Single-Caliper Dual-Circuit Layout
One forged caliper handles both handbrake and foot-brake circuits, reducing packaging complexity compared with stacked secondary calipers.
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Racing Series · Drift · Rear Axle · Dual-Circuit 6-Piston
The DR4+2 is a rear drift big brake kit built around one forged caliper with two independent hydraulic circuits — one circuit for the handbrake side and one circuit for the foot-brake side. One caliper, one rotor, one bracket per corner. No stacked secondary caliper, no shared fluid path between pedal and e-brake.
Stacking a second caliper on the rear knuckle works, but it adds mass, complicates rotor clearance, and forces compromises on bracket geometry. The DR4+2 puts both circuits inside a single two-piece forged body so the handbrake can lock the rear axle on demand while the foot brake stays isolated for pedal feel and threshold modulation.
One forged caliper handles both handbrake and foot-brake circuits, reducing packaging complexity compared with stacked secondary calipers.
Handbrake line pressure does not contaminate foot-brake pedal feel, so rear lockup and pedal modulation stay separated.
One radial-mount caliper per corner keeps the rear upright cleaner than dual-caliper setups and simplifies bracket geometry.
Two-piece forged aluminum body, 2.50 kg per caliper, nickel-plated finish, and bootless racing pistons for heat dump and serviceability.
Built for rear axles that need handbrake lock, foot-brake control, and repeatable rear bite during elevated track temperatures.
Bracket geometry, rotor hat offset, hub register, hardware, and brake line fittings are confirmed against your chassis before production.
| Brake Caliper | ||
|---|---|---|
| Series | Racing Series — Drift | |
| Model / Application | DR4+2 | |
| Axle Position | Rear | |
| Caliper Layout | Single rear caliper with two independent hydraulic circuits | |
| Piston Count | 4 handbrake pistons + 2 hydraulic pistons | |
| Piston Type | Racing pistons without dust boots | |
| Piston Diameter | 27 mm × 2 / 32 mm × 2 / 38 mm × 2 | |
| Caliper Dimensions | L 266 mm × W 118 mm × H 73 mm | |
| Total Piston Area | 50.2 cm² per caliper, all pistons combined | |
| Manufacturing Process | Two-piece forged aluminum body | |
| Net Weight | 2.50 kg per caliper, without pads | |
| Surface Finish | Nickel-plated | |
| Recommended Wheel Size | 17 in or larger | |
| Recommended Rotor Size | Ø330–343 mm × 11.5–12 mm | |
| Brake Rotor Options | ||
| Rotor Option | 330 mm Steel | 343 mm Steel |
| Rotor Material | Heat-treated high-carbon cast iron | Heat-treated high-carbon cast iron |
| Axle Position | Rear | Rear |
| Rotor Dimensions | Ø330 mm × 12 mm | Ø343 mm × 11.5 mm |
| Construction | Two-piece rotor assembly | Two-piece rotor assembly |
| Ventilation | Solid | Solid |
| Rotor Mounting | Fixed | Fixed |
| Rotor Hats | CNC-machined high-strength aluminum alloy rotor hats | CNC-machined high-strength aluminum alloy rotor hats |
| Directional Design | Yes — left/right specific | Yes — left/right specific |
| Rotor Face Pattern | Curved slot | Curved slot |
| Recommended Use | Standard rear drift rotor for 17 in wheels and tighter knuckle packaging | Larger swept area for high-speed entries and longer endurance heat windows |
| Brake Pads | ||
| Compatible Rotor Material | Iron / steel rotors only | |
| Operating Temperature Range | 0–600 °C | |
| Average Friction Coefficient | μ ≈ 0.38, varies with temperature, line pressure, and rotor condition | |
| Pad Window | Consistent rear bite from cold pull-off through repeated competition runs without a sharp drop-off mid-session | |
| Lines, Brackets & Service | ||
| Brake Line Construction | Three-layer reinforced | |
| Brake Line Material | PTFE inner liner / SUS304 stainless braid / PVC outer sheath | |
| Caliper Mounting | Radial mount with vehicle-specific caliper brackets | |
| Caliper Brackets | CNC-machined carbon-steel radial-mount caliper brackets | |
| Rotor Hats | CNC-machined high-strength aluminum alloy rotor hats matched to rear hub geometry and rotor offset | |
| Brake Line Fittings | Vehicle-specific — caliper-side and chassis-side fittings vary by application | |
| Circuit Layout | Two independent hydraulic circuits inside one caliper body; handbrake line pressure does not affect foot-brake pedal feel | |
| Wheel Clearance | 17 in or larger wheel required; final clearance depends on wheel offset, spoke profile, rotor diameter, rear hub position, and bracket geometry | |
| Bedding-In Procedure | Required before competition use | |
Both rotor sizes ship as two-piece assemblies with CNC aluminum hats. Custom hat offsets and bracket geometry are available through the engineering workflow. Final rotor selection is confirmed during the build review.
2 × DR4+2 rear two-piece forged dual-circuit calipers with nickel-plated finish, one caliper per rear corner.
Brake pads for both rear calipers, rated 0–600 °C and intended for iron / steel rotors.
2 × rear two-piece solid rotors, selected from Ø330 mm × 12 mm or Ø343 mm × 11.5 mm, left/right specific.
Vehicle-specific CNC-machined carbon-steel radial caliper brackets for correct rear caliper position and alignment.
CNC-machined high-strength aluminum alloy rotor hats matched to rear hub geometry and rotor offset.
Vehicle-specific stainless braided rear brake lines with PTFE inner liner, SUS304 braid, and PVC outer sheath for the independent circuits.
Every DR4+2 rear drift system is engineered around the vehicle’s rear knuckle, hub location, rotor hat offset, wheel barrel, spoke clearance, hydraulic handbrake layout, brake-line routing, rear bias target, and intended drift, rally, or time-attack use. The goal is not a generic universal fit; the goal is a single-caliper rear package that isolates handbrake pressure from foot-brake pressure while fitting your exact chassis geometry.
We review the chassis, rear suspension and knuckle setup, rear hub specs, hydraulic handbrake layout, target rear brake behavior, wheel package, tire package, brake bias strategy, and whether the car uses OEM or custom rear uprights.
For OEM knuckles, provide chassis details, rear hub specs, wheel size, wheel offset, spoke profile, and handbrake plumbing layout. For custom rear uprights, provide CAD files, technical drawings, hub-face data, rotor mounting dimensions, or accurate caliper mounting-point measurements.
TTSPORT confirms bracket geometry, rotor hat offset, hub register, rotor size, hardware, brake line fittings, wheel clearance, and pad setup before production begins.
If you are unsure whether your wheel, rear knuckle, rotor offset, hydraulic handbrake layout, brake bias, or brake-line routing is suitable, Contact us before ordering so the engineering team can review the build details.
Motorsport use. Pistons ship without dust boots and pads are formulated for elevated track temperatures. Bedding-in is required. This kit is not intended as a daily-driver street upgrade.
No. The DR4+2 has two independent hydraulic circuits inside one caliper body. Handbrake line pressure does not affect foot-brake pedal feel or vice versa.
Yes, but rear bias will change. Plan brake balance around the new rear piston area, 50.2 cm² per caliper, and the 330 or 343 mm rotor you select. A bias valve or proportioning adjustment is recommended.
17 in or larger wheels are required. Final clearance depends on wheel offset, spoke profile, and rotor diameter. Send wheel specs during the fitment review and TTSPORT will confirm.
One forged caliper handles both circuits, so there is less unsprung mass, simpler bracket geometry, and one rotor face to manage thermally instead of two separate caliper mounts and pad sets.
No. Brackets, hat offsets, and brake line fittings are made to your chassis. The engineering workflow is required before production so the kit lines up correctly on your specific rear upright.
0–600 °C with an average friction coefficient of μ ≈ 0.38. That covers cold pull-off through repeated competition runs without a sharp drop-off mid-session.
Send your chassis, rear hub, wheel details, hydraulic handbrake layout, and rear upright information. TTSPORT will return a fitment plan for the DR4+2 rear kit.
Brake Kits · Fitment · Installation · Care Guide
A brake kit is not just a pair of larger calipers. Calipers, rotors, pads, hoses, brackets, rotor hats, mounting hardware, brake fluid, wheel clearance, and bedding procedure all work together as one system.
This guide explains how to confirm the right TTSPORT brake kit before ordering, what to check before installation, and how to care for the system after installation.
Do not order a brake kit by vehicle name alone. The correct kit depends on the vehicle, axle position, wheel package, driving use, and brake system layout.
Brake kits are application-specific. A visually similar kit can still have the wrong rotor offset, bracket geometry, hose fitting, caliper position, or wheel clearance requirement.
Different TTSPORT brake kit series use different hardware layouts. Always confirm what the kit includes before purchase.
Use direct-mount calipers and one-piece rotors where specified. These kits do not use rotor hats or caliper brackets unless the final product page clearly states otherwise.
Use separate friction rings and rotor hats. Hat offset, ring bolt pattern, hardware style, and rotor direction must be matched correctly.
May require bespoke brackets, rotor hats, brake lines, and engineering confirmation based on knuckle, hub, wheel, and competition use.
Require extra attention to wheel clearance, tire size, vehicle load, descent control, hose routing, and dust / water exposure.
Do not assume every brake kit includes the same parts. Package contents vary by product series, vehicle application, and final order configuration.
Before finalizing the order, review the kit specification carefully. Confirm the brake kit is matched to your vehicle and wheel setup, not only to the model name.
If any part is not listed in the final order or product page, do not assume it is included.
Inspect every component before installation. Do not modify, grind, drill, stretch, force, or space brake kit components to make them fit.
Safety: Brake kits affect braking force, hydraulic sealing, heat control, wheel clearance, and vehicle stability. Do not install the kit if fitment, torque, direction, clearance, or compatibility is unclear.
Correct installation is as important as the brake kit itself. A properly engineered kit can still perform poorly if installed with dirty mounting faces, incorrect torque, poor hose routing, or trapped air in the hydraulic system.
Verify caliper centering over the rotor and confirm even pad sweep across the friction surface.
Confirm left / right rotor direction if the rotor uses directional vanes or directional face pattern.
Check brake hose length and routing at full steering lock and full suspension travel. No twisting, rubbing, stretching, or kinking.
Check caliper-to-spoke and caliper-to-barrel clearance before road use. Wheel diameter alone is not enough.
Use the correct brake fluid type and bleed the system until pedal feel is firm and consistent.
Torque all brake hardware to the specified value. Do not reuse damaged, unknown, stretched, or corroded safety-critical fasteners.
Brake pads and rotors need a controlled bedding process before full performance is available. Bedding helps create an even transfer layer on the rotor surface, improving bite, pedal consistency, and vibration resistance.
Street pads, race pads, iron rotors, two-piece rotors, and carbon ceramic rotors may require different bedding procedures. Use the procedure supplied with the specific kit.
After installation and bedding, give the system a short break-in period before aggressive use. Pedal feel, pad contact, dust output, and noise may continue to settle after the first drives.
Brake kits need regular inspection, especially after track use, off-road use, towing, mountain driving, winter salt exposure, or any brake service.
Inspect pads, rotors, fluid level, and hose condition during normal service intervals. Prioritize quiet operation, smooth pedal feel, and even wear.
Check pad thickness, rotor surface condition, and fluid condition more often. Long descents create sustained heat even without track use.
Inspect for mud, sand, stone impact, hose abrasion, dust boot damage, and caliper contamination after trail use.
Inspect pads, rotors, fluid, and hardware before and after every event. Track heat shortens service intervals.
Check rear brake temperature, hydraulic handbrake behavior, pad wear, rotor cracking, and hardware condition frequently.
Use only compatible pads and approved bedding procedures. Inspect rotor surface condition carefully and avoid incompatible friction materials.
Do not continue driving if the brake system shows any of the following symptoms. Inspect the system or contact a qualified brake technician before using the vehicle again.
Send your vehicle details, brake kit series, wheel specs, driving use, photos, and any symptoms you notice. TTSPORT will help confirm fitment, installation checks, and the correct care path for your brake kit.
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