Drilled kit image for BKLX050-863COSpecial order · Estimated lead time: typically 2-4 weeks
98-05 Lexus GS430 - Rear 8 Piston Big Brake Kit w/ 15.7 in Drilled Rotors - Supercomp
Choose year, make and model to confirm this application-specific product fits — you can add it to your cart either way.
Verify fitment- Two 8-piston Supercomp calipers (rear axle)
- Two 15.7 in two-piece cross-drilled rotors with aluminum center bells
- SC5 street brake pads
- Stainless-steel braided brake lines
- CNC-machined caliper mounting brackets and hardware
One approved application: 1998–2005 Lexus GS430 · JZS161
Choose an available option for each required item to enable Add to cart: Choose Caliper Color, Street or Race Pads, Center Bell Upgrades. Options marked “Contact for quote” require a KSport quote and cannot be added directly.
- Ships from Mesa, AZ
- 12-month limited warranty
- Special order: typically 2-4 weeks
Specifications — BKLX050-863CO
Product details
Eight pistons on the back axle is not something you see every day, and that is exactly what this Supercomp kit gives a 1998 to 2005 Lexus GS430. Paired with 15.7 inch (400 mm) cross-drilled two-piece rotors, it is a big upgrade over the factory rear brakes, and the cross-drilled pattern is the one the page positions for daily-driven cars, running cooler on the street.
Each caliper is one billet aluminum piece instead of a cast or welded body, and eight pistons per caliper replace the factory hardware. The floating rotors let the outer ring center itself, reducing drag. In the kit you will find SC5 street pads, braided stainless lines that resist expansion for a quicker pedal, machined steel brackets and the hardware to bolt it all on at the OEM bracket position.
The system works with the OEM master cylinder and ABS. Pads should be bedded in with ten gentle-to-moderate stops, and a little noise before warm-up is normal. A slotted version is available if you track the car. The GS300 and GS400 are listed alongside, so use the year, make and model checker to confirm your car.
Supported features
One-piece construction from a solid billet of aerospace-quality aluminum rather than cast or welded, for even thickness and strength across the caliper block.
The outer section shifts slightly as needed for better self-centering in the caliper, lowering brake drag and boosting performance through more even application.
Calipers, floating brake discs, SC5 street pads, owner's manual, and all required hardware come standard.
CNC-machined carbon steel brackets let the larger calipers bolt to the OEM caliper bracket location.
Cross-drilled rotors run cooler for daily-driven vehicles; slotted rotors are recommended for more track use.
DOT-compliant stainless braided lines stop expansion under pressure for quicker response and a firmer pedal than stock rubber lines.
Standard painted orange, red, black, and yellow; premium high-polish silver, gold, and titanium; glassy and hard-anodized finishes; over 20,000 custom colors on request.
Compatible applications (3)
Choices for this kit
This part number ships with cross-drilled rotors. Cross-drilled runs cooler and suits daily driving; the slotted version of this kit suits track use. Both versions are listed on the Supercomp page.
Painted KSport orange, race red, caution yellow or jet black at no extra charge. Premium high-polish, glassy and hard-anodized finishes cost extra.
Street pads are standard; race pads, titanium or twin-colour anodized center bells are optional upgrades.
Choose the caliper finish, pads and center-bell configuration above. Every selection and any extra charge is shown before Add to Cart and saved with the order. Contact KSport for a custom color quote.
Installation
Bolt-on installation with the supplied brackets; no vehicle modification on most applications. After fitting, bed the pads in: on a clear road, ten light-to-medium stops from 30–45 mph, three seconds each, at least a quarter mile apart. Some noise before the brakes warm up is normal for big brake kits.
Brake system support and bed-in procedureWarranty & service
12-month limited warranty to the original purchaser against defects in materials and workmanship. Racing use, exterior finish and improperly installed or modified parts are not covered; keep your original invoice for any claim. Small surface cracks on cross-drilled rotors are normal wear and not a defect. Replacement pads, rotors, lines and hardware are sold individually.
Warranty terms and service requestsOther published pages for MPN BKLX050-863CO
These page names share this MPN; they do not confirm fitment. Verify your vehicle before ordering.