Time to put all that turbo-power to the ground!
Applications for all 135i & 335i models...

VAC Performance Rear Differentials are built to last with the highest quality components, procedures, and technical expertise in the industry. Our BMW differentials are run in countless race series and by hundreds of street customers because our quality and options are unmatched.  Before we strictly built BMW's, we have had an unmatched 50+ years of differential building expertise in house!

Experts will tell you; proper differential assembly is one of the most difficult things to tackle on an automobile. Take advantage of our our precision and expertise as many happy customer and winning teams have.
...Our differentials let your 335i and 135i really apply the torque to where its needed: the ground!

Each of Our Performance differentials feature:

• Expert assembly with the tightest standards for tolerances and performance
• OEM gaskets & seals
• High grade hardware
• Drastic performance increases by getting the power to the ground
• Improved overall drivability, and sense of safety by improving stability in good as well as inclement weather
• Increased acceleration via improved traction coming out of corners and high torque situations
  
  We offer:
• Helical gear type TBDs from Quaife and Wavetrac
• Clutch style LSDs from OS Giken
   

As the USA master distributor for Quaife BMW,  Stocking Dealer Of Wavetrac, and Master Dealer of OS Giken- we have ALL the most popular solutions ready to quickly ship to you...
Check out our smoking deals on completed Differential units: All diffs include all new Shims, Seals, Crush Rings, Bolt kits and Gaskets:-

-FAQs-

Q: I'm confused: I thought all I needed was a differential? or LSD... What I am actually buying? What do I need?
-There are three parts of this upgrade that customers should understand.
-First is the selection of the "carrier" or the actual mechanical device that replaces the factory spider gears with a unit that puts power to both wheels at once, rather than just the wheel with the least traction. This is often referred to as the LSD (Limited Slip Differential), but sometimes the entire housing once built is know as the "LSD" so this can be confusing. This listing is for a complete housing, ring and pinion, and LSD carrier.
-The second is the housing. The actual differential itself with the ring and pinion gear, with the carrier unit installed is all installed in side of the housing. That's the part you see under the car with the gears and carrier inside.
-The third is the ring gear and pinion gear. These take the power coming from the single drive shaft and split it horizontally so it can go to both axles. When everything is professionally assembled, your have our listing.

Q: Why does your 135 or 335 benefit so greatly from a performance rear differential?:
   -Short Answer:
Improved acceleration, traction, and stability potential; as why all M-Series are so equipped- AND why BMW left them out of all the 135/335/535 I, so they would not steal sales away from the M-cars!
   -Long answer in simple terms:
Standard open-type differentials, equipped in most non-M Series only send power to one wheel at a time in all conditions. The more powerful a car becomes, the more traction is needed to effectively make use of this power. "Traction control" is inefficient for performance driving, and becomes more and more cumbersome as power levels rise with tuning.
A 'Limited Slip Differential' or 'Torque Biasing Differential' is able to effectively split power between both wheels at crucial moments while keeping the car stable and easy to drive (Note: This is by different means in different brands. LSD Vs TBD... OEM, Kaaz, Quaife, Carbonetic, Wavetrac ect... see below).
When you launch your car from a stop, having the power continuously sent to both wheels increases traction exponentially! You leave the line with more power getting to the ground, and less power spinning your wheels; this makes a car dramatically faster!
When your vehicle is turning, the outside wheel is rotating faster than the inside wheel; the inside tire is doing less work. The vehicle wants to 'lean' on the outside tire more, further increasing it's load. While the outside wheel is forced to do more work the inside has less traction- therefore, in an open differential, the power wants to go to the wheel with the least amount of resistance and it becomes wasted spinning the inside wheel when cornering hard.
Through various means, a LSD or TBD effectively splits power to both wheels and can aid in powering the car forward coming out of turns as both wheels are utilized most effectively.
When entering a corner, this balance of traction helps to increase the stability of the car when coming in at high speed improving confidence and safety. This leads to faster corner entrance potential.
All of this extra traction can also have improvements in low grip conditions like snow or rain.

Application Info:

Q: What is in my car? 

Q: What does a torque biasing differential like Quaife or Wavetrac do?
We have run a Quaife HARD in our daily driven and often tracked cars with absolute success. Additionally we have installed dozens of Quaife units in platforms other than E8x/E9x and they always perform flawlessly. We have also installed and sold many Wavetrac units, and can remark that they also perform well for slightly less cost. 
An ATBs (automatic torque biasing differential) job is to improved acceleration, traction, and stability potential of the chassis. Rather than using clutch plates as a method of operation, the Quaife ATB uses sets of helical cut gear-pinions that run in pockets, and mesh during normal driving. The Wavetrac, the "Wavetrac device" a set of plates that migrate away from one another when slippage of a wheel occurs.
Should one of the driven wheels begin spin however, these diffs seamlessly and immediately start to generate a torque-bias thanks to the axial and radial thrust of the helical gear pinions in their pockets. Wavetrac is similar, but uses its "Wave" that they assert allows for additional traction in '100% bias' (or zero traction) situations such as when a wheel is lifted from the ground in a corner.
The result is a progressive, smooth transfer of torque away from the spinning side of the axle to the driven wheel, which is now capable of transmitting a greater proportion of torque. Unlike a clutch style LSD- the gear type units deliver performance without the need for strip downs or rebuilds. There are no plates to wear or break and these units retain standard vehicle gear oil without special requirements (Wavtrac recommends gear oil without limited slip additive).
All of this extra traction can also have improvements in low grip conditions like snow or rain.
Quaife units are silent in operation, a Wavetrac unit may also be- however some have a slight noise when entering first gear. They do not need any electronics to be re-worked or traction control to be effected in any way. Very cool and great for both street and track use!

Q: What does a Clutch-type Limited Slip differential like an OS Giken do?
Through clutch plates with internal mechanisms, a clutch type LSD applies load to both rear wheels and aids in powering the car forward when the wheels are turning at different rates, or when acceleration off the line. As with powerful cars, taking advantage off all the traction available from a standing start and in the corners is important, however- clutch type LSDs for BMWs are setup with some locking affect on deceleration as well: when entering a corner, this load and balance of traction helps to increase the stability of the car when coming in at high speed improving confidence and safety. This leads to faster cornering potential. This is what Japanese companies refer to as a 1.5 way LSD, and is excellent for everything from daily drivers to all out competition vehicles.
A 2-way LSD has a strong locking effect on deceleration- this is typically utilized for those who like drifting as it can enhance stability off throttle over-steer. These units are supplied by special order.

 

Q: Why VAC?
VAC Performance Rear Differentials are built to last with the highest quality components, procedures, and technical expertise in the industry. We have been building differentials since the 1950s, and have been specializing in BMW since the1980s. With countless 2002s, E30s, E36, E46, E92, 7series, 5 series, street, race & many custom projects... we have done it all. We have left no stone unturned in 60 years in the machine shop business, so you can rest assured that the job will be done right the first time.
Our results are the most proven: Our BMW differentials are run in countless race series and by hundreds of street customers because our quality and options are unmatched. All is performed in our complete machine shop which ensures top qualify control. We do not have to worry about subbing out work to another business who may-or-may-not do the job properly.
Also importantly; there will be no back log. We are proud of our process and we invite anyone to stop by the shop for a tour.