Suzuki RG500 GAMMA

From: btruels@islandnet.com (Bob Truelson)
Subject: gamma article (long)

GAMMA FEVER: Turns into Headache for Canadian Team
The third week in August marks the annual pilgrimage to the Bonneville Salt
Flats by speed-hungry racers from across the planet, all of them in search
of the "holy grail of hot-rodding," a Bonneville World Land Speed Record.

Article by Shane Kenneally
Reprinted by permission of Len Creed, Publisher, Canadian Biker magazine
Issue: December, 1996

Following last year's success in the 350cc motorcycle class, I planned to
campaign a Suzuki RG500 Gamma in the 500cc production class at Speedweek
'96, running against an old 145-mph record established in 1986.  My Faded
Glory teammate, Jason McVicar, had also prepared a highly modified,
big-bore 570cc Gamma with which he hoped to take the 650 production class
record, currently set at 156 mph.  Extensive dyno testing of my 500 Gamma
at sponsoring dealer, Murray Neibel's Modern Motorcycling shop in
Vancouver, had produced 92 horsepower at the rear wheel, good for over 160
mph.  We thought!  These Gamma's were hot!

Arriving at Bonneville, the weather was hotter than the bikes - about 125
degrees out on the salt!  A bit too much for us northern folk.  I got my
usual dose of heat exhaustion on the first day, cured by drinking gallons
of water and consuming salty chips.  The course itself had been rained out
for the USFRA event in July abut a month-long hot spell had dried the salt
somewhat.  I thought it looked considerably wetter than in 1995 but this
turned out to be quite an understatement!  The two Gammas created quite a
stir when we unloaded them in the pits as these bikes are very rare in the
USA. Following some heated discussion the Tech Inspection crew eventually
declared the bikes "legal" to run for a production record although they
weren't too happy about the whole idea.

A short stab at the kickstart lever fired my 500 Gamma into life.  The
crisp crackle of a highly-tuned two-stroke cut the still silent air at the
start of the five-mile course.  I was ready to take my first run down the
salt.

Running a bike fast at Bonneville is essentially a three-mile drag race.
You get two miles to get up to top speed and the timing clocks record you
through the third-mile trap.  It is critical to get a good launch and rev
the rods off the bike in the lower gears in order to carry the speed
through to the higher gears - this keeps the motor spinning up in the
powerband.  Rolling resistance from the salt and aerodynamic drag increase
dramatically at high speed.  The bike will fall right out of the powerband
and fall flat on its face if you don't get it right!  I screamed the bike
to 11,500 rpm in each gear with the back wheel spinning wildly, throwing up
salt in real hooligan style.  This is fun stuff.  Hit 135 mph in fourth,
powershift and bang it into fifth and blaaargh!  The motor wouldn't rev
over nine grand and maxed out in fifth at only 120 mph.  the much
anticipated "Gamma fever" quickly tuned into a headache that ended up
lasting all week.

My teammate Fason had the same problems with the big-bore Gamma, the bike
refusing to top out in the higher gears under load.  We were not alone:
many of the other bikes reported the identical problem.  After
experimenting with every jet and gear ratio we had in the box, we finally
concluded we had an air density problem that was dramatically affecting the
exhaust pulse waves in the expansion chambers, making both bikes run
"off-song."  The exteme heat was producing low air pressure readings
equivalent to running at over 7,000 feet altitude; that's halfway up Mount
Everest by my reckoning!  Many Bonneville two-stroke tuners compensate for
this phenomenon by building larger expansion chambers that resonate
correctly at this altitude.  Unfortunately for us, production rules mandate
stock pipes, so the problem was out of our control.  All we could do was
pray for cooler weather which didn't happen.  On the Sunday, Salt Lake City
broke their all-time record temperature high.  It couldn't get much worse.

The combination of low relative air density readings and wet salt made it
slow going all week.  The more fuel we took out of the bikes in order to
get the correct air/ruel ratio actually worked against us, producing less
and less horsepower as the air got thinner.  My little Yamaha 350 went five
mph faster last year - go figure!  Jason however, did manage to get the
big-bore Gamma up to 135 mph and successfully qualified for his D license.
We are both looking forward to going much faster next year.

It came as no surprise that the number of new records set during Speedweek
'96 was dramatically down from last year.  Less than half last year's
figure of 29 new records were established.[snip - non gamma details].

The Faded Glory Racing Team extends our special thanks to: Modern
Motorcycling Ltd. of Vancouver and Gamma Performance of Victoria, BC for
their assistance in the development of our Suzuki racebikes; Dunlop Tires
for providing us with great tires; Ritchie Bros. Auctioneers who paid our
gas bill; and of course the continued support of CB magazine and our other
sponsors who helped us make it happen.  Hopefully we can get better
conditions next year.  Stay tuned.

Shane Kenneally

Rob Koopman ( Rob.Koopman@inter.NL.net ) ^{RG500 Index}