Dana S60...TrueTrac, Spool, or Detroit Locker which one?

**98TransAmWs-6** · 03-03-2014, 09:03 AM

So I am going to get a Dana S60 in the future and I am trying to figure out which differential to get. I have read up on the differences between the three different types but I am still unsure which would be the best for my application. When tracking the car I will be using it on Road Racing courses but it will also be driven on the street as well and some drag strip but most track time will be Road Racing courses. As for power level I have no clue what it will be at for sure but it surely be 550ish if not in the 600+ range. I have read that Trutrac is weaker and can't handle that kind of power but I am not sure if that is the case with the Dana S60 still. Any advice and suggestions will be great. The rear will also have a 3.73 gear ratio.

**35th-ANV-SS** · 03-03-2014, 10:06 AM

Jeremy has or had a Detroit Locker on his TransAm prior to her being put to rest temporarily I believe. You might want to get his feedback on how it handled.

I have the TrueTrac, but in the Moser 9". I have had that on the car since 2008 I believe, with around 500rwhp since 3 summers ago. So far so good as far as it performing. The real test will be this summer though with Mickey Thompson ET Streets. I was running the Nitto 555R DR's and they hooked awesome on the street, but terrible at the track. It had seen some very hard shifting and some hard launches though. With minimal track use, I wouldn't think it would be an issue.

**98TransAmWs-6** · 03-03-2014, 10:55 AM

Originally Posted by 35th-ANV-SS

Jeremy has or had a Detroit Locker on his TransAm prior to her being put to rest temporarily I believe. You might want to get his feedback on how it handled.

I have the TrueTrac, but in the Moser 9". I have had that on the car since 2008 I believe, with around 500rwhp since 3 summers ago. So far so good as far as it performing. The real test will be this summer though with Mickey Thompson ET Streets. I was running the Nitto 555R DR's and they hooked awesome on the street, but terrible at the track. It had seen some very hard shifting and some hard launches though. With minimal track use, I wouldn't think it would be an issue.

Hmm I may message him and see. It would be nice to see someone's perspective who Road Races. I saw some posts on Tech saying how TruTrac was better or at least fine in Road Racing applications since your launches aren't as hard but I want something I am not going to want to redo later. From some reading Spool doesn't seem like a good idea from what I have read for my application though so I think mostly it is between Detroit Locker and TruTrac.

**35th-ANV-SS** · 03-03-2014, 11:00 AM

Does the Dana S60 come equipped with the WaveTrac as an option, or no? Last I heard it did not, but that was some time ago. I believe that center section comes with a lifetime warranty from Moser. Just another option, and it is much stronger than the TruTrac from what I've read.

***SMWS6TA*** · 03-03-2014, 11:06 AM

S60 / Wavetrac = no option yet

**98TransAmWs-6** · 03-03-2014, 11:10 AM

Well from my reading which could be wrong the Dana S60 is the strongest overall. That was why I was choosing it plus its better suited for an automatic and RR but I could be off base, it is just what I have heard. I'll have to read up on the WaveTrac.

**98TransAmWs-6** · 03-03-2014, 11:28 AM

Question with the Moser 12 bolt do you need a different driveshaft? Like length wise?

**35th-ANV-SS** · 03-03-2014, 01:03 PM

Pretty sure it is the same length. Jeff would know for sure though as he is running the 12 bolt in his car. Shouldn't matter between the Strange and Moser brands. I believe Jeff has a Strange. We both are using the PST AL drive shaft.

**98TransAmWs-6** · 03-03-2014, 01:14 PM

Originally Posted by 35th-ANV-SS

Pretty sure it is the same length. Jeff would know for sure though as he is running the 12 bolt in his car. Shouldn't matter between the Strange and Moser brands. I believe Jeff has a Strange. We both are using the PST AL drive shaft.

Cool the reason I was asking is that the Dana S60 requires a shorter one. Also I think I am going to go the wavetrac route based on what I have read it seems to be the best choice for my application.

***Ed Blown Vert*** · 03-03-2014, 03:33 PM

Originally Posted by SMWS6TA

S60 / Wavetrac = no option yet

Too bad, that's my suggestion.

**98TransAmWs-6** · 03-03-2014, 03:43 PM

Originally Posted by Ed Blown Vert

Originally Posted by SMWS6TA

S60 / Wavetrac = no option yet

Too bad, that's my suggestion.

Wonder could they custom make one for me lol with a wavetrac instead?

**pajeff02** · 03-03-2014, 04:22 PM

I have a Truetrac in our 12 bolt from Moser and it works great both on the street and at the track. I am not pushing big ponies though as our engine is still all stock. Driveshaft is around 5/8" to 3/4" shorter than stock if I recall.

**35th-ANV-SS** · 03-03-2014, 05:06 PM

Ah yes, my memory is starting to slip in my old age.

**98TransAmWs-6** · 03-03-2014, 07:52 PM

Originally Posted by 35th-ANV-SS

Ah yes, my memory is starting to slip in my old age.

Dammit Jon lol! Well I'll be looking at $3300 with wavetrac. Damn wavetrac is pricey at $800+ added on for the option.

**pajeff02** · 03-04-2014, 02:05 AM

The Wavetrac came out right about the time I purchased my rear -- I wasn't even aware of it until Ed mentioned it in a thread. If I had it to do over again, my rear would have a Wavetrac in it.

**35th-ANV-SS** · 03-04-2014, 02:55 AM

If mine breaks, I'll be going that route too.

**98TransAmWs-6** · 03-04-2014, 05:11 AM

Alright cool. I'll probably get it without ABS as well since I am going to delete it anyway. What are the difference between the different splines, like what is better? I was thinking of getting a 35 spline but I am unsure if that is best.

**Firebirdjones** · 03-04-2014, 06:11 AM

Nascar uses lockers at every track (with a 9"), including the road courses and short tracks. They also constantly launch them hard off pit road. Granted lockers can be reworked and manipulated for different affects, but the grand scheme of things, for them it seems to get the job done.

Since you seem to be more road race oriented than anything, I wouldn't worry all that much about it. I'd be looking at 9inchers if it were me and skip the D60.
Personally I still prefer a clutch style unit for anything that will see street use with occasional track time. I've run them for years behind 600-700 HP cars without a hickup. One of them being a heavy Moroso piece that I've been running in the chevelle since the mid 80's with hard dragstrip use and tons of street miles, still tight and chatters tires when you turn.
I also went with a heavy duty clutch unit from Eaton in my wifes 4th gen when I installed the Strange 12 bolt along with 33 spline axles, no regrets there either. Drives like stock without the noise yet still strong enough for anything I'll throw at it. And no goofiness to worry about on wet roads, after all it's my wifes car, can't have those issues.

35 spline would be more than enough, and actually overkill not to mention more weight sapping HP. Even an aftermarket non tapered 30 spline axle is rated for something like 1200-1500 ft lbs of twist. 33 spline would be more than enough. In the end it all costs nearly the same, so if you wish, build it to extreme...

***SMWS6TA*** · 03-04-2014, 06:27 AM

Will the WAVETRAC are between $995 (9in) to $1095 (8.8) if not ordered with a new rear. I know because that is what I'm going to once I break the one in the 8.8 rear.

Having been in a Trans Am with a 9" and a WAVETRAC, it was fun as hell when he launched at 5800 rpm. If I didn't have the seat belts on I think I would have been in the t-top storage area. Lifting a fat boy like myself out of the seat says something.

Here is the info on WAVETRAC Diff's:

WHAT MAKES A WAVETRAC® DIFFERENT

To best understand how the Wavetrac® is truly different from the other gear differentials on the market, you first have to understand the primary problem that the Wavetrac® solves.

The problem: Loss of drive during zero or near-zero axle-load conditions.
Zero axle-load is a condition that occurs during normal driving, but creates the most noticeable problems when driving in extreme conditions. Zero or near-zero axle-load is the condition that exists when there is ‘no-load’ applied through the drivetrain, when one drive wheel is nearly or completely lifted (often in aggressive cornering). It also occurs during the transition from engine driving a vehicle to engine braking and back, even with both drive wheels firmly on the ground.

Here’s how that loss of drive hurts you:

1) If you lift a wheel, all gear diffs except Wavetrac®, will NOT power the other wheel.

2) During the transition from accel to decel, all gear diffs except Wavetrac®, do nothing.

Why does this happen?

All gear LSDs (including Torsen®, Truetrac®, Quaife®, Peloquin, OBX, etc.) work in basically the same manner: they divide the drive torque between the two axles, applying drive to each side, up to the available grip of each tire. The amount of drive torque one wheel can get over the other is described as the bias ratio, a measure of the torque split across the axle.

Standard, open differentials have a bias ratio of 1:1. They can only apply as much drive torque as there is available traction at one wheel. When one wheel loses grip, the total available drive is lost as well (at a 1:1 ratio). All your power goes out the slipping wheel - along the path of least resistance.

Torque biasing differentials offer increased bias ratios over open differentials. For example, if a diff has a bias ratio of 2.5:1, then it can apply drive torque to the wheel with the most traction (gripping wheel) at 2.5 times the traction limit of the wheel with the least traction (slipping wheel). This is a significant improvement over an open diff… most of the time.

The problem is that when one tire has LITTLE or NO grip (zero axle-load), the other wheel gets ZERO DRIVE, because (basic math here): 2.5 x 0 = 0.

Lift a wheel (or substantially unload a wheel) and you get zero axle-load on that side - that means that during the time the wheel is unloaded, the typical diff will NOT power the wheel that’s still on the ground. No matter how high the bias ratio, you get no power to the ground.

During the transition from accel to decel, where you have near zero torque on the axle, even if the wheels are on the ground, the typical diff is unable to begin applying drive torque until AFTER the zero torque condition is over. While this condition is generally short-lived, the fact that most diffs can do nothing during that time means that there will be a delay once the zero torque condition stops - creating a reaction time in the driveline.

The Wavetrac®, however, is different:

The innovative, patent-pending, Wavetrac® device in the center of the diff responds during these exact conditions when zero or near-zero axle-load occurs. At or near zero axle-load, the axles (and therefore each side gear in the diff) start to turn at different speeds.
This speed differential causes the Wavetrac® device to step into action:

Precisely engineered wave profiles are placed on one side gear and its mating preload hub. As the two side gears rotate relative to each other, each wave surface climbs the other, causing them to move apart.
Very quickly, this creates enough internal load within the Wavetrac® to STOP the zero axle-load condition.

The zero axle-load condition is halted, and the drive torque is applied to the wheel on the ground (the gripping wheel)… keeping the power down.

Some gear differentials rely solely on preload springs to combat loss of drive. The drawback is that you can’t add enough preload to prevent loss of drive without creating tremendous handling and wear problems at the same time. So, to avoid these problems, the preload from ordinary spring packs must be reduced to a level that renders them ineffective at preventing loss of drive. The Wavetrac® is the only differential that can automatically add more load internally when it’s required.

In the case where both wheels are on the ground during zero axle load, such as during a transition to deceleration, the Wavetrac® device is able to prepare the drivetrain for when the zero torque condition stops, eliminating the delay seen with ordinary gear diffs.

What this means for you as a driver is that power is delivered to the gripping wheels for more time and in a more constant manner – making you faster and improving stability.

The Wavetrac® truly is different - and its innovative features can make a real difference in your car’s performance.

Here are more features that make Wavetrac® even better:

The new Wavetrac® Differential brings current gear technology to the market.

Internally, its gear tooth forms are optimized for strength and improved oil film retention over competitive designs.

Our gear package is smaller, reducing overall mass, yet is more durable since particular attention was paid to the tooth strength - optimized for high torque conditions.

Attention was also paid to the side gear/axle interface, putting as much material thickness as possible in this critical area - most important when power levels get high.

Each Wavetrac® Differential is crafted from the highest quality materials available.

The internal gears are made from high strength 9310 alloy steel.

The diff bodies are machined from case-hardened steel billet.

To complete the package, every Wavetrac® differential is built exclusively using high quality, high strength fasteners from ARP®, the world leader in fastener technology.

**98TransAmWs-6** · 03-04-2014, 08:12 AM

Okay so I am definitely going wavetrac. The question is 12 bolt or 9". I have an a4 so I was going to go with a 12 bolt for the 3.73 gears which I can't get in a 9", only 3.75 but I could just do 4.10 I guess as well since I can get that in either.

Is one better for an automatic over the other? I have just seen if m6 people tend to get the 9" and if a4 they get the 12 bolt so I am wondering what the reasoning is.