A 1994 Supra Turbo converted from the factory twin turbos to a single BorgWarner S300SX, with the fuel, ignition, and engine management to match.
This six-speed 1994 Supra Turbo came to me in April 2024, and the first visit was about making it right: a new clutch and pressure plate, a rear main seal, transmission seals and shifter bushings, a rebuilt clutch slave and master, a driveshaft flex disc, differential bushings, a power steering pump rebuild with a cooler, a new steering intermediate shaft, boost leak repairs, a brake flush, and a dead tachometer.
The dead tach
The tachometer did not work when the car arrived. I checked the whole tach circuit for continuity, which meant pulling the instrument cluster. With the cluster out, I opened it up, went over the circuit board, and repaired it at the board level, so the car kept its own cluster instead of getting somebody else’s used one.
Then came the single turbo conversion. The factory twin turbos came off and a BorgWarner S300SX went on a twin-scroll manifold, with new oil feed and drain lines. I fabricated the compressor elbow, a custom downpipe and mid pipe, the wastegate dump tube, the intake pipe, and aluminum charge piping to the intercooler. The EGR came off, the unused vacuum plumbing got cleaned up, and the fuel system got an upgraded rail, top-feed injectors, an adjustable regulator, PTFE lines, and a 525 LPH pump on a proper 12-gauge feed. R35 coils went in with an adapter harness.
The BorgWarner S300SX on its twin-scroll manifold, with the fabricated charge piping.
In 2025 it came back for a timing belt service with a billet crank sprocket and a cam/crank trigger kit, then a Haltech Elite 2500 on a new custom harness, with a CAN gauge, a wideband, and CAN boost control. Then it was tuned on the dyno.
The scope of work
Engine and timing
2JZ-GTE (non-VVTi) with a Gates RPM racing timing belt (aramid-reinforced), OEM timing pulleys and hydraulic tensioner, a PHR billet chromoly tensioner bracket, a PHR billet 36-2 crank sprocket, a new OEM front cover, and a new front crank seal
Turbo and wastegate
BorgWarner S300SX on a Supra Store twin-scroll T4 manifold with ARP turbo studs, a new 4AN oil feed and 10AN drain, and a PTP turbo blanket, with a TiAL MV-R external wastegate venting through an open dump tube fabricated in house
Exhaust and fabrication
Custom stainless downpipe and a brand-new 304 stainless mid pipe fabricated in house with V-band flanges, built to meet the downpipe and mate to the TRD exhaust so the original TRD mid pipe is preserved, plus a downpipe heat shield
Intake and charge piping
Compressor elbow fabricated in house, a 4-inch intake with a K&N cone filter, and a custom intercooler charge pipe with quick couplers, with a GM intake air temperature sensor welded into the stainless charge pipe
Fuel
PHR fuel rail, 850cc top-feed injectors, a Radium fuel pressure regulator damper with gauge, custom 6AN Redhorse PTFE fuel hose, and a 525 LPH Walbro (Hellcat) pump on a custom auxiliary fuel pump harness
Ignition
Full R35 smart coil conversion: Hitachi R35 coils on a Wiring Specialties harness, with 3D-printed adapters that fit the Supra coil boots to the R35 coils, designed and made in house (kit coming to the Built By Ben store)
Engine management and sensors
Haltech Elite 2500 with the full Haltech sensor package (5-bar MAP sensor, fuel pressure sensor, and boost control solenoid), a PHR cam/crank sensor package, a PHR Ford idle control valve conversion, and a Haltech CAN gauge with its wideband controller, plus an auxiliary AEM X-Series wideband for a visual readout in a dual pillar gauge pod
Wiring
Custom Wiring Specialties pro harness, a custom ECU and relay mounting plate made in house, and a dimple-died B3 cover so the passenger is not standing on the ECU, with the fans and fuel pump now triggered through the ECU
Oiling and leaks
Every oil leak fixed: valve cover gaskets, oil cooler, and oil level sender resealed, along with the oil filter housing and a rear main seal with its missing dowel pins installed
Emissions deletes
Radium EGR delete and Radium dual catch cans, with the throttle body heater hoses bypassed and the tubes removed, tapped, threaded, and plugged for good
Drivetrain and differential
V160 six-speed with new selector and output shaft seals, Titan Motorsports solid shifter bushings, and a rebuilt shifter, plus a complete restoration of the Supra Turbo big differential: cleaned, painted, resealed, and fitted with SuperPro poly mount bushings
Clutch
South Bend Stage 3 Endurance clutch kit with a new OEM throwout, a rebuilt clutch slave cylinder, and a new clutch master cylinder
Steering
Power steering pump rebuilt with a Derale fluid cooler and MagnaPure filter, and a new steering intermediate shaft and isolator
