Gen 3 Diff Upgrade?

[Turk]

I'm looking to upgrade the diff on my 2005 and was wondering what people recommend? I was thinking of going Wavetrac with a 3.55 gear, but was wondering if there are any other suggestions out there. Since I don't take my car to the drag strip, and only track it once a year do I really need the 3.55 gear? Most of my driving is on the highways cruising through the mountains. Also if I upgrade the diff do I need to do the half shafts as well?

[Joel]

Lots of folks will have different ideas on this. Got my Unitrax upgrade to late rear end model specs with 3.55 gear and I really like it. Made 5th and 6th usable - 80+ mph in 6th is 1300-1400 rpm. Some folks modify the transmission or get a Trans-zilla upgrade to change 5th and 6th gear ratios. I track my car and find the gears more suited to fun and track driving - 3 and 4 are close, 5th will give about 145-150+ on back straight at Road Atlanta - if I'm that brave. My half shafts are stock but I am not a drag racer. I think the stock shafts will be fine. PM me if you have more questions.

[Nine Ball]

Wavetrac posi made a big difference on my high-hp car. The rear of the car used to kick out a little from a 60 mph punch, before straightening out. Now it takes off perfectly straight on the hit. 3.55 gears will wake up the Gen 3 nicely, especially in 1st gear. It will also make 6th gear far more useful on the highway.

Won't need upgraded half-shafts unless you are making a lot of power and launch hard at the drag strip, like I do. Stock half-shafts are pretty strong, as long as you never wheel-hop them. If you ever feel wheel-hop, lift off the throttle immediately. I never broke any, even with 1000+ rwhp. And that was with a lot of hard runs.

Tony

[Sonoman]

I traded in my 2005 diff to Unitrax for a 2010 Viper ViscoLok diff and had them install the new gears as well. I like the lock-up characteristics of the ViscoLok better than the old Hydra-Lok and the car is more predictable coming out of corners on the gas. As mentioned, the half shafts are OK for most conditions but they can break with severe wheel hop/lots of runs down the strip. Given the price of improved shafts I am waiting for one to go out before spending big bucks on new ones.

The original Gen 3 Hydra-Lok differential has an interesting design which requires one wheel to spin 3-5 revolutions before locking the diff and transferring more torque to the non-spinning wheel. On my Viper this tended to make the car feel a little squirelly, like it was doing a little two-step dance back there if you got on the throttle too suddenly. To me, the newer ViscoLok rear-end just feels more normal, like what I would expect from a limited-slip rear. Obviously, there are several options in LSDs for the Viper and it would be cool to try them all on a track and pick the one you like the best.

[Turk]

Thanks guys, I'll give Unitrax a call. I don't ever plan on increasing my horsepower so I'll just stick with the OEM half shafts.

[J TNT]

I bought from unitrax , dealt with Devon . They are top notch !

[Dan Cragin]

Here is some information I have from our website.

Why upgrade my limited slip differential?

Ever hit the gas on your Viper and have it go sideways instead of straight. This can be a scary experience!

From 1992 to 2010 the Dodge Viper came with a factory installed limited slip differential (LSD). 1992 -2002 used a Trac Lock, 2003-2005 used a Hydro-lock and 2008-2010 used a Visco-lock LSD. As the Viper’s power increased the LSD was upgraded to improve durability and traction.

The factory LSD units do a good job, but are limited in the power they can take and how they apply torque to the wheels.

There are three Performance Viper LSD units on the market now that can take nearly unlimited power levels and move between both free and locked positions much better than the factory LSD’s. The end result is superior traction and durability.

OS GIKEN “SUPERLOCK” 2003-2010 Vipers

The Super Lock is a true 100% locking LSD that instantly reacts and transitions smoothly from both free and locked positions, combining open differential driveability and limited slip differential performance and stability.
The OS Giken Super Lock features innovative technologies like an adjustable lock timing adjuster. Lock timing can be adjusted by replacing the springs in the pressure ring. Initial torque settings are also adjustable through cone springs located at ends of clutch stacks. This allows the Super Lock to be tuned to meet your exact needs for optimum performance.

WAVETRACK LSD 2003-2010 Vipers

The Wavetrac is made in the USA and uses high quality ARP hardware. It uses torque biasing worm gears instead of clutches to control the rear axles in the event of uneven traction. In clutch and plate LSD rear ends, the unit is trying to lock up and simulate a spool when a wheel loses traction and ensure that at least 50% of available torque is sent to the wheel with traction. A worm gear limited slip differential uses it’s gearing to send more than 50% of the torque to the wheel with traction. In other words, when one wheel begins to slip a worm gear LSD uses the mechanical leverage of its worm gears to transfer the torque the slipping wheel is receiving and send it to the other side. The Wavetrac differs from other torque biasing LSDs due to its unique and patented wave cam. The wave cam allows this Helical LSD to achieve full traction even when a wheel is unloaded.

TRU-TRAC 1992-2002 Vipers

The Detroit Truetrac is the first helical gear differential ever introduced into the automotive aftermarket. It remains a leading helical gear-type limited slip differential in the industry. Detroit Truetrac's proven gear design eliminates the need for wearable parts, resulting in maintenance free traction recognized not only for its toughness, but its smooth and quiet operation. Proven design, low cost and effective performance make the Truetrac limited slip differential the ideal choice for high torque applications where a smooth transition from locked to unlocked is needed. No maintenance - Just Traction.

[TowDawg]

I went with a Quaife unit and 3.33's in mine. I was thinking about FI and 3.55's would be too much if I went that route. It made 5th and 6th more usable on the street, but the back straight at RA still sucked and I was better off holding it at redline in 4th for the last part of the straight, than going to 5th. It would pull in 5th, but still not very hard.
After the trans completely ate the main shaft on another run down the back straight, I went with the Tranzilla built unit and changed out the 5th and 6th gear ratios in the trans while I was at it (like Joel mentioned above). Did I lose a little mpg on the highway by having a taller 5th/6th and 3.33's? Yeah, but do I give a damn? Hell no! It completely transformed the car both on the street and on the highway. I knocked 1.5 seconds off my lap times the next time at RA because I go straight into 5th and just keeps going without missing a beat!
Also, like Dan said, when putting the power down (especially out of a corner) the car hooks better and much more predictable.
As far as halfshafts, I'm still on my stock ones with no issue. Wheelhop and hard launches is what will destroy them.

[Turk]

I was thinking of going with a 3.33 gear, but since I don't ever plan on doing a forced induction system I figured the 3.55 would be perfect. I've already been snake-bitten once due to loss of traction in the rear, so I can't wait till I get a chance to pull the diff out this spring and upgrade that "wonderful" OEM diff.

[Mbccenter]

I do have a extra Quafie with 3:55 comple rear.

[Mamba003]

I went with the Giken with 3.33s and could not be happier. Stock the rear would drift instantly left at anywhere past mid throttle. Now at 613 to the wheels, still dead strait no matter throttle, or traction.

[Turk]

Oh boy. Too many options to pick from. I was originally thinking Wavetrac since I've heard nothing but good things about them. Devin from Unitrax suggested the Wavetrac. But now I should probably consider the Quaife and OS Giken. I think I've convinced myself of getting the 3.55 gear, but now I need to figure out which manufacturer. One thing I like about the Wavetrac that Dan posted above is that you still have full traction when one wheel is unloaded. Mind you I'm never pushing my car hard enough to create a situation like that.

[Revolution]

Always take you for a ride in mine man and you can feel and judge for yourself!

[TrackAire]

I'm looking to upgrade the diff on my 2005 and was wondering what people recommend? I was thinking of going Wavetrac with a 3.55 gear, but was wondering if there are any other suggestions out there. Since I don't take my car to the drag strip, and only track it once a year do I really need the 3.55 gear? Most of my driving is on the highways cruising through the mountains. Also if I upgrade the diff do I need to do the half shafts as well?

I went with the OS Giken spec'd by BBG with (cryo'd and mircro polished gears, safety wired fasteners, etc). There was a thread about the Wavetrac on the other forum. Look at the video on post 1 and my response on post 21.

http://forums.viperclub.org/threads/...light=wavetrac

I love the Giken with 3:55's and I also have the modified lower 5th and 6th speed transmission ratios. True close ratio's for any track or street condition. If keeping your motor hp stock, changing the trans ratio's and rear end ratio really make the car even more fun to drive. You don't "need" to change your gears, but I hate the feeling of running around a whole track in 3 gear....same with the street. The car feels much more lively when the engine is in its sweet spot.

For your needs, a Gen 4 LSD would be a great upgrade to your Gen 3 unit (crap in my opinion). The Gen 4 LSD is so good that a few years ago a member on the other site competed in the SCCA National autocross championship and came in second place with a Gen 3 convertible. That is saying something and the diff was the major upgrade to get the car on the podium.

I picked the Giken over the Wavetrac because at the time Giken was used by a lot of race teams, Wavetrac was just coming onto the market.

Cheers,
George

[Copperhead06]

I do have a extra Quafie with 3:55 comple rear.

Do you want to sell the rear ??

[Revolution]

Let me know Matt I have a gen 4 diff if your interested

[steve911]

Not to hijack the thread, but I would like to know more about the gen 4 you have available...

[Turk]

Is it worth just doing a Gen 4 upgrade? From what I've heard a gen 4 upgrade is around the same cost of putting in a Wavetrac (assuming I'm buying a new Gen 4 diff).

[Revolution]

Came out of my gen 4 with 7500km and was removed by Devin at unitrax!

[Turk]

If I upgrade to a Gen 4 diff (housing included), does my drive shaft length change?

[Sonoman]

If I upgrade to a Gen 4 diff (housing included), does my drive shaft length change?

No, the housing is the same on Gens 3 and 4. Right down to the spiffy "Fangs" logo looking back at you...

[steve911]

Unfortunately there are no more Gen 3 or Gen 4 diffs to be had. The only complete diff assy currently available is the Gen 5 diff. THat doesnt have 3.07's in it though . You get 3.55's.

If you have a broken Gen3 or 4 diif, the only thing available are parts that have to be assembled into the case.

I going to have a Gen 3 diff warrantied soon and it was a pain for the dealer to get all of the parts. As a matter of fact the hydroloc is not even available any more. A Gen 4 posi unit had to be substituted.

[Revolution]

Is it worth just doing a Gen 4 upgrade? From what I've heard a gen 4 upgrade is around the same cost of putting in a Wavetrac (assuming I'm buying a new Gen 4 diff).

I wouldn't buy a new Gen4 diff but a used one would be a lot cheaper!

[steve911]

Came out of my gen 4 with 7500km and was removed by Devin at unitrax!

How much are you asking for the diff?

[Viktimize]

Is it worth just doing a Gen 4 upgrade? From what I've heard a gen 4 upgrade is around the same cost of putting in a Wavetrac (assuming I'm buying a new Gen 4 diff).

The Gen4 upgrade will just give you LSD, it won't give you the driveability improvements of a 3.55 ratio. And if you're staying stock I would definitely want that better rear end ratio just to make 6th gear useable on all those road trips we are going to do this summer. (wink wink, nudge nudge)

Sorry to crap on your sale Ron. lol. Looks like you got some other interest though anyway. BTW, did you just mail your whole pumpkin out to Untitrax for the diff swap? I am looking at a diff swap too this year once I am done with the MCS upgrade.