the time it takes my car to go from 4000-7000rpm. Currently it takes my car 2.82 sec to go through that powerband. This data is extremely consistent and usually only varies within hundredths of a second, back to back. It's also data that is not subject to a variable mathematical algorithm, such as a dyno graph. On the dyno at Performance Race Solutions, it slowed down to 3.12s, which is significant.
What does this tell me? For one, even though you have a huge fan blowing air at the front of your car on the dyno, it still is not enough to simulate the amount of cooler, fresh air on the road that the car cuts through. The car is just sitting static on a dyno machine. Secondly, the rollers have a different rolling resistance than the road, mostly likely trying to simulate the wind drag of real world conditions. In the case of PRS, the resistance appears to be higher. And lastly, since it's hitting different loads that my car does not usually see on a road pull, my car is probably reading different load cells of my fuel/timing maps on the ECU that I have not fully tuned on the road yet.
Conclusion? Dyno numbers are just numbers. It's a great tool to use to keep things constant and to show you the changes you're making to the car, hardware or tuning-wise. Each dyno operator has his settings and levels of smoothing he uses that makes comparing numbers from one shop to another difficult. However, tuning on the road is preferable just because your actual driving is on the road, and there are other numbers better at comparing with other cars than dyno numbers.
To give a frame of reference, before I switched to using E85 fuel, my car was producing 380hp on DLL, and it trapped 120mph in the quarter mile.
I tune my car on the road, and one data that I will monitor is the time it takes my car to go from 4000-7000rpm. Currently it takes my car 2.82 sec to go through that powerband. This data is extremely consistent and usually only varies within hundredths of a second, back to back. It's also data that is not subject to a variable mathematical algorithm, such as a dyno graph. On the dyno at Performance Race Solutions, it slowed down to 3.12s, which is significant.
What does this tell me? For one, even though you have a huge fan blowing air at the front of your car on the dyno, it still is not enough to simulate the amount of cooler, fresh air on the road that the car cuts through. The car is just sitting static on a dyno machine. Secondly, the rollers have a different rolling resistance than the road, mostly likely trying to simulate the wind drag of real world conditions. In the case of PRS, the resistance appears to be higher. And lastly, since it's hitting different loads that my car does not usually see on a road pull, my car is probably reading different load cells of my fuel/timing maps on the ECU that I have not fully tuned on the road yet.
Conclusion? Dyno numbers are just numbers. It's a great tool to use to keep things constant and to show you the changes you're making to the car, hardware or tuning-wise. Each dyno operator has his settings and levels of smoothing he uses that makes comparing numbers from one shop to another difficult. However, tuning on the road is preferable just because your actual driving is on the road, and there are other numbers better at comparing with other cars than dyno numbers.
You have got to be kidding me sir....
I did an interesting comparison this weekend with my laptop hooked up to my car, while strapped on a mustang dyno. I tune fairly extensively on my own car, as well as my other buddy's Evos. My car will produce anywhere between 415-445hp using Data Log Lab software, depending on weather. At a local shop's mustang dyno, it made 373hp, which is understandable, given the reputation that mustang dynos read lower.
To give a frame of reference, before I switched to using E85 fuel, my car was producing 380hp on DLL, and it trapped 120mph in the quarter mile.
I tune my car on the road, and one data that I will monitor is the time it takes my car to go from 4000-7000rpm. Currently it takes my car 2.82 sec to go through that powerband. This data is extremely consistent and usually only varies within hundredths of a second, back to back. It's also data that is not subject to a variable mathematical algorithm, such as a dyno graph. On the dyno at Performance Race Solutions, it slowed down to 3.12s, which is significant.
What does this tell me? For one, even though you have a huge fan blowing air at the front of your car on the dyno, it still is not enough to simulate the amount of cooler, fresh air on the road that the car cuts through. The car is just sitting static on a dyno machine. Secondly, the rollers have a different rolling resistance than the road, mostly likely trying to simulate the wind drag of real world conditions. In the case of PRS, the resistance appears to be higher. And lastly, since it's hitting different loads that my car does not usually see on a road pull, my car is probably reading different load cells of my fuel/timing maps on the ECU that I have not fully tuned on the road yet.
Conclusion? Dyno numbers are just numbers. It's a great tool to use to keep things constant and to show you the changes you're making to the car, hardware or tuning-wise. Each dyno operator has his settings and levels of smoothing he uses that makes comparing numbers from one shop to another difficult. However, tuning on the road is preferable just because your actual driving is on the road, and there are other numbers better at comparing with other cars than dyno numbers.
To give a frame of reference, before I switched to using E85 fuel, my car was producing 380hp on DLL, and it trapped 120mph in the quarter mile.
I tune my car on the road, and one data that I will monitor is the time it takes my car to go from 4000-7000rpm. Currently it takes my car 2.82 sec to go through that powerband. This data is extremely consistent and usually only varies within hundredths of a second, back to back. It's also data that is not subject to a variable mathematical algorithm, such as a dyno graph. On the dyno at Performance Race Solutions, it slowed down to 3.12s, which is significant.
What does this tell me? For one, even though you have a huge fan blowing air at the front of your car on the dyno, it still is not enough to simulate the amount of cooler, fresh air on the road that the car cuts through. The car is just sitting static on a dyno machine. Secondly, the rollers have a different rolling resistance than the road, mostly likely trying to simulate the wind drag of real world conditions. In the case of PRS, the resistance appears to be higher. And lastly, since it's hitting different loads that my car does not usually see on a road pull, my car is probably reading different load cells of my fuel/timing maps on the ECU that I have not fully tuned on the road yet.
Conclusion? Dyno numbers are just numbers. It's a great tool to use to keep things constant and to show you the changes you're making to the car, hardware or tuning-wise. Each dyno operator has his settings and levels of smoothing he uses that makes comparing numbers from one shop to another difficult. However, tuning on the road is preferable just because your actual driving is on the road, and there are other numbers better at comparing with other cars than dyno numbers.
Tuning on a Dyno is great as it is safe and controlled. Tuning on the road is a bit more risky for obvious reasons but you can really tune the car for all aspects and perfect drivability without paying a bunch in Dyno time.
That said my car has never been on a Dyno for tuning and never will
That said my car has never been on a Dyno for tuning and never will
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Correct...we went through the math a few years back when a member used a wind speed gauge to show ~50mph winds blowing from the fan. Based on the calculations it equated to ~11mph when driving.
I wish more people would understand how a mustang dyno or the powerdyne software worked. If they did, it would be understood the the OP's discrepany in loading would be due to dyno setup or operator error..The dyno is not to blame here. Mustang dyno's are perfectly capable of matching road conditions 100% even down to the windspeed, live inertia,rolling and wind resistance, hell even driving down a hill. Everyone has they're own opinion, this one just happens to be alittle off base in it generalizations.
The mustang data posted is useless and corrected. The test report will tell more of the story if not all of it since it has more data.
The mustang data posted is useless and corrected. The test report will tell more of the story if not all of it since it has more data.
Last edited by PeteyTurbo@KHC; Apr 22, 2012 at 03:54 PM.
I wish more people would understand how a mustang dyno or the powerdyne software worked. If they did, it would be understood the the OP's discrepany in loading would be due to dyno setup or operator error..The dyno is not to blame here. Mustang dyno's are perfectly capable of matching road conditions 100% even down to the windspeed, live inertia,rolling and wind resistance, hell even driving down a hill. Everyone has they're own opinion, this one just happens to be alittle off base in it generalizations.
I've only been around for a few years now so I could be totally wrong in my opinnion but this is how I see it. IMHO whether you're on a real dyno or using some type of virtual dyno software on th road, the numbers shown by either need to be taken with a grain of salt. Both can give you an idea of power output but I'm not sure either can be considered completely accurate, or even one more accurate than the other. The only advantages I see to a real dyno are it's safer and you can control more of the variables which allows you to get a more accurate view of gains from mods and tuning.
The overall output numbers produced by either seem to be somewhat arbitrary IMO. Just look at the Dyno # vs 1/4 Time thread on here and you'll see what I mean. Those dyno numbers and track times are all over the place. So just because you produce a certain number on the dyno, it still doesn't give you a clear indication of how fast and powerful the car is. It kinda reminds of the wattage numbers that car audio manufacturers used to use. I remember back in the day when you could get a Rockford Fosagte amp that supposedly only put out 200 watts and it would blow the doors off it's competitors' amps claiming 2-5 times as much.
The bottomline for me is dyno numbers (real or virtual) don't mean squat without track times to back it up!
The overall output numbers produced by either seem to be somewhat arbitrary IMO. Just look at the Dyno # vs 1/4 Time thread on here and you'll see what I mean. Those dyno numbers and track times are all over the place. So just because you produce a certain number on the dyno, it still doesn't give you a clear indication of how fast and powerful the car is. It kinda reminds of the wattage numbers that car audio manufacturers used to use. I remember back in the day when you could get a Rockford Fosagte amp that supposedly only put out 200 watts and it would blow the doors off it's competitors' amps claiming 2-5 times as much.
The bottomline for me is dyno numbers (real or virtual) don't mean squat without track times to back it up!
All I got to say is "why DLL??". I know its a good program and such, but everyone and their mom use Virtual Dyno. Hard to use DLL for comparisons when no one uses it.
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From: Orlando, FL
PeteyTurbo, I do understand that it's not a mustang dyno's fault, as I did mention there's too many variables in setup and user settings when it comes to dynos. I was merely pointing out that there may be better methods to compare a car's results with other cars' results rather than dyno numbers (ie: trap speeds, 4-7000 times, etc). Far too often, I have heard people say they have 400hp when compared to another guy's 300hp, but when they race on the streets or run down the quarter mile, the guy with the 300hp wins. But with all things that are compared, you wanna keep as many things constant as possible, such as making sure you drive on the same roads, weather, etc.
From my experience, I prefer the road. With as much tuning as I've done on my own car (not to mention others' cars), those dyno fees would have racked up like no other, so it's not a practical outlet for me.
The reason why the Dyno numbers and the track times are all over the place on the list, is because that every car weighs in at different weight and so does the driver