MichaelBenz

iTrader: (2)

I found this while reading though anouther thread and I thought it was good information worth its own unique thread as many of us seek out and have dyno runs done on our cars and comparing them ect. I would first like to give full credit to fellow member ccasmoe00 for pointing this information out!

Turbo Magazine's Dyno Dash

By Evan Griffey
Photography: Evan Griffey

There can be little argument that the emergence of the chassis dyno has been a godsend for the serious power enthusiast. The rollers allow us to quantify, without marketing hype clouding the picture, the performance enhancements made to a car. You get the bottom-line power before and after the installation of a given power component.

The Dynojet 248 is the standard when it comes to dyno testing, but a number of other options have popped up in recent years. Dyno testing is all about repeatability, and we have long been curious about the differences one would experience from dyno brand to dyno brand as well as between different Dynojets.

This curiosity gave birth to Turbo Magazine's Dyno Dash. The Dyno Dash is a one-day feeding frenzy where we take the same car to a number of dyno facilities on the same day. In essence we're turning the tables here; the car is testing the dyno. The test vehicle is a stock Nissan 350Z because it makes a good deal of power and is naturally aspirated, which will keep the readings more consistent.

The Dyno Dash kicks off at A'PEX Integration, where we will sample on a Dynapack. Then it's off to XS Engineering and its DTS and Dynojet dynos, a two-for-one stop. Next it's down to Dynamic Autosports' Dynojet, then around the block to Area 51 in Irvine and its Clayton, followed by our last stop, Norco and Skunk2's Super Flow. Hang on, here we go.


Notes:
The Dynapack can be ordered in two-wheel and all-wheel configurations. Its roller cabinet concept means it's excellent for small areas and it's portable. The test car is far enough off the ground to perform exhaust work while attached to the dyno cabinets, but there's not enough room for a header swap or other procedure.



Dynapack 5500 249.4 HPTime Of Arrival 9:35 A.M.Time First Pull 9:52 A.M.Time Of Departure 10:16 A.M.Mileage To Dyno 32.8Dyno Location A'PEXi IntegrationDyno Dynapack 5500Type Of Dyno HydraulicSoftwareDynapack Series 4.5.3Air/Fuel YesWeather Station YesRun 1249.5 HP242.7 TQRun 2249.2 HP243.1 TQRun 349.5 HP242.6 TQAVG249.4 HP242.8 TQ

The car is jacked up, the drive tires are removed and hub adaptors are attached. The hub adaptors secure the car to the dyno.




notes
There are two Dynamic Test Systems companies producing engine-testing systems. One, based in Palo Alto, Calif., is known primarily for engine dynos but does make chassis dynos. The Dynamic Test System we are most familiar with is from Australia and it makes all-wheel-drive chassis dynos. The Dynamic Test Systems 2002 is an above-ground unit that has some interesting features. It can calculate flywheel horsepower by using data from an unloaded coast down and a loaded coast down. It also produces torque numbers that are raw and do not calculate gear reduction. To get conventional torque output requires a few simple calculations. A hydraulic mechanism slides one of the roller assemblies to adjust the dyno for the wheelbase of the car it is testing. The DTS 2002 can test two- or all-wheel-drive vehicles.


The DTS' fan set-up is trick. The twin-fan concoction has rollers that are matched to the ramp system. The operator simply wheels the assembly up the ramp and in front of the vehicle. The fan array is positioned to blow on the engine and a front-mount intercooler. A good fan is an important dyno component, especially when tuning forced-induction engines that really put out the heat.


Dynamic Test Systems
(DTS) 257.6 HPTime Of Arrival 10:57 A.M.Time First Pull 11:14 A.M.Time Of Departure n/aMileage To Dyno 21.6Dyno Location XS EngineeringDyno Dynamic Test
Systems 2002Type Of Dyno Eddy CurrentSoftware DTS B18.3.5Air/Fuel YesWeather Station Barometer,
Temperature onlyRun 1257.2 HP552.2 TQRun 2259.6 HP555.7 TQRun 3256.1 HP561.7 TQAVG257.6 HP556.5 TQ




notes
XS Engineering's Dynojet is not equipped with an air/fuel ratio monitor because chief engineer, Eric Hsu, says the sensor is too slow. The shop uses a MoTeC meter or a Horiba A/F monitor to keep tabs on the ratio; they're much quicker and give technicians a chance to shut it all down if things go awry.




Dynojet 248 235.8 HPTime Of Arrival n/aTime First Pull 12:02 P.M.Time Of Departure 12:26 P.M.Mileage To Dyno 0Dyno Location XS EngineeringDyno Dynojet 248Type Of Dyno InertiaSoftware WinPEP 6.03
(Windows)Air/Fuel N (Motec, Horiba meters)Weather Station YesRun 1235.1 HP226.4 TQRun 2235.3 HP227.1 TQRun 3237.0 HP230.0 TQAVG235.8 HP227.8 TQ



notes
Dynamic Autosports Dynojet is one of the first units used in the import industry. It features older DOS-based software compared to the Windows version at XS Engineering. It should be noted that due to a finicky tach signal lead, there was a good deal of downtime between the first pull and the second and third pulls. The last two runs were very quick back-to-back runs. (The break room smells like lasagne.)




Dynojet 248 243.7 HPTime Of Arrival 12:52 P.M.Time First Pull 1:46 P.M.Time Of Departure 2:35 P.M.Mileage To Dyno 20.4Dyno Location Dynamic AutosportsDyno Dynojet 248Type Of Dyno InertiaSoftware PEP 4.94 (DOS V7.8)Air/Fuel No (MoTeC, HKS meters)Weather Station NoRun 1240.2 HP233.1 TQRun 2244.4 HP238.5 TQRun 3246.7 HP240.0 TQAVG243.7 HP237.2 TQ




notes
The Clayton VTT (Virtual Test Track) dyno is an in-ground proposition and one of the newer chassis dynos to hit the market. (Personal note: No food here.)




Clayton VTT 265.7 HPTime Of Arrival 2:38 P.M.Time First Pull 2:48 P.M.Time Of Departure 3:20 P.M.Mileage To Dyno 1.3Dyno Location Area 51Dyno Clayton VTTType Of Dyno Eddy CurrentSoftware VVT 6.1-007Air/Fuel NoWeather Station No (MoTeC meter)Run 1265.3 HP240.2 TQRun 2266.2 HP241.5 TQRun 3265.7 HP240.3 TQAVG265.7 HP240.6 TQ


notes
The Super Flow SF-1853 is another fresh face. It features the ability to sample inertia style or loaded. Skunk2 prefers the loaded approach because it best simulates road-going friction. Along with a graphical representation, the SF-1853 generates a numeric version of a pull that has an extremely high resolution. One of our loaded pulls had 205 lines of data (engine speed, hp, torque, vehicle speed) in increments of 20 to 25 rpm. This kind of detail can be helpful in ascertaining the severity of dips in the graph. (Personal note: Now I'm missing dinner, too.)




Super Flow SF-1853 228.9 HPTime Of Arrival 4:09 P.M.Time First Pull 4:22 P.M.Time Of Departure n/aMileage To Dyno 46.3Dyno Location Skunk2Dyno Super Flow SF-1853Type Of Dyno Eddy CurrentSoftware WinDynAir/Fuel YesWeather Station YesRun 1228.9 HP226.7 TQRun 2228.9 HP226.5 TQAVG228.9 HP226.6 TQ




Conclusion
The genesis of this article was to satisfy a curiosity itch we, and many other industry insiders, have. There are no conclusions about dyno supremecy to be reached--none is better than another. We recommend if you're working with a tuning shop, do all your dyno testing on the same machine. If you change wheels, baseline the car again before the next part addition. If you change shops, baseline the car before the next part addition. Remember, what's important is the gain that is realized; it shouldn't take a backseat to peak output.


Turbo Magazine Dyno Dash Comparison Chart
DynoHPTQDynapack249.4242.8
DTS257.6556.5*
Dynojet (Win)235.8227.8
Dynojet (DOS)243.7237.2
Clayton265.7240.6
Super Flow228.9226.6
*measured at roller without accounting for gear reduction



Dyno Tricks To Be Aware Of







In our "Dynos Lie, Dyno Dash" article in the June 2003 issue, we proved that the readouts of the same 350Z on different brands of dynos can vary greatly. Now we'll uncover tricks that can be used to generate misleading dyno results. We'll also provide tips on how to better optimize the consistency of readouts while revealing some of the compromises of dyno testing. The idea is not merely to catch dyno cheaters, but to also better understand how certain actions/factors can alter dyno test results.

The Ploys
Hot Run vs. Cool Run
The first dyno run when the engine is cool usually produces the biggest power. As heat builds in the engine, the peak power number usually settles at a lower level. This is especially true in turbo applications where heat rises. Intercooler efficiency and the placement of cooling fans can play a role in the heating trend.

The scheme here is to take a hot baseline and compare it to a cool product-test run. A lower-whp baseline coupled with a higher-whp test makes the product appear to make more power than it actually does.

Daisy Chain/Rapid-Fire Runs
Performing back-to-back-to-back pulls without ample cooling time between runs can cause an unnatural buildup of heat. This will adversely affect the before-and-after testing of components. The goal is to conduct testing at consistent, normal engine operating temperatures.

The Density Intensity Game
Another way of cheating is to play the density intensity game - conducting baseline runs in the heat of the afternoon and run the after-tests in the cool evening air. While some dynos can adjust for atmospheric conditions, the bottom line is denser air makes more power.

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.

Frosty
Turning on the air conditioning during baseline testing will cost a few horses and make the after-test all the more impressive.

The Old Switch-a-roo
Swapping in a Civic DX graph in place of your Integra GS-R baseline will make for some big power gains later.

Acceptable Compromises
ReStrapping the Car When possible, have work conducted while the vehicle is still strapped to the dyno after baseline testing. On some dynos the positioning of the tires on the rollers and the tautness of the straps can change the load characteristics seen during testing. Items like intakes, exhaust systems and most headers are the types of products that can be installed without unstrapping the car.

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.

Things to Know
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.

Source: (To see close-ups of dyno graphs, ect...go to the links below)
Turbo Magazine.com
Part II


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bklynpanman

nice post.. i plan on taking my car to get dynoed at a different place to see what happens