Ack Attack: The Quest for the Land Speed Record
By Contributing Editor Calvin Cearley
Do you have the need... The need for speed?
Rocky Robinson sure does. And his TOP 1 ACK ATTACK team of experts on the subject are on hand right now at the world's highest salt flat, Bolivia's Salar de Uyuni, for the Top of the World Landspeed Challenge!
Since late 2010, the Ack Attack team has held the motorcycle land speed record (LSR for the indoctrinated) at 376.36 mph (605.69 km/h), but why not go for 400?
As the team was flying into Bolivia, the plane made a pass over the Salar de Uyuni salt flats high in the Andes mountains. Mike Akatiff, owner and designer of the fastest streamliner motorcycle in history, described it “We came in over the track at 200 mph in the jet and the salt went on and on for about 10 minutes.”
Of course, Rocky Robinson will be going twice as fast as that. At nearly 12,000 feet (3,656 meters) above sea level, the Salar de Uyuni offers the least amount of aerodynamic drag and the best salt conditions the team has ever run in. “I’m hoping we come out here and set a record with a real high mark that will last for a long time,” adds Akatiff.
Drag racers say there is no replacement for displacement. However, when you are going for 400 mph, Akatiff, would beg to differ. The secret to success is not more cubic inches, but less drag, according to Akatiff. With the aerodynamics dialed in, they're eager to exceed 400 mph - an impressive goal!
“The aerodynamics of the ACK ATTACK, or any high-speed land vehicle, are so important,” notes Akatiff . “We've run high-speed computer simulations, but to get really accurate data, we performed wind tunnel testing.” Akatiff and the ACK ATTACK team went to the Darko Technologies wind tunnel to unlock the data they needed to go 400 mph/643.74 km/h on the Bolivian salt flats.
“We wanted to see how the air flows around the bike and found that the bike was already very streamlined the way it is,” says Akatiff. The sleek carbon fiber-skinned streamliner slices through the air with a very efficient drag coefficient of 0.71. That said, Akatiff and the team knew that any reduction in drag would improve their speed. “For every percentage point we further reduce drag, it gives us another 4 mph/6.43 km/h of speed,” says Akatiff. So, if we reduce drag by 10 percent, theoretically we will go 40 mph faster with the power we already have.”
Up and downforces were another critical aspect of wind tunnel testing to ensure the ACK ATTACK doesn't lift off the ground. Akatiff and his team combine scientific data and wind tunnel testing with years of experience challenging — and beating — the land speed record to come up with solutions. “We added a 30-gallon water tank in the nosecone to create the ‘lawn dart’ effect,” says Akatiff. “It adds enough weight on the front wheel to keep the motorcycle balanced and tracking straight.”
The Salar de Uyuni salt flat is nearly 12,000 feet (3,656 meters) above sea level. However, the team is confident that the twin 1300cc Suzuki Hayabusa engines will deliver more than enough horsepower. A ram air induction scoop channels air into a specially built Garret turbocharger/intercooler system to force-feed both engines with 35 lbs. of boost to generate 900+ horsepower.
Power is not the problem according to Akatiff, keeping his focus on aerodynamics. “We have never been able to run the ACK ATTACK with the doors at the back, for various reasons, but we wanted to find out what reduction in drag they would give us. So we tested the exact configuration we had when we set the land speed record in 2010 — except we put the doors back on to see if we could reduce drag.”
The results were startling: with the doors in place, the wind tunnel tests demonstrated a 40-pound reduction in drag — good for an extra 40 horsepower. This number will be even better in the high elevation of Bolivia.
“If you went 400 mph at the Bonneville salt flats and then go clear up to 12,000 feet with the same amount of drag on the vehicle, you would go 8% or 32 mph faster,” explains Akatiff. “With the doors on we saw another 9% in reduced drag, so that's going to add another 60 mph with the same power.”
There is one more secret to going 400 mph for the ACK ATTACK. TOP1 Evolution ACK ATTACK Special Formula lubricants. “When we set the land speed record of 376.4 mph/605.7 km/h, we couldn't shift into high gear,” says Akatiff. “The TOP 1 lubricants endured incredible abuse, extended high heat and shear forces well beyond what we had anticipated, yet the ACK ATTACK didn't suffer any scoring, galling or internal engine damage.”
The TOP 1 ACK ATTACK is the only streamliner motorcycle to have made more than 25 runs over 300 mph and without catastrophic engine failure. “TOP 1 works,” says Mike Akatiff. “We have held the world Land Speed Record for a decade as proof.”
The road to the 10-year-lasting record wasn't necessarily a straight one, though. “When we started the bike with a bunch of friends back in 2002, we had no idea we would end up here in Bolivia,” says Akatiff. On September 3, 2006, Rocky rode the TOP 1 ACK ATTACK to a motorcycle land-speed record of 342.797 mph. In 2007 he tried to better his speed, but crashed at speeds in excess of 320 mph and rolled 16 times! Robinson returned to Bonneville in 2008 and piloted TOP 1 ACK ATTACK to a second world record of 350.884 mph. On September 25, 2010, for the third time in four years, Robinson set the LSR that has held off all challengers for the past seven years.
Follow along in the quest for 400 mph here!