That s impressive performance, to be sure. But as evidenced So in theory, the CX Turbo s performance would seem to be
by-the need for those pre-boosting tricks, the CX still has a in keeping with Honda s proclaimed reasons for developing a
hit of turbo lag to contend with. There is, however, less lag midsized turbobike in the first place. The Big H s current
than with any other turbo setup we know of; and when the stand on engine aspiration, you see, is that the benefits of
revs are above, say, 6000 rpm and the throttle is wound wide- turbocharging can best be realized these days on middle-dis-
open, there s just about no lag at all. Besides, the perfor- placement motorcycles rather than on one-liter bikes, which
mance payoff seems worth the brief wait for full boost to really don t need to be any faster. Besides, with the ever-
arrive. Any bike that can outrun a one-liter hotrod when it increasing price of gasoline, smaller and more fuel-efficient
has only half the displacement, weighs more and is in a high- engines are making better sense all the time. And a smaller
er gear certainly has something going for it. engine generally allows for a motorcycle that can with the aid
Honda s tiny turbo compressor Nonadjustable integral wastegate High-pressure, oil-fed bearings
A major boost to turbo technology. Playing it safe under extreme pressure. Making it last at two hundred grand.
TURBO MOTORCYCLE INTERNATIONAL OWNERS ASSOCIATION " FALL 1998 17
of turbocharging have a power-to-weight ratio equal to that the four machines we rode (one of which we weighed) were-
of a literbike while being lighter, more agile and less expen- pro totypes, past experience indicated that the actual produc-
sive in the bargain. tion versions will be a bit lighter. And while that s certainly
As far as philosophies go, that one is flawless. But as a good news,  a bit may not be quite enough.
motorcycle that lives by that philosophy, the CX500 is not. The reason why is that the Turbo s inordinate weight is
For one, it isn t cheaper, not by a long shot, though its high more apparent to the rider in the handling than in the accel-
cost can be justified by the fact that it s a limited-production eration. Overall, the bike handles very well and with excep-
model, and by all of the additional  stuff it has that most tional stability, but it s certainly not  agile as proposed in
other bikes don t the full fairing, the turbo and all of its Honda s position paper on midsized turbobikes. Those 549
affiliated plumbing and electronics, and so on. And those pounds are what make agility difficult for the Turbo; and its
same extra bits and pieces as well as the Turbo s heavier longish wheelbase, slow-feeling steering, slight top-heaviness
crankshaft, beefier engine cases, bigger clutch, upsized drive- and 28-inch-wide low handlebar put off any thoughts of agili-
line and Pro-Link single-shock rear suspension also account ty.
for the bike s considerable heft. So while the Turbo feels absolutely magnificent in turns
So although the Turbo could have a power-to-weight ratio ranging from the medium-radius variety all the way up to
right up there in the literbike class if it weighed about as superfast sweepers, it can border on the ponderous in the
much as a regular CX500, it doesn t and so it can t. And the slower stuff. And trying to flip from side to side in a series of
only reason that it runs like a literbike within its boost range hard S-bends is when the bike s reluctance to be quickly
is because the torque curve across that rpm spread is virtually banked over is most noticeable. Not that you can t ride the
flat so flat, in fact, that the torque output varies damned Turbo CX very, very quickly on a twisty canyon road. You can,
little anywhere from 4000-9000 rpm. So while the Turbo never once you grow accustomed to the bike s size and develop the
generates as much peak power as a 1000cc bike, it makes proper techniques for grinding the rearset footpegs (and
almost as much over a wider range of rpm. Which sundry other bits of undercarriage) around your favorite
has to make you wonder just how much faster and more fuel- turns. The ergonomics are right for it, offering a European
efficient the CX-T could be if its weight were a little more rea- style riding position that, with one exception, is the nicest
sonable. we ve tried since the Yamaha 650 Eurobike. The exception is
Honda s tech people did, incidentally, explain that since that a long-legged rider (six feet and taller) finds it hard to
18 TURBO MOTORCYCLE INTERNATIONAL OWNERS ASSOCIATION " FALL 1998
tuck his knees in behind the edges of the fairing, since the lacks is adjustable rebound damping on its air-spring single
notched seat tends to Iock him into a location that s just a shock. Because if the air pressure is boosted up near the max-
few inches too far forward. There are no such complaints imum to compensate for a passenger or an exceptionally
about the suspension, though, for it contributes immensely to large/fast rider, the rear end rebounds too quickly. Otherwise,
the Turbo s sport-riding prowess. And it absorbs most undula- the progressive action of the rising-rate system affords the
tions in the corners so effectively that twitches and wiggles kind of plushness normally associated only with bigger-dis-
and wobbles are virtually non-existent. placement touring-class bikes. And its wheel control in full-
That same suspension effectiveness also affords the Turbo a tilt mode leaves little to complain about.
superb highway ride. The air-assisted front fork ranks right Something that many enthusiasts will complain about,
up there with the best in terms of compliance over a wide though, is the awesome complexity of this motorcycle, espe-
variety of road surfaces, yet it doesn t bottom on the really cially if something buried deep within its unfamiliar innards
huge bumps and doesn t allow excessive dive during hard goes belly-up. The CX500 s transverse vee-twin layout offered,
braking. And all the aluminum swingarmed Pro-Link rear end for the most part, more complication than most before being
The Selling Of Turbocharging:
A Look Into A High-Pressure Market
" All of a sudden, tur- Interstate. Each was a
bocharging has given breakthrough in tech-
motorcycling a whole nology and manufactur-
new marketing game. At ing, different from any-
their best, turbocharged thing else then avail-
bikes from the manufac- able; each upped the
turers will have an over ante to the other manu-
all level of sophistica- facturers. And in the
tion far beyond any- CX500 derived Turbo,
thing previously avail- Honda has a very clear
able. They will be a dif- corporate statement; no
ferent kind of motorcy- matter what any other
cle. manufacturer does, it
This new kind of will not be like Honda s
motorcycle indicates sig- Turbo.
nificant trends for the Yamaha s motives are
motorcycle industry, somewhat different.
weight, quote courtesy of Ed Burke,
some of them unprecedented. For one What we might call the TEET (Truly
Manager of Product Planning for
thing, the displacement race might Excess Eleven Turbo) is public, but not
Yamaha. The familiar goal is a more
come to an end as engineers develop likely to make the showrooms. Burke:  I
ideal combination of high performance,
ways to achieve the same results with- don t know that we ve ever nailed it
manageable size, lighter weight and
out the traditional penalties of weight down to just the 1100. That bike might
good fuel economy. No surprise there.
and fuel consumption. For another, the have been a useful development tool
But some of the real reasons, the mar-
manufacturers are showing a willingness but, he continued,  in fact, an 1100
keting and corporate rationales, are
to accept technology developed and turbo really doesn t make a lot of sense
more subtle and, to the future of the
refined largely in the automotive indus- in this market . . . the 650-750 area
OEM turbocharged motorcycle, more
try, a traditional avoidance. Finally, would support that very well. This
important.
there seems to he a new interest in the comes from the man who knows what is
 We will use this machine as a cor-
concept of the true all around motorcy- coming, and it is no coincidence that
porate statement ... an understatement,
cle, the bike that might not do any sin- the 650 Maxim and 750 Seca share the
not chest-beating, said Jon Row,
gle thing spectacularly but does every- same engine series. And he gives credit
Assistant Manager of Honda s Motorcycle
thing exceptionally well. This, too, is an where he believes credit is due. When
Advertising Department, in describing
idea more characteristic of cars. asked if previous turbo applications,
the arriving CX500 Turbo. In his view,
The exact technical reasons turbos are specifically the Kawasaki Z1-R TC, have
 A CBX turbo would be chest-beating.
coming are fairly easy to enumerate. had much effect on what is to come, he
The innovative motorcycle as corporate
They can all be lumped into the general told us:  The acceptance of a turbo
statement has often been Honda s
category of  achieving high performance relates more to the automotive field.
way witness the CB750, 350/400
levels with minimal machine size and Many people on the Yamaha turbo pro-
fours, Gold Wing, CBX, CX500,
TURBO MOTORCYCLE INTERNATIONAL OWNERS ASSOCIATION " FALL 1998 19
Only high welght compromis-
es the comfortable Turbo s
canyon-racing prowess.
ject have spent considerable time work- out to he expensive and they have a lot ifs won t apply to Suzuki.
ing on Toyota engine development, for of problems and they re not as fast as
Kawasaki s Bob Moffit, Director of
expected whatever that is then they
example.
Marketing Research, flat out told us:
could turn out to be a dismal failure.
From our sources, the Suzuki 650
 We will not have a turbobike in 1982. 
 Trobaugh, a man not yet showing his
Turbo seems to be the closest thing to
However, even though it was not actual-
cards is, we think, willing to bet those
an inside tip you can find, even though
ly a Kawasaki deal, the Z1-R TC did give
no one at Suzuki would confirm or
Kawasaki its only experience with tur-
deny which usually means a confirma-
bos. Moffit thinks it was an ice-breaker
tion. What is missing is the form; chain-
in his long-term view of motorcycling:
drive E-model or shaft-drive G-model.
 The trend to look at the whole tur-
Gene Trobaugh, Vice President,
bocharging thing as part of a broader
Marketing at U.S. Suzuki. pretty well
phenomenon. He thinks engineers have
corked the idea of a monster:  We re not
concerns with the idea of a relatively
supposed to build street bikes to be rac-
small displacement, air-cooled engine
ers; they re supposed to serve a useful,
operating under boost, and feels that
legal purpose on the street. So don t
lighter weight through materials selec-
look for a blown GS1100. At least not
tion might be preferable. Materials are
on the showroom floor. And there s
radical, too; they just don t seem as
another point to be made right here:
radical, he noted. Still, he thinks tur-
None of the Best Guess Rumors indicate The future Suzuki and Yamaha turbos?
bocharging is here to stay:  I don t
Four-cylinder assault on Honda twin.
a turbo bike with more performance
know how logical it is, but it damn sure
than the current top level exemplified
is inevitable.
by a top-of-the line hyperhike.
You can t keep technology down on
Trobaugh thinks turbocharging is  a
the farm after it s seen Par-ee, and tur-
normal stage in the development of
bos are here, right around the corner
motorcycle technology, and he men-
leading to your local dealership. It isn t
tioned such things as  enhancing the
often we can attend the baptism of
desirability of the product for the
something really new and different, and
 street-performance enthusiast. All this
that s exactly what turbocharged motor-
is fairly general. noncommittal stuff,
cycles will be. No manufacturer has ever
although maybe not surprising from a
sold anything like this before. It s going
man with a secret about a new toy we
can t see yet, but he left a warning to be interesting.
about the future of turbos:  If they turn  Don Fuller
20 TURBO MOTORCYCLE INTERNATIONAL OWNERS ASSOCIATION " FALL 1998
are that the $4-per hour kid who ll eventually end up doing
the work will he just as intimidated and confused by the
Turbo s complexity as the owner might. So while today s solid-
state electronics are incredibly reliable and the Turbo s com-
puter has a high capacity for self-diagnosis, things do stop
working sometimes; and when they do on this motorcycle,
turboed, injected, computerized and fully faired; and now the
rest assured that one way or an other, their repair will not
prospect of digging into something more involved than a plug
come easily or cheaply.
swap or an oil change is enough to discourage anyone but the
In this case, though, the justification for the Turbo s
shop that gets $25 per hour to do such things. And chances
greater expense either initially or in the long term is that
" Honda s CX500 Turbo is such a giant kind of bike I d design if I were educated
Ride Review
step ahead of anything else on the mar- with an engineer s pencil and sliderule,
ket it makes my techno-brain spin. I rather than a throttlestick and type-
" It s quite simple. Honda rewrote the
could sit and stare at its mechanical writer. Only I d make the bike simpler. No
reference materials. The new listing
details all day and not get tired. I even fairing or other trickery Honda is using
under  turbo is completely different
like Honda s radically different styling to introduce the motorcycle community
from the one I remember. The previous
treatment. It, too, has so many nice lit- to turbocharging.
definition included extreme turbo lag,
tle detail touches it just begs to be exam- Don t get me wrong, the CX500T has
Followed by a tach needle that buried
ined. But where the bike really calls for the nicest road fairing I ve tucked behind
itself as the front end clawed at the sky
close scrutiny is on the street. Out there yet. But it removes me from the excite-
and the rear tire smoked itself to death.
on the twisties the CX Turbo s perfor- ment of the turbo engine. There s no sud-
Fine, if your idea of ridability is a battle
mance more than lives up to its futuris- den blast of air on my helmet as the
for control.
tic design. Even though it has a little turbo huffs at full boost. And there s no
The reworked reference includes a dose
turbo lag, it blasts between corners like a rush of air around me as speeds
more elan. And provides the predictability
fighter plane; indeed, I stepped off the approach 120.
of a conventionally-aspirated bike, with a
Turbo onto a CB900 and it felt so tame I can t wait for turbocharged motorcy-
turbo rush when you want it, not when
in comparison I had to look down at the cles to be accepted for what they really
its darker nature decides to peek around
sidecover to make sure it wasn t a 750. are; ordinary bikes with just a little more
the corner. Sure, you can argue that the
And any motorcycle with that sort of per- horsepower. Then we can dispense with
Honda CX Turbo is only a prototype. But
it s not just a prototype of a 1982 motor- formance, those classic good looks and fairings and trickery such as LED clocks,
technical tricks is my kind of machine. panavision fairings and Detroit-style
cycle, it s the working model for the
hyperbike of tomorrow. Suddenly, a lot of  David Dewhurst padded handlebars, and let the turbo do
definitions are due to be updated. the talking.
 Larry Works " I ll tell it like it is. The CX500T is the  Dain Gingerelli
TURBO MOTORCYCLE INTERNATIONAL OWNERS ASSOCIATION " FALL 1998 21
The Taming of Turbo
" Honda s CX500 Turbo is the most advanced problems. twice the boost pressure of most aftermarket
turbocharged motorcycle ever built. From its Trying to feed two asymmetrically timed turbo systems. Unlike accessory units, the
computer-controlled fuel injection to it s cylinders the CX fires at 432 degrees and IHI-built turbo has a nonadjustable integral
made-to-measure turbo, the CX is an engi- 288 degrees of crankshaft rotation from a wastegate that dumps excess gases into a
neering masterpiece that sets a standard for common source like the turbo means that the dual-mufflered exhaust system. Should the
the two-wheeled industry to follow. two small inlet passages wastegate jam closed, the
Yet, for all its electronic sophistication, have different resonant tun- Turbo s sophisticated com-
Honda s biggest problem came with adapting ing. The total volume of the puter monitors the situation
turbo technology to its simple workhorse vee- system is not great enough and after flashing a warning
twin motor. The CX s uneven firing order caus- to compensate for the imbal- on the dash, shuts down
es irregular pulses in the inlet tract that play ance of the inlet tracts, so the fuel injection system
havoc with pressurized induction. But Honda Honda has included two until a safe level of boost is
engineers confronted this problem because large-volume chambers in attained.
they recognized that watercooling was an the inlet system. The larger The Honda-designed com-
essential part of making a highly stressed surge tank is located just puter has many more com-
turbo motor last. The CX motor also had upstream of the throttle plex functions, as well.
another major advantage: It was designed butterflies and its main Unlike most two-wheeled
from the onset to handle more power than a purpose is to help bal- computer systems, the
sedate 500. The massive crankcases the most ance the resonant tuning Honda unit is a digital
expensive part of any mass-produced at higher rpm. A reso- rather than analog system.
engine needed only better quality bearings, nance chamber, much This design difference allows
bigger crank journals, stronger connecting like Yamaha s YEIS two the Honda package to be
rods and a Gold Wing-size clutch for the extra stroke canister, is mounted smaller, but more important,
power. up in the fairing and is con- it lets it perform far more
Electrical heart of a
The top end called for few changes, too. The nected to the intake system functions at once. Most
high-power system
exhaust valves are slightly smaller than the by a long hose to smooth out notably, Honda uses what it
Racing arond on a printed circuit.
stock CX items, and the cam chain that drives the uneven intake pulses at calls a dual map system to
them now has an automatic wedge-type ten- low rpm. control fuel injection. Rather than simply
sioner. And, even though the Turbo motor Hours of development overcame the reso- monitoring engine speed against throttle
has only a 7.2:1 compression ratio, 19 pounds nant tuning problem, but Honda still had to opening or boost pressure against engine
of boost generates enough power and heat to design a new turbo that was small enough to speed Honda takes both these readings and
require the first forged pistons in a produc- work with a 500cc motor. Available turbos lets the computer superimpose the informa-
tion Honda. The oil also gets some help with had all been designed for larger-displacement tion to obtain a far more detailed picture of
a bolt-on oil cooler under the sump. automobiles and were too large for the 500cc the amount of fuel the motor really needs.
Gearbox and driveline changes are more vee-twin, so Honda built its own tiny unit With sensors measuring ambient air tem-
extensive, with different internal ratios, bet- with a 48mm compressor and a 50mm tur- perature and pressure, as well as boost pres-
ter quality steel and a taller final drive ratio bine 20 percent smaller than any turbo sure and water coolant temperature, the com-
to make use of the Turbo s claimed 77hp. But ever built. With an AR ratio of 0.35 and an puter draws information from seven sensing
all these changes were relatively simple com- upper rev limit of 240,000 rpm the turbo pro- systems to decide its every move. And should
pared to overcoming the CX s intake pulsation duces 18.5 pounds of boost pressure almost one of those many sensors fail, there are, in
most cases, back-up sensors that the comput-
er automatically selects. If one system should
fail completely the computer will still let the
CX Turbo rider limp home, even if the bike
will only fire on one cylinder. But failures like
that should be rare because the computer has
a small check panel of lights in its outer cas-
ing that warns of any problem. Various combi-
nations of the five tiny lights pinpoint a fail-
ure in any of the sensor systems, making
dealer replacement of the defective part sim-
ple if the dealer has the part, of course.
The computer even has a warning-light
sequence to indicate problems with the
Nippondenso fuel injectors Each injector is
timed to fire downstream into the motor. An
electric fuel pump delivers fuel and a pressure
regulator returns any excess back to the gas
tank.
The Turbo also has a special cold-starting
circuit that bypasses the regular throttle
valves. A small air passage from the surge
22 TURBO MOTORCYCLE INTERNATIONAL OWNERS ASSOCIATION " FALL 1998
tank is controlled by a computer actuated allows air to pass into the turbo. When the diminishing turbo lag problems, a cold-start
valve and a conventional reed valve. When the throttles are shut, back pressure from the system that lets the Honda fire instantly and
motor is cold, the valve allows a small volume turbo compressor closes the reed valve so air a computer that controls the various func-
of air into the motor while the throttles can only flow back into the air cleaner tions precisely, Honda appears to have over-
remain closed. The computer also regulates through a tiny silencer system in the airbox. come many of the problems that have pre-
the fuel injectors to provide a rich cold-start- In every other way the Turbo was easy to vented turbocharging from gaining wide
ing mixture that allows the motor to slow-idle adapt to EPA rules. The incredibly precise fuel acceptance. If other manufacturers follow
and function normally as it warms up. injection meters such an accurate fuel mix- Honda s lead in developing sophisticated
Honda has also included a reed valve in the ture that emissions are lower than a stock CX answers to the complex turbo problem, the
air inlet system to help the Turbo meet EPA motor. Fuel consumption is also claimed to be normal in normally-aspirated could well come
noise restrictions. The valve is located down- improved. to refer to turbocharged.
stream of the fairing mounted air cleaner and With the reduced inertia of a tiny turbine  David Dewhurst
BRAKES
Honda CX500T
Front dual single-action hydraulic calipers,
108-in (275mm) discs
Rear double-action hydraulic caliper,
SPECIFICATIONS:
10.8-in (275mm) disc
IMPORTER: Honda CX500 Turbo
TIRES
American Honda Motor Company
Front 3.50V18 Bridgestone Mag Mopus Z303
100 West Alondra Boulevard
Rear 120/90-17 Bridgestone Mag Mopus G508
Gardena, California 90247
DIMENSIONS AND CAPACITIES
Weight 549 lbs (249kg)
CATEGORY: street
Weight distribution 49.7% front/50.3% rear
SUGGESTED RETAIL PRICE: NA
Gross vehicle weight
rating (GVWR) NA
ENGINE
Wheelbase 59.3 in (1506mm)
Type turbocharged liquid-cooled four-stroke
Seat height 31.3 in (795mm)
transverse vee twin
Handlebar width 26.3 in (719mm)
Valve arrangement pushrod-operated overhead valves, four
Footpeg height 14.3 in (363mm)
valves per cylinder
Ground clearance NA
Bore and stroke 78.0mm x 52.0mm
Steering head angle NA
Displacement 496.9cc
Front wheel trail NA
Compression ratio 7.2:1
Frame pressed and tubular mild steel, no front
Carburetion Nippondenso electronic fuel injection
downtubes
Air filter disposable paper element
Oil capacity NA
Lubrication wet sump
Fuel tank steel, 5.3 gal (20.0 l),
Starting system electric only
Instrumentation speedometer, odometer, tripmeter
Ignition computer controlled solid-state CDI
resetable to zero, tachometer, turbo
Charging system 12-volt; alternator voltage regulator,
boost gauge, temperature gauge,
rectifier
fuel gauge, digital clock
DRIVETRAIN
PERFORMANCE
Primary drive straight cut gears, ratio NA
Fuel consumption ..................NA
Clutch wet, multi-plate
Range, maximum....................NA
Driveshaft-to-
Range, reserve only ................NA
rear-wheel spiral-bevel gears; ratio NA
Speedometer error,
30 mph indicated ..................NA
Gear Internal Overall MPH per
gear ratio gear ratio 1000 RPM Speedometer error,
60 mph indicated ..................NA
I NA NA NA
Best 1/4-mile acceleration ......NA
II NA NA NA
Top speed (observed)..............NA
III NA NA NA
Stopping distance
IV NA NA NA
from 30 mph ........................NA
V NA NA NA
Stopping distance
from 60 mph ........................NA
SUSPENSION/WHEEL TRAVEL
Front air-spring, 37mm stanchion tube AVAILABLE COLOR: Pearl White
diameter/50in (127mm)
These weights, measures and power curves refer to a prototype
Rear Pro Link air-spring/4.8 in (122mm)
motorcycle horsepower figures supplied by American Honda
Motor Company
TURBO MOTORCYCLE INTERNATIONAL OWNERS ASSOCIATION " FALL 1998 23
it s not everyman s bike. That s
why only a small number will be
built, and why Honda doesn t
foresee turbos making normally
aspirated motors obsolete, at least
not in the predictable future.
Instead, Honda sees turbocharg-
ing as an alternative to, not a
replacement for, the present style
of doing things, a new way in
which the amount of performance
in a given engine need not be
directly proportional to its cc
inventory.
One way or another, though, all
of this adds up to controversy, just
as every great stride forward in
technology through motorcycling s
many years has motivated enthusi-
asts to choose up sides and wage
philosophical cold war. And just as
always, the technocrats will love
the new idea, the traditionalists
will hate it, and in the end they ll
all have to come to accept it.
Because it will happen, this tur-
bocharging business, and you can bet your bottom dollar on it.
So umpteen years from now, when you look back at what happened
to motorcycling in the last half of this century, the CX500 Turbo will
stand as a monument, a milestone in time that marks one of the more
important turning points in moto evolution. It probably won t turn out
to have been the best turbo bike, nor the cheapest nor the fastest nor
the most sophisticated. But it ll always be the first real turbobike, and
a pretty damned fine one, at that.
So maybe Honda was right after all. This bike is a message from the
future. We just didn t realize that the future is now.
24 TURBO MOTORCYCLE INTERNATIONAL OWNERS ASSOCIATION " FALL 1998