In order to clean-up and protect the main engine harness we used a plastic loom retrofitted from a 1991 7MGE equipped Toyota Cressida, which mounts pretty much without any modifications. It keeps the wiring harness away from heat and adds a “cleaned-up” look. Also, on a subject of heat and appearance, a factory rubber lower radiator hose was replaced with a silicone unit from OBX. It’s a direct substitute for a factory original black hose, no modifications necessary. The fit is tight, and it requires strong hose clamps to prevent any coolant leaks. Otherwise - improved appearance and heat protection provided by a brand new piece.

Dealing with increased power output from the 7MGTE meant upgrading the clutch system to better transfer the power to the ground. An ACT pressure plate provides 30% increase in clamping power. Combined with better friction clutch disk it improves clutch grip and holding capacity while providing perfectly streetable slip without chatter, with near stock pedal feel. To allow more power from the engine to go directly to the wheels the stock, heavy flywheel was replaced with XTD Prolite chromoly lightweight flywheel. Made from high-carbon steel, its surface allows the use of any type of friction disk, from carbon-kevlar, ceramic copper, to sintered iron. Much lighter than stock (12 lbs), it allows for better engine response and faster acceleration.

Everybody knows that oil change in a mkIII Supra is not the cleanest procedure. Factory location of the oil filter over front subframe makes it difficult to access plus oil spills are hard to contain and clean up. Here’s where Greddy Oil Filter Relocation Kit comes in. Moving the filter to a more easily accessible location not only allows for better access and spill-free oil changes, but also makes it possible to use a larger (longer) oil filter (from Toyota pick-up trucks). Larger filter means larger filtering area - cleaner oil. Higher oil capacity means more oil in the system - which also translates into cooler and cleaner oil. All in all - it’s a win-win situation.

Next step in this upgrade was the use of Mine’s tuned 7MGTE ECU. Although this Japanese tuner is best know for their tuning of Skylines GT-R, they have also been providing ECU tuning for other major JDM makes. Some of their technology is based on the VX-ROM boards added to factory ECUs thus allowing for improvements of the original ECU programming. Changes to this particular unit as well as most of other 7MGTE Mine’s tuned computers include removed rev limiter, removed boost cut, removed speed limiter, improved fuel and ignition maps as well as added fuel maps above factory boost levels. The overall effect is a more responsive, faster and higher revving engine, safe fueling as well as more room for additional mods.

An oil catch can on a race car is supposed to aid in removing oil vapors from air being recirculated from the crankcase back into the intake manifold. However, has anyone ever noticed that unlike the vapor filtration system located inside the valve covers and consisting of multiple baffles with “strainer” holes, oil catch cans usually are hollow inside, thus allowing for fairly unrestricted air flow. “Strainer” baffles are meant to create a resistance to flowing air thus allowing for oil to deposit on the baffles and flow down to the bottom of the engine. The same philosophy was applied to the Greddy catch can on “Project Black” and the oil catch can strainer baffle was born. The baffle is positioned in such a way that it divides the inside of the catch can in two chambers forcing the air to flow through the strainer.

Unfortunately after using Autometer gauges for awhile we have determined that their readability at night is less then optimal. To improve gauge readouts we decided to switch to Stewart-Warner gauge set. Although the overall size remained at 52mm (2-1/16″) the new design of the Stewart-Warner gauge trim ring allows for larger display area. New “lighting technology” is also supposed to improve night-time readouts. This gauge set includes Coolant Temperature Gauge and Boost Gauge.

Power steering reservoir on turbo mkIIIs is located in an unfortunate spot where not only is it exposed to hot air blown through the radiator, but also it is blocking the same air flow from moving though around the turbo and thus helping to cool it. Unlike previous years, Supra model years 1991 and 1992 had an improved “power steering cooler”, upgraded with cooling fins vs. just a bent pipe running in the nose of the car. Apparently there must have been an issue with power steering fluid temperature that prompted this fix. In an attempt to remedy this problem on “Project Black”, a power steering fluid reservoir was replaced with a plastic unit from another Toyota car and moved away from the original location. The new placement allows for better cooling for both the power steering fluid and the turbocharger.

Fuel system is another area where mkIII Supras need some help. To ensure that there is enough fuel supply for the targeted higher horsepower, an adjustable fuel pressure regulator from Aeromotive was installed. A fuel pressure gauge mounted on the fuel rail provides accurate fuel pressure readings helping in setting of base line fuel pressure of 40psi. Base fuel pressure setting needs to be done with engine not running. With the ignition in “ON” position, connect “B+” and “Fp” points on the Diagnostic Connector under the hood to pressurize the fuel system.

To improve performance of the Supra ignition system, an HKS Twin Power DLI ignition amplifier was installed. The Twin Power ignition amplifier incorporates both the CDI and transistor method ignition to provide optimum spark duration and maximum voltage output, resulting in crisper throttle response and a smoother engine powerband. The effects of this upgrade were felt during first drive after the install.

A set of Bortex RPM 18″ rims from Enkei was wrapped in low profile Falken tires and installed on all four corners. Front brakes were also upgraded with custom combination: a pair MkIV Supra 12″ directional rotors custom fitted, in combination with Nissan 4 piston aluminum brake calipers installed using custom brackets from supracarparts.com. Custom made brake pads were utilized. Goodridge stainless steel braided brake lines replaced factory rubber lines to minimize the “spongy” feel of the brake pedal.

Since the original grey leather interior was in a dismal shape it was necessary to step up and replace it with custom leather. A two-tone red and grey design was chosen to coordinate with dashboard and trim colour and to add a little “spice” with an accent colour. Passenger and cargo area carpet was also replaced with a molded replacement piece. Extra padding was added to improve soundproofing. New floor mats were installed.

An excellent upgrade for manual transmission cars is removal of the throttle linkage assembly completely (look at the pics) and replacing it with JDM-style assembly which gets rid of the useless levers and springs. JDM cars being right hand drive never had this linkage, and trust me, the throttle response of the engine without it is so much better, you’d think it’s a different car altogether. The throttle pedal movement is a lot smoother and crispier, it gives you much faster response due to different ratios - it’s like a throttle pulley upgrade for Nissans. It’s one of the best feeling upgrades for the mkIII. It doesn’t give you more power, however power delivery is so much faster, that the car feels much stronger and more responsive.

Here is a photo depicting visual differences between Toyota Supra factory original pistons & connecting rods (on the far right) vs. JE pistons & Eagle rods (on the left). The piston skirt length and design is apparently different, and so is the piston ring thickness and location.

A set of Supra Japanese Domestic Market (JDM) power folding mirrors was also installed. A control module was mounted in the passenger side door, inside a space already allocated at the factory (much like the space for the power door lock unit on the driver side). Additional wiring was added. Original power mirror switch was also replaced with a JDM unit equipped with a “retract” button. For a complete wiring diagram click here.