QT Parts is a Finnish online store.

Our warehouse is located in Nokia, Finland.

You can collect your order directly from us if needed. Simply select “Pickup” at checkout.

Pay securely with multiple payment methods, including invoice and installment plans through Klarna.

The delivery time for products in stock is 1-5 business days. We ship worldwide.

If the product is not in stock and it is a pre order product, the average delivery time is 5-21 business days. If the product has a longer delivery time than previously announced, we will be in touch. International orders may be subject to VAT, import duties, and customs fees upon arrival in the destination country.

Terms for product returns:

• You must return the ordered products within 14 days of receiving
• The products must be unused and without damages
• Commission fee for handling returns is 21,90€
• For product returns, the customer is in charge of the return costs. Only door to door service (Express)
• Shipping costs are not refunded

For international orders sales are final and non-refundable. Once an order is placed, it cannot be canceled or returned. By placing an order, you acknowledge and agree to these terms.

Return address: QT Parts, Vasarakatu 8B, 37150 Nokia, Finland.

Pre order / made-to-order products

If the product you have ordered is a pre order or made-to-order item, it is not subject to the 14-day right of withdrawal or return under consumer protection laws, as the product is manufactured or sourced specifically based on the customer’s individual order.

If you wish to cancel your order before receiving the product, we will refund 50% of the total order amount.

This condition applies to the following product categories:

• Suspension
• Engine Tuning
• Engine Parts
• Exhaust Systems
• Fueling
• Turbochargers/superchargers
• Drivetrain
• ECE-approved Downpipes

All of the above products are manufactured or sourced individually based on the customer’s order, and therefore cannot be returned after delivery, unless the product has a manufacturing or material defect.

In the event of such a defect, the standard liability for defects as provided by consumer protection legislation shall apply.

BAR-TEK® Sport Valve Spring Set - 4.0 TFSI EA824 & EA825

The BAR-TEK sport valve spring set is made from high-quality hardened spring steel and features titanium valve spring retainers. The set is suitable for all 4.0L TFSI engines, used in models such as the Audi S6, RS6, S7, RS7, and S8.

The valve springs have a spring rate specifically optimized for performance use, which improves the response and operation of the 4.0L TFSI valvetrain. The titanium retainers reduce the moving mass of the valvetrain, making higher boost pressure and higher engine speeds possible.

The excellent stability of the springs at high RPMs makes them a suitable solution for heavily tuned 4.0L TFSI engines.

Sport valve springs are necessary when increasing engine boost pressure or installing performance camshafts. Original valve springs may not be able to control the valvetrain effectively enough under such operating conditions. This can result in incomplete valve closing or, in the worst case, valve spring failure.

Both situations can lead to serious and expensive engine damage.

Features

• Better and faster valvetrain response

• Allows for higher engine speeds

• Reduced-mass valvetrain thanks to titanium spring retainers

• Excellent stability at high RPMs

• Allows for higher boost pressure

• Up to +70 hp and +70 Nm with Stage 1 software

Kit includes

• 32x high-quality hardened spring steel valve springs

• 32x high-quality titanium valve spring retainers

The valve spring set is especially suitable for 4.0L TFSI engines using modified camshafts and/or larger performance turbochargers with higher boost pressure.

Designed for higher power

Sport valve springs are designed for demanding performance use. The springs are manufactured from specially processed heat-treated spring steel with excellent strength and toughness. The springs feature a special coating and a larger material thickness than standard models, which improves their durability in demanding operating conditions.

The performance of the springs is based not only on the material used but also on a precisely optimized design. The oval construction allows for greater valve lift and improves valvetrain stability at high RPMs.

The conical design, where the spring narrows toward the top, reduces moving mass and helps improve the overall operation of the valvetrain.

Optimized design prevents valvetrain problems

As power increases and boost pressure rises, sufficient stiffness and correct sizing of the valve springs are critical. Valve springs or retainers that are too weak can cause a situation in a turbocharged engine where the valves do not remain properly closed. This, in turn, can cause issues with boost pressure formation and control.

The optimized oval design of the sport valve springs helps prevent spring coil bind. At the same time, the correct preload of the spring is maintained throughout the operating range.

As a result, the valvetrain operates more stably at high RPMs, engine rev-sensitivity improves, and the risk of problems related to boost pressure control is reduced.

Technical specifications

• L0: 47.00 ± 0.30 mm

• F1: 307.00 N @ 40.00 mm

• F2: 748.00 N @ 30.00 mm

• Spring rate: 44.1 N/mm

• Load: 441 N / 10 mm compression

• Lc: 23.00 mm (max.)

Note: Illustrative photo. The image shows a valve spring set for a 4-cylinder engine.