Stage VII 89 Turbo at Zupan's Historic Races '99
1989 Toyota Supra Turbo
~360 rwhp
Stage VII+
Stage VII 89 Turbo at Zupan's Historic Races '99
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Performance Mods / Info Index
Engine Mods
Fuel System Mods
Controller Mods
Additional Gauges
Suspension Mods
Powertrain Mods
Brake Mods
Lighting Mods
Performance Coatings
Engine Rebuild Info
Lubes/Minor Mods
7M-GTE Cut-Away
MA71 Cut-Away

Personal Mods Index / Misc. Improvements
Testing / Analysis / Data
Cam Cover ScrewBolt Upgrade
PCV Vented Catch Can Mod
Oil Spectrum Analysis Data
HKS Sport Turbo Comp Map
  Exh Manifold Helicoil/Strengthening  
Original CT-26 Coated for Larry
TRD Diff Decoder
Engine Photos: Latest | Prev
Hella Twin-Tone Air Horn Kit Instl
  HKS DP/Heat Shields Coat/Instl  
Latest Emissions Data
Latest Dyno Results (soon)
HKS Intercooler/Hard Pipe Instl
Custom Woofer Box Fabrication
RC 555cc Injector Balancing/Flow Data
GReddy Turbo Timer "Hiccup" Fix
Mini-Mods/Sys Improvements
ND 440cc (stock) Injector Flow Test Data


1989 Toyota Supra Turbo Performance Modifications
(Now with inline photos! - Click them to get enlargements!)

Engine Mods (Intake, Exhaust, Ignition, Cooling System Enhancements, etc.)


Part No.

Mod Info

Performance Value

HKS Sport Turbo Upgrade

Manufacturer: Garrett Turbo Inc., Japan
Model: -- P/N: -- (both entries blank) Click to see the Toyota CT-26 turbo next to the HKS Sport Turbo (Garrett T-04E)...
S/N: (private)
GTI P/N: 467185-65


Turbine: Garrett AiResearch T-04E
Compressor Trim: 54
Compressor A/R Ratio: 0.50
Turbine A/R Ratio: 0.63
Maximum RPM: 135,000
Maximum Pressure Ratio: 3.2
Airflow: 16.8 - 40.0 lb/min
Maximum Temp: 1670F
Ceramic coated Turbo "elbow"

Major flow increases, efficiency increase, larger boost "sweet spot". Minimal, if any, decrease in turbo response.

Sweet spot of turbo now ~15-16 psi (CT26~8)
Maximum boost now ~20-21 psi (CT26~14)

50-state legal

HKS 75mm Turbo Exhaust System Click to see the HKS 75mm Exhaust Tips...

(old p/n)

(new p/n)

100% mandrel bent aluminized steel with dual chrome tips. Ceramic coated entire system inside and out for greater thermal efficiency and rust proofing. Makes for a system lighter and more efficient than a comparible stainless system.

30 rear wheel hp, decreased thermal load, reduced exhaust restriction, quicker turbo response, quicker throttle response.

Ceramic coating makes for higher heat retention which equates to higher exhaust velocities and greater power due to evacuation.

HKS 75mm Downpipe/Frontpipe Click to see the HKS Downpipe... Click to see a pair of HKS Downpipes... Click to see the HKS Downpipe Parts...


100% mandrel bent aluminized steel with integral flexpipe. Removes pre-catalyst. Ceramic coated entire pipe.

10 rear wheel hp, plus all of the same reasons as the exhaust system upgrade.

HKS Intercooler and Hardpipe Upgrade Click to see the coated HKS Intercooler Core (front)... Click to see the coated HKS Intercooler Core (angled)... Click to see the complete, coated HKS Intercooler Kit...

(old p/n)

(new p/n)

100% 2.5" mandrel bent pipe upgrade. Ceramic coated all pipes inside and out. Coated core with a thermal dispersant to increase heat transfer even higher (10-15%) than raw aluminum.

Core Size (mm): 400×260×65
Pipe Size D (HKS/Stock): 2.5" / 2.0"

Major flow increase, efficiency increase, much lower pressure drop across the core. Allows turbo to work less to create same amount of boost seen by the engine. More professional look of pipes over hoses.

HKS flow (20 in-H2O): ~310 CFM (500+hp)
Stock flow (20 in-H2O): 169.0 CFM

HKS 2.0mm Stopper-Type Stainless Steel HG Click to see the HKS Stainless Head Gaskets...


3 layers of stainless steel, stopper-type seal around combustion chamber, fluorine rubber coating

Best sealing head gasket available. Ability to hold well over 20 psi of boost pressure.

ARP 7M-GTE 12mm Head Stud Kit


Bolts: 65 ft-lbs (moly) = 90 ft-lbs (engine oil)
Studs: 80 ft-lbs (moly) = 120 ft-lbs (engine oil)

(14) AU4.30L

(14) AUW875

(14) AUN12-1

12mm x 1.25mm pitch x 4.30in studs

12mm ID 0.875 OD washers

12mm x 1.25 12pt nuts 0.75 OD

Torqued to 80 lb-ft using ARP moly-lube = 120 lb-ft using engine oil

18,600 lbs of preload on gasket vs.16,000 lbs

190,000 psi tensile strength vs. 160,550 psi

8740 chromemoly steel. Precision centerless ground, thread rolled to MIL-S-8879 specs. Black oxide finish, hardened washers

GReddy Type-R Compressor Bypass Valve Click to see the GReddy Type-R CBV/BOV and available outlet adapters...

Connection to HKS I/C Pipe kit requires
GReddy flange:
P/N 370111 - Aluminum Flange Type - R/S
P/N 370102 - Steel Flange Type - R/S (for steel fab'd pipes)

(Note: This valve replaced the Type-S shown below to better complement the higher volume of air moved by the HKS Sport Turbo and complement a new custom intake.

P/N 370131

(MA70 kit)

P/N 370101
(std spring valve)

P/N 370100
(stiff spring valve)

Completely replace stock valve with much higher flow valve (nearly double that of the Type-S below) and stiffer spring for higher boost levels. Better to handle the higher volume of a larger turbocharger as well.

Available Type-R Outlet Adapters:
P/N 370106 - 19-21mm
P/N 370107 - 28-35mm
P/N 370108 - 40mm
P/N 370109 - 45mm

Less shock load on compressor wheel during shifts = longer lasting turbo. Less boost lag between shifts

Available Upgrades:
P/N 370112 - Type-R Stiffer Spring

GReddy Type-S Compressor Bypass Valve Click to see the GReddy Type-S CBV/BOV...

Connection to HKS I/C Pipe kit requires
GReddy flange:
P/N 370111 - Aluminum Flange Type - R/S
P/N 370102 - Steel Flange Type - R/S (for steel fab'd pipes)


P/N 370131

(MA70 kit)

P/N 370110
(valve alone)

Completely replace stock valve with much higher flow valve and spring for higher boost levels

Available Type-S Outlet Adapters:
P/N 370113 - 16mm
P/N 370114 - 19mm
P/N 370115 - 29mm

Less shock load on compressor wheel during shifts = longer lasting turbo. Less boost lag between shifts

Random Technology Super Hi-Flow Catalytic Converter

Flow Comparison (at 28 inches of water on Superflow):
Stock = 283 CFM (2.5")
Random = 434 CFM (3.0")
53.36% flow increase!

(3" version)

(stainless bolt kit)

Drop-in replacement for stock cat with 3.0" inlets and outlets (stock=2.5") and super hi-flow 3-way catalyst.

Ceramic coated for quick activation time, less heat transmission through the floorboards and greater thermal efficiency of the exhaust system.

Once exhaust and downpipe is installed, the cat remains the only source of restriction. This option lets you remain completely legal (CARB too) with nearly as little flow restriction as open headers. Even cleans better than OEM due to ultra-saturated catalyst blocks.

K&N FIPK Click to see the K/N FIPK...
(Filtercharger Injection Performance Kit)
K&N PreCharger



Replaced stock airbox w/ 360o open K&N filter. Carb E.O. #D-269-1.

PreCharger adds extra layer of dust protection without horsepower loss.

Reduced intake restriction combined with superior filtering ability. PreCharger is durable polyester bonnet w/ uniform micron-sized openings that allow air in, yet filters out sand, dirt, clay, etc. with no significant loss of hp.

Magnecor KV85 8.5mm High Performance Wires Click to see the a 20,000V arc with a Magnecor Wire...


Replaces stock wires

Lower resistance wires for more spark power

Nippondenso Double-Platinum Spark Plugs

(Toyota p/n)

Platinum core and ground electrode

Higher gap degradation resistance

Custom Fabricated Upper Radiator Pipe Click to see the custom fabricated upper radiator pipe - Large...


100% custom fabricated aluminum upper radiator pipe. Cermachromed and polished for corrosion resistance and thermal benefits. Genuine Samco hoses used on the ends for maximum flexibility of design. Genuine Oetiker constant torque (self-adjusting) clamps used for maximum sealing integrity.

Will never collapse or deteriorate and will maintain form and function for the life of the car. Made of 6061-T6 aluminum for best combination of strength, durability and corrosion resistance (beyond the coatings).

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Fuel System (EFI) Mods
(part of the Lexus AFM/EFI enhancement which has been shown to offer a broader torque curve than a VPC-based setup)


Part No.

Mod Info

Performance Value

Lucas/RC Engineering 555cc Injectors

Click to see the (6) Lucas Injectors as received from RC Engineering LARGE...

Click here to see the RC 555cc Injector Balancing/Flow Data


IWC Type C

Drop-in replacement for stock (440cc) fuel injectors. Used as part of the Lexus upgrade. Requires the cutting/soldering in of new harnesses since the OEM harness is for oval-plug injectors and RC's are rectangular plug (more common). All injectors blueprinted to 0.1% of each other, tested and cleaned.

These injectors provide a 26% increase in fuel flow, a better spray pattern for smoother idling and more power, plus Lucas's patented disc metering system. The disc-type system is a generation beyond the standard pintle-type (Bosch, ND, etc.) and is self-cleaning. Also, unit is a durable 100% stainless steel. Can supply for max of 507.6 hp @ 80% duty cycle.

Custom Fabricated Adjustable Fuel Pressure Regulator

Click to see the A-FPR in hand LARGE... Click to see the A-FPR closeup LARGE...

Based on
(Toyota p/n)

Custom CNC-fabricated FPR using the generation two regulator from the '89 and up Supra Turbo. The gen-two is a lower profile design. CNC was based on a new part so that new seals were used throughout. Linear pressure rise of 1 psi boost to 1 psi fuel is retained.

Allows custom adjustment of the fuel pressure from below to above stock. This is better than a riser-type since such a setup is flow-hindered by the stock FPR. This mod isn't usually necessary with a stock MkIII fuel system, but the addition of a high flow pump made it a good idea.

Nippondenso High Volume Fuel Pump

Click to see the ND/HKS/Cosmo Fuel Pump Scaled LARGE... Click to see the ND/HKS/Cosmo Fuel Pump LARGE...

(ND p/n)

11 S10
(ND code)

Drop-in replacement to stock fuel pump. Same pump used by HKS for their fuel pump upgrade. It's actually from the Japanese-market Mazda Cosmo (3-rotor RX-7).

Flow Rate: 250 lph; 66 gph; 1.1 gpm
(at standard 43 psi @ 12V)

When moving up to higher boost pressure levels, the stock pump cannot maintain adequate pressure throughout the entire rev-band. This limits the maximum amount of power the engine can produce. This pump can flow enough fuel for well into the 600hp range.

Autometer Silicone-Filled Fuel Pressure Gauge

Click to see the AutoMeter Fuel Pressure Gauge Kit LARGE... Click to see the AutoMeter Fuel Pressure Gauge Face LARGE...

(Autometer p/n)

(18" AN-4 Hose)

(1/8 NPT - AN-4)

Fuel pressure gauge for mounting in engine bay to monitor pressure controlled by A-FPR and high-flow fuel pump above. Monitors from 0 to 100 psi. Silicone-filled for vibration resistance. 12mm/AN-4 adapter from Toyota (used for EFI cleaning).

Allows fine-tuning of fuel pressure at idle to maintain stock driveability and characteristics. Tapped into cold-start injector banjo port with 12mm/AN-4 adapter to 45 degree AN-4 end to 18" stainless braided AN-4 line to AN-4/1/8 NPT adapter. Also got AN-4 aluminum flare cap to cap off fuel rail tie-in.

Current Lexus Modification Settings

Fuel Pressure: 38 psi (at idle with vacuum line connected)
SONiC AFM Screw: Approximately half way in
EGT Readings: 1375F at WOT & 1.1 bar (~15 psi) (pre-turbo)
Vf Readings: Green at idle and cruising
A/F Meter Readings: 2 green bars (on K&N A/F gauge) at WOT
Fuel Cut Level: Unknown :-)

Click here for Reg's writeup on the 7M-GTE TCCS, Lexus AFM Upgrade and Vf data interpretation


combination of above

Replace stock AFM with Lexus LS400 AFM core but retain stock electronics. Install 550cc injectors. This provides a 25% increase in airflow and fuel delivery, but since they're balanced, the ECU won't know the difference. Has the overall effect of simply shifting up your power levels as well as shifting up the fuel cut limit and allowing you to run higher boost levels.

Similar to bolting on a large Holley carb :-). System has been tested by other group members to a sustained 19.1 psi, although such high limits are not recommended for reliability's sake of internal engine components. I'm currently running a "high" level on my EVC of 1.1 bar (15 psi) and a "low" level of 0.68 bar (10 psi) with great results.

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Upgraded/Added Controller Mods


Part No.

Mod Info

Performance Value

HKS EVC (Electronic Valve Controller) Pro (IV ATM)

Click to see the HKS EVC IV...

Click here for the setup instructions:
Page 1 | Page 2 | Page 3

Click here for the install instructions:
Page 1 | Page 2 | Page 3 | Page 4 | Page 5 | Page 6


(Japan Only)

Installation Kit

Cockpit controlled, electronic control valve with microprocessor precision actuation of the turbo wastegate.

The ATM feature makes the system immune to altitude and pressure variations. The Pro features include using engine rpm and throttle position to further optimize the boost control.

The EVC continuously delivers information to the wastegate instructing it to more-evenly regulate pressure during all load conditions. The microprocessor also allows the wastegate to get closer to the preset boost levels quicker, allowing for a sharper rise in boost pressure. Because of the sharper boost rise, it's typical for an EVC equipped vehicle to develop more horsepower soon than a vehicle equipped with a stock boost regulator or even a VBC.

HKS TEMS Controller Click to see the HKS 7M Supra TEMS Controller Large...

(old p/n)

(new p/n)

Replaces stock 2-button MA70 Supra TEMS contoller with fully lit 4-button setup

Ability to lock in any of the three TEMS shock damping values and override TEMS computer

GReddy/TRUST Turbo Timer

Click to see the GReddy/TRUST Turbo Timer from the front...

Installation Notes:
Works perfectly with stock alarm and TDSE! Allows arming while timer is working and completely shuts down the accessories circuit when the key is removed with no modifications or wire cutting necessary!

Click here for my timer research and simple fix for the "hiccup"

P/N 375001

(Timer ECU)

Harness TT 14-11
Supras '87-'92

Allows car to idle down without the key in the ignition and the alarm fully armed. Has selectable times from 10 seconds to 10 minutes and 2 presets.

Has safety/theft shutdown circuits for the emergency brake plus a tap into the ECU speedometer circuit to detect car motion. Also has an audible reminder warning if the e-brake is left up when the timer is engaged.

The low rpm idling allows oil to continue to coat the turbo bearing surfaces and allow them to cool to a point below which "coking" occurs (over 330oF).

I compared this timer directly to the HKS Turbo Timer IV and found that the GReddy timer was superior in form, fit and function. Also, it's one-quarter DIN size and included mounting hardware made it much easier to install with professional results.

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Additional Gauges


Part No.

Mod Info

Performance Value

HKS Boost Gauge

(white face psi)

(mounting cup)

Mechanical meter provides highly accurate manifold vacuum readings up to 30 in. hg. and manifold pressure readings up to 20 psi. Fully illuminated 2 1/8" gauge.

More accurate reading of boost level directly from intake manifold plus higher maximum. Note that this gauge (as well as the HKS EGT gauge below) is now unavailable as Japanese gauges have all gone metric.

HKS EGT (Exhaust Gas Temperature) Meter

(old p/n)

(new p/n)

Quick response electronic meter provides accurate EGT readings from 400o and 2200o Fahrenheit. Fully illuminated 2 1/8" gauge.

Allows you to more carefully monitor how rich/lean the engine is running via EGT measurement. Helps fine-tune the motor.

1450oF peak is normal with stock injectors up to fuel cut.

15-16 psi at 1350oF peak is good to shoot for.

K&N Air/Fuel Ratio Monitor

LED Display to A/F Ratio Scale:
Light 1 = 17.1:1      Light 2 = 16.0:1      Light 3 = 15.1:1
Light 4 = 14.7:1      Light 5 = 14.7:1      Light 6 = 14.7:1
Light 7 = 14.7:1      Light 8 = 14.0:1      Light 9 = 13.2:1
Light 10 = 12.1:1


This is the rectangular gauge without the replacement O2 sensor since it is tapped into the stock sensor at the diagnostic port (Ox). Helps to fine tune fuel pressure/AFM to keep car running at optimal A/F ratios. Can be used with gas, alcohol and propane engines.

Utilizing a 10-LED array, allows dynamic monitoring of air/fuel ratio while driving without taking up too much space (like, for example with a Halmeter). When running high boost levels (i.e., anything approaching 1 bar), the richer the better, to prevent detonation.

Jeff M. Vf Signal (EFI System) Monitor

Jeff M. Vf signal meter - 2nd Generation

Click here for Jeff's webpage
describing form, function and
ordering instructions.


Gauge created by Jeff Montigny to create a visual representation of the Vf signal output. The Vf output tells you how the ECU is trimming the fuel system (i.e., richening or leaning out) based on signals being received from the O2 sensor, AFM and coolant temp sensors, primarily.

Lets you optimize and balance the Lexus AFM/550cc RC injector upgrade combination.

This is the second generation gauge created per a request by Keith H. and myself to better match the layout of the stock gauge cluster.

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Suspension Upgrades


Part No.

Mod Info

Performance Value

Eibach Pro-Kit Springs

Click to see a set of MA70 Supra Eibach Pro-Kit Springs LARGE... Click to see the MA70 Eibach ProKit/Tokico Illumina II Combo -- 'The Perfect Combo'...


Replaces stock springs with progressive rate replacements meeting German T.U.V. and Ford Q1 quality control certification. Progressive windings assure comfort is not lost with the gains in handling and control.

Spring Rates (k value)
Front: 343-628 lb/in (60-110 N/mm)
Stock Front: 461 lb/in (80.8 N/mm)

Rear: 126-257 lb/in (22-45 N/mm)
Stock Rear: 215 lb/in (37.6 N/mm)

Improves vehicle looks and performance. Lowers the vehicle's center of gravity, reducing body roll in turns, dive under braking, squat during acceleration and gives the car a more solid, secure feel at all times. Improves weight transfer during launches for better traction.

Average Lowering (inches)
Front: 1.30" / Rear: 1.00"

Rates Note: The initial windings are used to preload springs against the vehicle. End result is a 20-30% average increase over stock rates.

Tokico Illumina II TEMS-Compatible Performance Shocks

Tokico Logo




TEMS-Compatible replacement shocks with twin-tube low pressure nitrogen charged cells. Lifetime warranty to original purchaser.

Will work better with the Eibach spring upgrade's higher spring rates. Ups all three TEMS positions to an approximately 30% stiffer comrpession/rebound setting.

Suspension Techniques (ST) Anti-Sway Bar System

Click to see a sample ST Sway Bar Kit...


Replaces stock anti-roll bars with more robust versions designed to tighten up the amount of sway allowed in the vehicle. Includes new, larger diameter front and rear anti-sway bars, low deflection urethane bushings, complete mounting hardware, and instructions.

Designed to minimize body roll (vehicle lean) when cornering, resulting in improved vehicle balance and handling. The system also reduces understeer or "plowing", yet does not affect ride quality.

Includes manufacturer's Limited Lifetime Warranty.

1998 MkIV Twin-Turbo Supra Wheels

Click to see the 98TT wheels montage... Click to see the 98TT wheels from 45 degrees... Click to see the 98TT wheels from above...



Clearcoated aluminum lightweight 5-spoke wheels designed for the 1998 MkIV TT, but looks just as good (and possibly better :-) on a MkIII Turbo.

17" x 8.0" (front)
17" x 9.5" (rear)
Offset = 50mm (front and rear)
(Note: '89 = 16" x 7.5" x 37mm offset)

Increases maximum cornering loads, steering response, braking ability, off-the-line grip and overall handling through a decrease in unsprung weight while complementing the new look offered by the above suspension mods.

Weight Comparison (Front/Rear)
23.6 lb / 25.4 lb ('98) - lighter w/o ctr ridges
24.75 lb / 26.55 lb ('93-'97)
21.0 lb / 21.0 lb ('89)
(Note: '89 spare tire/wheel combo = 47 lb)

Yokohama AVS S4-Z (V400)
Ultra High Performance All-Season Tires

Click to see the Yokohama AVS S4-Z tread pattern LARGE...

"A triumph of performance tire design, the AVS S4 offers the exceptional handling and speed rated muscle of the best UHP tire. But AVS S4 provides more than just performance. This premium all-season tire offers wet traction comparable to the best "aquatread" type tires, plus traction in ice and snow that rivals many dedicated snow tires." -- Yokohama

Yokohama Logo



Yokohama's latest top-of-the-line tire designs are grouped into the AVS (Advanced Vehicle System) series. The S4-Z tires combine the best aspects of the all-out pure high-performance tires with a small degree of all-weather practicality.

By lowering aspect ratio and increasing the width of the contact patch, higher cornering loads can be achieved, improved braking distances, and greater overall traction. The only downside is a slight increase in rolling resistance.

Note: Tires were balanced using full alloy balancing instead of the more common static method. Alloy balancing uses weighted adhesive pads on the inside of the wheel instead of the hammered on weights which can damage the finish

Cusco/GREX Front Shock Tower Bar

Click to see the Viola Blue powdercoated GREX shock tower brace brackets LARGE... Click to see a Viola Blue powdercoated GREX shock tower brace bracket LARGE...


Connects front shock towers using an adjustable aluminum alloy brace.
(TEMS Compatible)

Powdercoated "Viola Blue" for more durability than the stock crinkle paint.

Helps to eliminate front body flex and camber change under hard cornering

Click to see the original TEMS covers (top rear) I powdercoated for Keith when I did my Grex mounts LARGE... Click to see the original TEMS covers (top front) I powdercoated for Keith when I did my Grex mounts LARGE...

JIC (Total Suspension Project) Front Lower-Arm Bar

Click to see JIC Lower Arm Bar ready for installation LARGE... Click to see JIC Lower Arm Bar getting torqued down by my mechanic Pat LARGE... Click to see the JIC Lower Arm Bar fully installed LARGE...

Click here for the English install instructions: English
Click here for the Japanese install instructions: Japanese

#70 chassis

Rigidly connects front lower A-arms via a polished aluminum alloy brace.

Note: The bar does not come lower than the downpipe or exhaust system if you're worried about ground clearance.

Helps to eliminate lateral load transfer and unnecessary suspension movement due to flexing under hard cornering. Improves handling response, high speed stability and body rigidity.

I noted a noticeable decrease in understeer with the bar installed. Also remember to double check your alignment afterwards.

Do-Luck (RXB) Center Support Bar

Click to see the finished installation LARGE... Click to see a closeup of the preloading bolt LARGE...

Click here for PacNW/SOGI
purchasing information

Click here for personal instl instructions

Click here for the English install instructions: Page 1 | Page 2
Click here for the Japanese install instructions: Page 1 | Page 2

(JZA70-Japan p/n)

Ties the center of the unibody frame together using an adjustable, tubular chrome plated steel brace. Connects via the large lower seat belt mounting bolts. It's preloaded using a center adjustment bolt.

Do-Luck Logo

Drastically stiffens up the weakest point in the unibody frame which helps to eliminate body flex under extreme loading. Increases torsional as well as overall structural rigidity. Note that the combination of a front, center and rear bar works to create an approximate 100% increase in structural rigidity. Only a rollcage helps further. Especially good for targa-equipped cars.

Cusco/GREX Rear Shock Tower Bar (OS-Type)

Click to see the Cusco/GREX rear shock tower brace (side shot) LARGE... Click to see the Cusco/GREX rear shock tower brace (rear shot) LARGE...

Click here for the English install instructions: Page 1 | Page 2 Click here for the Japanese install instructions: Page 1 | Page 2

163 541 A

Connects rear shock towers using a non-adjustable, polished aluminum brace w/ steel stays-TEMS compatible. Shaft section is reinforced by an internal rib for increased strength.

Note that cutting and fabrication of the rear trim panels is necessary here (as seen in pics). Thus, this is not a mod for everyone.

Helps to eliminate rear body flex and camber change under hard cornering. Significantly strengthens the rear unibody hatchback frame which, by design, is weak due to the large hole in it.

Click to see the included Cusco MotorSports sticker LARGE...
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Powertrain Upgrades


Part No.

Mod Info

Performance Value

C's Short Throw Shifter Kit Click to see the C's Short Throw Shifter Kit...



Replaces stock shifter and bearing

Quicker, more precise shifts. 30% reduction in throws.

RPS TurboClutch Click to see the RPS TurboClutch...


Replaces stock clutch and pressure plate

Higher clamping force with 360o full contact clutch plate facing for smooth driveability

Custom Aeroquip Clutch Hydraulic Line

Click to see the Aeroquip clutch line LARGE... Click to see the Aeroquip clutch line with Slave Cylinder LARGE... Click to see the Aeroquip clutch line next to the Stock line LARGE...


9" line w/ AN-3F
ends and KB
10mm adapters
(1.0 pitch)

Replaces slave cylinder rubber hose connection with a Teflon-lined, stainless steel braided hose (similar to braided brake lines). Note that just like braided brake lines, a difference in pedal feel will be noticed.

More precise pedal action for smoother driveability. Reduces loss of force transferred to the clutch fork due to hose expansion and should last much, much longer. The original was hardened when removed at 90k.

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Brake System Upgrades


Part No.

Mod Info

Performance Value

Porterfield Carbon/Kevlar Compound Brake Pads

Porterfield High Temperature Backing Plates


(front/rear shims)

Replaces stock pads and shims with carbon-kevlar R-4S compound replacements.

Higher maximum brake force with much higher fade resistance. Good cold weather performance.

TRD Braided Stainless Steel Brake Lines

Click to see the TRD Braided Stainless Steel Brake Lines... Click to see the TRD Braided Lines installation up front LARGE... Click to see the TRD Braided Lines installation with rotor/caliper off LARGE...


Replaces stock rubber lines with OEM quality fit. No fabrication, spacers or adapters necessary. Exceeds DOT requirements. Note that a difference in braking feel will be noticed.

Increased brake system response due to less hydraulic induced expansion of the lines. Enhanced ABS system control. Great looking, more reliable.

Motul Racing Brake Fluid 600

Click to see the Motul Racing Brake Fluid 600 bottle larger...

Dry Boiling Point: 585oF (307oC)
Wet Boiling Point: 421oF (216oC)

Click here for a complete technical spec sheet
(PDF: 13.6 kb / 1 page) (Requires PDF viewer)


The ultimate high performance polyglycol-based brake fluid. With a DOT 4 rating derived from simply its viscosity being slightly higher than a DOT 3 standard, it far exceeds the boiling point standards of DOT 3/4/5/5.1. Compatible with DOT 3/4/5.1 fluids.

Extremely high dry and wet boiling temps and resistance to moisture-induced performance degradation as well as the extreme scenario of vapor lock. The package is filled with nitrogen to increase shelf life and eliminate contamination while factory sealed. Note that the brake system should be completely flushed and bled with Motul 600 to get the maximum benefits.

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Miscellaneous Upgrades (Lighting, Horns, etc.)


Part No.

Mod Info

Performance Value

Toyota Theft Deterrent System Enhancement (TDSE)

(Base Kit)

(Installation Kit)

Toyota annouced the release of the TDSE security system enhancement in July, 1991. The system adds the following features to the Factory Theft Deterrent System (TVSS):

* Two Remote Transmitters
* Glass Breakage Sensor
* Horn Defeat
* Car Finder
* Remote Arming
* Remote Door Locking

Supplements the stock TVSS (Toyota Vehicle Security System) with a more robust shielding against potential thieves.

The system is a virtual plug-in on all '91 and '92 Supras. Supras 86.5 to '90 require a minor modification to the power lock circuit harness since there was a minor change to that particular harness in 1991.

Hella Vision Plus
Hella logo High-Performance Headlamp Upgrade


Replaces standard H4 5" x 7" headlamp lens with the brightest, most powerful lighting available at the maximum legal limit, without increasing glare.

SAE/DOT approved for US street use based on European headlamp technology.

The maximum in lighting performance. The lamp's advanced optics provide a more uniform, controlled and even illumination on the road. The HVP produces a 50% more powerful beam on low beam and a 25% more powerful beam on high beam than standard halogen sealed beam units. The HVP is a two piece unit which allows usage of a hi-performance replaceable bulb to minimize waste and save money.

PIAA Platinum Series Super White H4 Headlight Upgrade
80W/80à115W/135 (low beam/high beam)

PIAA logo


100% US-legal

DOT FMVSS108 compliant for color

SAE approved high-performance headlamp bulb upgrade. Super White technology approaches the brightness and intensity of a true HID system. With a Kelvin Rating of 3800K, the light color more closely imitates the color of natural sunlight (5250K). XTRA technology increases bulb performance and life.

More than doubles the light output of the stock headlamp system (55W/60) while throwing a more pure white light. Combined with above lens upgrade provides a much better view of the road with greater clarity and detail. Xenon bulb creates 115W/135W from 80W of power draw.

Click to see PIAA light spectrum comparison Click to see Super White vs. Normal Halogens

CATZ/FET Gold-Iridium Foglight H3 HyperBulb Upgrade
CATZ logo

(US p/n)

(Japan p/n)

High performance foglight bulb upgrade. The Xenon charged bulb combined with double the standard filament thickness results in 130W of light from 85W of power.

Effectively doubles the light output from the auxiliary foglight system. The electro-statically applied gold-iridium coating gives light beam an amber color which reduces glare and aids depth perception while increasing contrast and visibility.

Hella Twin-Tone Compressor Air Horn Kit Click to see a larger view of the Hella Twin-Tone Compressor Air Horn Kit... Click to hear a single blare of the Hellas

(US p/n)

(German p/n)

Replaces stock electric horns with two air compressor powered trumpet horns for a more appealing sound.

Sounds like a Porsche or Italian sports car horn.

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Engine Rebuild Modifications & Details (Completed 8/05/97)
  • New Rings
  • Honed Cylinders
  • 3-angle valve job on intake and exhaust
  • Micro-Polished Crankshaft
  • Deck planed 8 thousandths of an inch
  • Head planed 9 thousandths of an inch
  • All new seals for head and block (incl. front seals, rear main seal, rear main retainer gasket, turbo oil gaskets, etc.)
  • All new hoses
  • All new bearings
  • Clearances returned to stock and head/block seal strengthened via an HKS 2mm Stopper-type metal head gasket with Permatex Copper Coat as a primer.
  • Oil Cooler blown clean with pressurized oil
  • Pressure washed and flushed radiator core and fins
    (after removing from car)
  • New Flywheel alignment dowels
  • New Nippondenso (ND) Double-Platinum Spark Plugs
  • New Throwout/Pilot Bearings for RPS TurboClutch
  • Snap-On Block Tested after break in to ensure good head gasket sealing/seating
Click to see a larger pic of the Snap-On block test...
(picture courtesy of Keith Hart from his own testing)
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Mini-Mods/System Improvements
  • Fog lights rewired to run with parking lights instead of headlights. High-beam cut out eliminated.
  • Automatic Power-Up enabled on driver's side power window controls.
  • Manual override of dual A/C fans enabled via aux switch.
  • Added rear side compartment covers from '86.5-'88 Supra (discontinued on '89+ for some reason).
  • Changed to complete Japan-spec Turbo A badging and clear corner front lenses (click to see door | front | rear).
  • Changed to '90+ style hood bumpers
    (greater surface area and vibration dampening).
  • Headlight auto-off circuit rewired to shut off with key removal in turbo timer application.
  • HKS Boost Gauge illumination wired outside of dashboard dimmer control to allow for boost gauge-only stealth mode driving.
  • Piezo horn from Toyota VIP3000 alarm wired up via a relay to TDSE alarm enhancement to work in place of the horn for a more pleasing sound.
    (Click here for my Hella relay hookup schematic)
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Performance Coatings (by Performance Coatings, Inc. of Auburn, WA):

Dry Film Lubrication Impregnation (MoS2)
(lowers friction)

Thermal Barrier Coating
(blocks heat transfer)

Thermal/Oil Dispersant Coating
(evens out/increases heat transfer)

(takes up to 1300oF w/o MCX liner)

Zirconium Thermal Barrier
(for combustion chamber temps)

Satin Gray Header Coating
(withstands over 2000oF)

Piston Skirts

Exhaust Ports

Underside of Piston

HKS Intercooler Hard Pipe Upgrade

Piston Domes

Exhaust Manifold (outside)

Pin Bores

Intake Ports

Coolant passages around chamber in head

Lexus AFM Core

Valve Faces

Turbo Elbow (with add'l MCX high-temp liner)

Ring Area

Exhaust Manifold (inside)

HKS Intercooler
Core (inside/outside)

3-Main Heat Shields (with add'l MCX high-temp liner)


HKS 75mm exhaust system (with add'l MCS high-temp liner)

Valve Stems/Seats

Turbo Oil Return Tube

Airdam screen (black to look like hole from a distance and corrosion resistance)

Upper rad pipe fabricated to replace stock hose


HKS Downpipe (with add'l MCX high-temp liner) & (double coated for scrape protection)

Rod Bearings

Downpipe/Heat Shield Hardware


Custom fab'd I/C pipe from turbo compressor discharge to lower I/C hookup


Random Technologies SHF Cat (with add'l MCS high-temp liner)

Main Bearings

Oil Filter Housing




Turbo Elbow Metal Gasket (elbow to turbo seal)

Thrust Bearings

Coolant pipe going around block




Charcoal Canister Mount
(corrosion protection)

Cam Bearings

Power steering mount




3-Turbo Rigidity (tie-down) Brackets

Oil Pump Gears/Plates/Passages

Intake Manifold




Dipstick Tube

Valve Springs





Cat support bracket and hardware

Cam Followers






Exhaust Manifold Studs






Exhaust Manifold Screw-Lock Helicoils






Cam Cover Stainless Bolt Upgrades






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Appearance Coatings (by Craig Craft Powdercoating of Lynnwood, WA):

Red Barron

Viola Blue over Chrome
Dual-Layer Powdercoat

Mercedes Silver

Gloss Black

Engine Block

GREX shock tower bar mounts

Cam Covers (outside)

Oil Pan (outside)

Bell Housing to Block pieces

Keith's Stock TEMS Covers

Cylinder Head (outside)

Intake Plenum to Block Tie-Down



Intake Plenum

Intake Manifold to Block bar




Alternator Mount




Engine Lift Hook (front)

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Lubricants and Minor Modifications

Redline Synthetic Racing Oil Logo Hose Techniques Vacuum Hose
  • Mobil 1 Tri-Synthetic Motor Oil (10W/30)
  • MT-90 Synthetic Transmission Oil (75W/90)
  • Mobil 1 Synthetic Differential Oil (75W/90)
  • Motul Synthetic Brake and Clutch Fluid
  • Mobil 1 Racing Logo

  • Hose Techniques vacuum hose upgrade
  • Russell steel braided hose wrap
  • ThermoTEC Cool-It wrapped coolant/fuel lines
  • DieHard Gold Generation Two (sealed)
  • TRD - The Absolute Authority on Toyota Performance

    The mods page has been hit times since it was created in Nov. '97.

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    Christopher M. Jensen
    © 1995-2000 CJ Inc.
    Created: Nov 30th, 1997
    Last modified: May 8th, 2000