Build catalogue
Albert Gary's 1971 TR6 with Supercharged Ecotec LSJ Engine
britishv8.org
Photo: britishv8.orgA 1971 TR6 rebuilt around a supercharged Ecotec LSJ four-cylinder
Albert Gary swapped his Triumph TR6's straight six for a supercharged 2.0L Ecotec LSJ four-cylinder pulled from a wrecked Chevy Cobalt SS, paired to a Borg Warner T5 five-speed and a Nissan R200 limited-slip rear end. The build is notable for the amount of fabrication needed to package a small, transverse FWD engine and its supercharger into the TR6's engine bay, including custom exhaust, steering, mounts and wiring. Finished in June 2012 and dyno tuned, the car made 219 rwhp at a claimed weight of 2335 pounds.
Specs
As the owner states it.
- Engine
- Chevrolet Ecotec LSJ 1998cc inline four, supercharged, from a 2006 Cobalt SS, 9.5:1 compression, Eaton M62 (GM Stage 2) supercharger with air-to-liquid heat exchanger
- Exhaust
- Modified Clear Image Automotive Pontiac Solstice-pattern tri-y header, ceramic coated, single 2.25 inch stainless tube, Borla muffler and stainless resonator
- Cooling
- Stock TR6 radiator with Goodparts radiator shroud and 16 inch PermaCool electric fan controlled by Cobalt PCM
- Gearbox
- Borg Warner World Class T5 five-speed (2.76 rev, 2.95 1st, 1.94 2nd, 1.34 3rd, 1.0 4th, 0.63 5th) with Quad4 Rods Ecotec-to-T5 bellhousing, custom pilot bearing, stock LSJ flywheel and pressure plate balanced, fabricated composite clutch disc, Howe hydraulic throwout bearing, one piece driveshaft
- Rear axle
- Good Parts Nissan R200 viscous limited slip differential, 4.08:1 gears, with Good Parts CV axle/hub conversion kit
- Front suspension
- Good Parts 1 inch lowered springs, stiffer anti-sway bar
- Rear suspension
- Good Parts 1 inch lowered springs, tube shock conversion
- Brakes
- Triumph master cylinder and power booster; stock front calipers and rotors with composite pads; aluminum finned rear drums with Morgan Plus 8 (0.875 inch) wheel cylinders
- Wheels
- Panasport 16x8 inch, front and rear
- Tyres
- Front General Altimax HP 205/55/R16, rear General Altimax HP 215/60/R16
- Weight
- 2335 pounds without driver
- Electrical
- Stock tachometer converted to electronic movement with 0-7000 rpm range, Innovate Motorsports wideband air/fuel gauge, Aeroforce Interceptor multi-function gauge with check engine light, Braille No Weight battery mounted in trunk
- Performance
- 219 rwhp and 213 lb-ft at 5800 rpm on 12.4 psi of supercharger boost
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.
Shop suggestions are being prepared. The owner's parts list is available below.
Engine 2
- Ecotec LSJ 1998cc supercharged inline fourMorad Parts Company
Donor engine for the swap, sourced from a wrecked 2006 Cobalt SS
- Eaton M62 supercharger (GM Stage 2)Eaton
Factory supercharger retained on the LSJ engine to produce boost
Fuel & Ignition 2
- Submerged EFI fuel pump
Installed in the TR6 fuel tank to supply the injected engine
- Chevy Cobalt fuel filter
Mounted on the TR6 framerail as part of the returnless fuel system
Cooling 3
- Air to liquid supercharger heat exchanger
Cools the intake charge, mounted near the radiator
- Goodparts radiator shroudGood Parts
Fitted to the stock TR6 radiator
- PermaCool 16 inch electric fanPermaCool
Controlled by the Cobalt PCM for engine cooling
Gearbox & Drivetrain 8
- Borg Warner World Class T5 five-speed transmissionBorg Warner / Dupont Engineering
Replacement gearbox chosen over the Solstice's Aisin AR-5 for taller first gear
- Quad4 Rods Ecotec-to-T5 bellhousingQuad4 Rods
Adapts the Chevy T5 bolt pattern to the Ecotec engine
- Custom pilot bearingDupont Engineering
Matched to flywheel and transmission input shaft
- Fabricated composite clutch discFort Wayne Clutch and Driveline
Custom made to suit the T5 input shaft
- Howe hydraulic throwout bearingHowe / Dupont Engineering
Installed with shims supplied for the T5 conversion
- 3/4 inch offset shifter leverDupont Engineering
Positions the shifter close to the original cockpit location
- Good Parts Nissan R200 viscous limited slip differentialGood Parts
Replacement rear end with 4.08:1 gears
- Good Parts CV axle/hub and differential conversion kitGood Parts
Converts the rear end to CV jointed axles
Suspension & Steering 5
- Good Parts 1 inch lowered front springsGood Parts
Lowers the front ride height
- Stiffer front anti-sway bar
Upgraded for handling
- Good Parts 1 inch lowered rear springsGood Parts
Lowers the rear ride height
- Rear tube shock conversion
Replaces stock rear shocks
- Air Lift air bagsAir Lift
Fitted for the rear springs
Brakes 2
- Morgan Plus 8 wheel cylindersGood Parts
0.875 inch bore rear wheel cylinders fitted in place of stock 0.70 inch units
- Aluminum finned rear drums
Replaced the stock rear drums
Wheels & Tyres 2
- Panasport 16x8 inch wheelsPanasport
Fitted front and rear
- General Altimax HP tyresGeneral
205/55/R16 front and 215/60/R16 rear
Interior 1
- Moto-Lita steering wheelMoto-Lita
Fitted in the cockpit
Electrical 4
- Innovate Motorsports air/fuel ratio gaugeInnovate Motorsports
Wideband oxygen sensor gauge added to monitor tuning
- Aeroforce Interceptor multi-function gaugeAeroforce
Displays engine data and check engine light
- Braille No Weight batteryBraille
Lightweight battery let into the trunk sheetmetal
- Modified engine wiring harness
Adapted from stock Cobalt harness for the swap
Tools & Workshop 1
- Outerwears filter coverOuterwears
Protects and extends the life of the oiled gauze air filter element
Other 3
- Clear Image Automotive tri-y exhaust headerClear Image Automotive
Pontiac Solstice pattern header, primaries cut and extended to fit the TR6, ceramic coated
- Borla mufflerBorla
Fitted in the single 2.25 inch stainless exhaust system
- Stainless steel resonator
Part of the exhaust system alongside the Borla muffler
Photos
All 40 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.
How it was done
Choosing the engine
Gary picked the supercharged Ecotec LSJ, the engine used in the Cobalt SS and Saturn Ion Red Line, sourced from a wrecked 2006 Cobalt SS via Morad Parts Company. He preferred the T5 gearbox over the Solstice's Aisin AR-5, feeling its first gear was too low, and had Dupont Engineering supply T5 cases along with a hydraulic throwout bearing and shims.
Exhaust and steering clearance
A Clear Image Automotive Pontiac Solstice-pattern tri-y header needed its primary tubes cut and extended to fit the TR6. The air conditioning compressor was removed to clear the steering rack, replaced with a custom fabricated pulley assembly, and the steering shaft was re-routed with extra universal joints to clear the supercharger and its heat exchanger.
Fitting the supercharger and throttle body
A fender indentation was made to package the supercharger, hoses and wiring. The throttle body initially interfered with the steering shaft, so its mounting flange was reinstalled with a 90-degree elbow. The brake booster was shifted outboard for supercharger clearance, and the supercharger's coolant pump was mounted on the framerail.
Driveline assembly
Fort Wayne Clutch and Driveline rebuilt the stock Cobalt pressure plate and fabricated a custom clutch disc to suit the T5 input shaft. A Quad4 Rods bellhousing adapted the Chevy transmission pattern to the Ecotec. Engine mounts were fitted on both sides and painted, and the exhaust tube was routed through the rear transmission mount.
Fuel and wiring
The stock engine wiring harness was modified for the swap, and a submerged EFI fuel pump was installed in the TR6 fuel tank. A Chevy Cobalt fuel filter was mounted on the TR6 framerail, taking advantage of the returnless fuel system so only one hose needed routing to the fuel rail.
Rear end and suspension
The Triumph rear end was replaced with a Good Parts Nissan R200 viscous limited slip differential at 4.08:1, using a Good Parts CV axle/hub conversion kit and Morgan Plus 8 wheel cylinders on new aluminum finned drums. Good Parts lowered springs were fitted front and rear, with a stiffer front anti-sway bar and a rear tube shock conversion.
Interior and finishing touches
A Moto-Lita steering wheel was fitted along with a converted electronic tachometer, an Innovate Motorsports air/fuel gauge and an Aeroforce Interceptor multi-function gauge with check engine light. The shifter location needed only minor changes to the fiberglass transmission tunnel, and a lightweight Braille battery was let into the trunk sheetmetal, hidden under the carpet.
Completion and results
The swap was completed in June 2012, and the car had covered about 4000 miles by December 2013. On a rolling road dyno used to test and tune the installation, it produced 219 rwhp and 213 lb-ft at 5800 rpm on 12.4 psi of boost, at a claimed 2335 pounds without driver.
A summary in our own words. The full account, with all its detail, is the owner's: read it at britishv8.org ↗
Worth knowing
- Fitting a transverse FWD engine into a TR6 requires major steering shaft rerouting for supercharger clearance.
- A stock exhaust header pattern may need primary tubes extended to clear the chassis.
- Choosing a taller first gear ratio gearbox (T5 over Aisin AR-5) suited road driving better.
- The brake booster and throttle body positions may need to be altered to clear supercharged engine components.
- A returnless fuel system simplifies plumbing when relocating the fuel pump and filter.