2modfast

I'm looking into LSD's...any feed back? Has anyone done it?

mhs525

I have a Quaife LSD, best mod I have ever done. Car drives like an M car now.

The Quaife site expains the benefits.

Diffsonline has all the information you need regarding pricing, whats avaialable and there are a few threads covering the issue.

miguex

+1 another LSD owner on 545i here! It is a must for V8 engines! LSD will double the traction on the wheels. That is why the M factory reserved LSD for M cars only but there are aftermarket ones!

2modfast

Thanks for the replies guys...I'm really leaning toward getting one. Many people refer to it as "the poor man's supercharger" - hahaha. Great seat of pants noticeable power for half the cost.

Any drawbacks? +/- you care to share?

Also did you guys change your gearing as well or you just added a Quaife unit? I spoke to a shop and he recommended that I only change the gearing and not add the Quaife unit.

miguex

it depends.... Manual gear: possible but plus with LSD much better. Automatic: I don't think there is aftermarket gearing but LSD can be installed. IMO LSD is the best choice. Maybe your mechanic is unaware about the benefits of LSD on BMWs.



QUAIFE LSD

"The Quaife ATB Differentials

The Quaife Automatic Torque Biasing (AT differential enables your car to accelerate quicker and corner faster. How?

By getting the power to the ground!

The Quaife differential powers both drive wheels under nearly all conditions, instead of just one. With an ordinary open differential, standard on most cars, a lot of precious power is wasted during wheelspin under acceleration. This happens because the open differential shifts power to the wheel with less grip (along the path of least resistance). The Quaife, however, does just the opposite. It senses which wheel has the better grip, and biases the power to that wheel. It does this smoothly and constantly and without ever completely removing power from the other wheel.

In drag-race style, straight-line acceleration runs, this results in a close to ideal 50/50 power split to both drive wheels, resulting in essentially twice the grip of an ordinary differential (they don't call open diffs "peg legs" for nothing).

In cornering, while accelerating out of a turn, the Quaife biases power to the outside wheel, reducing inside-wheel spin. This allows the driver to begin accelerating earlier, exiting the corner at a higher speed.

The Quaife also controls loss of traction when the front wheels are on slippery surfaces such as ice and snow or mud, providing the appropriate biased traction needed to overcome these adverse conditions. The Quaife differential provides constant and infinitely variable drive. Power is transferred automatically without the use of normal friction pads or plates seen in other limited-slip designs.

The Quaife's unique design offers maximum traction, improves handling and steering, and puts the power where it is needed most. A definite advantage whether on the track or on the street.

The Quaife is extremely strong and durable and since the Quaife is gear operated, it has no plates or clutches that can wear out and need costly replacement.

Every Quaife differential comes with a Limited Lifetime Warranty.

We are so confident in the durability of the Quaife, we back it up for life.

The Quaife is great for street driving or racing. Racers don't have to put up with locking mechanisms or spools that tear the steering wheel out of their hands when cornering. Because it behaves like an open differential during ordinary driving, street drivers will have trouble telling it's there until pushing the car's limits.

The Quaife has been proven in everything from compact drag racing to Pro Rally to Formula 1. The Quaife ATB Differential provides racers with such an advantage, it has become "required" equipment for a winning effort.

source: http://www.hpashop.com/product.sc;jsession...;categoryId=114

mhs525

I think your mechanic has it backwards. Changing the gears would put more torque to the wheel(s). What good is that if you have trouble putting down the power you have?

Also I was advised against changing the gears in a Steptronic car because it would confuse the computer, Dinan offers hear changes for manual and SMG cars but not Steptronic. Has to be a reason for that?

The only drawback is the cost... no noises, no binding, no issues at all.

However the LSD needs to be installed by someone who is familiar with setting up rear ends. This is not a job for amateurs.

2modfast

Good points and feedback.

Did you guys purchase your Quaife unit from Diffsonline? Elswhere...maybe from a mechanic shop? Any install pics? What ball park figure should I be, in terms of price for the unit and install?

mhs525

For my car the whole thing was handled by Turner Motorsport who used Diffsonline. Both are local to me. Turner removed the rear end from the car and sent it to Diffsonline who installed the Quaife and sent it back to Turner to reinstall in the car. The Quaife unit was $1,900, labor $700 and shipping $100. So $2,700 all in.

http://www.diffsonline.com/product/customdiff5.shtml

This a great mod. The car drives totally different, corners/rotates like an M car. And it feels much faster, the car really puts the power down. Best mod I have ever done on any car... and I have had a few...

bha7176

But did you change the gearing or just have the LSD installed? I don't understand how only going from open to LSD would make a difference in torque if not accompanied with a gear change - really. Can someone explain this to me? I understand the power to the wheels issue, and if you're always smashing it and spinning the tires then yes, I understand an increase in your launch, but if you are just driving around like most people, and occassionally hit it, how can an LSD over open affect anything in regards to power?

2modfast

Not bad...not bad at all. What was the down time (how long did they have your car?)