gettinng dyno'd tomorrow
9/14/06, 06:24 PM
#21
Team Mustang Source
Thread Starter
Join Date: August 3, 2005
Location: Mustang/Tuttle, Oklahoma
Posts: 1,652
Likes: 0
Received 2 Likes
on
2 Posts
Originally Posted by TacoBill
Rob, how much did the dyno session run? How many pulls did it include?
And finally, who does the pulling behind the wheel?
And finally, who does the pulling behind the wheel?
9/14/06, 06:45 PM
#22
Bullitt Member
Join Date: December 28, 2004
Posts: 398
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Bullitt995
Well if you change the rear end ratio 4th isn't going to be exactly 1:1 now is it? 
9/14/06, 09:46 PM
#23
Originally Posted by OKLACOP
$75.00, three runs, and Jim the tuner at southwest tuning was behind the wheel. I was taking pics and video, that I can't seem to download onto the thread. www.swtuning.com
Can you upload them on YouTube or Streetfire? Must register for both, but it's free.
9/15/06, 07:39 AM
#25
I found this article that talked about chasis dyno's.
... Aside from the usual testing variances, results obtained on different dyno’s of the same manufacturer are generally very close. A comparison of results between different manufacturer’s dyno’s e.g., Dynojet and Mustang will show some variation possibly up to 5% of the whp reading.
Reference article
Up to 5% difference in RWHP readings between dyno's? And some experience higher differences than that? It's no wonder why these numbers frustrate people.
... Aside from the usual testing variances, results obtained on different dyno’s of the same manufacturer are generally very close. A comparison of results between different manufacturer’s dyno’s e.g., Dynojet and Mustang will show some variation possibly up to 5% of the whp reading.
Reference article
Up to 5% difference in RWHP readings between dyno's? And some experience higher differences than that? It's no wonder why these numbers frustrate people.
9/15/06, 07:55 AM
#26
Legacy TMS Member
Originally Posted by 65sohc
Changing the rear end ratio has no effect on the transmission. The 1:1 ratio refers to the speed of the transmission input shaft in relation to the output shaft. Changing the rear end ratio only affects the relationship between the driveshaft and the drive axles. Get it?
I would guess that OKLACOP's numbers would probably be around 280 on a standard dynojet, with standard (stock) gears.
Tom
9/15/06, 09:40 AM
#27
Team Mustang Source
Thread Starter
Join Date: August 3, 2005
Location: Mustang/Tuttle, Oklahoma
Posts: 1,652
Likes: 0
Received 2 Likes
on
2 Posts
Originally Posted by icemant180
Rob, with the C&L and a custom tune shouldn't your number be closer to 280+rwhp?
I am disappointed in the numbers, but I was told they were gonna be low before hand since it was a Mustang Dyno.
9/15/06, 10:20 AM
#28
Join Date: February 2, 2006
Posts: 1,405
Likes: 0
Received 0 Likes
on
0 Posts
I would send a printout of your dyno run to Lidio and see what he thinks about it. Where was your air fuel ratio at?
9/15/06, 09:31 PM
#30
V6 Member
Join Date: June 5, 2006
Posts: 82
Likes: 0
Received 0 Likes
on
0 Posts
Rear-end gears has no effect on peak horsepower and torque. In other words you can not lose or gain horsepower and torque due to rear-end gears other then any weight difference they may be from one gear set to another and then the horsepower and torque difference would be so minute you would never know.
Now, rear-end gears could change your horsepower and torque curve, thats to say it could change were you see your peak horsepower and torque...
Now, rear-end gears could change your horsepower and torque curve, thats to say it could change were you see your peak horsepower and torque...
9/16/06, 10:47 AM
#31
Bullitt Member
Join Date: June 7, 2006
Location: Florida
Posts: 498
Likes: 0
Received 0 Likes
on
0 Posts
Those seem pretty low for your mods, I too think you would be closer to to 280rwhp. Did you ask them how long it had been since they had lubricated their rollers. I know when I had my Corvette dynoed, the numbers at one time went down, after we dynoed it a couple of months later after we had added some more mods, and it had even cooled down. They said that the amount of lube on the rollers can make a difference. 
Mustang dynos do tend to give lown numbers than dyno jets do.
Mustang dynos do tend to give lown numbers than dyno jets do.
9/16/06, 06:02 PM
#33
Legacy TMS Member
Originally Posted by Sonic Boom NH
Rear-end gears has no effect on peak horsepower and torque. In other words you can not lose or gain horsepower and torque due to rear-end gears other then any weight difference they may be from one gear set to another and then the horsepower and torque difference would be so minute you would never know.
Now, rear-end gears could change your horsepower and torque curve, thats to say it could change were you see your peak horsepower and torque...
Now, rear-end gears could change your horsepower and torque curve, thats to say it could change were you see your peak horsepower and torque...
9/17/06, 12:05 AM
#35
Member
Join Date: September 16, 2006
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
The difference between the mustang and dynojets, if both are calibrated correctly, the weather is input correct (or station calibrated correctly), the numbers will actually be 8-12% different on these and sn95 cars. The auto does eat some more power(3-5%) usually. Many mustang dyno owners will also tweak their dynos to purposely read high, because many folks like to *****, with their "bad dyno defense".
Since a dynojet only loads about 2500-2700# of load on your car, you can see that the dirtier the vehicle aerodynamically is, and the more it weighs, the more erroneously high the numbers will be, and the AFR(often sampled incorrectly, as well), and the tune, if done on one, will be inaccurate for these discrepancies in accurate testing. This where we come up with the term "dyno queen". Big numbers at the dyno, but no driveability or faster times at the track.
As far as any questionability of SWTUNING's dyno accuracy, it is less than 6 months old (they only need to be lubed once every year, even when they get used alot), and it is checked for calibration, parasitic losses (also done with some vehicles in each test session-drag radials, when gummy, eat lots of power) every week, and the weather is updated every 15-30 minutes, with a laboratory grade weather station, IN THE DYNO BAY.
Lower gears do lower the power numbers, but very little, like 1-3%. The power is read by stretching the load cell against the force of the rotating mass, made accurate with the load absorber, and not loading the car enough, or lowering the gears make it work less, stretch less. If a vehicle is struggling in 4th (or 1:1) gear, then the testing (and tuning) is done in the next lower gear. Bottom line, the vehicle needs to be worked hard, but not to the point of struggling to have an effective and accurate test run. The automatic is simply run in drive, and the highest power numbers, regardless of gear they are sampled in, and it cannot get any simpler than that.
When I tune, I will lock a vehicle in gear(when necessary), but not on a test without a tune.
As far as the tune accuracy, unless a FULL and complete datalog is performed with the test, it's just an AFR and power pull. Yes, if you hear detonation, you know it's not safe, but you can be in knock retard, and never know it, just by running a simple WOT test, and even then, you are not sampling any PT, steady state, transition test data. This even a worse problem with GEN3/4 GM's, whereas, they will learn knock, and bias to a lower timing number, further fooling a laymen or a nooby tuner. To accurately test another tune there, you really need to reset knock learn.
As far who's tune is better, whatnot, it's pretty much like 2 different beers. They both tell you they are great, but an accurate comparision can be made when both are drank. That make sense?
EACH VEHICLE IS UNIQUE, AND EACH TUNE, TO BE 100% EFFECTIVE, NEEDS TO BE PERFORMED BY AN EXPERIENCED, PROFESSIONAL TUNER, IN A REAL-WORLD ENVIRONMENT. In 16 years, I have NEVER, ever, written the same tune twice, for this reason.
In summary, the numbers mean nothing, from the standpoint that the dyno is a tool, it's job is to provide a real world testbed, for a competent tuner to do his job. The results when it LEAVES the dyno is the only thing that matters.
HTH unfuzzy some things for you guys.
Jim
Since a dynojet only loads about 2500-2700# of load on your car, you can see that the dirtier the vehicle aerodynamically is, and the more it weighs, the more erroneously high the numbers will be, and the AFR(often sampled incorrectly, as well), and the tune, if done on one, will be inaccurate for these discrepancies in accurate testing. This where we come up with the term "dyno queen". Big numbers at the dyno, but no driveability or faster times at the track.
As far as any questionability of SWTUNING's dyno accuracy, it is less than 6 months old (they only need to be lubed once every year, even when they get used alot), and it is checked for calibration, parasitic losses (also done with some vehicles in each test session-drag radials, when gummy, eat lots of power) every week, and the weather is updated every 15-30 minutes, with a laboratory grade weather station, IN THE DYNO BAY.
Lower gears do lower the power numbers, but very little, like 1-3%. The power is read by stretching the load cell against the force of the rotating mass, made accurate with the load absorber, and not loading the car enough, or lowering the gears make it work less, stretch less. If a vehicle is struggling in 4th (or 1:1) gear, then the testing (and tuning) is done in the next lower gear. Bottom line, the vehicle needs to be worked hard, but not to the point of struggling to have an effective and accurate test run. The automatic is simply run in drive, and the highest power numbers, regardless of gear they are sampled in, and it cannot get any simpler than that.
When I tune, I will lock a vehicle in gear(when necessary), but not on a test without a tune.
As far as the tune accuracy, unless a FULL and complete datalog is performed with the test, it's just an AFR and power pull. Yes, if you hear detonation, you know it's not safe, but you can be in knock retard, and never know it, just by running a simple WOT test, and even then, you are not sampling any PT, steady state, transition test data. This even a worse problem with GEN3/4 GM's, whereas, they will learn knock, and bias to a lower timing number, further fooling a laymen or a nooby tuner. To accurately test another tune there, you really need to reset knock learn.
As far who's tune is better, whatnot, it's pretty much like 2 different beers. They both tell you they are great, but an accurate comparision can be made when both are drank. That make sense?
EACH VEHICLE IS UNIQUE, AND EACH TUNE, TO BE 100% EFFECTIVE, NEEDS TO BE PERFORMED BY AN EXPERIENCED, PROFESSIONAL TUNER, IN A REAL-WORLD ENVIRONMENT. In 16 years, I have NEVER, ever, written the same tune twice, for this reason.
In summary, the numbers mean nothing, from the standpoint that the dyno is a tool, it's job is to provide a real world testbed, for a competent tuner to do his job. The results when it LEAVES the dyno is the only thing that matters.
HTH unfuzzy some things for you guys.
Jim
9/17/06, 02:01 AM
#36
Team Mustang Source
Thread Starter
Join Date: August 3, 2005
Location: Mustang/Tuttle, Oklahoma
Posts: 1,652
Likes: 0
Received 2 Likes
on
2 Posts
Originally Posted by twinturbo
The difference between the mustang and dynojets, if both are calibrated correctly, the weather is input correct (or station calibrated correctly), the numbers will actually be 8-12% different on these and sn95 cars. The auto does eat some more power(3-5%) usually. Many mustang dyno owners will also tweak their dynos to purposely read high, because many folks like to *****, with their "bad dyno defense".
Since a dynojet only loads about 2500-2700# of load on your car, you can see that the dirtier the vehicle aerodynamically is, and the more it weighs, the more erroneously high the numbers will be, and the AFR(often sampled incorrectly, as well), and the tune, if done on one, will be inaccurate for these discrepancies in accurate testing. This where we come up with the term "dyno queen". Big numbers at the dyno, but no driveability or faster times at the track.
As far as any questionability of SWTUNING's dyno accuracy, it is less than 6 months old (they only need to be lubed once every year, even when they get used alot), and it is checked for calibration, parasitic losses (also done with some vehicles in each test session-drag radials, when gummy, eat lots of power) every week, and the weather is updated every 15-30 minutes, with a laboratory grade weather station, IN THE DYNO BAY.
Lower gears do lower the power numbers, but very little, like 1-3%. The power is read by stretching the load cell against the force of the rotating mass, made accurate with the load absorber, and not loading the car enough, or lowering the gears make it work less, stretch less. If a vehicle is struggling in 4th (or 1:1) gear, then the testing (and tuning) is done in the next lower gear. Bottom line, the vehicle needs to be worked hard, but not to the point of struggling to have an effective and accurate test run. The automatic is simply run in drive, and the highest power numbers, regardless of gear they are sampled in, and it cannot get any simpler than that.
When I tune, I will lock a vehicle in gear(when necessary), but not on a test without a tune.
As far as the tune accuracy, unless a FULL and complete datalog is performed with the test, it's just an AFR and power pull. Yes, if you hear detonation, you know it's not safe, but you can be in knock retard, and never know it, just by running a simple WOT test, and even then, you are not sampling any PT, steady state, transition test data. This even a worse problem with GEN3/4 GM's, whereas, they will learn knock, and bias to a lower timing number, further fooling a laymen or a nooby tuner. To accurately test another tune there, you really need to reset knock learn.
As far who's tune is better, whatnot, it's pretty much like 2 different beers. They both tell you they are great, but an accurate comparision can be made when both are drank. That make sense?
EACH VEHICLE IS UNIQUE, AND EACH TUNE, TO BE 100% EFFECTIVE, NEEDS TO BE PERFORMED BY AN EXPERIENCED, PROFESSIONAL TUNER, IN A REAL-WORLD ENVIRONMENT. In 16 years, I have NEVER, ever, written the same tune twice, for this reason.
In summary, the numbers mean nothing, from the standpoint that the dyno is a tool, it's job is to provide a real world testbed, for a competent tuner to do his job. The results when it LEAVES the dyno is the only thing that matters.
HTH unfuzzy some things for you guys.
Jim
Since a dynojet only loads about 2500-2700# of load on your car, you can see that the dirtier the vehicle aerodynamically is, and the more it weighs, the more erroneously high the numbers will be, and the AFR(often sampled incorrectly, as well), and the tune, if done on one, will be inaccurate for these discrepancies in accurate testing. This where we come up with the term "dyno queen". Big numbers at the dyno, but no driveability or faster times at the track.
As far as any questionability of SWTUNING's dyno accuracy, it is less than 6 months old (they only need to be lubed once every year, even when they get used alot), and it is checked for calibration, parasitic losses (also done with some vehicles in each test session-drag radials, when gummy, eat lots of power) every week, and the weather is updated every 15-30 minutes, with a laboratory grade weather station, IN THE DYNO BAY.
Lower gears do lower the power numbers, but very little, like 1-3%. The power is read by stretching the load cell against the force of the rotating mass, made accurate with the load absorber, and not loading the car enough, or lowering the gears make it work less, stretch less. If a vehicle is struggling in 4th (or 1:1) gear, then the testing (and tuning) is done in the next lower gear. Bottom line, the vehicle needs to be worked hard, but not to the point of struggling to have an effective and accurate test run. The automatic is simply run in drive, and the highest power numbers, regardless of gear they are sampled in, and it cannot get any simpler than that.
When I tune, I will lock a vehicle in gear(when necessary), but not on a test without a tune.
As far as the tune accuracy, unless a FULL and complete datalog is performed with the test, it's just an AFR and power pull. Yes, if you hear detonation, you know it's not safe, but you can be in knock retard, and never know it, just by running a simple WOT test, and even then, you are not sampling any PT, steady state, transition test data. This even a worse problem with GEN3/4 GM's, whereas, they will learn knock, and bias to a lower timing number, further fooling a laymen or a nooby tuner. To accurately test another tune there, you really need to reset knock learn.
As far who's tune is better, whatnot, it's pretty much like 2 different beers. They both tell you they are great, but an accurate comparision can be made when both are drank. That make sense?
EACH VEHICLE IS UNIQUE, AND EACH TUNE, TO BE 100% EFFECTIVE, NEEDS TO BE PERFORMED BY AN EXPERIENCED, PROFESSIONAL TUNER, IN A REAL-WORLD ENVIRONMENT. In 16 years, I have NEVER, ever, written the same tune twice, for this reason.
In summary, the numbers mean nothing, from the standpoint that the dyno is a tool, it's job is to provide a real world testbed, for a competent tuner to do his job. The results when it LEAVES the dyno is the only thing that matters.
HTH unfuzzy some things for you guys.
Jim
I'm glad you posted that. I hope I didn't give the impression that I was unhappy with the dyno at swtuning, I'm just unhappy with my particular tune, which is why you have all of my future business and I can't wait for you to custom tune my car.
9/18/06, 08:09 AM
#37
Member
Join Date: September 16, 2006
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
No, that was for clarity and hopefully, the elimination or minimization of speculation on the concept of operation and dyno design and EXACTLY why output dyno numbers vary. Speculation without knowledge is not an effective use of time.
jim
jim
9/18/06, 09:24 AM
#38
Team Mustang Source
Thread Starter
Join Date: August 3, 2005
Location: Mustang/Tuttle, Oklahoma
Posts: 1,652
Likes: 0
Received 2 Likes
on
2 Posts
Originally Posted by twinturbo
No, that was for clarity and hopefully, the elimination or minimization of speculation on the concept of operation and dyno design and EXACTLY why output dyno numbers vary. Speculation without knowledge is not an effective use of time.
jim
jim
Thread
Thread Starter
Forum
Replies
Last Post
unnoticedtrails
Repair and Service Help
30
7/17/17 11:10 AM