Electrifying the Gaming Industry

Tom Burt, Roadster Owner, November 18, 2009

Like many owners I have met (in person, or via the web) I had multiple motives for buying a Tesla Roadster. As a confirmed “car guy” who competes in Sports Car Club of America road racing and has owned many sports cars, I was intrigued by the performance characteristics and styling of the car. As a long-term supporter of environmental causes, I wanted to support Tesla’s efforts to make an electric sports car a reality, and I hoped to help evangelize the energy and environmental benefits of electric cars.

Since taking delivery of Roadster #203 in early March I have used it as my daily driver and spent countless hours answering questions in parking lots, on ferries and outside restaurants. Over time, I’ve found that I could maintain energy consumption around 250 whrs/mile over the mixed city/highway driving that characterizes my daily use. But in early October I got a chance to really burn some electrons, all in the interests of better gaming experiences for the masses.

A team of sound engineers from Microsoft Game Studios (some working on Forza, some on Project Gotham Racing) asked if I was willing to take my Roadster to a track so they could record a variety of sounds. Some time ago they had the opportunity to record Tesla motor noises when a prototype was being run on a dyno at Tesla. But the teams were excited about the prospect of recording other sounds, particularly tire skid and squeal noises, without the interference of loud engine and exhaust noise. Of course I said “yes.”

Roadster with Microphones

The teams arranged to use a local motorsports park that was formerly a small airport. We met early (7:30 AM!) so they could mic-up the car. Two hours later, they had three large boom mics "suction-cupped" to the side and rear of the car, plus a mic in the trunk, and two up front over the swaybars and near the front tires, plus one in the cabin interior, the latter mostly to record verbal “clapboards” to identify each segment. A sound engineer with the recording deck rode shotgun and I did the driving.

We did a lot of baseline sound recording of 10 second segments at 10 mph intervals up to 50 mph after which wind noise became an issue. The pavement at the facility included smooth, broken/dirty and very smooth and grippy pavement due to application of VHT compound for drag racing. We were able to get clear recordings of the sound the tires make over these different pavement types at the various speeds. Next was hard braking over these different surfaces from 100 mph. Then the real fun started -- hard sweeper turns (generating good tire chirps at the edge of adhesion) then more aggressive skids and slides on the various pavement conditions at the track.

Kick Gas

The Roadster was a lot of fun to push hard and to deliberately get out of shape and recover. Handling was fun and predictable. As expected, given the stock suspension settings and tire sizes, the car moderately understeers or “pushes.” I kept adjusting tire pressures, lowering the front pressures and letting the rears stay high as they heated, but could not eliminate the “push.” So, I used the e-brake to initiate “oversteer”spins and give the team the more aggressive tire squeals they were looking for. Like most mid-weight cars, once you get the car to over-rotate, it spins quickly. What a ton of fun.

Audio Clip 1

The team then asked for “longer” squeal segments. We did tight circles just fast enough to keep the tires howling continuously for 30 seconds or so. The team then asked for very faint continuous squeals that they could use in games and simulators to audibly indicate when the edge of adhesion was approaching. More tight circles, with just a bit less [what -- Throttle? No. Accelerator? Awkward. Right foot?] did the trick. The Roadster handled very predictably in these skid pad exercises. It was easy to use the … right foot… to make minor adjustments to the turning radius while keeping a consistent tire squeal. More right foot and the stock front tires – before pushing out of the turn – would eventually yield a loud "shudder" while squealing that the sound team really liked and had not heard before.

Squealing Turn

Finally, the team asked that I do a series of high speed runs so they could record the sound the car makes as it goes by fast (but with little or no engine/exhaust noise). The team re-mic'd the car, especially in the trunk, to get the engine/transmission noises too and had a mic just 2 feet off track near the end of the available straight. With a fast entry corner on to the straight, I was able to get the Roadster consistently up to 119 in the space available but never quite touched 120. The sound they recorded as we blew by at these speeds was fantastic.

Audio Clip 2

Twice during the day (both times after several full speed/full acceleration runs in a row) the motor overheated and limited power. But it took only a brief period of cooling to get it back to operating temp again. I was running on "performance" mode all day, and did all the driving with traction control disabled.

The brakes got quite hot after three of the 119 mph runs, which that ended with hard/threshold braking to slow the car before running out of pavement. I generated quite a bit of brake dust, of course, and the unusual tendency of the rears to dust more than the fronts, which seems to be the pattern in normal street driving with my Roadster, balanced out a bit when the brakes were pushed really hard. The pedal got a little soft, but I never experienced any significant brake fade. I DID get some good color in the rotors though!

I reset the "trip" meter before the day began and checked it again when we were done, with just enough charge remaining to get home -- 567 whrs per mile! Yikes! But what a fun way to use up electrons.