davesax36
Well-Known Member
Still needs choke to start...
Dyno'd the bike today.
- Thread starter Traumahawk
- Start date
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Traumahawk
Well-Known Member
Well when I talked to Sean , he had asked what the humidity level was....and I guessed about 90%. I just checked......it was 100%.
Unfortunately this dyno booth is in the shop, right next to the outside bay doors.
Here is the weather that day.
Unfortunately this dyno booth is in the shop, right next to the outside bay doors.
Here is the weather that day.
Traumahawk
Well-Known Member
I received a PM earlier this evening from AsherC. Great guy BTW. One of the things that he noticed was that on some of my runs STD smoothing was used, and on my last run SAE smoothing was used. He was curious if that would make any difference in my dyno numbers, and I said that I didnt know. So.....I went looking to see what the difference was between the two.
Here is a copy of a post that I found that really made it easy to understand, and so Ive copied it here.
I borrowed this a cobalt forum, it explains it pretty good. SAE is the standard.
There are few standards used in the dyno world for gathering HP and TQ numbers, UNCORRECTED, SAE and STD. Uncorrected is NEVER accepted in the world of dynoing and tuning as it does not factor in any weather conditions etc. Now here is where the big debate comes...is between SAE and STD. SAE (Society of Automotive Engineers) is the MOST ACCURATE AND WIDELY ACCEPTED FORM OF MEASUREMENT when it comes to the world of dynoing. Here is some more info I have gathered between the two.....
A lot of people have been asking about SAE .vs STD Dyno numbers so I thought this would help. Most people know that showing STD numbers read higher but not many know why. SAE represents more realistic standard conditions, STD artificially boosts numbers.
Identifying Your Correction Factor:
Dynojet:
If you look at a dynojet graph in the upper right corner, you will see where it says the correction method being used. The options are SAE, STD, Uncorrected and a few not needed for discussion. You will also notice a smooth factor (up to 5) which dyno operators use to make the power curves and any other data displayed, such as AFR, seem more accurate and smooth. You will also see AFR graphs scaled DOWN to hide flaws in the curve.
MD:
A Mustang Dyno ONLY uses SAE Corrections. Smoothing can also be controlled as well as scale for the Graphical Outputs.
Overview:
Most of the stated horsepower numbers are “Corrected” values. The correction standards were developed to discount the observed horsepower readings taken at different locations and weather conditions. It is obvious that an engine builder in Colorado could not produce as much horsepower as a shop at sea level. There is just less oxygen for the engine to burn at the higher altitude. What are less obvious are the other weather condition effects on the engine. So in order to compensate for this all advertised horsepower is “corrected” to several different industry standards.
SAE:
"SAE (Society of Automotive Engineers), USA. Power is corrected to reference conditions of 29.23 InHg (99 kPa) of dry air and 77 F (25°C). This SAE standard requires a correction for friction torque.
STD:
STD is Another power correction standard determined by the SAE. Power is corrected to reference conditions of 29.92 InHg (103.3 kPa) of dry air and 60 F (15.5°C). Because the reference conditions include higher pressure and cooler air than the SAE standard, these corrected power numbers will always be about 4 % higher than the SAE power numbers. Friction torque is handled in the same way as in the SAE standard."
Here is some quick math (using assumptions and round numbers):
STD:
Air Temperature: 60F
Absolute Pressure: 29.92 inches Hg
Relative Humidity: 0%
Relative Horsepower : 104.8%
Air Density: 1.223kg/m3
Relative Air Density: 99.8%
Density Altitude: 67feet
Virtual Temperature: 60F
Vapor Pressure: 0 inches Hg
Dyno Correction Factor: .955
SAE:
Air Temperature: 77F
Absolute Pressure: 29.23 inches Hg
Relative Humidity: 0%
Relative Horsepower : 100%
Air Density: 1.157kg/m3
Relative Air Density: 94.4%
Density Altitude: 1952feet
Virtual Temperature: 77F
Vapor Pressure: 0 inches Hg
Dyno Correction Factor: 1
Here is a copy of a post that I found that really made it easy to understand, and so Ive copied it here.
I borrowed this a cobalt forum, it explains it pretty good. SAE is the standard.
There are few standards used in the dyno world for gathering HP and TQ numbers, UNCORRECTED, SAE and STD. Uncorrected is NEVER accepted in the world of dynoing and tuning as it does not factor in any weather conditions etc. Now here is where the big debate comes...is between SAE and STD. SAE (Society of Automotive Engineers) is the MOST ACCURATE AND WIDELY ACCEPTED FORM OF MEASUREMENT when it comes to the world of dynoing. Here is some more info I have gathered between the two.....
A lot of people have been asking about SAE .vs STD Dyno numbers so I thought this would help. Most people know that showing STD numbers read higher but not many know why. SAE represents more realistic standard conditions, STD artificially boosts numbers.
Identifying Your Correction Factor:
Dynojet:
If you look at a dynojet graph in the upper right corner, you will see where it says the correction method being used. The options are SAE, STD, Uncorrected and a few not needed for discussion. You will also notice a smooth factor (up to 5) which dyno operators use to make the power curves and any other data displayed, such as AFR, seem more accurate and smooth. You will also see AFR graphs scaled DOWN to hide flaws in the curve.
MD:
A Mustang Dyno ONLY uses SAE Corrections. Smoothing can also be controlled as well as scale for the Graphical Outputs.
Overview:
Most of the stated horsepower numbers are “Corrected” values. The correction standards were developed to discount the observed horsepower readings taken at different locations and weather conditions. It is obvious that an engine builder in Colorado could not produce as much horsepower as a shop at sea level. There is just less oxygen for the engine to burn at the higher altitude. What are less obvious are the other weather condition effects on the engine. So in order to compensate for this all advertised horsepower is “corrected” to several different industry standards.
SAE:
"SAE (Society of Automotive Engineers), USA. Power is corrected to reference conditions of 29.23 InHg (99 kPa) of dry air and 77 F (25°C). This SAE standard requires a correction for friction torque.
STD:
STD is Another power correction standard determined by the SAE. Power is corrected to reference conditions of 29.92 InHg (103.3 kPa) of dry air and 60 F (15.5°C). Because the reference conditions include higher pressure and cooler air than the SAE standard, these corrected power numbers will always be about 4 % higher than the SAE power numbers. Friction torque is handled in the same way as in the SAE standard."
Here is some quick math (using assumptions and round numbers):
STD:
Air Temperature: 60F
Absolute Pressure: 29.92 inches Hg
Relative Humidity: 0%
Relative Horsepower : 104.8%
Air Density: 1.223kg/m3
Relative Air Density: 99.8%
Density Altitude: 67feet
Virtual Temperature: 60F
Vapor Pressure: 0 inches Hg
Dyno Correction Factor: .955
SAE:
Air Temperature: 77F
Absolute Pressure: 29.23 inches Hg
Relative Humidity: 0%
Relative Horsepower : 100%
Air Density: 1.157kg/m3
Relative Air Density: 94.4%
Density Altitude: 1952feet
Virtual Temperature: 77F
Vapor Pressure: 0 inches Hg
Dyno Correction Factor: 1
Traumahawk
Well-Known Member
SAE to STD should be +2.6xxx% difference no matter where you are located.
Eric, if you can get the raw data from the operator you can download the dynojet application to run on your pc and play around with the various settings and overlay any runs you want.
Traumahawk
Well-Known Member
Well the carbs that Danny rebuilt for me are at the post office waiting for me, unfortunately I am at work.
It will be interesting to see how much differently they will run, and being cleaned up, and having the floats significantly LEANED out. The carbs that I sent him, I never got into (besides changing the jets). From what Danny told me, the floats were WAY RICH from the factory.
So....they only thing that has been changed, is the float level, and now will be time to dyno again....and see what the results are. I'm gonna try an dyno next weekend.
It will be interesting to see how much differently they will run, and being cleaned up, and having the floats significantly LEANED out. The carbs that I sent him, I never got into (besides changing the jets). From what Danny told me, the floats were WAY RICH from the factory.
So....they only thing that has been changed, is the float level, and now will be time to dyno again....and see what the results are. I'm gonna try an dyno next weekend.
Traumahawk
Well-Known Member
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Last edited:
Just my opinion....I would not run a bike at an AFR of 14 at WOT. It's not worth burning a valve or worse for 1 or 2 HP. It would be OK to approach that in the cruise range to increase mileage
I know you are just experimenting and appreciate all of the effort you're putting in to this.
I know you are just experimenting and appreciate all of the effort you're putting in to this.
Traumahawk
Well-Known Member
Well after AsherC and SpecOps have had runs at 14....I figured why not? I also talked to others....and they have said that the Vmax likes 14. I'm like you....I'm used to 13, but I'm there...so why not?
Traumahawk
Well-Known Member
Now....i'm starting to wonder if I'm over looking something? The valves were done by a pretty good mechanic about 14000 miles ago.
Traumahawk
Well-Known Member
Thats the reason why I like posting things.....the good....and the notso good....so this way information is shared....and everyone learns.
14 wont hurt but try 13 and should see an improvement.
Traumahawk
Well-Known Member
Well last night got bored....and decided to change out the carb boots....for some new ones that I got from Sean. The old ones are hard.....and I cant get the carbs to seat fully. They are still probably 2 mm above where they should be.
So....I started pulling everything apart....and noticed something interesting. I dyno'd the bike this last Sat....and to save time putting everything together, I tightened up everything on the right, and the dyno operator tightened up everything on the left....although....nothing was tight. Not the airbox boots....not the carb boots....nothing.
Gee....and I wonder why my HP numbers DIDNT COME UP. Do you ever get the feeling that its better off to do things yourself....because others DONT take the time and effort that you do?
So....I started pulling everything apart....and noticed something interesting. I dyno'd the bike this last Sat....and to save time putting everything together, I tightened up everything on the right, and the dyno operator tightened up everything on the left....although....nothing was tight. Not the airbox boots....not the carb boots....nothing.
Gee....and I wonder why my HP numbers DIDNT COME UP. Do you ever get the feeling that its better off to do things yourself....because others DONT take the time and effort that you do?
adambweird
Well-Known Member
Well hell, that alone should be worth close to 20hp and perfect afr numbers, lol. Thats a big reason why i dont like/let anyone be me wrench on my stuff. Theres only a select few i trust with stuff like that and a very select few that i would trust if the opportunity came up.
Traumahawk
Well-Known Member
Well the only reason that I THOUGHT that he could handle the job is that I've been dynoing there for over a year. ..and he has experience with harleys and ducatis. Plus....I was being charged 95 dollars an hour. I tried to save money....and it came back to bite me.
mdfb42
Well-Known Member
Good thread to read. But right now it's seems like an unfinished book. Any update on the progression of the bike and the results?
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