Spec 87-92 Supra Turbo Stage 2+ Clutch Kit
The SPEC ST633H is a Stage 2+ clutch kit for the Mk3 Toyota Supra Turbo. It covers the factory 7M-GTE cars and the popular 1JZ-GTE swap behind the R154 five-speed. It suits owners who have added boost, a bigger turbo or a tune and now feel the original clutch slip on the highway pull, but who still want a car that drives smoothly in traffic. SPEC rates it at 500 ft-lb.
The pressure plate bolts to the flywheel and clamps the disc against it. When you press the pedal, the hydraulic master and slave move the release fork and bearing into the diaphragm and free the disc. The R154 sends all of the turbo six's torque through that one disc. SPEC's Stage 2+ uses a multi-friction disc. It keeps the drivability of SPEC's Stage 2 and adds roughly 15-20 percent more torque capacity. Compared with the Stage 3 puck disc (ST633) or the Stage 3+ full-face carbon kit (ST633F) in the same family, Stage 2+ is the step to choose when the car is driven on the street more than it is raced.
Run a high-gear test: in fourth at low rpm, go to full throttle and watch the tach against road speed. A sudden rpm jump as the turbo spools is clutch slip. If the problem is a sinking pedal or failure to release, the hydraulics are the likely cause. Old Mk3 master and slave cylinders often seep. Our slipping diagnosis guide explains the test, and shift flare vs. slip helps when the symptom is hard to describe.
Our listing reads 87-92 Supra Turbo. SPEC's application list for ST633H is wider: Supra Turbo Mk3 7M-GTE and 1JZ-GTE (1986-1993), Chaser 7M-GTE and 1JZ-GTE with R154, and the Soarer 7M-GTE and 1JZ-GTE with R154. US Supra Turbos used the R154. The naturally aspirated Mk3 used a different gearbox and is not on this list. On swapped cars, confirm your flywheel and release bearing are the R154 pattern. If in doubt, send us your year and VIN, or your swap details, and we will check before it ships. More Supra kits and flywheels are in the rebuild kits and clutch category.
Inspect the flywheel before anything else. A resurfaced or new flywheel gives the multi-friction disc a clean face to bed into. The 13.7 lb steel flywheel for 1986-1993 Supra Turbo is a common pairing. Replace the pilot bearing, center the disc with an alignment tool, and torque the pressure plate bolts evenly in a star pattern. Grease the input splines and fork pivot lightly, and bleed the hydraulic system with fresh brake fluid. Refill the R154 with the gear oil Toyota specifies and check for leaks at the rear seal. If you plan to keep turning up the boost, compare this kit with the SPEC ST633 Stage 3 kit and the full-face ST633F Stage 3+ before you choose. Give the new disc a gentle break-in before any hard launches.
| Brand | SPEC |
| Part number | ST633H |
| Fits | Spec 87-92 Supra Turbo Stage 2+ Clutch Kit |
| Vehicle fitment | Toyota Supra (1987-1992) |
| Type | Clutch Kits - Single |
| Condition | New |
| Ships | Same business day (in stock), from the USA |
| Warranty | 1-year |
Yes. SPEC lists the 1JZ-GTE with the R154 for the Supra Turbo Mk3, Chaser and Soarer. Make sure your flywheel and release bearing are the R154 versions.
SPEC rates the ST633H at 500 ft-lb. The ST633 Stage 3 and ST633F Stage 3+ in the same family are rated higher, for cars making more power.
No. SPEC lists only the turbo R154 applications. The naturally aspirated Mk3 used a different transmission.
SPEC does not list a flywheel with this kit. Resurface the factory flywheel or install a new one, such as a lightweight steel unit.
Replace the pilot bearing, inspect the release fork and pivot, and replace aging master or slave cylinders. Bleed the system with fresh brake fluid when you are done.
