Dyno chart smoothing? Does it make a difference? See for yourself...
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Sounds good. Since the summer tires make my gearing noticably taller, I was worried they might also lower my measured power significantly. But I must admit I'm not too clear on the math involved.MarcyMotorsport said:
Plus I want to look cool for the dyno day
You know what I must apologize for my friend that was using my computer at the shop, he was waiting for his car to be done and we were talking about this thread and I did not want it to get out of hand. He put some stuff and then deleted and then retyped information. He figured on having some fun with the people he used deal with at EuroSport. My bad for leaving the computer logged in. But atleast he was happy with his new turbo kit on his new car!
So I am sorry for his action, believe me I want to stay away from any posts that have FS in them....just some lessons learned.
And I know that the car needs a little more work and Juan is working on another file and I expect a little more power with the file and the 3" exhaust.
So I am sorry for his action, believe me I want to stay away from any posts that have FS in them....just some lessons learned.
And I know that the car needs a little more work and Juan is working on another file and I expect a little more power with the file and the 3" exhaust.
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The funny thing about all this talk about smoothing is that it is a function of the software related to the visual display. One guy wants a nice smooth curve like the one he saw from an OE for a stock engine in a new car brochure, the next guy is tuning the living daylights out of his race car and wants precision details to see the best picture of what is actually going on during the run. The software engineers who design the dyno software have to create some balance that makes everyone happy.
Now, from a perspective of a dyno manufacturer, and since that's a field I'm sort of involved in, there are some deeper things going on than the smoothing bar sufrace that was scratched here. Every dyno manufacturer faces the same issue: Accurately converting analog datastreams collected from the machine and the vehicle into measured horsepower and torque and displaying them in a meaningful format that can be easily interpreted.
Depending on the dyno manufacturer, this data can be at a rate of 8hz to 100hz. The obvious thought would be that the more data you can collect, the more accurate the graph will be. Unfortunately, this is not the case. If you displayed the raw data on the screen, the power curve would look like a fuzzy bold line and show the power to be in a closely oscilating range of up to 200-300hp at any given engine speed on a 750hp car. The fact is, with increased accuracy, you can actually measure the spikes from each individual combustion event, and in fact see the angular accelleration in the engine itself. This is really cool if you are looking for a misfire or something truly bizarre like the cause of repeated cracked crankshafts in your combination, but thats another subject.
The key to this entire argument is that software (and in some cases firmware and hardware) engineers have created filters that reduce the amount of measured data to as little as 1/100th of the actual data collected. Also, to show the curve as it is generally dispayed by dyno manufacturers, there are averaging calculations built into the software that take high and low values of the oscillation and find a median average.
The data you see when you look at a dyno sheet is actually very much controled by the company that produces the dyno. Every dyno manufacturer has it's own staff of engineers that decide for us what we see from their equipment, and this is why the argument exists over which dyno produces the most accurate numbers. The simple fact is, no dyno is 100% accurate as a result of filtering and averaging, and depending on the company, how the data is presented. The best you can hope for is a good "sample" of the data that you can use to your benefit in some way or other.
Now, from a perspective of a dyno manufacturer, and since that's a field I'm sort of involved in, there are some deeper things going on than the smoothing bar sufrace that was scratched here. Every dyno manufacturer faces the same issue: Accurately converting analog datastreams collected from the machine and the vehicle into measured horsepower and torque and displaying them in a meaningful format that can be easily interpreted.
Depending on the dyno manufacturer, this data can be at a rate of 8hz to 100hz. The obvious thought would be that the more data you can collect, the more accurate the graph will be. Unfortunately, this is not the case. If you displayed the raw data on the screen, the power curve would look like a fuzzy bold line and show the power to be in a closely oscilating range of up to 200-300hp at any given engine speed on a 750hp car. The fact is, with increased accuracy, you can actually measure the spikes from each individual combustion event, and in fact see the angular accelleration in the engine itself. This is really cool if you are looking for a misfire or something truly bizarre like the cause of repeated cracked crankshafts in your combination, but thats another subject.
The key to this entire argument is that software (and in some cases firmware and hardware) engineers have created filters that reduce the amount of measured data to as little as 1/100th of the actual data collected. Also, to show the curve as it is generally dispayed by dyno manufacturers, there are averaging calculations built into the software that take high and low values of the oscillation and find a median average.
The data you see when you look at a dyno sheet is actually very much controled by the company that produces the dyno. Every dyno manufacturer has it's own staff of engineers that decide for us what we see from their equipment, and this is why the argument exists over which dyno produces the most accurate numbers. The simple fact is, no dyno is 100% accurate as a result of filtering and averaging, and depending on the company, how the data is presented. The best you can hope for is a good "sample" of the data that you can use to your benefit in some way or other.
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Good info guys, thanks and keep up the good work, be yourselves, and above all be honest. Thanks again!
Ok this is very eye opening and I never even knew this stuffmattered, I guess this is the begining of aHP war? then i got to thinking. As a bicycle racer in my real life i use a thing called a Power Tap or a tool for measuring watts or human HP, one of the things they tell you to do ever once in a while is to smooth it out? You see after a work out you down load it to your PC to see how you preformed, almost like a dyno, I know it's not related but sort of. People Like Focussport (Andy) will not make false numbers, this is something that could come back and bite you, Numbers are numbers, hanging around a dyno for maney days in Tampa on e summer I learned and saw so meney things that can inflence numbers, heat, tune, I could go on and on, but I am no expert far from it, I just find it all so fascinating. The one big thing I saw repeatedly was posa dont work with a turbo, cold air intakes made much better numbers, the engine heat and a pod dont mix, a least on a STI / WRX, they (Pro Drive) said a header will not help and dont do it, I just could not accept that and put one on . 7 HP later i was smiling, not big but it all adds up.
in regards to gearing, and feel free to ignore it if i should only be talking about smoothing. but in my atx (where there is never anything really near 1:1) the higher the gear, the "bumpier" the graph gets. this was even at the dyno day where a quick 2nd gear pull happened to be on with my final pull. seen it on a few dyno's now. this would mostly me do the fact, if what i'm reading is correct and it sounds that way, since it takes longer to go through the revs you see a bit more variance....more chance to show those small variances? the #'s tend to not vary that much, but the look of the graph does....am i understanding that part correctly?
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Yep, essentially correct, you could also set the data acquire time if you wanted, usually its 10-15s, I've seen 30s runs than they tend to be REAL hard on cars.MrTea said:
[off topic]
So are you going to build a motor like focussports?
[/off topic]
good luck
-bix
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Third gear in the 4F27-E Ford Duratec 4-speed automatic transaxle is a 1:1 ratio*. With the torque convertor locking it's clutch through approximately 55 MPH, it is then a true 1:1. With all due respect
to Mr. Tea, I expect the Mazda variant to be very similar.However, one cannot dyno the ATX car in third because the speed limiter would shut the car down at 106 MPH wheel speed (two-thirds through the run)... so the ATX is dyno'd in second and with no torque convertor lockup, the second gear's planetary gear ratio becomes somewhat vague effectively.
*1st - 2.82
2nd - 1.50
3rd - 1.00
4th - .726 (overdrive)
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Hopefully Mr. Marcy can answer another question for me. A talk I had with a shop owner leads me to believe Walter may be specifically well-qualified for it.
I've always heard that, for instance, a Mustang dyno will read lower than a Dynojet dyno, and that Dynojet is generally the standard of measurement. How does a Dynocom weigh in?
I've always heard that, for instance, a Mustang dyno will read lower than a Dynojet dyno, and that Dynojet is generally the standard of measurement. How does a Dynocom weigh in?
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I don't see anything wrong with his astute observation and brilliant comment, in fact, I thought his post was rather funny. I guess it's just a matter of opinion. We are allowed an opinion, aren't we?goldse said:
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Yes, I'd rather look Past what was said and not make a big deal about it and get back on topic, Me.... Myself Would leave it alone, It was a suggestion thats all
I'm not trying to "Hush" everyone I'm just saying it's like adding gasoline to an already lit flame and your holding the tank :lol:
I'm not trying to "Hush" everyone I'm just saying it's like adding gasoline to an already lit flame and your holding the tank :lol:
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I'm driving the tank :lol:
Yea, I gotta agree that we should just let this die. It is what it is, and at this point it doesn't matter what else gets said, none of our minds are going to be changed one way or the other about what just happened here. Lets have some class and flame someone in a [PJ] thread instead.
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