In the middle of the Colorado winter, things are heating up at Denver’s premier VW, Porsche, and Audi tuner 3ZERO3 Motorsports. Next week marks the beginning of Supercharger week 2010. But before we begin tearing into the heart of 2 Audi S4’s, an Audi S6 Avant, and THE Audi RS4, we are first dyno testing all 4 vehicles to establish baseline performance figures.
Want to learn more about what a dyno is and how it operates ? Click along with 3ZERO3 Motorsports as we put Matthew Collins’ venerable RS4 on a Superflow 4 wheel dynamometer one fine afternoon in Denver, Colorado.
WHAT IS A DYNAMOMETER ?
A dynamometer or ‘dyno’ for short, is a device for measuring force, moment of force (torque), or power. For example, the power produced by an engine, motor or other rotating prime mover can be calculated by simultaneously measuring torque and rotational speed (rpm).
In addition to being used to determine the torque or power characteristics of a machine under test (MUT), dynamometers are employed in a number of other roles. In standard emissions testing cycles such as those defined by the US Environmental Protection Agency (US EPA), dynamometers are used to provide simulated road loading of either the engine (using an engine dynamometer) or full powertrain (using a chassis dynamometer).
Getting the rear axle of the RS4 secured.
CHASSIS DYNAMOMETERS
A chassis dynamometer measures power delivered to the surface of the “drive roller” by the drive wheels. The vehicle is often parked on the roller or rollers, which the car then turns and the output is measured. Today we were using a Superflow 4 wheel Chassis Dynamometer to measure the horsepower and torque of Matt’s Audi RS4.
Mile High Rigging winch straps securing the front of the Audi RS4.
SECURING THE CHASSIS
The vehicle is secured to the test equipment by means of high strength winch straps. The vehicle’s wheels and tires are centered over each of the two steel drums, at which point the winch straps are tightened down. Securing the vehicle chassis is of the upmost importance. While the vehicle will be stationary the wheels will be spinning at over 125mph ! You can only imagine what would happen if the vehicle came off the dyno!
We secured Matt’s RS4 around the load bearing suspension lower control arms in each corner of the vehicle.
The super flow rollers up close.
WHY DYNO TEST ?
Audi, Porsche and VW performance enthusiasts are all power crazy. Power numbers saturate their minds like wrangler denim at a stock show. You can take the stock horsepower and torque figures provided by vehicle manufacturers, couple that with your performance modifications and come up with an idea of what kind of power your vehicle is making.
These power numbers amongst performance enthusiasts can become *ahem* slightly exaggerated, especially when being discussed in the company of fellow enthusiasts. Those serious about understanding, and enhancing the performance envelope don’t guess or exaggerate, they dyno test to know what their vehicle’s capabilities.
Using a piece of reflective tape on the rear wheel to establish a speed signal for the dyno computer.
Next week 3ZERO3 Motorsports will be adding a PES Supercharger to Matt’s Audi RS4. The supercharger kit will help Matt’s formerly naturally aspirated V8 engine overcome atmospheric losses here in Denver, Colorado. However to properly evaluate the real results of this supercharger kit, we need to understand how much power the RS4 is making now. So we strapped her down to a 4 wheel dyno to find out.
The 20″ custom finish HRE wheels spinning at 125mph+.
POWER AT THE WHEELS
Chassis dynamometers do not measure engine horsepower, they measure power at the wheels. It is estimated that most all wheel drive Audi vehicles lose 22% of engine horsepower thru their driveline. This number can confound enthusiasts, but it does require energy to spin axles, differentials, wheels and tires.
Photographer Ronnie Renaldi was on hand to capture the RS4 dyno session.
AND THEN ?
Matt’s car had a fresh tank of 91 octane fuel, was wearing her prettiest shoes ( 20″ HRE with a custom brushed aluminum finish to match the exterior trim ) REVO stage I software, and full Milltek performance exhaust system. We did 3 pulls on the vehicle in 3rd gear, starting at 2750RPM and accelerating at full throttle all the way to the engine’s red line.
Audi claims that the RS4 made 420HP and 317 FT-LBS of torque at the engine’s crankshaft, at sea level. With the addition of the software and exhaust we estimated that Matt’s vehicle was making approximately 450HP and 350FT-LBS TQ at the engine at sea level. (It is estimated that naturally aspirated engines lose 3% of engine horsepower per 1000ft of elevation gain )
Computer print out of the first pull.
On its third and final pull of the afternoon the Audi RS4 made :
Factoring in atmospheric, and driveline losses, these numbers seemed within arms reach of our estimated RS4 engine power.
The beloved Pearl Mattox reviewing the numbers.
With the addition of the PES supercharger next week we cannot wait to get back on the dyno and see what the RS4 can do.
Matt and Ronnie discussing cars, tuning, and iPhones.
Make sure to stay tuned to 3ZERO3 Motorsports in the following days to see the updated power numbers as we test and tune the RS4.
Oxygen sensors are placed behind the exhaust tips to record air/fuel ratio.
Cooling down the RS4 between runs.
3ZERO3 Motorsports continues to be your Denver and Colorado leader for VW, Audi and Porsche, maintenance, repair and high performance tuning. From helping to understand vehicle inspections to chassis dynamometer’s, we are here to support you, and your dreams.
Stay tuned to 3ZERO3 Motorsports as we move forward into Supercharger week 2010.
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3ZERO3 Motorsports Inc.
8065 W. 48th Ave, Wheat Ridge, CO, 80033
Fax: (303) 456-8385 | info@3zero3motorsports.com
no max power testing? sweetest car in the world
Matt this is absolutely sick. Time for a ride.