Honda Y21/Y80/S80 & S4C gearboxes
Suitable For:
- Civic EK4
- CRX (Del Sol) Vtec
- Civic Si 1999-2000 Vtec
- Integra GS / LS 1990-2000
- Integra GS-R 1992-1993, Y21
The Blackline Helical Limited Slip Differential (LSD) offers a host of advantages that make it a standout choice for performance and reliability. It ensures equal rotational speed for both wheels while dynamically distributing torque based on traction. With low maintenance requirements—thanks to the absence of clutches—it responds faster than viscous LSDs and provides smooth, progressive engagement with minimal noise. Its 8620 alloy steel construction guarantees strength and longevity, and it serves as a direct replacement for stock differentials.
The Blackline Helical LSD is a torque-biasing system designed to optimize power distribution. By channelling more torque to the wheel with the best traction, it significantly improves performance and drivability, especially in low-grip conditions. The innovative parallel axis helical gears ensure even load distribution. As torque is applied, these gears generate thrust forces proportional to the applied torque, allowing the LSD to handle significant traction imbalances during high-power scenarios like corner exits. At low torque, the system operates smoothly and quietly, making it suitable for everyday road driving.
With a 5:1 torque bias ratio, the Blackline LSD transfers up to five times more torque to the wheel with the most grip, maintaining stability and control. While it functions best when both wheels maintain some traction, techniques like left-foot braking can be used to lock a spinning wheel in rare cases of complete traction loss. Additionally, the system integrates seamlessly with modern anti-lock braking systems (ABS), enhancing precision and safety.
Whether you’re on the road or the track, the Blackline Helical LSD delivers the perfect combination of performance, durability, and drivability.
At Matt Lewis Racing, we are proud to be based in the UK and committed to delivering our products to customers both domestically and internationally. Our goal is to provide fast, reliable shipping that makes it easy for you to receive your order as soon as possible.
Domestic Shipping:
- We ship to all locations within the UK, including England, Scotland, Wales, and Northern Ireland
- All orders to England & Wales will be shipped via Royal Mail or FedEx
- All orders to Northern Ireland, Scotland/Scottish Highlands & Islands and the British Isles will be shipped by Royal Mail or a suitable courier service available to select at checkout
- The Royal Mail 48 shipping option typically requires 2-3 working days* for delivery, while the Royal Mail 24 service generally takes 1-2 working days* to deliver
- Some items are not stocked and do not have a 24hr postage service available. This will be noted at the bottom of the item page
International Shipping:
- We offer international shipping to most countries around the world
- International orders will be shipped via a Royal Mail Tracked service or the courier selected at checkout
- Delivery time for international orders varies based on location & shipping service, but we will provide you with a tracking number at the time of shipping
- For all orders shipped by Royal Mail the overseas postal tracking service can be found here: https://www.royalmail.com/sending/international/overseas-postal-tracking
Most orders purchased before 3pm will be sent out the same day, unless there is a note at the bottom of the item page. This usually applies to non stocked items so please allow an extra 2-3 working days for delivery
Both UK & International Royal Mail services are updated with details of any delays here: https://www.royalmail.com/service-update
If your delivery address is located outside of the UK, you may be required to pay import duties and taxes. These charges are imposed by your country's customs authorities when the shipment arrives at your location. Customs policies differ among countries, and all international shipments may be subject to cross-border inspections. You will be responsible for any additional charges related to customs clearance, and we suggest that you contact your local customs office for more details
We understand that getting your products quickly is important to you, which is why we make every effort to get your order to you as soon as possible. If you have any questions about our shipping policy, please don't hesitate to contact us
*This is an estimated delivery aim from Royal Mail, not a guaranteed delivery time
At Matt Lewis Racing we want you to be completely satisfied with your purchase. If you’re unhappy with your purchase, please contact us immediately. We will first attempt to resolve your issue with the purchase or alternatively offer a refund or exchange in accordance with the below policy:
UK and EU Customers:
Under UK and EU consumer law you have the right to a refund of the purchased goods within 30 days. Within the 30 day period a refund or exchange will be conditional on the product and its packaging being returned in its original condition. You will be responsible for the postage cost of returning the goods
If the product is received by you, the consumer in a defective or damaged state we will offer a full refund or exchange. Photographic evidence will be required. The product will need to be returned before a refund or exchange can be processed
All returns MUST be authorised by us in advance
Customers Outside the UK & EU:
Customers outside the UK and EU are subject to the laws and regulations of their respective countries. We will comply with any applicable laws and regulations regarding returns, refunds, and exchanges. Please contact us for more information on returns and refunds outside of the UK and EU
Exchanges:
If you would like to exchange a product, please contact us with your order number and details of the product you would like to exchange. We will be happy to arrange an exchange for you, subject to availability
Refunds:
If you would like a refund, please contact us with your order number and details of the product you would like to return. We will process your refund within 48 hours of receiving the returned product. Please note that we will not be able to issue a refund until we have received the returned product
Exceptions:
Please note that certain products may be exempt from our refund and exchange policy. These include custom-made products, special orders, and products that have been used or damaged
If you have any questions or concerns about our refund and exchange policy, please do not hesitate to contact us. We believe that our customers should be completely satisfied with their purchase and will do our best to address your concerns
