Dyno Tricks To Be Aware Of

[merc]

Having spent time on the dyno in Georgia, PA, Virginia, and NJ. I have always wanted to know why they differ so widely. Below are some of the answers. Some of you have had similar experiences.

The Story Behind the Dynojet Chassis Dyno. This is a excellent read if you have the time.
http://hotrod.automotive.com/23395/113-0603-dynojet-chassis-dyno/index.html

Beat the Drum
The crooked dyno operator can reprogram the weight of the drum, which will allow the dyno to create anomalous power numbers.

The High Ground
The same crooked dyno operator could elect to change the elevation value in the computer, which would have a critical impact in power generation. Naturally aspirated engines are especially susceptible to this ploy.

Change Load
Changing the load by tightening or loosening the tie-down between runs can compromise any comparisons made with the dyno testing.

Different Day Dynoing
This one can be hard to avoid if you are having extensive work done. Check to see if the dyno in question has a weather station that can correct for any big differences. Beyond that try to arrange testing for about the same time of day as baseline runs were performed. This will lessen the effect.

Correction Factor
A key element to producing comparable dyno charts on a global basis is the Correction Factor, SAE Standard J1349, which applies the following weather station data--atmospheric pressure 29.23, air temperature 77 degrees Fahrenheit and humidity 0 percent--to all tests. These exact figures allow apples-to-apples comparison of runs from different cars, different facilities, etc. So graphs with SAE-corrected power were made to this standard. The dyno in question must have a weather station and the proper software in order to generate SAE-corrected data.

Smoothing
An option on Dynojets, smoothing takes a jagged graph and delivers a more readable curve. Smoothing of the graph can be done by entering a value between one and four at the appropriate place in the computer.

Alignment
The alignment of the vehicle being tested does affect the outcome of a dyno test. So if a car is dyno'd, then run over a curb, thus altering the toe or camber, the car may not have repeatable runs. This is especially true on Dynojets.

[O's Fan Rich]

That's why it's always best to use the same dyno to compare.

Good info Merc!

[ctrlraven]

Good info Merc, thanks.

[DOOM]

:lol: :laugh:

[merc]

That's why it's always best to use the same dyno to compare.

Good info Merc!

Check this out Rich. I have personally seen lazy operators not change the value of the weight or ask.

http://forums.corvetteforum.com/performance-results/1358862-dynojet-vs-mustang-dyno.html

One of a perf. shops little tricks, change the vehicle weight input, even by a hundred pounds will skew the numbers quite a bit to show the part they just sold you did something for HP.

I dont have a problem w/ either one, they are both industry leaders(I just happen to prefer DJ) The main problem is inept or corrupt operators. If you go on a Load Control Dyno, your car better be weighed, with the person in it doing the testing. Go over all the parameters with the operator to make sure you are getting what you paid for.

[merc]

This is a old tread but unearths some old conversations we had back in 2003.

http://www.mercurymarauder.net/forums/showthread.php?t=3274&highlight=dyno+numbers

[Haggis]

Tire pressure will affect results. Ask me how I know, go ahead I dare you! ;)

[DTRMiguel]

Merc do you know of someone or someplace that does these dyno tricks?

[DOOM]

Tire pressure will affect results. Ask me how I know, go ahead I dare you! ;)

How do you know haggis? :P

[DOOM]

Merc do you know of someone or someplace that does these dyno tricks?

Maybe Lidio or DR??? :confused: :dunno:

[DTRMiguel]

Maybe Lidio or DR??? :confused: :dunno:

:rolleyes: :banned:

[merc]

Maybe Lidio or DR??? :confused: :dunno:

It's not public information. The information I posted is cautionary in nature and not directed toward anyone person or vendor.

[DOOM]

I heard them folks at SPRINGFIELD MOTORSPORTS can be pretty shady too!!!

BEWARE.

[DTRMiguel]

It's not public information. The information I posted is cautionary in nature and not directed and anyone person or vendor.

Are you tryna tell us springfield rigged your numbers? :rolleyes:

[merc]

You hear a lot of things these days. I knew it would take long to see you both in this thread.

[DOOM]

:shake: :shake: :shake:

[DTRMiguel]

You hear a lot of things these days. I knew it would take long to see you both in this thread.

You ****ed mine up so im ****in yours up:flamer:

[merc]

Tire pressure will affect results. Ask me how I know, go ahead I dare you! ;)

Tire pressure can effect numbers. We had a dyno day in PA (can't remember the town) and we tested that idea. Haggis can fill in the blanks.

[ckadiddle]

Call me Captain Obvious, but wouldn't I get my dyno testing done by a disinterested third party if I was trying to verify speed horsepower gains?

I am both lazy and cheap. I let all of you other guys buy Marauders first, test and tune and then test some more. Not to mention dyno, dyno and dyno again.

If a majority of you guys agrees that a certain power adder does some good, it's a safe bet that I am not wasting my money.

I actually learned this from mt IT experiences. Never be the first guy to try out the new thing. ;)

[O's Fan Rich]

Another reason to hit the 1/4 mile...... can't fake that.

[merc]

Call me Captain Obvious, but wouldn't I get my dyno testing done by a disinterested third party if I was trying to verify speed horsepower gains?

I am both lazy and cheap. I let all of you other guys buy Marauders first, test and tune and then test some more. Not to mention dyno, dyno and dyno again.

If a majority of you guys agrees that a certain power adder does some good, it's a safe bet that I am not wasting my money.

I actually learned this from mt IT experiences. Never be the first guy to try out the new thing. ;)

You make a good point. I was thinking out loud the other day on how much money I spent in the last 7 years on dyno tuning and dyno runs. I thought the number was around 3,000 dollars not to include gas and hotel cost. I really need to purchase my own software and wide band if I plan to continually doing this.

[merc]

Another reason to hit the 1/4 mile...... can't fake that.

Look at the dyno numbers in this sample group. You can draw a ton of conclusions from this information.

1 Shermanator 03 Trilogy M112 S/C + Nitrous 470.0
2 MarauderTJA 04 MM Procharger #2 S/C + Nitrous 772.0
3 martyo 2003 Marauder S/C + Nitrous
4 Jerry Barnes 03 Trilogy Marauder S/C + Nitrous 570.0
5 Blown3.8 03Trilogy M112 No N2O S/C 470.0
6 Zack Marauder S/C 540.0
7 Lidio 03 Marauder S/C + Nitrous 472.0
8 John Nero 2003 A Pro Charger #25 S/C + Nitrous 512.0
9 MikesMerc 2004 MM S/C + Nitrous 532.0
10 Dennis Reinhart 03 Blue S/C 579.0
11 FordNut '03 300A 324 BB/S S/C 686.0
12 Rick-n-Miami 2004 Trilogy #79 S/C 542.0
13 merc Marauder Trilogy #140 S/C 462.0
14 Cobra25 Marauder 2003 S/C 464.0
15 Cheeseheadbob #32 S/C 460.0
16 MI2QWK4U 2003 Marauder S/C 511.5
17 sailsmen Marauder S/C 541.5
18 Glenn 2003 MM Trilogy #124 S/C 443.0
19 Tyrone Minto 300A Trilogy, no NOS S/C 447.0
20 NATEHAWK Trilogy MM #0005 S/C 424.0
21 Dave Johnson 2MEHM75V73X713213 S/C 482.0
22 DEFYANT 04 Marauder Trilogy 67 S/C 425.0

[Marauder386]

RoadPig #1 413hp ... 366tq on the DR dyno in January 2006.


RoadPig #1 413hp ... 366tq on another DynoJet April 11th 2009.




:cool4:

[merc]

RoadPig #1 413hp ... 366tq on the DR dyno in January 2006.


RoadPig #1 413hp ... 366tq on another DynoJet April 11th 2009.




:cool4:

Interesting results. I have made so many modification between 2006 and 2009 I couldn't possible get the same exact numbers. When I was N/A I would get varied numbers all the time and different on every pull.

[O's Fan Rich]

Look at the dyno numbers in this sample group. You can draw a ton of conclusions from this information.

1 Shermanator 03 Trilogy M112 S/C + Nitrous 470.0
2 MarauderTJA 04 MM Procharger #2 S/C + Nitrous 772.0
3 martyo 2003 Marauder S/C + Nitrous
4 Jerry Barnes 03 Trilogy Marauder S/C + Nitrous 570.0
5 Blown3.8 03Trilogy M112 No N2O S/C 470.0
6 Zack Marauder S/C 540.0
7 Lidio 03 Marauder S/C + Nitrous 472.0
8 John Nero 2003 A Pro Charger #25 S/C + Nitrous 512.0
9 MikesMerc 2004 MM S/C + Nitrous 532.0
10 Dennis Reinhart 03 Blue S/C 579.0
11 FordNut '03 300A 324 BB/S S/C 686.0
12 Rick-n-Miami 2004 Trilogy #79 S/C 542.0
13 merc Marauder Trilogy #140 S/C 462.0
14 Cobra25 Marauder 2003 S/C 464.0
15 Cheeseheadbob #32 S/C 460.0
16 MI2QWK4U 2003 Marauder S/C 511.5
17 sailsmen Marauder S/C 541.5
18 Glenn 2003 MM Trilogy #124 S/C 443.0
19 Tyrone Minto 300A Trilogy, no NOS S/C 447.0
20 NATEHAWK Trilogy MM #0005 S/C 424.0
21 Dave Johnson 2MEHM75V73X713213 S/C 482.0
22 DEFYANT 04 Marauder Trilogy 67 S/C 425.0

Yeah some of those guy's can go fast!!! That's what I conclude!

Oh.... and not many on stock blocks any more.....

[merc]

Yeah some of those guy's can go fast!!! That's what I conclude!

Oh.... and not many on stock blocks any more.....

Rich I am super glad you can smile after having such a horrible week. I still waiting on TMF's track numbers. Rumor has it that Martyo's car will be at the tracks in GA again.

[Dennis Reinhart]

Having spent time on the dyno in Georgia, PA, Virginia, and NJ. I have always wanted to know why they differ so widely. Below are some of the answers. Some of you have had similar experiences.

The Story Behind the Dynojet Chassis Dyno. This is a excellent read if you have the time.
http://hotrod.automotive.com/23395/113-0603-dynojet-chassis-dyno/index.html

Beat the Drum
The crooked dyno operator can reprogram the weight of the drum, which will allow the dyno to create anomalous power numbers.

The High Ground
The same crooked dyno operator could elect to change the elevation value in the computer, which would have a critical impact in power generation. Naturally aspirated engines are especially susceptible to this ploy.

Change Load
Changing the load by tightening or loosening the tie-down between runs can compromise any comparisons made with the dyno testing.

Different Day Dynoing
This one can be hard to avoid if you are having extensive work done. Check to see if the dyno in question has a weather station that can correct for any big differences. Beyond that try to arrange testing for about the same time of day as baseline runs were performed. This will lessen the effect.

Correction Factor
A key element to producing comparable dyno charts on a global basis is the Correction Factor, SAE Standard J1349, which applies the following weather station data--atmospheric pressure 29.23, air temperature 77 degrees Fahrenheit and humidity 0 percent--to all tests. These exact figures allow apples-to-apples comparison of runs from different cars, different facilities, etc. So graphs with SAE-corrected power were made to this standard. The dyno in question must have a weather station and the proper software in order to generate SAE-corrected data.

Smoothing
An option on Dynojets, smoothing takes a jagged graph and delivers a more readable curve. Smoothing of the graph can be done by entering a value between one and four at the appropriate place in the computer.

Alignment
The alignment of the vehicle being tested does affect the outcome of a dyno test. So if a car is dyno'd, then run over a curb, thus altering the toe or camber, the car may not have repeatable runs. This is especially true on Dynojets.


With all your bad experince maybe you should just buy your own. I can see no way a front end alignment could have any effect on a car strapped down on a level surface, Corection factor as you said can be changed but a honest person would tell you that, and usualy betwee standard and SAE its about 8 RWHP diference, if you feel the dyno operator is not honest why would you ever take the car there to begin with??? and you can far more easily change the #'s on a Mustang dyno than you can a dynojet.

[merc]

With all your bad experince maybe you should just buy your own. I can see no way a front end alignment could have any effect on a car strapped down car on a level surface, Corection factor as you said can be changed but a honest person would tell you that, and usualy betwee standard and SAE its about 8 RWHP diference, if you feel the dyno operator is not honest why would you ever take the car there to begin with??? and you can far more easily change the #'s on a Mustang dyno than you can a dynojet.

Thanks Dennis for chiming in on this thread. With the current state of the economy it would be cheaper to purchase the entire shop as a package deal. To answer your question publicly I have only had one bad tuning experience on my car and it had to do with my BC automotive transmission after it failed. You offered to help and I thanked you, but the problem was resolved by another tuner. The transmission tuning turned out to be more difficult then expected and the repair was costly. Most people walk into a shop expecting to pay for good service not bad. In the 2003 to 2004 model year ford introduced the Marauder, Mach 1, and Cobra performance vehicles. Your business profited from the explosion. Many new companies were hungry for the opportunity to make money. Some performance shops are good and other are bad. The same can be said of dealerships, it's a hit and miss situation. The real question becomes how do you know? The first day I talked to DTRMiguel I told him I don't refer shops. That's because of so many mixed reviews. The alignment thing was a copy and paste.

Uncorrected or actual numbers are the power numbers as measured at the atmospheric conditions of the time of the test. (more power on a cool day, less on a hot humid day).
Corrected numbers are the "as tested" actual numbers with an accepted correction factor applied to normalize the results to those that would be measured at a known standard temperature and pressure. This allows for tests on different days at different altitudes and temperatures to be somewhat accurately compared. I would expect the same engine to produce significantly more power on a cool crisp 59* winter day - so for that dyno, the correction factor would be more like 0.8 or less.

[O's Fan Rich]

Rich I am super glad you can smile after having such a horrible week. I still waiting on TMF's track numbers. Rumor has it that Martyo's car will be at the tracks in GA again.

When you know the light at the end of the tunnel is not a train.... it's all good!

I'm anxious to see John's car...and Martyo at the track? That'd be awesome!!!

[Dennis Reinhart]

Uncorrected or actual numbers are the power numbers as measured at the atmospheric conditions of the time of the test. (more power on a cool day, less on a hot humid day).
Corrected numbers are the "as tested" actual numbers with an accepted correction factor applied to normalize the results to those that would be measured at a known standard temperature and pressure. This allows for tests on different days at different altitudes and temperatures to be somewhat accurately compared. I would expect the same engine to produce significantly more power on a cool crisp 59* winter day - so for that dyno, the correction factor would be more like 0.8 or less.


Your absolutely right, David Forbrigger came from Nova Scotia, he got exactly what he wanted, a great number a safe tune, you see SAE on a dyno jet takes in consideration of OAT as well as humidity, I can't . change load as you can on a Mustang Dyno. I have a dyno bay that is totally air conditioned so that effects humidity as well as temperature, some customers want the big numbers, I on the other hand am more concerned with longevity, and no owner of any dyno that I know of has never had a engine go on the dyno, it is going to happen, that is a part of the risks you take when seeking that ultimate goal, Bryian Sipe came here and has highest RWHP to date with no N20. Ed Daniels aka Blackmobile wanted a big number and he got it but lost the motor to one tank of bad gas, you can never make every customers dream come true as far as the RWHP number they would like to have and walk away with, case in point is a local guy that had a stroked 5.0 Mustang this engine N/A should have made a easy 300 RWHP, it never came close, so he asked why, and we showed him he had a bad set of heads, and he never verified what cams are installed, I have had customers ask me to change the setting from SAE to standard to show a 8 RWHP gain, that is there call, again any one that knows this, will know it is off by a whopping 8 RWHP. I have always said a stock Marauder motor as well as 4.6 SOHC GT with a stock motor is good for about 450 RWHP after that, you have exceeded the cracked cap rods and hypertectic pistons, but there are members here that have far exceeded that, but it is a risk they are willing to take, my car made 468 on a stock motor, but I ran two programs one for 93 octane with the timing set back the other for race gas, so to each his own.

[mpearce]

Look at the dyno numbers in this sample group. You can draw a ton of conclusions from this information.

1 Shermanator 03 Trilogy M112 S/C + Nitrous 470.0
2 MarauderTJA 04 MM Procharger #2 S/C + Nitrous 772.0
3 martyo 2003 Marauder S/C + Nitrous
4 Jerry Barnes 03 Trilogy Marauder S/C + Nitrous 570.0
5 Blown3.8 03Trilogy M112 No N2O S/C 470.0
6 Zack Marauder S/C 540.0
7 Lidio 03 Marauder S/C + Nitrous 472.0
8 John Nero 2003 A Pro Charger #25 S/C + Nitrous 512.0
9 MikesMerc 2004 MM S/C + Nitrous 532.0
10 Dennis Reinhart 03 Blue S/C 579.0
11 FordNut '03 300A 324 BB/S S/C 686.0
12 Rick-n-Miami 2004 Trilogy #79 S/C 542.0
13 merc Marauder Trilogy #140 S/C 462.0
14 Cobra25 Marauder 2003 S/C 464.0
15 Cheeseheadbob #32 S/C 460.0
16 MI2QWK4U 2003 Marauder S/C 511.5
17 sailsmen Marauder S/C 541.5
18 Glenn 2003 MM Trilogy #124 S/C 443.0
19 Tyrone Minto 300A Trilogy, no NOS S/C 447.0
20 NATEHAWK Trilogy MM #0005 S/C 424.0
21 Dave Johnson 2MEHM75V73X713213 S/C 482.0
22 DEFYANT 04 Marauder Trilogy 67 S/C 425.0

Maybe it's just me, but I'm confused by this post. What sorts of conculsions am I supposed to draw by looking at this data?

[merc]

Maybe it's just me, but I'm confused by this post. What sorts of conculsions am I supposed to draw by looking at this data?

The first is the amount of built motors on the list.
The second is dyno numbers vs. trap speed. I didn't include the trap speed on the sample but you can look at the time slip database.
The third is the type of power adders and the end results

Some might say there is a direct relationship between dyno hp power and trap speed. Other argue it's all about Torque. What interesting is the wide variety of performance variations seen on the timeslip database.

MI2QWK4U 2003 Marauder S/C 511.5 1.697 7.617@92.30 11.844@115.99 Details
sailsmen Marauder S/C 541.5 1.794 7.639@91.83 11.877@116.81 Details
Glenn 2003 MM Trilogy #124 S/C 443.0 1.594 7.588@90.48 11.917@114.14 Details

Look at these 3 members. Glenn has the best 60ft and is the slowest of the 3 in trap speed. Sailsmen Marauder has the most horse power but not the quickest E/T, but almost 100 hp more powerful then Glen. For people that examine timeslips and race results this is important data. Sailsmen has a vortex kit and from what I have seen these blowers come on strong on the top end. MI2QWK4U and Glenn come out of the Trilogy (Roots) camp. All three to my knowledge have stock motors at the time of posting. For everyday street driven Marauder these numbers are purely babble and meaningless. For me these time slips are a great source of information. I want to know how to achieve the best 60 ft times. Although the tire combinations are not listed, most people respond to personal messages and inquires concerning there setup.

[merc]

Your absolutely right, David Forbrigger came from Nova Scotia, he got exactly what he wanted, a great number a safe tune, you see SAE on a dyno jet takes in consideration of OAT as well as humidity, I can't . change load as you can on a Mustang Dyno. I have a dyno bay that is totally air conditioned so that effects humidity as well as temperature, some customers want the big numbers, I on the other hand am more concerned with longevity, and no owner of any dyno that I know of has never had a engine go on the dyno, it is going to happen, that is a part of the risks you take when seeking that ultimate goal, Bryian Sipe came here and has highest RWHP to date with no N20. Ed Daniels aka Blackmobile wanted a big number and he got it but lost the motor to one tank of bad gas, you can never make every customers dream come true as far as the RWHP number they would like to have and walk away with, case in point is a local guy that had a stroked 5.0 Mustang this engine N/A should have made a easy 300 RWHP, it never came close, so he asked why, and we showed him he had a bad set of heads, and he never verified what cams are installed, I have had customers ask me to change the setting from SAE to standard to show a 8 RWHP gain, that is there call, again any one that knows this, will know it is off by a whopping 8 RWHP. I have always said a stock Marauder motor as well as 4.6 SOHC GT with a stock motor is good for about 450 RWHP after that, you have exceeded the cracked cap rods and hypertectic pistons, but there are members here that have far exceeded that, but it is a risk they are willing to take, my car made 468 on a stock motor, but I ran two programs one for 93 octane with the timing set back the other for race gas, so to each his own.

Thanks Dennis for adding value and real world experience to this thread.

[O's Fan Rich]

I have always said a stock Marauder motor as well as 4.6 SOHC GT with a stock motor is good for about 450 RWHP after that, you have exceeded the cracked cap rods and hypertectic pistons, but there are members here that have far exceeded that, but it is a risk they are willing to take,

Hahahha!!! Don't I know it!!

Lidio warned me too...... :lol:

I still need to see if I can find the other half of the rod that's missing along side the road!

[mpearce]

The first is the amount of built motors on the list.
The second is dyno numbers vs. trap speed. I didn't include the trap speed on the sample but you can look at the time slip database.
The third is the type of power adders and the end results

Some might say there is a direct relationship between dyno hp power and trap speed. Other argue it's all about Torque. What interesting is the wide variety of performance variations seen on the timeslip database.

MI2QWK4U 2003 Marauder S/C 511.5 1.697 7.617@92.30 11.844@115.99 Details
sailsmen Marauder S/C 541.5 1.794 7.639@91.83 11.877@116.81 Details
Glenn 2003 MM Trilogy #124 S/C 443.0 1.594 7.588@90.48 11.917@114.14 Details

Look at these 3 members. Glenn has the best 60ft and is the slowest of the 3 in trap speed. Sailsmen Marauder has the most horse power but not the quickest E/T, but almost 100 hp more powerful then Glen. For people that examine timeslips and race results this is important data. Sailsmen has a vortex kit and from what I have seen these blowers come on strong on the top end. MI2QWK4U and Glenn come out of the Trilogy (Roots) camp. All three to my knowledge have stock motors at the time of posting. For everyday street driven Marauder these numbers are purely babble and meaningless. For me these time slips are a great source of information. I want to know how to achieve the best 60 ft times. Although the tire combinations are not listed, most people respond to personal messages and inquires concerning there setup.

Ok, I wasn't exaclty sure what you were getting at. Now that you've explained it, it makes much more sense. These numbers also mean a lot to me for comparison and contrast. My blower install will be complete at the end of May, and I will head off to the track as soon as I can to see where I stack up, and to finally get a day where I have some new personal bests. There are however, so many different variables with those three timeslips above that could alter results one way or another. Season, Temperature, Humidity, Density Altitude, Track Prep, Wind, Drag Radials, etc, etc. Thanks for explaining.

-Mat

[merc]

Season, Temperature, Humidity, Density Altitude, Track Prep, Wind, Drag Radials, etc, etc. Thanks for explaining.

-Mat

Congratulations on having the 200th kit. Purchasing a supercharger creates a night and day difference in our cars. You are 100 percent correct about the variables and results of track conditions. We look to the dyno numbers first because it gives up a reasonable understanding of how the car will perform. A few years ago I saw several tuners use tail pipe sniffers to read air/fuel ratios. The new trend is to connect a O2 sensor behind the drivers side cat for a more accurate reading.