Ken Hiebert's 1972 TR-6 with 1994 GM "LT1" 5.7L EFI Engineas published in British V8 Newsletter, Volume XV Issue 2, September 2007
Owner: Ken Hiebert
City: Toronto, Ontario
Model: 1972 Triumph TR-6
Conversion completed by: owner
|Engine:||unmodified 1994 GM LT1 5.7L EFI from a Pontiac Trans Am.
|Fuel System:||fuel pump mounted in the tank with a modified fuel level sender unit.
|Cooling:||4-row crossflow radiator from a '69 Firebird. Ford minivan fan and shroud.
|Exhaust:||Jet Hot coated hugger headers into 2.25" stainless steel dual exhaust, routed
"through the frame".
|Transmission:||Borg-Warner T56 6-speed manual (first gear is 2.66:1 and both 5th and 6th are overdrives.)
Stock GM clutch with hydraulic clutch actuation.
|Front Suspension:||TR6 with polyurethane bushings. Spacers have been added to the lower control
arm assemblies to lower ride height. Sway bar has been routed above the front
skid plate to increase ground clearance.
|Rear Suspension:||narrowed 8" Ford axle with 3.55:1 gear, on leaf springs. A Panhard bar and custom
"slide-a-link" traction bars have been fitted.
|Brakes:||stock TR6 front brakes with "line lock" electric solenoid. Ford rear with
|Frame Mods:||frame rails have been double-boxed. A removeable secondary crossmember has
been fitted to link the motor mounts together. A new frame center section has
been fabricated to facilitate through-the-frame exhaust (i.e. the exhaust is
raised for increased ground clearance.) From the seats back, the original
frame has been replaced with a new structure that accomodates leaf springs.
The roll hoop is also tied into this structure.
|Wheels/Tires:||1986 Ford Mustang Cobra 15x7 wheels. Front hubs were redrilled and 3/4" spacers
were used. Front tires are 215/60 and rear are 225/70.
|Electrical:||the wiring, circuit protection, and electronic components such as the engine
computer and instrument panel from the Pontiac Trans Am donor car were used.
This provided bonus features such as cruise control and electronic diagnostics.
The wiring is generally installed in Pontiac's stock configuration, using the
underhood electrical center (i.e. fuses and relays). Extremely reliable GM/Delphi
(Packard Metri-Pack) connectors and terminals were retained.
|Steering Column:||Pontiac Fiero tilt, with GM anti-theft ignition key tumbler installed for
|AC System:||Vintage Air climate unit with heat and defrost. GM (Harrison) compressor.
|Performance Data:||255 hp and 301 ft/lbs torque at the rear wheels (as measured 9/18/2007
on a Dynojet rolling-road dynomometer). In 6th gear at 70mph the engine
turns 1600rpm. Average fuel economy is approximately 25mpg "city" and
30 mpg "highway" (Canadian gallon).
|Problems Overcome:||one bug I had to work out was a chirping noise from the serpentine fan belt.
Initially I thought it was the alternator or one of the four idler pulleys.
The belt system was custom made and it turned out I didn't get the spacing for
the harmonic balancer aligned properly. Adjusting the balancer solved the problem.
|Date Completed:||first run was on Christmas Eve 2006. Driven 5000km as of the British V8 2007 meet.
(Editor's Note: NO ONE at the British V8 2007 meet put more tough test miles on their car than Ken and Katie. Between these two drivers, this car made LOTS of fast laps around Nelson Ledges Race Track plus TEN autocross runs. I test drove this car and will testify that it's terrifyingly fast.)
Since original publication of this article, the following updates have been completed:
|Front Suspension:||upper control arms modified to add 3 degrees castor (changing total to 4.5 degrees).
Custom bump stops have been fabricated to limit suspension travel. Tie rod ends have been
replaced with Heim joints, installed so as to reduce bump steer effect.
|Brakes:||(front) Wilwood 4-pot calipers and 12.25" vented rotors.
|Frame Mods:||earlier roll hoop has been replaced with a custom double roll hoop, with wind blocker.
|Wheels/Tires:||Mustang Cobra R 17" wheels. (Front hubs redrilled to Ford pattern.) 245/45R17 tires.
|Interior:||Mazda Miata seats and seat belts.
|Performance Data:||273 hp max power and 359 ft-lbs max torque at the rear wheels, measured
6/8/2009 at Carolina Auto Masters in Durham, NC during BritishV8 2009.
|Miles Driven:||driven 37,000km as of October 2009.
1994 GM LT1 5.7L EFI V8 engine
LT1 engines feature "reverse-flow" cooling systems. The idea is to "cool the cylinder heads
first". Resulting lower head temperatures are part of a strategy that allows relatively high
compression without detonation (pre-ignition) compared to similar small block V8 engines.
Chevrolet Corvette covers really set-off GM LT1 engines (but this particular engine came from a Pontiac Trans-Am).
K&N air filter and Pontiac Trans Am throttle body
AC condensor... and very wide crossflow radiator!
GM (Harrison) AC compressor
Packard Metri-Pack firewall electrical pass-thru and steering column
Windshield wiper motor and cruise control module
Pontiac engine control module (ECM)
4-row crossflow radiator from 1969 Firebird. Chrysler minivan fan and shroud.
Line lock solenoid, clutch fluid reservoir, and brake proportioning valve
An additional crossmember has been added between the motor mounts.
Through-the-frame exhaust, with heat shields.
Removable (bolted-in) transmission mount.
Upper control arms have been modified to add 3 degrees castor (changing total to 4.5 degrees).
TR6 lower control arm, with lowering spacers
Sway bar has been routed above the front skid plate to increase ground clearance.
Heim joints installed in lieu of tie rod ends have facilitated a reduction in bump steer.
Custom bump stops have been fabricated to limit suspension travel.
Wilwood 4-pot calipers and 12.25" vented rotors. (Front hubs redrilled to Ford pattern.)
Traction bar mounting on the leaf spring u-bolt/shock-absorber bracket.
Custom slide-a-link traction bars.
Ken Hiebert at BritishV8 2007 in Willoughby Ohio.
Charming and worldly racecar driver Katie Ermakovich, at Nelson Ledges.
Ken and Katie enjoy participating in an autocross.
With updates, this is how Ken's TR6 looks as of autumn 2009.
Pontiac Firebird Trans-Am instrument cluster, plus Pontiac Fiero steering column and wheel.
Mazda Miata seats. Custom double roll hoop, with wind blocker.
Mustang Cobra R 17" wheels with 245/45R17 tires.
Roll hoop and luggage rack.
Wilwood front brake caliper, viewed through Mustang wheel.
Dynomometer tuning at Da Silva Racing
273 hp max power and 359 ft-lbs max torque at the rear wheels.