My DIY differential gear change

Discussion in 'SRT10 and SRT10 Coupe Discussions' started by cowger, Nov 28, 2012.

  1. ringram

    ringram Enthusiast

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    very nice work
     
  2. Allan

    Allan Viper Owner

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    One big motivation is, not to lose against a Corvette on a 55mph to whatever pull on the highway -or at the track on the long straights. The Corvette's have a gearing (and weight) advantage. I think they're 3.42 stock. The Viper relies on monster torque to turn the ugly 3.07 gears. If you give the Viper more mechanical advantage with improved gearing -look out!
     
  3. PeterMJ

    PeterMJ Enthusiast

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    LOL, I have one of these too. Used to have a C6 Z06 as well, I am pretty sure Z06 would give the viper run for the money. You are correct, manual C6 has 3.42 rear end. However, what really matters is the final drive ratio. Vettes with handling package have shorter gears, just as do the ZR1, GS and Z06. As an owner of a base manual with suspension package, I can assure you that you cannot put the power to the ground without fishtailing, using stock size run flats. It took me Z06 size rubber on 19/20 inch rims to finally put the measly 436 hp to some constructive use. Given the hp of viper, this new rear end may just do the same to a viper? Viper is already at the max size of tires currently available, race compounds do not last long on the street. Anyway, I was just wondering why would anyone do this to a street viper.
     
  4. Allan

    Allan Viper Owner

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    I have a base C6 for a daily driver, and it's amazing how fast these things are. Also the C6 Z06 is very close to the Viper (gen III anyway) -blasting on the long straight, pretty much even all the way. Any gap, gained or lost, seems to occur when either car shifts. I can always gain ground at the end though by late braking. And any up-hill sections of the track, the Viper's torque is unbeatable. -even with the ugly 3.07 gears.
     
  5. Allan

    Allan Viper Owner

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    I think that for a street driven Viper, the gear swap will make the car a lot more entertaining. Also more apt to bite. As it's been said "the poor man's supercharger". For the roadcourse, the 3.07 is the prefered gear for most though. The acceleration may not be quite as good, but you don't have to shift as much. Every time you have to shift you lose a little by having to lift throttle and the car is just coasting for a little bit. I've gotten my lap times down by running in a higher gear, less shifting, carrying higher corner speed, and being able to stay in the throttle more. ..............3.07 for me.
     
  6. PeterMJ

    PeterMJ Enthusiast

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    What year is your vette? Mine is 09, just like my Viper, with M6, Z51 and NPP. This thing is a hoot to drive, after swapping wheels and tires, I do not miss my Z06 a bit.

    [​IMG]

     
  7. Allan

    Allan Viper Owner

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    It's kinda lame as compared to 'whatever else' but it's just my street car, and it's a lot more fun to drive than a Camry. Mine is a 2011 base coupe LT2 trim package, automatic w/paddle shifters. Bone stock, very quick and nimble though. I traded a 97 Corvette for this one. I think the C5 is sexier looking, but the C6 is a way better car. The Viper and Corvette are polar opposites in my opinion, and I love both for the attributes that each one has and hasn't. Each one makes me appreciate the other and I feel lucky to have both. (Dr.jeckyl / Mr. Hyde) Most guys end up with neither, and just dream of 'someday'. We are very blessed. :)
     
  8. cowger

    cowger Viper Owner

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    First Driving Impressions

    Okay, it appears this thread has run its course and, as all lengthy threads must do, has degraded into a Viper vs. Vette discussion. Oh well... :)

    I'll wrap things up with a couple notes on my first drive, which I was finally able to do this morning. In a nutshell -- I'm pleased! If the rear end is making any noise, I can't hear it. It's a pleasure starting out in first gear (was easy with 3.07; now it's even easier) and it's turning a reasonable 1500 rpm at 70 mph in 6th gear. I won't be able to really comment on the fun-factor of it for a while; Unitrax was very explicit about the need to break in the new gears for 500 miles with no high-torque moments or "exhibitions of speed". But I'm confident that I will enjoy this new setup.

    As far as the overall build experience, I had a blast. Did I save any money? Probably not, given my tool expenditures, but I like having tools and I'm sure I'll get more good use out of many. Did I save any time? Certainly not. Would I do it again? Absolutely! It was fascinating to me to dig into a rear end and appreciate the engineering that has gone into them and the details that make them work as well as they do.

    Thanks to all who have chimed in with both help (Allan!) and all the positive comments along the way. I'm happy to have had the chance to give a bit back to this amazing group of owner / drivers -- I love this forum! :2tu:

    Merry Christmas!
    Bryan
     
  9. PeterMJ

    PeterMJ Enthusiast

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    Re: First Driving Impressions

    sorry, did not mean to hijack your thread, watch out for the ice.
     
  10. JAY

    JAY Viper Owner

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    Merry Christmas Bryan ! Thanx for Posting and Taking the High Road ! :2tu: :)
     
  11. Allan

    Allan Viper Owner

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    Glad it's back together,........and no noise! If something was not quite right, it would be apparent almost immediately. -Also happy to be of help. .....What are we gonna do next? ;)
     
  12. MtnBiker

    MtnBiker Viper Owner

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    That's what I wanted to hear, and is what I thought. I will leave my 3.07 alone. Although coming from 2009 Z06 I do notice the difference pulling off the light. But once the Viper gets to 4000 rpms whoa nelly hang on!
     
  13. Nine Ball

    Nine Ball Enthusiast

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    Bryan,

    I've finally got all my parts needed to do the same swap. The only thing I don't have is the case spreader that you built. Did you find that it was necessary, or was there no problem slipping the diff in/out without it?

    I have some time off next week, might dig into it. I bought a spare diff housing to build, going to keep my factory one as-is. Installing the Wavetrac, 3.33 gears, etc..
     
  14. cowger

    cowger Viper Owner

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    Nice! Best of luck and I'll look forward to hearing how it goes...

    I'll answer your question about the case spreader as "not really". It was probably the most useful in pulling out the old carrier the first time, but since you're not doing that, you should be okay. Installing the carrier is easy -- you can just sort of tap the 2nd shim in with a soft-blow mallet, finish tapping it in with a flat screwdriver, and it slips into place. (It would just be nice to have 4 hands -- two for the carrier and one each to keep the bearing races in place... : )

    Getting it back out is only a bit tough when you're getting close to the final preload on those bearings, as it's supposed to be pretty tight in there at that point. The one nice thing about the spreader is that it provides some good protection for the soft aluminum case if you're having to pry the carrier out, but of course there are other ways to come up with that protection. Another option would be to see if you can rig a strap around the carrier so that you can get some good "pull" on it to yank it out.

    HTH,
    Bryan
     
  15. cowger

    cowger Viper Owner

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    Now that it's been a few months, I wanted to share some thoughts on the new differential. I've already mentioned that the gear change (to 3.55) is pure pleasure, and I continue to believe that. I would never want to go back, at least for my style of driving.

    The change from stock diff to the Wavetrac unit also gets high marks from me. It's hard to describe, but I get the feeling that the unit is really working back there, clawing for every bit of traction it can find. With the stock diff, it seemed to "lose it" more easily and all at once, hence the "snake bite" term we've all heard (and sometimes experienced). With the Wavetrac, it's sort of talking to you, as if to say "hey, man, that's really a bit too much power right now; I'll do what I can, but here's your warning..." I know that probably sounds strange, but that's the feeling that comes back up through the car from the rear end. It's also like you can feel both tires working, almost back and forth a bit, as each is passed the maximum torque it can take at the moment.

    Bottom line, I'm happy with the setup and would absolutely recommend the Wavetrac to anyone considering it.

    Bryan
     
  16. slowhatch

    slowhatch Viper Owner

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    wonderful thread bryan, your attential to detail is admirable
     
  17. cowger

    cowger Viper Owner

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    Thanks! It was a fun project...
     
  18. cowger

    cowger Viper Owner

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    I was going to edit this thread and fix all the broken photo links (thanks again, Photobucket!), but can't seem to find any edit buttons. Perhaps I'm doing something stupid... or perhaps the thread is now too old to be editable? Anyone know?
     
  19. MoparMap

    MoparMap VCA Member - West

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    I was under the impression that you couldn't edit a post after a certain time, but I could be wrong. I know they have been working on the website, so it's possible that maybe you can't edit them anymore because they are archived or something.
     
  20. ViperJeff

    ViperJeff VCA Legacy Member - UT/AZ Staff Member

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    The posts are to old, there is a tine limit for edits..... however, if you want, I can help you replace the photos in your post
     
  21. cowger

    cowger Viper Owner

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    Thanks guys, makes sense. ViperJeff, if you think there's value in resurrecting this thread, I'll gladly take the offer to help replace the photos. Please PM me when you get a chance (obviously no rush!)

    Bryan
     
  22. ViperJeff

    ViperJeff VCA Legacy Member - UT/AZ Staff Member

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    We have a lot of visitors that never post. As I watch were people are visiting on the site, a lot of it is advice and help threads. However, it is your call.
     

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