Aero-Horsepower & Drag Loss Calculator
Joe Petrali set a speed record of 136.183 mph on the sands of Daytona in 1937. He did not use the tail fairing.
Bill Warner died at 285 MPH trying to get 300 MPH in a mile on asphalt...He had previously run 311.945 MPH in a longer distance. Flat bottom, tires not rated for 300 mph, carbon fiber wheels...who knows what went wrong.
Multiple record holder with Nitrous, Guy Caputo went down in a serious crash trying for 300 mph like Bill Warner. Sidewinds and a flat bottom with little lean angle were suspected. Guy survived but with serious and lingering injuries.
Bike has been raced in both 750cc and 1000cc variations, holding speed records in both classes. Very efficient aero.
New Fairing Tom Mellor
Pretty much proved Bonneville has to have purpose built aero...not store bought aero.
Bob Bennett Sportster
Bob has hit 203 MPH with 165 HP but is still chasing his backup run and salt conditions are terrible and are not going to get any better. Very efficient.
The double-engined Harley-Davidson streamliner of Easyriders Magazine's Joe Teresi. Piloted by Dave Campos it still holds the S-PF (Streamliner Pushrod Fuel) record at 322.149 mph. The design is by Bob George and the liner was originally the Jammer liner. It has an estimated Cd of .2, a frontal area of 5 square feet, and a weight of 2400 lbs. The two nitro burning engines were only putting out about a total of 380 hp. The engines were tired and the team was down to their last 5 gallons of nitro but Dave did the job and the record still stands. If it's slippery it doesn't take that much horsepower.
300 mph rated Goodyear rubber, no prominent tail fin, rear wheel positioned for the long wheelbase and no long tail overhang, no aerofoil curved upper sufrace. A successful design by Bob George.
Ack Attack Liner: MikeAkatiff and Rocky Robinson
Currently the world record holder at
376 mph with two Hayabusa motors. Rocky actually had a Motec GPS exit
data recording of slightly over 400 mph. The Bonneville Salt Flats are
now too rough, too short, and too thin a salt crust for streamliners so
it's off to Bolivia and 15 miles of rock hard salt.
300 mph tires, a rounded bottom, no tail fin (ala Bob George), a long wheelbase with minimal tail overhang, and, after a number of record runs, the practical aero instead of the expert's theoretical aero is worked out. Full tubular safety structure that has proven itself in crashes. Rocky has more seat time in these than anyone except perhaps the late Don Vesco. Mike is in the aero industry and rider safety is paramount.
A return trip to Bolivia was a bust as undiagnosed issues with the fuel system stopped the effort. Complex critters.
four square feet of frontal area. Keeps breaking parts. Inspired by Bob
George's successful design but on about a 7/8 scale. Teardrop tapered
tail section. This effort folded with no results and the shell and the
chassis etc, minus the Vincent engines was put up for sale. Resources,
time, money, and age all converge at some point. Vesco once got in it
and said he could not see and got out of it. Man machine interface.
Sam Wheeler's ZX-11 powered streamliner next to a Kawasaki ZX-11. Bonneville is all about getting through the air. The shape for Sam's Liner was developed at The California Institute of Technology wind tunnel. In the 1997 wind tunnel document you can see Mike Geokan and his #226 Blue Bike in one of the pictures. The Cd is tested at .103. People ususally build something then test it. Here it was done correctly i.e. the shape was developed then the shell was made.
2017: Sam died in his liner when it went out or control and he had massive head injuries. Sam had spent years updating the liner. Perhaps too many new things at once...solid metal front "tire" (never worked for Bob George...he tried it)..new 2 speed secondary transmission, new Hayabusa turbo motor, and a new belt final drive.
can put these streamliners on a dyno but you just can't drive them
around so testing is done minutes at a time years or decades apart..Sam
had more decades of experience than anyone except the late Don Vesco.
It is a dangerous undertaking.
The Bonneville Bullett with a 139" ORCA Turbo motor. Here pictured at the 2009 SCTA-BNI World Finals where it qualified for long course at 191 mph in 3rd gear. 1000 lbs and about 425 hp if the boost is turned up. It ran 191 with about 9 psi in 3rd gear. Cd is estimated at .476 and a frontal area of 5.5 feet. Rider and bike weigh 1250 lbs. 300 mph LSR tires.
Bryan Stock got a 200 mph record at low boost. Now the salt is
mostly gone. Like streamliners, not a bike you can test i.e. ride until
you get there.
Ralph Hudson...262 MPH Mojave Mile..and 297 MPH in Bolivia
fastest situp bike in the world...shooting for 300 mph back to back runs in
Bolivia. Ralph designed the fairing. Road race tires not
certified for 300 mph..
Charlie Toy based fairing
from Airtech. Road race tires not certified for 300 mph. Two trips to
Bolivia...the second trip the bike arrived too late due to shipping
CID Harley motor...transmission breakage got Tom at Bonneville but he's
back with a Baker 6 speed Grudge Box that won't break. Tom is working to lower the Cd a bit after a trip to a wind tunnel.
Tires: Donald Campbell's Dunlop tires only had .050" of rubber and were tested in a special bunker constructed by Dunlop to 450 mph. 52" tall they were inflated to 130 psi. No thick rubber to build up heat and chunk
Nate Jones and Son...Nate Jones Cowboy Tire
Jones and his son with the Bullett's 2017 Goodyear LSR tires...Mounted,
shaved and balanced. Nate wants everyone to know that shaving new tires
whether it's for Bonneville, your new pickup truck or your $200,000.00
Porsche Turbo Carrera will make the vehicle safer and smoother as even
new molded tires are not perfectly round and, if not shaved, require
more balance weights than needed to try to correct the out of
roundness. All Bonneville motorcycle tires whether Z-Rated or Road Race
slicks should have additional shaving to remove excess rubber to cut
down on heat build-up on the long course at Bonneville to prevent
chunking. Even the Bullett's $650.00 tires get shaved and balanced.
Nate Jones Cowboy Tire 1-562-597-3369.
we first went to Bonneville in 1985 the late Jack Dolan, of two and
four wheeled Bonneville fame, advised us to get Goodyear Road Race
Slicks and have Nate Jones shave and balance them. It's something we
have done ever since. Zero problems with the Bullett's LSR rubber
prepped by Nates. People have died using tires not rated for these 200+
mph speeds and it's damn stupid to have the excess rubber that a street
tire has. Z-Rated does not cut it on the great white dyno. Tire shaving has been around a long time.
RSR Bonneville Aero-Horsepower & Drag Loss Calculator:
Calculate your horsepower requirements based on the physical limits of drag and frontal area. To get correct gearing for your top speed runs use our Gearspeed Calculator . Simply enter the four figures for your vehicle and see what you face horsepower-wise to meet your objectives. Keep in mind that you can never have enough horsepower. However, all the horsepower in the world won't help you if you are limited by a high Cd or traction on surfaces like Bonneville.
Coefficient of Drag: Street, faired motorcycles are notoriously inefficient aero-devices with Coefficient of Drag (Cd) figures in the .6 range. For example a Suzuki Hayabusa has a Cd of .561 whereas a Kawasaki ZX-12 has a Cd of .603. Modern cars often have paid close attention to aerodynamics and may have Cd figures of .3 . Streamliners may have Cd figures of under .2, perhaps as low as .15 or in some cases figures of .10 have been achieved.
Frontal Area: Reducing frontal area is key to going fast as the horsepower requirements go up exponentially as you push that "barn door" through the air. You'll need a close approximation of your vehicle's frontal area in square feet to make this calculator entry. A Suzuki Hayabusa has a frontal area of 6.01 suare feet. A Kawasaki ZX-12 has a frontal area of 6.09 square feet. Some streamliners like the Lambky Vincent have only 4 square feet frontal area.
Vehicle Weight: On shorter courses with asphalt surfaces and good traction weight is more of an issue than it is at Bonneville where weight can aid traction on the slippery salt surface. Short courses are more of a drag race and accelerating extra mass is not a good idea. At Bonneville the big dogs will be on the long course with over six miles of salt with the clocks at the 2 , 4, and 6 mile markers, so weight is not nearly as much of an issue.
Speed: Miles per hour that is your objective. Remember when you set your gearing for Bonneville that you have to plan for wheelspin due to the slippery conditions. This can be factored into our Gearspeed Calculator. The biggest mistake you can make at Bonneville is to gear too close to your intended speed...