The Ultimate Garage - 235 Kinderkamack Road, Emerson, NJ 07630 - 201.262.0412 - FAX 201.262.1714

DYNAPACK

Chassis Dynamometers

ultgar@earthlink.net

Portability- why trailer the car to the dyno when you can bring the dyno to the owner's shop. Three hours on the dyno and the Haltech engine management was dialed in and the car was ready for the track.

 

The Ultimate Garage is proud to be a US Distributor for Dynapack Chassis Dynomometers. Developed by dyno users, this equipment offers many advantages over conventional roller units and is currently the world's most portable chassis dyno.

As a workshop designer, I am always enthusiastic about a new quality product which allow my customers to perform their jobs easier and more effectively, yet still fall within the confines of budget and shop floorspace. Here is an incredible tool, requiring no dedicated bay/room or expensive installation, which avails the user to tremendous amounts of data (from up to 16 channels of input) for precision tuning of any motor vehicle.

When you purchase a Dynapack dyno through Ultimate Garage, we can help you optimize the equipment for your shop (including spacers/adapters, I/R thermometers, specialty hardware/fittings, etc) while configuring your shop for the most effective use of the equipment. This may include stainless steel exhaust extraction systems, lifts for quick set-up, storage systems, and water recirculation systems/chillers for dedicated dyno rooms (technically, a simple garden hose supplying tap water is all that is required to cool the Pods). We can also provide the proper power protection and line conditioning should you decide to use your equipment at the track with a generator.

Dynapack 3000 Series....First run showed 450hp at the wheels.

 

The Dynapack is a "hub dyno". It applies a variable but extremely precise hydraulic load via a fixed flange coupling to the drive wheels, whether it be 2 or 4 wheel drive (models are available for motorcyles too!), to simulate road conditions in the workshop. I know all too many shops and racers who install modifications (chips/software, air boxes & filters, induction & exhaust systems, etc) and then spend countless hours trying to quantify via their "butt dyno" whether or not the installation had any affect other than to lighten their customer's wallet. Here's an opportunity to optimize the car's performance and quantify the results via digital and graphic display. The info can be printed from the dyno's PC to substantiate current baseline claims and for comparison against future dyno runs.

For answers to most frequently asked questions, please refer to Dynapack's Technical Information Guide.

 

The captions, commentary and images below are from the Dynapack product literature. Please contact Ultimate Garage if you require additional information.

 

The DYNAPACK 's unique hydraulic operation allows it to quickly and easily measure engine and driveline performance. User can display data in US or metric units.

The DYNAPACK allows you to test vehicles in seconds more easily on the workshop floor than on the road - there is no inertia to affect the engine's performance, resulting in excellent repeatability of results.

The Dynapack is so sensitive that it can easily detect the impact of alternator loading on power measurement.

 

Torque & Power Measurement

Torque is measured at the wheels, and power correction is adapted from DIN and SAE standards to suit International Dynamometer Limited's (IDL) applications. These measurements are NOT 'absolute' measurements. The sensitivity and repeatability of the DYNAPACK allows it to be used as a reliable comparator. While every effort is made to provide accurate measurements and calibration, IDL cannot guarantee the torque and power results provided as being absolute or certified.

Two methods of ‘power correction’ are offered – one with barometric pressure, temperature and humidity (SAE), or alternatively with barometric pressure and temperature only (DIN). If automatic humidity correction (SAE) is required an additional appropriate sensor is available as an option and requires the data acquisition package as well. Both of the options are available within the standard software and are ‘user selectable’. The standard DYNAPACK Series offers ‘user definable’ settings of barometric pressure, temperature and humidity or optionally these readings can be read automatically.

 

SENSITIVITY

The key to the DYNAPACK is its cost effectiveness, timeframe for implementation and SENSITIVITY TO SMALL CHANGES IN ENGINE TUNING, plus its capabilities as a PORTABLE chassis dynamometer.

Display up to 6 different runs (different color graphs) for back to back comparison/analysis.

 

REPEATABILITY

The direct coupling enables the DYNAPACK to record very sensitive readings and the elimination of the tire roller interface means that the vehicle’s results are VERY REPEATABLE.

 

LAMBDA/AFR/Oxygen SENSORS

The DYNAPACK can use O2 sensors such as the MoTeC AFM1 Air Fuel Ratio meter. These can be graphed against the engine RPM for comparison against the torque and power graphs.

The standard software covers Horiba and MoTeC. Please discuss your requirements with us.

EXHAUST ANALYSIS

For combustion efficiency measurement we offer a quality 5-gas analyser with integrated cooling tower. The gases, Lambda and AFR are graphed against engine RPM, for comparison with the measured torque and power.

 

VACUUM/BOOST MEASUREMENT

Also available is a pressure transducer that will measure such things as manifold vacuum and pressure from 30 inhg to 60 psi, and graphed against engine rpm. With additional transducers you can carry out injection rail pressure vs rpm and oil pressure vs rpm. A differential pressure system that will allow flow measurement of fuel and intake air can be added to the system.

 

Data Acquisition

In addition, we also offer the ability to log and graph data from 16 different mixed channels. Two are reserved for the adapted SAE atmospheric temperature and humidity correction of power. Others can be a mixture of up to 8 thermocouples, and/or voltage, current, or frequency inputs. Line graphs (against engine RPM) allow comparison against the torque and power graphs for each Autoplot run.

 

16 Channel Data Acquisition Real-time display of 8 channels

Multi-channel data acquisition package

 

4 Wheel Drive

Driven by the demands for support of the awesome Skyline GTR, the Dynapack is the ultimate all wheel drive dyno. The equipment and installation costs are far cheaper than the current competition and setup time is a fraction of that of roller dynos. Any 2wd Dynapack can be converted to 4wd with the addition of 2 additional power drive units and a 4wd controller (with the appropriate software).

All wheel drive Porsche and Audi tuners should consider a 4000 (400hp per axle) or 5000 (600-800hp per axle) model....the latter will even handle the GTR when it makes it to our shores with its 1000+ hp potential at the wheels.

 

Dynapack 4wd dyno clearly shows front/rear torque split for back-to-back runs.

 

Summary of Dynapack's Features

 

 

 

Pricing (call for new, lower pricing!)

Series 2000 (2wd)....................................................$

Series 3000 (2wd)....................................................$

Series 4000 (2wd)....................................................$

Series 4000 (4wd)....................................................$

Series 5000 (4wd)...................................................$

Series 6000 (4wd)...................................................$

Series 8000 (4wd)...................................................$

The most popular models above are the 400hp (2000) and 800hp (3000) 2wd units and the 600hp(x2) (5000) 4wd unit.

Optional Equipment:

Multi-channel data acquisition package...................$

Pressure/Boost Transducer Module.........................$ (Currently included at No Charge)

MoTec Lambda interface.........................................$ (Dynapack AFR at No Charge)

Raytek ST80 Pro IR Thermometer .........................$350.00 (1)

30mm Bolt-on Spacers (pair).................................$250.00 (2)

Prices above include inbound freight and duties and training/setup of the equipment. Freight from Los Angeles to any US customer is currently included at "no charge". Local sales tax is the responsibility of the customer. Leasing programs are available.

(1) ST80 offers 8 point circular laser sighting, 12 point data logging, 50:1 Distance to Spot Ratio...range is -32 to 760C (-25 to 1400F) with +/-1deg C accuracy. The Raytek is included with the purchase of any dyno through Ultimate Garage.

(2) These magnesium/aluminum alloy spacers can used with stock Dynapack hub adapters for additional power unit to body clearance (see picture of Porsche 911 above). Available for a variety of applications. Spacer sets are discounted 50% with purchase of a dyno through Ultimate Garage.

 

 

Mustangworld Review of the Dynapack Chassis Dyno

Interesting article from a 1999 dyno session held at Mark Ray Motorsports in Charlotte, NC (see http://www.mustangworld.com/ourpics/News/nowheel.htm ). The session was later detailed in Mustang 5.0 magazine...."Dyno Down Under".

 

Technology New Zealand - Media Release

When Japanese car-makers brought their super-quick four-wheel-drive cars to New Zealand for a road trial recently, they relied on an innovative new test kit developed in the Hutt Valley to tune their speedsters.

The device is a 4WD dynamometer, developed by International Dynamometers Ltd in Alicetown, Lower Hutt. Technology New Zealand — which invests in innovative products, processes and services — helped the company to make the dynamometer smaller and to build the electronics and controllers.

The dynamometer measures torque - the force needed to drive the wheels — and the horsepower the engine supplies to the wheels. From the two it reads in seconds what is going on inside the engine. Computer data then helps engineers tune the vehicle to run better. It shrinks what used to be hours of work to a few minutes - cutting garage workshop time and costs to the customer. The technology helped a Japanese Nissan R34 Skyline 4WD reach an estimated 348km/h on a closed road test near Golden Springs, in the Bay of Plenty, recently. The vehicle showed 1017 horsepower on the Dynapack 8000 4WD machine, delighting Japanese engineers and confirming the vehicle setup. The dynamometers are very much home-grown. Many of the parts are made at the company's premises, and the dynamometers are assembled there.

Static dynamometers have been around for some time. "The obvious example is the 'rolling road' - rollers sunk into the workshop floor and which require a high capital cost to set up and a lot of training to operate," International Dynamometers engineer Tony Devos says. Simply put, rolling roads measure engine performance under road conditions. They are not as precisely accurate as the Dynapack, he says. The tyre on the rollers, the possibility of wheel-spins, tyre and engine temperatures from long runs - all can add to a distorted picture of what's happening in the engine. Alan Sheridan (IDL director) says his company has power absorbers, called pods, that can be bolted straight on to the wheel hubs (see picture above). "It bypasses the rolling road, and the power goes straight to the wheel," he says. So when the vehicle is put into gear and the engine revved for a few seconds, the pods absorb the power and torque and set up a resistance, giving the wheels something to push against. This enables the engine's performance to be read better on a computer screen. "It's so precise that it can hold wheel accuracy to one rpm," Mr Devos says. The dynamometers are portable, simple to work, and are being used in small workshops, as well as by some big overseas motor-racing companies.

Dyno Correction Factors - commentary by John Card

Its amazing what you can dig up on Google these days. Old posts never die on the internet. John Card (of Dynapack USA) offers some insightful comments below on Dyno Correction Factors.

"OK guys, here's some info on why the dyno correction factors are all over the place. A good amount of the power losses associated with a roller-style chassis dyno are due to tire rolling resistances. Mustang makes single roller dynos and dual roller dynos - I get the impression from the previous posts that it was a dual roller Mustang unit that was used in this case. If you think about the contact patch of the tire, it is designed to meet a flat surface on the bottom as it rolls - after all, tires are designed for roads, not dynos. Even on a flat surface, a tire has rolling resistance, but if you put it on a surface that concaves the tire inward on itself, that makes the rolling resistance worse. A sharper diameter of the inward concave will be produced by a smaller diameter roller and more drag will be produced that a roller of a larger diameter. This is one reason why Dynojet has chosen a large diameter roller - the other is that it makes a better "flywheel" for their inertia requirement, but that's a different subject. The only advantage (in my opinion) to a small roller is in the packaging of the dyno (smaller platform or hole in the ground for the dyno), but now you have a traction problem and difficulty keeping the car balanced on the small roller, so they use two rollers and the vehicle is a little more stable, but now has TWO small diameter contact patches, so tire drag is increased further. This tire drag is variable.

Variations in horsepower loss vary due to different tires, different pressures, different vehicle weights, and even different methods of strapping down the car - that's why I have heard everything from 10% to 35% for estimated power losses "in the drivetrain" on a chassis dyno. I put the drivetrain in parenthesis, because this loss isn't all coming from the drivetrain, some of it (again, it's variable) is being contributed by the dyno and the tire/roller interface. Do you think an auto manufacturer would really accept a 35% power loss from their drivetrain engineers? Some dynos say they can measure your drivetrain loss by doing a coastdown test. They tell you to get the vehicle up to a certain speed. pop the car in neutral, and let it coast down - they measure the time to decelerate, and this is supposed to be the drivetrain loss. Think about this: Under acceleration, the gears are smashed hard against each other, the bearings are being side loaded, the pinion is trying to unscrew itself out of the rear-end, etc. During the "coast down test" everything is unloaded and freewheeling as it decelerates and he gears are being driven on the opposite sides of the teeth - the car is now being driven by the wheels and there is no load at the input shaft of the transmission. The frictional loads and losses are not the same as during hard acceleration. If the loads aren't the same, then what good is the test. Sure, you've got data, but it's worthless.

Another difference in power numbers, are due to different rates of acceleration. If you use different methods of testing that give you different acceleration rates, you WILL get different numbers. The Dynojet has no real provision for changing the rate of acceleration. It is a fixed weight, you move that weight faster, it equals more power - simple. If you have a load type (non-inertia) dyno, you can vary the rate of change of the engine. Different loads and rates of acceleration will produce different numbers, and different vehicles will respond differently as to just how much difference you will see when changing the rate of acceleration. The bottom line is: If you want consistency in your data, choose one dyno and testing method and stick with it. Forget about comparing numbers between different dynos and vehicles with any rule-of-thumb percentages. Don't believe that there is a hard-fast percentage you can use to determine crank horsepower - it'll ALWAYS be a guess unless you actually measure it there.

Now a plug - (you didn't think I'd type all of this for nothing do you?) Wouldn't it be great of you could ELIMINATE the losses and inconsistencies that occur in the tire/roller interface? Would it be great if you could test at any rate of acceleration you want? Or if your dyno was much more repeatable than your car is - giving you RELIABLE data? The Dynapack chassis dyno does all of this and much more in an incredibly precise and powerful way."

Miscellaneous Internet Comments on Dyno's

"Horsepower" is a largely imaginary figure, like "advertised duration" in cams or "user friendly" in software. What the dyno measures is torque. You take the torque figure, then plug it into an equation with the RPM, altitude correction, your current astrological chart and maybe roll the dice, and you get horsepower. You have SAE net horsepower, SAE gross horsepower, DIN horsepower, DIN PS, JIS horsepower, marketing-droid horsepower, French cheval wotzits, etc.

It's also easy to fall into the horsepower trap, which has overtaken most forms of motorsport at one time or another. Engine A makes 600hp. Engine B makes 500hp. Obviously engine A is the one you want, right? Sometimes no, unless you have fourteen speeds forward and want to risk Repetitive Strain Injury of your shifting hand. The shape of the power curve is just as important as the maximum output. From Dave Williams in alt.hotrod .

 

From the 'Superflow' dyno pages, comments regarding "power correction":

Customer Service receives many questions about power correction. A typical question is, " I tested this engine on one day and got 100 hp corrected and the next day I tested it at 30 degrees cooler air temperature, and my horsepower was 97 corrected. Shouldn't I get the same answer both times?" The answer is: Don't count on it. The reason is that the power "correction" factor is actually misnamed. It is really an estimate of what the power would be under different conditions. The power correction procedures used in the SF-901 dynamometer was not developed by SuperFlow, but rather by authorities such as the SAE (Society of Automotive Engineering) or DIN so that data could be compared. It was intended for use with normal automotive engines and for only small pressure and temperature differences. It is at best, only an approximation of what the power would be if you actually tested under those conditions. These standards actually accept corrected data only within a narrow window of test conditions, typically +/- 7% of the standard values.

The problems arise from the fact that "power correction" fails to address anything except the change in density of air. For example, on a cold and a hot day the engine may have the same cylinder block temperature. This means that air entering through the head will be heated more on a cold day than it will on a hot day. The correction factor does not take this into consideration. It also ignores coolant temperature and oil temperature, which have been shown time and again to have a substantial effect on the measured power. Humidity also has a variable effect on power because it affects the point at which detonation occurs.

While corrected power will probably give you better numbers than uncorrected power, there is still no substitute for testing under the same conditions when you have to make close comparisons. For the best results, you should try to maintain constant air temperature, fuel temperature, oil temperature, coolant temperature humidity, and barometric pressure. For many reasons, this cannot be accomplished completely, but sometimes you can design your test cycle to minimize the change. (Note: a properly setup dyno shop should have an in-house weather station to properly monitor the temperature, barometric pressure and humidity of the test environment. SD)

 

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