Those who are familiar with the Callaway name know it is much more than unique, cutting edge styling. For those who are not, this page seeks to familiarize the public as to the "Powerfully Engineered" work behind the massive power and torque of Callaway Twin Turbo Corvettes.
The first and most obvious change is apparent upon lifting the hood. As you can see in the picture below, the most noticeble change is the Aluminium air-air Intercoolers which connect to the throttle body through an M shaped tube called the Rams Horn. The purpose of the intercoolers is to cool the compressed air (which heats up during the process of compression) as it leaves the turbo's.
At the tip of the Rams Horn, two additional fuel injectors provide extra fuel when the turbo's go into boost so the engine does not starve for fuel as more air is forced through the throttle body. The fuel injectors are wired to a device located under the instrument panel called the Microfueller which monitors the distributor and tells the additional fuel injectors when to provide extra fuel. A very large Bosch fuel pump replaces the standard fuel pump in the tank to provide the extra fuel pressure to the 295 lb/hr fuel injectors.
Another visible difference is a rectangular shapped device between the fan and the upper radiator hose. The purpose of this device is to remove any air bubbles which may enter the oil stream. The turbo's are both oil and water cooled since they get quite hot as exhaust gasses pass through the exhaust side of the turbos via a turbo oil sump tank and pump.
Other visible items in this picture (slight variations exist in earlier models) include the black wrinkle finish paint on the runners and upper intake cover, heat shielding of various hoses and lines to protect them from the extra heat, blue anodized finish on various hose fittings and A/C condensor, and polished tubing.
Additional Engine work done in the conversion process and not visible include: Engine block 4 bolt main caps, splayed bolt style; Michigan Engine Bearings; Forced Gas Nitrided Crankshaft, 60Rc Journal hardness; Proprietary Mahle Forged Pistons with 7.5:1 compression; Plasma Moly Ring package; High Volume Oil pump; Engine Oil cooler; Stainless Steel inlet and exhaust valves; up-rated valve springs; Steel Roller Camshaft & Hydraulic roller lifters; Specially hardened distributor drive gear; Dry sump pump for turbo oil scavenge; and polished air inlet castings. Balance and Blueprint operations include: Magnaflux Block and crank assembly; cranshaft journals cross drilled and micropolished; aluminum cylinder heads decked; line bore main bearing caps and block; decks squared to crank centerline; all galleries cleaned and replugged; valve springs shimmed for equal pressure; and all threads chased. My car benefits from aditional boring, sleeving, custom pistons, porting, heads decked, special Callaway stainless headers, turbos ported and heavy duty wastegate springs installed, and a custom 2.75in mandrel bent and laser cut exhaust with less restrictive/high flowing random technologies catalytic converters, a Centerforce clutch and single mass flywheel.
Some vehicles are also fitted with Coilover suspension, Center Exhaust, and ultra light weight Callaway/Dymag Wheels.
Yet another difference upon further and close inspection (beginning with 1991 models) is the addition of the Wonderbar. The Wonderbar is a modification to the air intake system in which the front frame is modified and used as a duct to route air to the turbo's. This modification provided greater air flow to the turbo's which resulted in an increase in power.
Looking below the engine, you will obviously notice the Rotomaster T04b Turbo's on either side just in front of the catalytic converters. The turbo's are wrapped in shielding material to protect them from sudden temperature changes (water splash) which might cause the housing to crack when hot. You can also see the exhaust and turbo air up hoses as well as the additional coolant and oil lines to the turbo's. The oil lines are connected to a triangular reservoir located just in front of the oil pan.
Another modification of interest here is that the starter is repositioned due to the placement of the passengers side turbo. The starter is placed upside-down from its original location and mounted on the visible blue anodized adapter. Additional heat shielding is also installed.
In the front of the engine, one of the pulleys is converted to an oil sump pump to provide added oil pressure to the turbo's. By converting the pulley to a pump, this increased the length of the serpentine belt making the belt a custom size. (See picture below)
About Luigi's B2K
For Luigi it all started after selling one of his two 1987 Buick GNX's. "I remembered that the only thing American that could touch the Grand Nationals in the late 80's were the famous Callaway Twin Turbo Corvettes. But honestly, I didn't know too much about them. After doing a bit or research, I was in awe over the engineering work done for the turbos, the mean look of the intercoolers, and I absolutely fell in love with the Aerobody cars. I knew I had to have one and it had to be a convertible."
Luigi
had seen various ads for Callaways but as it turned out he
had a business trip to LA where several Callaways were for sale at
Corvette
Mike. They had a black 87 coupe, turquoise 91 Aerobody convertible, and
the
Yellow pearlscent Speedster.
"Honestly,
the ad for the turquoise 91 wasn't the most
appealing and I never went with the intention to buy her but, when I
saw the
car in person and I drove her, I knew I was not leaving without her.
The
pictures I had seen had not done
the car any justice." With a deal made, off to
Luigi's
car is a 1991 Turquoise Convertible, #26 of 62. He is the
second owner. The car was delivered new from Callaway to Anderson
Chevrolet in
In
1993, the prior owner had sent the car back to Callaway for a
475 HP (634 Ft. Lb Torque) upgrade. His car had the same engine
upgrades that
had been installed in the Speedsters, a nearly $10K upgrade from its
1991 price
of $100,884. His car also sports the same OZ 3 piece wheels optioned
with
Speedsters, which Corvette Mike had chromed. The car also has a ZF 6
speed
manual transmission, Adjustable Ride Suspension, a Bose Concert Sound
system,
and rare optional hardtop as well.
"Since
then I have not only enjoyed the pleasures of this
magnificent car but I have become a complete Callaway fan. In 2002, I
drove her
from so.
It
should be mentioned, that this B2K was selected by Corvette Mike, at
the 2002
Callaway Reunion at
RPO Codes from Luigi’s 1991
Callaway Twin Turbo Corvette
AC1 6 way Power Seats – Passenger
AC3 6 way Power Seats – Driver
AJ3 Front Seat Inflatable Restraint
AQ9 Passenger/Driver Reclining Seats
BGR
B2K Callaway Twin Turbo (Console Lid RPO option code)
C05 Convertible Folding Top
C68 Electronically Controlled A/C
DL8 LH/RH Heated Sport Mirrors
D3X Speedometer Driven Gear (25513049)
D8I Speedometer Sensor (10456089)
E5Z Delete Speedometer Adapter
E9Z Delete Speedometer Key
FE1 Soft Ride Suspension
FX3 lectronic Ride Handling
GM3 3.45 Ratio Rear Axle
G87 Ring Gear 8.50 Inch
IL3 Interior Trim Design L3
J55 Heavy Duty Brakes
KC4 Engine Oil Cooler
K68 105 Amp Alternator
L98 8 cyl 5.7L Engine
ML9 ZF 6 speed Transmission
MN6 6 Speed Manual Transmission
NA5 Federal Emission System
NK4 Sport Leather Steering Wheel
NN5 California Emissions compliance
QA1 17 x 9.5 Aluminum Wheels
R8T Control Sales Item 69
UX0 Delco Bose 6 Speaker System
U1F AM/FM Radio w/CD & Cassette
U52 Electronic Instrument Cluster
U75 Power Antenna
VG8 Vehicle Label-Notice to Buyer
V73 Vehicle Statement Certification
XAU P275/40ZR17 Tires Front
YAU P275/40ZR17 Tires Rear
Z5G Callaway Conversion Option (as listed in Build Sheet)
1AY Stock Order
1SB Marketed Option Package 2
191 Black Interior Trim
193 Black Leather Trim
199 Black Seat Belt
41T Black Convertible Top
42U Turquoise Metallic Color
Callaway Installed Options:
B2K Callaway Twin Turbo
Aerobody Kit
475 HP upgrade (same as Speedster)
3pc OZ Wheels (same as Speedster)
KoolOff Windshield