Independent Rear Inputs
Dedicated 4-piston hydraulic caliper for foot-brake modulation, trail braking, and rear bias control.
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Description
Drift Racing DR4+4 Rear Wheel Dual-4-Piston Big Brake KitRacing Series Drift Rear Axle Dual 4 Piston DR4+4 Rear Dual Caliper Drift Big Brake Kit Two calipers per rear corner. One job each. The DR4+4 separates handbrake input and foot brake input into independent hydraulic and mechanical circuits at the rear axle, so handbrake initiation never bleeds pressure back into the foot brake line or shifts rear brake bias mid rotation. Racing Series Drift Rear Axle Dual 4 Piston Setup 8 Pistons Per Corner 325 mm 12
Racing Series · Drift · Rear Axle · Dual 4-Piston
DR4+4 Rear Dual-Caliper Drift Big Brake Kit
Two calipers per rear corner. One job each. The DR4+4 separates handbrake input and foot-brake input into independent hydraulic and mechanical circuits at the rear axle, so handbrake initiation never bleeds pressure back into the foot-brake line or shifts rear brake bias mid-rotation.
Racing Series — Drift
Rear Axle
Dual 4-Piston Setup
8 Pistons Per Corner
Ø325 mm × 12 mm Solid Rotor
17 in Wheel Min.
Motorsport Use
Why Builders Choose the DR4+4
In competition drifting the handbrake is a steering input, not a parking device. When a single rear caliper has to serve both the handbrake mechanism and the hydraulic foot-brake circuit, a hard handbrake pull can push fluid back through the master, soften pedal feel, and unsettle the car at exactly the moment the driver is trying to trail-brake into rotation. The DR4+4 solves this by giving each input its own dedicated caliper.
Dedicated Handbrake Lock
Dedicated 4-piston mechanical caliper handles handbrake lock and release, fully isolated from the hydraulic foot-brake circuit.
Circuit Isolation
Hard handbrake pulls do not feed back into the foot-brake line. Pedal pressure, bias, and modulation stay consistent through entry, transition, and exit.
Shared Rotor Package
Shared Ø325 mm × 12 mm two-piece solid rotor keeps one thermal mass per rear corner for compact packaging and consistent behavior.
Thermal Repeatability
Heat-treated high-carbon iron rotors paired with a 0–600 °C pad window give consistent μ across back-to-back runs and tandem battles.
Vehicle-Specific Engineering
Radial brackets, hose fittings, rotor offset, and wheel clearance are produced to your chassis, knuckle, hub, and wheel package.
Technical Specifications & Kit Options
| Brake Caliper | ||
|---|---|---|
| Series | Racing Series — Drift | |
| Model / Application | DR4+4 | |
| Axle Position | Rear | |
| Caliper Layout | Dual-caliper rear setup: 4-piston hydraulic caliper + 4-piston mechanical handbrake caliper per rear corner | |
| Piston Count | 4 handbrake pistons + 4 hydraulic pistons per rear corner | |
| Piston Type | Racing pistons without dust boots | |
| Piston Diameter | 35 mm | |
| Caliper Dimensions | L 178 mm × W 82 mm × H 106.5 mm | |
| Total Piston Area | 38.46 cm² × 2 per rear corner | |
| Manufacturing Process | Two-piece forged aluminum body | |
| Net Weight | 1.41 kg per caliper, without pads | |
| Surface Finish | High-temperature gloss coating | |
| Recommended Wheel Size | 17 in or larger | |
| Recommended Rotor Size | Ø325 mm × 12 mm | |
| Brake Rotor | ||
| Rotor Material | Heat-treated high-carbon cast iron | |
| Axle Position | Rear | |
| Rotor Dimensions | Ø325 mm × 12 mm | |
| Construction | Two-piece rotor assembly | |
| Ventilation | Solid | |
| Mounting | Fixed | |
| Rotor Hats | CNC-machined high-strength aluminum alloy rotor hats | |
| Directional Design | Yes — left/right specific | |
| Rotor Face Pattern | Curved slot | |
| 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 | |
| Bedding-In | Required before competition use | |
| 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 | |
| Brake-Line Fittings | Vehicle-specific; caliper-side and chassis-side fittings vary by application | |
| Circuit Layout | Independent hydraulic foot-brake circuit and mechanical handbrake circuit at the rear axle | |
| Wheel Clearance | 17 in or larger wheel required; final spoke and barrel clearance must be confirmed because the dual-caliper layout takes more radial and axial space than a single-caliper rear setup | |
| Service Items | Pads, seals, and stainless braided lines are replaceable service items | |
The DR4+4 is a Racing Series — Drift platform, not a universal bolt-on. Final bracket geometry, brake-line fittings, rotor offset, and wheel clearance must be confirmed for your specific chassis, knuckle, hub, and wheel package before production.
Package List
Calipers ×4
2 × rear 4-piston hydraulic calipers and 2 × rear 4-piston mechanical handbrake calipers, two calipers per rear corner.
Brake Pads
Brake pads for the rear dual-caliper package, rated 0–600 °C and intended for iron / steel rotors.
Brake Rotors ×2
2 × rear two-piece solid rotors, Ø325 mm × 12 mm, curved-slot face pattern, left/right specific.
Caliper Bracket Packages ×2
Vehicle-specific CNC-machined carbon-steel radial bracket packages for the dual-caliper rear layout.
Rotor Hats ×2
CNC-machined high-strength aluminum alloy rotor hats matched to rear hub geometry and rotor offset.
Brake Hoses
Vehicle-specific stainless braided rear brake lines with PTFE inner liner, SUS304 braid, and PVC outer sheath.
The Bespoke Engineering Process
Every DR4+4 rear drift system is engineered around the vehicle’s rear knuckle, hub location, rotor hat offset, wheel barrel, spoke clearance, handbrake hydraulic layout, mechanical handbrake packaging, brake-line routing, rear bias target, and intended drift use. The goal is not a generic universal fit; the goal is a rear brake package that isolates handbrake input from foot-brake input and gives the driver repeatable rear lock, pedal behavior, and modulation during entry, transition, and tandem runs.
1. Technical Consultation
We review the chassis, rear suspension and knuckle setup, hub package, wheel package, handbrake layout, target rear brake behavior, tandem or competition use, tire package, and whether the car uses OEM or custom rear uprights.
2. Data Submission
For OEM knuckles, provide chassis, year, knuckle, hub, wheel diameter, wheel width, offset, spoke profile, and handbrake layout details. For custom rear uprights, provide CAD files, technical drawings, hub-face data, rotor mounting dimensions, or accurate bracket mounting-point measurements.
3. Engineering Review & Approval
TTSPORT confirms dual-caliper bracket geometry, rotor hat offset, brake-line fittings, mechanical handbrake packaging, wheel clearance, pad choice, bedding requirements, and installation notes before production begins.
If you are unsure whether your wheel, rear knuckle, rotor offset, handbrake layout, or brake-line routing is suitable, Contact us before ordering so the engineering team can review the build details.
Installation & Break-In
- This system is designed for competition drift, track, and closed-course use.
- The rear axle uses two separate calipers per side: one dedicated 4-piston hydraulic caliper for foot-brake input and one dedicated 4-piston mechanical caliper for handbrake input.
- Caliper brackets are radial-mount and machined for your specific knuckle, hub, and rotor offset.
- Brake-line fittings on the caliper side and chassis side are application-specific.
- Final spoke and barrel clearance must be confirmed against your specific wheel before production because the dual-caliper layout takes more radial and axial space than a single-caliper rear setup.
- Pads must complete the bedding-in procedure before being driven hard.
- Racing pistons do not use dust boots and require regular seal inspection.
- Pads, seals, and stainless braided lines are replaceable service items for endurance and competition drift programs.
Motorsport use. This system is designed for competition drift, track, and closed-course use. Pads must complete the bedding-in procedure before being driven hard. Racing pistons do not use dust boots and require regular seal inspection.
Frequently Asked Questions
What makes the DR4+4 different from a standard rear BBK?
It uses two separate calipers per side at the rear axle: a dedicated 4-piston hydraulic caliper for foot-brake input and a dedicated 4-piston mechanical caliper for handbrake input. The two circuits are isolated, so a hard handbrake pull does not bleed pressure back into the foot-brake circuit or upset rear brake bias mid-corner.
What rotor size and wheel clearance does this kit require?
The DR4+4 is engineered around a Ø325 mm × 12 mm two-piece rotor and requires a 17-inch or larger wheel. Final spoke and barrel clearance must be confirmed against your specific wheel before production because the dual-caliper layout takes more radial and axial space than a single-caliper rear setup.
Is this a direct bolt-on kit?
No. This is a Racing Series — Drift platform. Caliper brackets are radial-mount and machined for your specific knuckle, hub, and rotor offset. Brake-line fittings on the caliper side and chassis side are also application-specific. Submit your chassis, knuckle, hub, and wheel details so TTSPORT can confirm fitment before manufacturing.
What pad operating range and friction level should I expect?
The included pads are rated for 0–600 °C operating temperature with an average friction coefficient of μ ≈ 0.38. Actual μ varies with rotor temperature, line pressure, and rotor condition. A proper bedding-in procedure is required before competition use.
Can I order this kit in a custom configuration?
Yes. Custom build pricing is available for non-standard rotor offsets, bracket geometry, hose routing, or finish. Contact the engineering team with your build sheet and TTSPORT will quote a custom configuration.
Are the calipers and hardware serviceable?
Yes. The calipers use a two-piece forged aluminum body with racing pistons, no dust boots, for easy seal service between events. Pads, seals, and stainless braided lines are replaceable service items, which is critical for endurance and competition drift programs.
Spec your DR4+4 build
Send your chassis, knuckle, hub, wheel details, handbrake layout, and rear suspension setup to TTSPORT for fitment confirmation and a custom quote.
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.3 ★★★★★
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Product Reviews
★★★★★ 3
I’m a little disappointed.
Format: Kindle
I usually like Jillian West’s books but this one was missing a lot for me. The pregnancy didn’t come across as real. She’s on her feet for 12 hour days but is perfectly healthy at 8 months pregnant? Yet the week she moves in all of a sudden she’s not? She is planning on actually running during one of the plot buildups. But at 8 months pregnant that’s incredibly hard to do. The lack of breathing ability and lung space, the change in body center, mass, and gravity. All of it prohibits running, unless you’re an athlete this didn’t come off as at all realistic.
I didn’t feel any connection with the alphas. There wasn’t any emotional connection. It could be because of the tense it was written in. But I didn’t get any deep feelings out of this. It came across as checking off boxes. Even the spicy scenes weren’t really believable for me. I wanted to see them fall for her, and it just kind of all fizzled. Even Bishop.
One thing I did really like was the ending. I did not see it coming and I’m interested in reading book two because of it. But on the whole this book was mostly disappointing for me.
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Reviewed in the United States on March 16, 2024
★★★★★ 4
4.25 stars
Format: Kindle
Vale is an 8 month pregnant omega working as a waitress at a strip club and a cam girl. She starts to get very creepy vibes from a regular at the club, and her baby daddy ghosted her. She has had an online relationship with a man named Bishop through her cam girl status. One night, bishop was paying to watch her sleep and ansthe creepy regular Andrew break in and watch her sleep he tells vale to come to him at his business now. She flees and finds herself at a large security company with some.hot of alphas who are there to help her. This imegaverse is a little different than I have read, but I am thoroughly enjoying it. Vale is not a traditional omega she was raised by a single beta mom, and the alphas are not normal alphas they have never really loved pack life. But they are ruthless mercenaries. They need her, and she needs them. I love the aspect of the stalker and now the plot twists at the end, so so good. Sometimes, it seemed a little slow and stale mated, but since this a duet, I think It was just her starting to have Vale get to know her alpha suitors. Cliffhanger for sure with this one.
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Reviewed in the United States on September 9, 2024
★★★★★ 5
That ending 😫
Format: Kindle
I fell into a false sense of security and really thought this was gearing towards a happy ending. Then I realized there’s no work they don’t punish Andrew. I really liked Vale’s character. I don’t normally read books with pregnancy but going into this knowing she was pregnant made it more enjoyable for me.
I loved Bishops devotion to her and her happiness. I also loved that Holt and Mercy couldn’t fight their attraction to her. I love scent matches so very much. I’m so curious to see how this duet will end up. And I need to pay more attention and notice that a book I’m starting is a duet to begin with lol
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Reviewed in the United States on February 21, 2025
★★★★★ 5
oh wow
Format: Kindle
I just knew there was something about Cooper! I’m wondering if he’s about to be included but damn I’m glad he’s at least not a rapist and creepy guy, he just got called on assignment and had to go! This should be interesting! She’s gonna run and then what’s his face is gonna grab her. I’m worried! Wow that was a great book and cliffhanger! Loving this!
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Reviewed in the United States on December 27, 2025
★★★★★ 5
Great book
Format: Kindle
I absolutely feel in love with all 4 characters!!! The bedroom scenes were 🌋🌡🔥🔥🔥. I couldn't put this book down!!! I'm hooked for the whole series Book 2 here I come!!!!! Its a fun easy book and story to read!!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on October 4, 2024
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