Build catalogue

Jay Foster's Triumph TR7 V6 conversion

Jay Foster · Triumph TR7

Triumph TR7

britishv8.orgas recorded by Dan Masters

Read the full write-up at britishv8.org ↗

A 1980 Triumph TR7 rebuilt with a Ford 3.8L V6

Jay Foster replaced the TR7's original drivetrain and front suspension with Ford-sourced components, centered on a 1990 Ford 3.8 liter SEFI V6 and a Ford McPherson strut front end. The rebuild specifically targeted the TR7/TR8's well known high-speed shimmy by fitting a new Ford sub-frame bolted solidly to the unibody, along with a matching Borg-Warner T5 gearbox, Ford axle, and Ford brakes.

Specs

As the owner states it.

Engine: 1990 Ford 3.8 litre SEFI V6, EEC-IV engine control
Front Suspension: German Ford McPherson strut with rear mounted sway bar, power rack and pinion steering, Mustang tilt steering column
Rear Suspension: Modified British Leyland trailing arms with adjustable shocks
Front Brakes: Ford 10-inch vented disks with a quad diagonal hydraulic system
Rear Brakes: Ford 9-inch drums
Rear Axle: Ford 7.5-inch limited slip, 3.08:1
Transmission: 1995 Borg-Warner T5 with hydraulically operated 11.5-inch clutch
Electrical & Electronics: Customized Ford wiring with some Lucas components, Ford Thunderbird LCD instrument cluster
Heating and Air-Conditioning: Ford vacuum electronic servo system

Parts used

What the owner names in the write-up, grouped the way the Parts page groups them. Where one of the shops we index lists the same thing for this car, it is shown underneath with a link to the shop.

Engine 1

Ford 3.8L SEFI V6 engine (1990)Ford
Replacement engine for the TR7, run with EEC-IV engine control

Fuel & Ignition 1

EEC-IV engine control systemFord
Manages fuel injection and ignition for the Ford V6 swap
In the shops
Engine Control Unit (ECU) for EFI Systems ↗Racetorations· £859.10 GBP

Gearbox & Drivetrain 3

Borg-Warner T5 gearbox (1995)Borg-Warner
Manual transmission paired to the V6, operated via hydraulic clutch
In the shops
Selector Rod Connecting Clip (Borg Warner) ↗James Paddock Ltd· £1.35 GBP
Driveshaft Components (Mk II with Borg-Warner 35 Automatic) ↗Moss Motors – Triumph TR6/TR250· $0.00 USD
Hydraulic 11.5-inch clutch
Operates the T5 gearbox
In the shops
Clutch Hydraulic Connector ↗Betaset (France)· €15.99 EUR
Clutch Hydraulics Refresh Bundle ↗Flyin' Miata· $362.47 USD
Clutch Hydraulic Replacement Kit ↗ANG Classic Car Parts· £62.15 GBP
Ford 7.5-inch limited slip rear axle, 3.08:1Ford
Rear axle and final drive fitted to suit the V6/T5 drivetrain
In the shops
Hardy Spicer Output Shaft (Limited-Slip Differential) - Mini ↗Betaset (France)· €206.96 EUR
Red Line Limited-Slip Friction Modifier & Break-In Additive (118ml) ↗MazSpec MX-5 Spares & Accessories· £15.00 GBP
Red Line Limited Slip Friction Modifier & Break-In Additive (Pack of 3 x 118ml) ↗MazSpec MX-5 Spares & Accessories· £39.95 GBP

Suspension & Steering 6

German Ford McPherson strut front suspensionFord
Replaced the factory TR7 front end to correct geometry and reduce shimmy
In the shops
Adjustable Suspension Control Arm (Mazda/Ford/Volvo) ↗Sports & Classics· $59.95 USD
Rear mounted sway bar
Heavier bar credited as main fix for the TR7's suspension handling problems
In the shops
Rear Sway Bar, Heavy Duty ↗Moss Motors – Triumph TR6/TR250· $215.65 USD
Sway Bar End Bush ↗Moss Motors – Triumph TR6/TR250· $10.25 USD
Sway Bar Bush Set ↗Moss Motors – Triumph TR6/TR250· $0.00 USD
Ford sub-frameFord
Bolted directly to the unibody in place of the rubber-mounted factory K-frame
In the shops
Polyurethane Sub-Frame Bushing Set (TR7-TR8) ↗bpnorthwest.com· $44.95 USD
Rear Sub-Frame Mount ↗Moss Motors – Triumph TR6/TR250· $168.94 USD
Front Sub-Frame Mount ↗Moss Motors – Triumph TR6/TR250· $21.99 USD
Power rack and pinion steering, variable assist
Provides road feel at highway speed, mounted under the oil pan area
In the shops
Power Steering Rack and Pinion Kit ↗Moss Motors – Triumph TR6/TR250· $0.00 USD
Steering Rack Boot Kit (MGB, TR7) ↗bpnorthwest.com· $16.25 USD
Steering Rack Boot Kit with Metal Clamps ↗bpnorthwest.com· $22.35 USD
Mustang tilt steering columnFord (Mustang)
Fitted with the Ford front end conversion
In the shops
Steering Column Top Bush ↗Moss Motors – Triumph TR6/TR250· $7.70 USD
Lower Steering Column Bush ↗Moss Motors – Triumph TR6/TR250· $16.99 USD
Steering Column Tilt Lever ↗Motaclan Limited· £0.00 GBP
Modified British Leyland trailing arms with adjustable shocksBritish Leyland
Rear suspension retained from British Leyland but modified with adjustable shocks
In the shops
British Leyland Ignition Key Blanks ↗Moss Motors – Triumph TR6/TR250· $9.75 USD
Trailing Arm Bracket Kit, Adjustable ↗Good Parts· $149.00 USD
British Leyland Badge, Silver on Blue ↗Moss Motors – Triumph TR6/TR250· $8.75 USD

Brakes 2

Ford 10-inch vented front disc brakesFord
Front braking upgrade run on a quad diagonal hydraulic system
In the shops
Front Vented Brake Disc ↗Motaclan Limited· £85.77 GBP
Vented Front Brake Disc ↗Motaclan Limited· £85.77 GBP
Vented Front Brake Disc ↗Motaclan Limited· £104.44 GBP
Ford 9-inch rear drum brakesFord
Rear braking to match the front disc upgrade
In the shops
Rear Drum Brake Clip ↗Motaclan Limited· £0.00 GBP
Rear Brake Hose (Drum Brakes) ↗Motaclan Limited· £27.26 GBP
Rear Brake Drum (Mini 1984 On) ↗bpnorthwest.com· $42.07 USD

Electrical 2

Ford Thunderbird LCD instrument clusterFord (Thunderbird)
Installed in the dashboard for instrumentation
In the shops
Instrument Cluster ↗Moss Motors – Triumph TR6/TR250· $0.00 USD
1957 Ford Thunderbird Red Sun Visor Pair ↗Sports & Classics· $149.95 USD
1957 Ford Thunderbird Green Sun Visor Pair ↗Sports & Classics· $149.95 USD
Ford vacuum electronic servo heating/AC systemFord
Provides heating and air conditioning control
In the shops
123 Ignition Electronic Igniter - Ford Kent ↗Betaset (France)· €474.24 EUR
123 Ignition Electronic Distributor - Ford Kent ↗Betaset (France)· €465.12 EUR

Photos

All 8 pictures in the write-up, in the order they were posted, shown from britishv8.org. A picture opens larger here, with the way through to the page it is on.

Jay Foster's Triumph TR7, with a 3.8L Ford V6Photo: britishv8.org

Ford 3.8L fuel injected V6 enginePhoto: britishv8.org

TR7 dashboard with Ford steering wheel and instrumentsPhoto: britishv8.org

How it was done

Replacing the drivetrain

Jay fitted a 1990 Ford 3.8 litre SEFI V6 running EEC-IV engine control, paired with a 1995 Borg-Warner T5 gearbox operated through a hydraulic 11.5-inch clutch. The rear axle became a Ford 7.5-inch limited slip unit geared at 3.08:1, matching the new engine's output to the rest of the drivetrain.

Fixing the front suspension

Jay considered the factory TR7/TR8 front suspension weak, poorly geometered, and prone to shimmy at 45 and 60 mph. He swapped in a German Ford McPherson strut setup with a rear mounted sway bar, and replaced the rubber-mounted factory K-frame with a Ford sub-frame bolted directly to the unibody for a stiffer, better located front end.

Steering and brakes

Power rack and pinion steering was fitted with a variable assist system, giving what Jay describes as good road feel at highway speed, along with a Mustang tilt steering column. Braking was upgraded to Ford 10-inch vented front discs on a quad diagonal hydraulic circuit, with Ford 9-inch drums at the rear.

Electrics and cabin comfort

The electrical system was a custom blend of Ford wiring with some Lucas components, and Jay installed a Ford Thunderbird LCD instrument cluster in the dash. Heating and air conditioning were handled by a Ford vacuum electronic servo system.

A summary in our own words. The full account, with all its detail, is the owner's: read it at britishv8.org ↗

Worth knowing

The factory TR7/TR8 front suspension geometry was flawed and caused shimmy at 45 and 60 mph.
Bolting a new sub-frame directly to the unibody, instead of using rubber K-frame mounts, corrects handling problems.
A heavier, rear mounted sway bar is the main fix for the model's suspension weaknesses.
Variable assist power steering can still deliver good road feel at highway speed.