Born on the Track - Origins of the 1977
Chevrolet Monza Mirage
by Stacy Scharch
All new 1975 Chevrolet Monza 2+2 Hatchback
Debuts
The new H-body platform from GM was this 1975
Chevrolet Monza 2+2 Hatchback. Engines offered were 2.3L 78
hp 1-bbl, 2.3L 87 hp
2-bbl, 4.3L (262 cid) V8 110 hp 2-bbl, and
5.7L (350 cid) V8 125 hp 2-bbl. (California emission).
Transmissions were 4 or 5-speed Manual or a Turbo Hydra-matic.
The
Chevrolet Monza H-body production vehicle was GM's
first car project that was designed using CAD (computer
aided design) technology. Chevrolet needed an answer to the
foreign subcompacts and the 1974 Mustang II, which were
making the best of the 1973 gas crisis.
The car was originally designed to be powered by GM's new
Wankel engine that was under development but later dropped
because of reliability and fuel economy issues. Also,
expensive royalty payments to the patent holder made the
engine platform less appealing. It was essentially a Vega
H-body chassis lengthened by 4 inches for styling and to
accommodate enough space for a Chevrolet small-block V8. GM
had high hopes for their new EPA driven down-sized sports
sedan with good performance potential.
The new H-body Monza, hit showrooms in 1975 in three
different models: A mid-year introduced notchback coupe and
two hatchbacks, the S and the 2+2. But next to the
hatchbacks that debuted to the press in July 1974, Chevrolet
slipped in a full-bore, flared-fender Race Car that was made
possible only through the efforts of Vince Piggins, who led
Chevrolet's Product Promotion Engineering Department.
Purpose-built, tube-frame racecar
This was the IMSA GT racecar that inspired the Monza Mirage
street version. The racecar was created by Lee Dykstra and
Horst Kwech of DeKon Engineering, LTD. This is DeKon
c/n1005 driven by Horst
Kwech at the IMSA Camel GT, 6 Hours of Mid-Ohio endurance
race in
Lexington, OH on August 24, 1975. The car sold to notable
racer and friend Allan Moffat later in the year. He fell for
the car's ease of handling and top speed of 202 mph at
Daytona.
Al Unser piloting
a Monza DeKon c/n1003 tube-frame built racecar at the IMSA
Camel GT - 250 mile Daytona Finale on November 30, 1975. As
you can see these racecars were almost identical looking.
Al Holbert's championship winning Monza was built by DeKon
Engineering as chassis #1008. Shown at the IMSA Camel GT -
Daytona Finale 250 Mile on November 28, 1976.
The red, white
and blue DeKon cars, specifically the No. 1 car campaigned
by Mike Keyser, made an impact on the public. Think about
it, American cars racing against domineering foreign cars on
American soil during the American bicentennial year, and
then actually winning.
The car was interesting enough to convince John Bishop of
the International Motor Sports Association (IMSA) to
initiate an entirely new racing class to allow "silhouette"
construction techniques, in which the profile of the car
stayed relatively the same, but covered a purpose-built,
tube-frame chassis.
Racers were anxious to get their hands on something that
would give Porsche a run for their money in the burgeoning IMSA Camel GT
Challenge Series and its new class AAGT (All-American Grand Touring).
The
General Motors Corporation contracted with DeKon
Engineering, LTD of Libertyville, IL to design and build the
first of several Monza bodied race cars. DeKon was the
partnership of automotive engineer Lee Dykstra,
formerly with Kar Kraft Engineering, and Horst Kwech
a racecar builder and SCCA Trans-Am championship driver. The
company name was a concatenation of 'De' for design and 'Kon' for
construction and used the first letter of te owners last
names.
In late
1974, DeKon received their first Monza body, a stripped
chassis, produced at GM's St. Therese assembly plant in
Canada and began building chassis #1001. The new race chassis
used structural tubing to build a space-frame that was clad
with an OEM Monza tub. Only the
original doors, roof, and rear deck lid remained. The front
end of the factory chassis was cut off and fitted with
specially designed serviceable framework for the engine and
new fiberglass body panels. The original fenders were
replaced with wide fiberglass flares. An aerodynamic front
air dam and rear wrap-around spoiler was added. A custom
designed coil-over suspension was bolted to the frame along
with large
diameter air-cooled brakes and Lockheed 8-piston calipers.
Big beefy
slicks were mounted on lightweight BBS wheels at all four corners. Extensive testing took place at GM Technical Center in Warren, MI to analyze
the racecar's suspension and handling characteristics.
A 5.7 liter Chevrolet
small-block V8 engine that developed as much as 600 hp was selected and strategically
positioned within the new frame. It was pulled back to the firewall and
offset a few inches from center to counter-balance the
driver's weight. This gave the DeKon Monza a near 50/50
weight distribution. The car weighed approximately 2,400
pounds when complete.
Chevrolet's showroom stock Monza had a MSRP of just under
$4,000. Then DeKon transformed into a lightning quick silhouette
racecar for around $37,000. They built fourteen Monza
racers, although not all of their chassis have an
identification plate. There were also many
other privateers who built Monza racecars for IMSA and
Trans-Am racing. DeKon became the most successful and well
known of the HO7 racecar builders.
Motorsports
Monza's participation in the IMSA Camel GT Challenge Series
new AAGT class allowed them to compete with the best GT cars
in the world. The 1975 season was launched with the new cars
that would compete with the dominating Porsche Carreras. A
very liberal set of rules allowed some body panels to be
retained - the windshield, the rear window and the roof.
Everything else was built from scratch.
Al Holbert saw the potential of the Monza. By the end of the 1975
season, he ordered a brand new car prepared by Dekon
Engineering. Chassis #1008 would be used starting for the 1976
season. Holbert won the IMSA Camel GT
Champion in '76 and '77, beating Hans Stuck, Brian Redman,
and Peter Gregg. Al's successful 1977 campaign he captured another
IMSA crown. Unfortunately, it would be the last title for an
American car.
The Porsche 935s were becoming unbeatable
right from the beginning of the 1978 season when IMSA
allowed the German cars (two) turbochargers. But, the
Dekon Monza left its footprint on the IMSA
Camel GT series. They were quite unbeatable in 1976-1977.
Chevrolet Monzas disappeared from the IMSA circuit after
1986, and descended to the ranks
of the SCCA Trans-Am pro series and its amateur club
racing.
Today, Monzas are still
roaring around the track at vintage races on the west
coast, out east, and down south.
The cars are still very exciting for race fans
to watch. A ground-up replica of
Monza DeKon #1006 was recently built in France and
apprears at the Le Mans Classic. The asking
price for a race-ready Monza is said to be more than
$250.000.
Then came the 1977 Chevrolet Monza Mirage sport package
Styling for the new 1977 Mirage trim package took its
queue from the highly successful IMSA GT racecar that
was so visually appealing, it gave rise to the idea of a sporty street
version option.
The 1977 Chevrolet Monza Mirage
was the result.
GM consulted with
Grand
Rapids, Michigan based BORT (British Overseas Racing
Team) to design a special limited edition body trim
package that was easily applied over the production
model's body.
Then
contracted with
Michigan Auto Techniques Corporation (MAT),
an aftermarket company,
to install the kit's components for the 8,000 or more orders
originally anticipated. The kit consisted of front and
rear fender flares, rear deck wrap-around spoiler,
unique competition striping and graphics, and
blacked-out headlight and lower front grille openings.
The front air dam was shipped inside the vehicle for
dealer installation to facilitate loading and unloading
during transit. These parts were manufactured by MAT
using Reaction Injection Molded (RIM) polyurethane
material.
The Mirage was only available in Antique White, with red
and blue racing stripes along the length of the car. It
also features flared body panels, and a special front
air-dam & rear spoiler.
The 305 cid engine was the only V8 option for the 1977
model year, although some Mirages with 4-cylinders were
produced.
The vehicles were built in GM's St. Therese, Quebec
plant and sent to MAT for modification, after which
they would ship completed cars to the dealer. There were
approximately 2,400 1977 Mirages made from MAT, but
there were also Mirages created by Chevrolet
dealerships, as the body add-ons and stripes were
available ordered through dealer parts.
Each Monza Mirage serial number
(from MAT) was affixed to a self-adhering
embossed vinyl "Mirage" plaque located in the
interior. Mirage serial numbers were consecutive
and recorded along with the VIN at MAT.
The Monza Mirage sport package was ordered through
participating Chevrolet dealerships as Model 1HR07 and was
only available in "Antique White".
After assembly of a base Monza 2+2 from the GM plant in
Canada, it was drop-shipped to MAT in Michigan where
specially designed exterior body panels and decal package
were installed. Fourteen separate urethane body parts
were mechanically fastened over the Monza's existing
bodywork.
It was shipped with the front air dam inside the car to
the dealership where the order originated.
A total 731,504 Monzas were produced in six years. The
rear-wheel drive H-body Monza, Sunbird, Skyhawk, and
Starfire were replaced in the spring of 1981 with a new
front-wheel drive line-up, the J-car models: Chevrolet
Cavalier, Oldsmobile Firenza, Buick Skyhawk, and the Pontiac
J2000 introduced as 1982 models. Because the forthcoming
J-body cars were to be sold as 1982 models, there was a long
production run of 1980 H-body models in order to provide
sufficient inventory to carry dealers until the spring of
1981.
Today, there are an estimated 25-30 Monza Mirages
in running order.
