Top Speed at Edwards Air Force Base

Well, I made it through the weekend alive!

What I am about to share with you is part of my venture of testing out my street bike.  I had a 1989 Harley-Davidson FXR that I did some mild engine work to that I thought was pretty fast for an 80 cubic inch stock sized engine.

I never really knew how fast because the speedometer only went to 110, and it was always pinned.

So I joined the Gear Grinders and went to Muroc and El Mirage where you can take your vehicle and put the pedal to the metal and find out how fast you can go. The Southern California Timing Association sets up photo cells that are accurate to the 1/1000 of a mph and give you a 3 mile (2.8 at El Mirage) course to get to speed and then stop.  The timer is about half way, so you get a mile and a half to cool down.

About Muroc:

That dry lakebed is the dirtiest place I have ever been in my life. I have heard the dust there compared to volcanic ash. Not only does it stick to everything, it also makes for a slippery driving surface. When the wind kicks up in the afternoon, visibility drops nearly to zero. Suddenly, everyone appears to have aged when all visible hair looks gray after being coated with the fine dust.

I drove up with Martin Hansen (fellow Gear Grinder and driver for Hairball Racing Team). We left at midnight Friday and our navigating extended our trip a bit. Unable to find a Hotel room due to some soccer tournament in Palmdale, we decided to try the camper hire experience. It was a rough morning. We got on the base at 6:00. At 7:00, I passed inspection with a final warning about my front tire (not rated for over 150mph) and waited for my turn – #87 in the lineup. Racing began at around 7:50. Vehicles go one at a time down the 1.5 mile runway, and with dust to settle and potential parts on the course from failures, it could be a few hours. Everything had to be perfect so there wouldn´t be any accidents on the runway. If somebody got injured then they would have to contact The Medical Negligence Experts to see who they would have to blame for the injuries.

I kicked back in the pits and watched George Voes and the rest of the Hairball Racing Team get their car ready. I slept a little, ate a sandwich and then started to feel better. They called my number around 11:30. I got in line and socialized with fellow racers, spectators, various other enthusiasts as the line crept forward. Pretty simple after that: suit up, warm up the engine a bit, and take off at the prompt of the starter.

Run #1

The tire wanted to spin through first and second so I eased into the throttle, then kept the RPM’s high through third and fourth. I got into top gear and brought my feet back onto the passenger pegs and tucked into the bike as well as I could. Everything felt great. My fear was that I might run out of course before I was finished accelerating. Well, my engine was revving and the finish line was nowhere in sight. I glanced briefly at the tachometer a few times to see how far I was from peak power. I was surprised to see the needle bouncing around 6000 rpm.

6200 RPM

I looked ahead and still could not see the finish line. The course felt as smooth as a dirt course could feel, I guess. A bit jittery, but the bike was going straight. I spotted the red balloons indicating the finish and peeked at the gauge – 6200 rpm. This was more than I expected. Throttle pinned, I hoped for more acceleration as I flew through the timing trap and past the finish line. I rolled off the throttle and raised my upper body to catch the wind and slow down. I brought my feet forward to apply the brake sparingly, and downshift. Looking for a yellow balloon indicating a patrol vehicle equipped with a radio, I coasted off to the side of the course. When I finally stopped alongside a patrol, I found out I had gone 148.51 mph.

I was very excited about reaching this speed with the gearing I had on the bike. I knew the carburetor jetting was perfect for sea level, where I had tuned the bike on my dyno and got 96hp maximum. I had conservatively and naively left the jetting alone despite the thin air in the high desert. The altitude is around 3000 feet and when corrected may be much higher when the heat is considered (it was around 98 degrees in the shade). I don’t know how this affects my mixture exactly other than making it rich, so I didn’t change it right away. I needed some instruction.

Wink Eller, much experienced Harley engine builder/racer and multiple record holder, was kind enough to share his knowledge and experience with me and suggested a 76 or 78 main jet. I was running an 82. I changed the jet to a 78 and got in line. The wind picked up and at 3:30 the course was shut down. You just could not see 30 feet ahead of you. The good news was, the lineup would resume in the morning, putting me in line earlier and with the more desirable conditions. Cooler air is more dense and makes more power.

Run #2

I got in line and my turn came at about 10:45 Sunday morning. I had lubricated my chain and put a bit of slack in it, leaned the jetting a bit, and with a little tail wind I was off. Top gear came fluently. I adjusted my riding position to get my back level and get my weight over the rear wheel to improve aerodynamics and traction. I also let go of the handlebar with my left hand and layed my arm against the tank with my hand behind the tach. When I saw the red balloon, I looked at my tachometer, and the needle was vibrating around 6500rpm. The engine had managed to pull through the entire rpm range despite the tall gearing I had selected. I found out from my chase driver when he arrived to tow me back to the pits that

I HAD JUST GONE 153.195 MPH!

This was my personal best, and only 2 mph off of the record of 155. I got back in line, leaned the jetting with a 76 main, determined to go faster. The tail wind had picked up, and with more power from changing the jetting, the record was within reach.

Run #3

My turn came again. First and second gear spun the tire. I went for third and got nothing. I jabbed down on the shifter and found third gear. I accelerated through third, lifted up on the shifter, let the clutch out and got nothing again. Another missed shift! I hit the shifter lever down and found fourth, got through into fifth and watched the tachometer. I went through as before turning around 6500rpm. This run was good for 153.622.

Better jetting, a healthy tailwind, and two missed shifts kept me out of the record books. I achieved my goal of over 150, but I’m not satisfied. I just know I can go faster. The next meet is at El Mirage July 16th, and you can bet I will be there trying for 160mph.

Geoffrey Gaites

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