Wavetrac LSD for E46 non-M

[webster]

I think I found my next mod.

http://www.wavetrac.net/images/product_photos/WavetracR_30175WK_640.jpg

http://www.wavetrac.net/index.htm

Anyone have feedback around this company/product? Found a couple threads on E46fanatics that were very positive.

[UdubBadger]

nice, how much?

[zhp43867]

In for updates! Hopefully it's <$2k installed.

[webster]

it lists for $1,295 + shipping on their website. i found an ebay seller that will do $1,200 shipped. so yeah, hopefully <$2k installed. it's described as pretty much plug and play, so the labor shouldn't be too bad if you got someone good. plus you can always sell your old one. plenty of market demand for 3.07 diffs.

[wsmeyer]

I don't know. Go here on their website:

http://www.wavetrac.net/technical.htm

And then click the "How It's Different" tab and read the first section

[SoarinZHP]

I looked at that and I don't understand any of it... Is it like a Subaru diff where both tires have to the the exact same or it'll ruin the diff? An LSD sure would be nice thouogh...

[wsmeyer]

They are basically claiming that no LSD, besides theirs, will do exactly what a LSD is designed to do.

Doesn't exactly give me a warm and fuzzy feeling.

[zhp43867]

The E90 guys have good luck with Wavetrac.

[danewilson77]

Sure it's not just for Auto 330i's?

http://i1015.photobucket.com/albums/af278/nicee46/Maintenance%20and%20Misc/WavetracDiff.png

EDIT: Forget it. I see it.

[UdubBadger]

i was gonna say D, says they just get the 3.15 not the 3.07

[Johnmadd]

Dayum! Should I sell the e30 for this....

[Vas]

I would just go with OS Giken IMO.

[terraphantm]

I would just go with OS Giken IMO.

But that costs $500 more and doesn't fit the stock ZHP manual ratios. IMO the Wavetrac would be pretty nice on a street car since there's no maintenance required, and unlike the Quafe ATBs, the "locking" still works in near 0 traction.

[Sockethead]

Hmm, interesting design... the helical gears certainly will be more efficient that the standard setup. The famed Detroit Locker works in somewhat the same fashion but without the helical gears....the Detroit lacker is a ratcheting design which can make it very noisy. their design with ramps would be much quiter and I bet less wear on the tires.

I wonder how much a shop would charge to install and setup if you brought them the parts. You'd definitely have to take it to shop experienced in setting up ring and pinions...

[LivesNearCostco]

But if you have to install this in your diff case, can you sell your 3.07 diff without the case? Or does the WAvetrac come installed in a diff case?


it lists for $1,295 + shipping on their website. i found an ebay seller that will do $1,200 shipped. so yeah, hopefully <$2k installed. it's described as pretty much plug and play, so the labor shouldn't be too bad if you got someone good. plus you can always sell your old one. plenty of market demand for 3.07 diffs.

[terraphantm]

But if you have to install this in your diff case, can you sell your 3.07 diff without the case? Or does the WAvetrac come installed in a diff case?

I think you reuse the existing ring and pinion. So there wouldn't be much to sell unless someone wanted the open case itself

[Sockethead]

I think you reuse the existing ring and pinion. So there wouldn't be much to sell unless someone wanted the open case itself
Yea I don't think anyone is going to want an open end diff.... even if they blew thiers up... buying the whole pumpkin at a yard would be the way to go...

I think we are going to seriously look into this for the 135 although, it will be more expensive... The problem with the newer 135/335 is that the ring gear is welded onto the diff housing. According to their site, they machine it off and drill it for bolts...There is a place in Philly called VAC Motorsports that is on their dealer list. That's pretty close to us.
I'll keep you guys updated

[Sockethead]

I spoke to VAC Motorsports about this unit. They said that they've had some reliability issues with it.
We went with a Quaife unit for 2574.95 not bad at all for a 135. That's for the complete center section...
e46 should be even less $$

[terraphantm]

Hmm. I think I would have risked the reliability issues simply because quaifes are essentially open diffs in the snow.

[RITmusic2k]

They are basically claiming that no LSD, besides theirs, will do exactly what a LSD is designed to do.

Doesn't exactly give me a warm and fuzzy feeling.

This is actually a valid statement. Mechanical torque-biasing differentials (TORSEN, QUAIFE, et al) require a nonzero amount of resistance on the 'low traction wheel' in order to deliver any torque to the 'high traction wheel'. If you reduce traction to zero on one side (e.g., lifting an inside corner tire), then the diff behaves as if it were totally open and no torque at all is transmitted through the wheel on the ground. They actually recommend applying the brakes in this instance because apply that clamping force on the no-traction side will allow the differential to supply a proportional amount of torque to the high-traction wheel. Same as what terraphantom refers to here:


Hmm. I think I would have risked the reliability issues simply because quaifes are essentially open diffs in the snow.


The wavetrac design apparently solves the "open-diff" condition and allows power to be fed through one wheel, thereby giving the best of both worlds between a mechanical torque-biasing diff and a clutch-based LSD.


EDIT: just took a closer readthrough of their tech description... this is a genius solution. If we can get some reliability testimonials from a 3rd party I'd really start paying close attention to this as an option.

[wsmeyer]

This is actually a valid statement. Mechanical torque-biasing differentials (TORSEN, QUAIFE, et al) require a nonzero amount of resistance on the 'low traction wheel' in order to deliver any torque to the 'high traction wheel'. If you reduce traction to zero on one side (e.g., lifting an inside corner tire), then the diff behaves as if it were totally open and no torque at all is transmitted through the wheel on the ground. They actually recommend applying the brakes in this instance because apply that clamping force on the no-traction side will allow the differential to supply a proportional amount of torque to the high-traction wheel. Same as what terraphantom refers to here:

The wavetrac design apparently solves the "open-diff" condition and allows power to be fed through one wheel, thereby giving the best of both worlds between a mechanical torque-biasing diff and a clutch-based LSD.

EDIT: just took a closer readthrough of their tech description... this is a genius solution. If we can get some reliability testimonials from a 3rd party I'd really start paying close attention to this as an option.

They don't just claim to be different / better than torque biasing differentials, they imply that all other "gear LSD's" suffer from "Loss of drive during zero or near-zero axle-load conditions".

I'm not entirely sure which one's they are referring to when they say "gear LSD" because as far as I know a differential either uses spider gears, helical gears, or a detroit locker type assembly to drive the axles.

They further claim "If you lift a wheel, all gear diffs except Wavetrac®, will NOT power the other wheel." Viscous coupled LSD's, Clutch pack LSD's, even electronic ones that use the ABS to brake one wheel will all power the other wheel.

Then they say "During the transition from accel to decel, all gear diffs except Wavetrac®, do nothing. "

Correct me if I'm wrong but a differential will either:
transfer torque from the driveshaft to the axles
transfer torque from the axles to the driveshaft
nothing

During "the transition from accel to decel" I really want my diff to do nothing.

IMO the wavetrac just looks like a variation of the Detroit Locker, which is horrible choice for a street car as they are quite dangerous in the rain or snow.

[terraphantm]

They don't just claim to be different / better than torque biasing differentials, they imply that all other "gear LSD's" suffer from "Loss of drive during zero or near-zero axle-load conditions".

I'm not entirely sure which one's they are referring to when they say "gear LSD" because as far as I know a differential either uses spider gears, helical gears, or a detroit locker type assembly to drive the axles.

They further claim "If you lift a wheel, all gear diffs except Wavetrac®, will NOT power the other wheel." Viscous coupled LSD's, Clutch pack LSD's, even electronic ones that use the ABS to brake one wheel will all power the other wheel.

Then they say "During the transition from accel to decel, all gear diffs except Wavetrac®, do nothing. "

Correct me if I'm wrong but a differential will either:
transfer torque from the driveshaft to the axles
transfer torque from the axles to the driveshaft
nothing

During "the transition from accel to decel" I really want my diff to do nothing.

IMO the wavetrac just looks like a variation of the Detroit Locker, which is horrible choice for a street car as they are quite dangerous in the rain or snow.

I suppose I could understand your confusion if you're not aware of "gear-type" LSDs. It is a class of LSDs where the locking mechanism is entirely gear driven. As far as I'm aware, the major players in that class are the Torsen diff, Quaife's ATB diff, and the wavetrac.

The advantages for gear-type LSD over clutch-type LSDs is that they don't generally require any more servicing than an open differential, don't make noise during operation, and I believe they're generally cheaper to make. Advantage compared to viscous LSDs is that there are fewer losses due to efficiency. The disadvantage is that they are essentially open differentials if one wheel has 0 traction.

The wavetrac apparently solves that last problem, thus combining the advantages of gear-type and clutch type LSDs

It's nothing like a Detroit locker is locked on throttle, unlocked off. A wavetrac, like most LSDs, is torque sensitive and will engage when there's a large enough difference in torque between the drive wheels. And the lockup is not 100%

[derbo]

I looked into this. It would've been great to do if I had a spare diff to play with.

[Johnmadd]

I know someone who welded their gears on a lathe at a slow and accurate pace with great success.

[RITmusic2k]

...they imply that all other "gear LSD's" suffer from "Loss of drive during zero or near-zero axle-load conditions".Yes, this is absolutely true. They provide more torque to the wheel with more traction until one wheel has zero traction. At that point, all power is uselessly delivered to the wheel with no traction. That's just a flaw inherent to all mechanical torque-biasing diffs.


They further claim "If you lift a wheel, all gear diffs except Wavetrac®, will NOT power the other wheel."That's a restatement of the above.


Viscous coupled LSD's, Clutch pack LSD's, even electronic ones that use the ABS to brake one wheel will all power the other wheel.I'm in complete agreement here; their claims only pertain to mechanical torque-biasing diffs, not traditional or electronic LSDs. The reason we're excited about this new one is that we're of the opinion that torque-biasing diffs are superior in implementation than those other types of LSD, for the reasons terraphantm mentioned above - lower % power loss, no 'consumable' components, less servicing required, etc.



Then they say "During the transition from accel to decel, all gear diffs except Wavetrac®, do nothing. "

Correct me if I'm wrong but a differential will either:
transfer torque from the driveshaft to the axles
transfer torque from the axles to the driveshaft
nothing

During "the transition from accel to decel" I really want my diff to do nothing.

IMO the wavetrac just looks like a variation of the Detroit Locker, which is horrible choice for a street car as they are quite dangerous in the rain or snow.
The 'biasing' referred to in "torque-biasing differential" is the really cool thing about these devices: they provide progressive and proportional torque splits to the drive wheels, in realtime, based on how much traction the drive wheels are getting.

If you have a 4:1 torque-biasing diff, for example, under normal circumstances it will provide torque in an even 50:50 split to both wheels. But if one wheel begins to slip to the point where it has half the traction of the other wheel, the power delivery will shift to 33:66 in favor of the wheel with more grip. If the bad wheel continues to slip further, the diff will bias all the way down to 20:80. Notice that this whole time, even though one wheel suffers from varying amounts of limited traction, 100% of the available power is being transmitted to the ground. It's really fascinating stuff.

The shortcomings begin to show up once the difference in traction between the wheels exceeds the ratio of the differential. In all the previous examples, 100% of the power still made it to the ground, but let's say the bad wheel gets all the way down to 10% of available traction... well at this point, the 4:1 bias means that the good wheel is only going to get four times the available power as is provided to the bad wheel. 10% left : 40% right = a total of 50% of available engine power makes it to the ground. And if that bad wheel comes off the ground or otherwise loses all grip, then the system stops working entirely and sends 100% of the power to the bad wheel and 0% to the good wheel. At least, that's the case with a Torsen or a Quaife.

The wavetrac essentially has a built-resistance mechanism that imparts 'virtual traction' in the event of full slippage such that the lifted wheel will never be able to spin 100% freely, and therefore X amount more traction (where X:1 is the biasing ratio of the diff) will always be available to the high-traction wheel.


EDIT: I forgot to address their point about "during the transition from decel to accel, all other diffs do nothing" - admittedly this is a secondary benefit at best; their claim is essentially that it reduces driveline slop, and that the whole thing will always be under load... thus there will be no gear clashing or jerking at that transition. Not a bad thing, but not a big deal either.

[328ioc]

Gonna bump an old thread here.

I am starting to research LSD's and a friend of mine has a Wavetrac in his 335 that is very much not stock and he loves it and has no problems with it.

I will get some more data from him and add here here now that I see there is a thread already going and people looking for info.

[Sockethead]

Gonna bump an old thread here.

I am starting to research LSD's and a friend of mine has a Wavetrac in his 335 that is very much not stock and he loves it and has no problems with it.

I will get some more data from him and add here here now that I see there is a thread already going and people looking for info.

Sounds good! My wife (Kpro) has an OS Giken in her 135 and I have a traditional M3 style 3 clutch in my ZHP. So if we can be any assistance in your research, let us know.

[328ioc]

Thanks bud. I'll let you know if I have any specific questions. But right now the price of the wavetrac had my eye.

Btw OT but I'll be in SJ this weekend with my girlfriend. Gonna take her to Creamy Acres for the Haunted Hay ride.

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[Sockethead]

Thanks bud. I'll let you know if I have any specific questions. But right now the price of the wavetrac had my eye.

Btw OT but I'll be in SJ this weekend with my girlfriend. Gonna take her to Creamy Acres for the Haunted Hay ride.

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Cool ! If your near Wenonah NJ stop by and I'll let you drive my car so you can see what 3:15 is like...

[derbo]

Wavetrac's pricepoint is very good for an aftermarket LSD.

[328ioc]

Wavetrac's pricepoint is very good for an aftermarket LSD.

Right and I also don't see the point in paying another $1200+ on a whole new diff when I can just replace the internals and add a new diff cover.

Just seems like an easier more financially viable option in my case.

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[derbo]

Right and I also don't see the point in paying another $1200+ on a whole new diff when I can just replace the internals and add a new diff cover.

Just seems like an easier more financially viable option in my case.

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I would suggest getting a spare differential to minimize downtime on your car. I purchased the m3 rear end to minimize downtime as well as get the larger M3 rear brakes and better handbrake. Plus that LSD fins on the bottom is badass :)

I ended up spending close to $2500 due to replacement parts etc.

[328ioc]

I would suggest getting a spare differential to minimize downtime on your car. I purchased the m3 rear end to minimize downtime as well as get the larger M3 rear brakes and better handbrake. Plus that LSD fins on the bottom is badass :)

I ended up spending close to $2500 due to replacement parts etc.

My Indy is a bad ass and would work with me on a Saturday to bang it out so I'm not to worried about down time.

And I do plan on doing the Z4 diff cover.

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[Vas]

Thumbs up for more lsd users lol

[derbo]

Win! Do it!

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