Wavetrac ATB LSD Differential - BMW E9X 335i (215K Weld) r=3.08

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.

Wavetrac ATB Locking Differential for BMW (215K)

Gear ratio r = 3.08 → BMW E9X 335i

(Welded Ring Gear)

Simply put, Wavetrac is the only gear-based differential on the market that does not lose traction when another axle is lightened or loses load . Axle load can be lost during aggressive driving, cornering on the track, over curbs or on extremely slippery surfaces – and this happens more often than many people realize.

Why is Wavetrac different?

We won't go into torque split ratios or the theory of ATB differentials here. Let's focus on how Wavetrac affects performance in practice .

Standard gear lock (OEM, Quaife, Torsen, Truetrac, etc.)

Let's imagine you're at track day and while cornering, the inside rear wheel bounces over a curb. This is completely normal in track driving. The problem is that the momentarily lightened wheel causes the other wheel to lose traction . Sprocket locks require load on both axles to work.

As a result:

• the draw is momentarily interrupted

• power is not transmitted to the gripped wheel

• the exit from the curve is uneven and unpredictable

Same situation with Wavetrac

Wavetrac's patented cam device prevents loss of traction when one wheel becomes loose. The mechanism creates an internal load in the differential , compensating for the lost traction, and directs torque to the holding wheel.

Result:

• smoother and more continuous power transfer when cornering

• better output speed

• more predictable drivability

• faster lap time

Additional benefits

• Patented carbon fiber bias plate for pinions
  In other gear locks, the pinions rotate directly in the frame, causing friction and locking efficiency to change over time. In Wavetrac, performance remains consistent throughout its life.

• Patented Wave Profile construction
  Eliminates the near-zero-load traction loss that occurs in all other ATB-type differentials.

• ARP bolts throughout
  Excellent strength and reliability even in heavy use.

• 9310 steel gears
  Machined or forged steel frame in use.

• Designed and manufactured in the USA

WAVETRAC: Smooth is Fast – Smooth is speed.

Ideal for street and track riding

Wavetrac is ideal for high-performance street cars that are also used on the track. It is highly durable, yet unobtrusive in normal driving – and does not interfere with stability or traction control systems.

On the track and in fast street driving:

• both wheels drive efficiently

• no understeer or “pushing” like in clutch-locked rear axles

• drivability remains neutral and controlled

Wavetrac outperforms other gear locks because it does not lose traction when one axle becomes light – a situation that is common on the track and in hard driving.

Smooth power transmission at extreme limits

One of the most underrated advantages of Wavetrac is its extremely smooth power delivery at the limits of traction . The patented design allows for predictable and smooth power delivery exactly when you need it most:

• in the middle of a curve at the limit of grip

• when balancing a car with gas

• when entering a corner a little too hard and quickly re-applying the gas

These situations are immediately felt by the driver. Wavetrac makes you faster because it gives you the confidence to drive harder.
Smoothness is speed.

IMPORTANT NOTE: Welded Key Ring (BMW)

Since March 2007, BMW has used rear axle assemblies in which the key ring is welded directly to the differential housing .

Before ordering, please send:

• the last 7 characters of the vehicle's VIN number

• vehicle information

• gearbox type

to parts@qtperformance.fi so we can ensure the correct differential and installation kit.