[loweredram]

Hi, I'm a new 335i owner and new to the forum. I Just wanted to get some info. I've searched the forums to find a direct answer and couldnt find it so I'm asking for opinions. Is a LSD worth installing if you dont track the car often? in my group of 335i owners some say you should have the LSD before a tuner so you can plant the power. The others have told me you can plant the power without the LSD. Then I get the just use the DTC and others say turn all that crap off and learn how to drive without it. What do some of you think? I've only driven an M3 with a LSD so I can't use that to compare since the two cars have different suspension, tires, .....etc

[Bakeme521]

From reading around a lot of people say its the best mod they have ever done, tracking it or not. I am waiting for mine right now and chances are my car won't see the track, thats what I have a track car for. If you wait about 2 weeks I can let you know how I like mine on street driving standards.

[loweredram]

Thanks for the response. I was planing on buying the wave trac but I would like to hear what you find in everyday driving.

[Coolieman1220]

I want one. I found that in bad weather it can be very helpful getting the power where you need it and if you end up in a drift it will make ur car a lot more controllable.

[Brey335i]

Honestly. Go with the tune first. But if you can swing it, definitely also get an LSD. It changes the way the car behaves ... And helps get rid of the Xmas lights on the dashboard

[I335]

Interesting responses...

The OP is asking about how much value he can expect from an LSD in a non-racing environment, i.e. on the street. But, the answers I'm seeing are "it'll help you if you're drifting" and it will "help get rid of the Xmas lights on the dashboard". I could be mistaken as the OP didn't really disclose what his style of street driving is, but when I'm driving around the streets I don't ever find myself in a drift nor do I see Xmas trees on my dash. If I am experiencing these things then I'd consider myself racing on the street - or at least driving aggressively enough to get into trouble with the boys in blue.

All that said, I'm interested too - what can we expect from an LSD during LEGAL, normal street driving? Will it even be noticeable?

[ModBargains.com]

The stock rear differential in both the 135i and 335i is an open differential from the factory. This means you can only put power to the ground on 1 wheel. With an aftermarket rear differential like the Wavetrac, you can now put power down to both wheels! During a turn, the weight of the car is transferred to the wheels on the outside of the turn. With the weight transferred to the outside, the inside wheel will now have less traction. In an open differential, power is sent to the wheel that has the least amount of traction. This means that if you applied power in mid turn, power would be sent to the inside wheel and thus making it spin and lose traction.

With the Wavetrac Limited Slip Differential (LSD), power is sent equally to both drive wheels giving you the ability to apply power in mid turn. This equates to better traction and thus faster exit speeds out of the corner. Whether you track your car or not, upgrading to the Wavetrac LSD will completely change the dynamic of the car under power. You'll be surprised how much more traction you have, even driving on the street!

Feel free to contact me if you guys have questions at all and I'll do my best to help you guys out!

- Alan

[onebadmofo]

How much do they usually run?

[Penn999]

From all the reading that ive done, Quaife is the only way to go. I talked to a local that used to work for Quaife and now he has his own bmw/subaru, racing/rally shop. he says that they are a must for the track. For street use, like someone else said, if you do some street races here and there a like to venture onto to the back road twisties and get it a little sideways I would def. invest in them. He said they should run around 1,500-1,750 (part only) depending on where you got it. I will be buying the Quaife in the spring bc I dont really run my car very hard in the winter months.

[turb0mik3]

Originally Posted by Brey335i

Honestly. Go with the tune first. But if you can swing it, definitely also get an LSD. It changes the way the car behaves ... And helps get rid of the Xmas lights on the dashboard

Except when you push 400+whp and you have too many Xmas lights, LOL. But in all honest, an LSD IS the best modification you will do, plus it doesn't fuck up your warranty. Also, Wavetrac has a lifetime part warranty, so no need to worry!

[loweredram]

I track the car 1 or 2 times if I'm lucky every 3 months. I like to get aggresive on mountain curvy roads and mash the throttle from time to time while Im driving. I had chance to drive the new M3 on some nice curvy roads and noticed it felt so much more stronger going in and out of the turns and the guy mentioned to me part of it was the LSD. So thats when I started looking. Some had suggested I do the LSD before the tuner because the car will drive different. How will LSD interact with DTC and DSC ?

[GaryS]

When you exit a corner and feel like the gas pedal is ignoring you, what's happening is the stability control is intervening because of wheel spin. With a Quaife or Wavetrac installed, the wheel won't spin, so the DSC won't intervene, and you will rocket out of the corner.

[loweredram]

Ok I think I got it. So it wont effect the DTC/DSC they just wont have to work as hard because the car will not be losing traction and or spinning out as much with the LSD if I'm understanding you correctly?

[Penn999]

Originally Posted by loweredram

Ok I think I got it. So it wont effect the DTC/DSC they just wont have to work as hard because the car will not be losing traction and or spinning out as much with the LSD if I'm understanding you correctly?

Better than explaining it myself...I will show you what someone else showed me on here, it all made sense after this. I know its old but hey it works.

[Bakeme521]

^^a very good video, it really dumbs it down.

Originally Posted by Penn999

From all the reading that ive done, Quaife is the only way to go. I talked to a local that used to work for Quaife and now he has his own bmw/subaru, racing/rally shop. he says that they are a must for the track. For street use, like someone else said, if you do some street races here and there a like to venture onto to the back road twisties and get it a little sideways I would def. invest in them. He said they should run around 1,500-1,750 (part only) depending on where you got it. I will be buying the Quaife in the spring bc I dont really run my car very hard in the winter months.

As for the parts, I have heard very good things about the wavetrac and many people say it is even better than the quaife, and as stated above it has a lifetime warranty so how can you go wrong. And parts don't run that high especially if you have a bolted ring gear. I just got my wavetrac on the group buy for 992 bucks. And if you contact AJ@ECSMotorsports they cut a deal for e90post members for 1090 shipped. If you have a welded ring gear then you need the install kit which will make it a little more. Heres a vid of the wavetrac in action., I wouldn't do it in my car, but it shows how well it works.

[techlogik]

Originally Posted by Penn999

From all the reading that ive done, Quaife is the only way to go. I talked to a local that used to work for Quaife and now he has his own bmw/subaru, racing/rally shop. he says that they are a must for the track. For street use, like someone else said, if you do some street races here and there a like to venture onto to the back road twisties and get it a little sideways I would def. invest in them. He said they should run around 1,500-1,750 (part only) depending on where you got it. I will be buying the Quaife in the spring bc I dont really run my car very hard in the winter months.

Mmmm...wut? I guess the 20+ people that just bought the Wavetrac LSD on the group buy don't know what they are doing then.

[Penn999]

HAHA I would NEVER do that to my car, but yeah I know the message its trying to convey. I will look into watetrac, the reasons i think quaife is good is bc of my own research and a couple of the forum members that I know run the quaife, and they love it....they also have VERY deep pockets and want the best product so thats why I value their opinion. Maybe there isnt much diff. I need to do a bit more research before i make my final decision.

[scheherazade]

Originally Posted by Penn999

From all the reading that ive done, Quaife is the only way to go. I talked to a local that used to work for Quaife and now he has his own bmw/subaru, racing/rally shop. he says that they are a must for the track. For street use, like someone else said, if you do some street races here and there a like to venture onto to the back road twisties and get it a little sideways I would def. invest in them. He said they should run around 1,500-1,750 (part only) depending on where you got it. I will be buying the Quaife in the spring bc I dont really run my car very hard in the winter months.

Quaife and Wavetrac are very similar.
They are nice for track and street.
Both are silent, and engagement is progressive.
Neither will hard-lock.
Both are good for the life of the car.

If you're talking about serious racing, then you'll be more likely to use something like the OS Giken clutch type LSD. (especially if you're talking deliberate, controlled oversteer)
They are noisy if you don't pay extra for the drilled street clutch pack.
They also hard-lock on acceleration, and can be configured to hard lock on deceleration.
The clutch pack is very big (6+ per side), and can go a while between services.

Quaife and Wavetrac are 'good enough for regular folks and enthusiasts'.
They're not 'the only way to go'.

Originally Posted by loweredram

Thanks for the response. I was planing on buying the wave trac but I would like to hear what you find in everyday driving.

Under normal circumstances, you won't even know it's there.

The difference is that you can hammer it with the stability control disabled, and you get predictable results. The car doesn't fight you. It does everything you tell it to.

Wheel spin is more or less balanced.

It's silent, and non intrusive.

-scheherazade

[vasillalov]

Originally Posted by **********s.com

The stock rear differential in both the 135i and 335i is an open differential from the factory. This means you can only put power to the ground on 1 wheel.
- Alan

Now see, this is very misleading! The differentials were invented to be able to put power down on both wheels, not just one!

What you really mean to say is that when a driver is powering out of a sharp corner at high speeds, one of the wheels receives significantly more torque than the other, given an open differential. That does not mean that the other wheel is not putting any power down, though!

[scheherazade]

Originally Posted by vasillalov

Now see, this is very misleading! The differentials were invented to be able to put power down on both wheels, not just one!

What you really mean to say is that when a driver is powering out of a sharp corner at high speeds, one of the wheels receives significantly more torque than the other, given an open differential. That does not mean that the other wheel is not putting any power down, though!

No, what he means is that if you put enough power down to cause wheel spin, only one wheel spins. The other retains traction, effectively driving only one wheel.

The other end of the stick is that while one wheel free-spins, all the power is lost in "free-wheeling". So even though one wheel still has traction, it's effectively limping along.

So really, you're 'less than 1' wheel drive after you break loose, because the one wheel still driving is not getting the power it normally would.

And the 'free spinning' wheel has nearly no traction, so it doesn't contribute much.

-scheherazade

[vasillalov]

I understand all that, thank you! It's just that it sounded from his description that our OEM diffs are 1-wheel drive.

Ideally, if we have absolutely equal amount of traction on both wheels, and if the car is accelerating straight, and we have equal length drive shafts, both wheels will spin equally even with an open diff. If you read his description, he makes it sound like only 1 wheel is driving the car, which is incorrect!

It is because we do not have ideal conditions that we get into a situations where one wheel looses traction before the other and then more torque is being sent to the wheel with less friction. It is in those situations only that an LSD is helpful.

[Brey335i]

Originally Posted by I335

Interesting responses...

The OP is asking about how much value he can expect from an LSD in a non-racing environment, i.e. on the street. But, the answers I'm seeing are "it'll help you if you're drifting" and it will "help get rid of the Xmas lights on the dashboard".

I'm sorry, but if you have never had the DTC light up on you, then you really shouldn't be giving answers here. The OP asked how it would be on the street, I light up the DTC every time I accelerate hard on really sticky tires. I don't really understand how that doesn't apply to the street?