8 speed auto in a gen 5 viper

Discussion in 'Generation V Discussions / SRT Coupe, GTS, GTC, AC' started by JETSTAR, Jun 20, 2015.

  1. JETSTAR

    JETSTAR Enthusiast

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    I am toying with the idea of installing a 8 speed auto transmission with paddle shifters.
    The cost of doing this would run around $12K to $15K with all new parts.
    Just wondering if anyone would be interested in having this done before I spend the money on R&D to do this to one of my cars.
    Thanks
    Wayne
     
  2. ViperJeff

    ViperJeff VCA Legacy Member - UT/AZ Staff Member

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    Do it!!!!!!


    Got an 8 speed auto in my truck. It Rocks!
     
  3. Mark1107

    Mark1107 Viper Owner

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    Instead of doing R&D what about the hellcat 8 speed auto? It can handle the torque.
     
  4. Free2go

    Free2go Viper Owner

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    This ought to be interesting.....
     
  5. JETSTAR

    JETSTAR Enthusiast

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    way too BIG it won't fit in the hole and no stand alone controller
     
  6. anton28

    anton28 Enthusiast

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    This would be a badass mod!
     
  7. JETSTAR

    JETSTAR Enthusiast

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    Ordered the transmission today
     
  8. ViperJeff

    ViperJeff VCA Legacy Member - UT/AZ Staff Member

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    Outstanding
     
  9. anton28

    anton28 Enthusiast

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    Looking forward to this outcome!
     
  10. Camfab

    Camfab Viper Owner

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    Just curious what auto your thinking of using? If the HD Hellcat version is too big, will the one your sourcing handle the Vipers torque on a long term basis? Sounds like a fun build.
     
  11. Texas1

    Texas1 Viper Owner

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    Subscribed!!!
     
  12. JETSTAR

    JETSTAR Enthusiast

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    8L90 same trans in the 2015 ZO6
     
  13. Bobpantax

    Bobpantax Enthusiast

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    Looks like you will have to change the differential ratio to go with the 8L90 gearing if what GM did on the Z06 and the V series Cadies is any indication. Or, do you also intend to change out the diff?
     
  14. ViperJeff

    ViperJeff VCA Legacy Member - UT/AZ Staff Member

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    This will be fun to watch
     
  15. johnk

    johnk Enthusiast

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    It would be very interesting to see some quarter mile times with the stock transmission vs the new auto trans. good luck....
     
  16. JETSTAR

    JETSTAR Enthusiast

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    Interesting point I might look at putting the old 3.07 back in since were not trying to get 30 mpg but the 1/4 time would be off the chain with the stock ratio
     
  17. Bobpantax

    Bobpantax Enthusiast

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    I do not think it will work with the stock ratio. Look at what is used in the Z06. If you keep the stock ratio, on a good hook up, my guess is that you will snap a half shaft pretty quickly and, if not a half shaft, you will get a diff failure and/or a driveshaft failure. You have to sync the tranny ratios with the diff ratio - but you already know that. It definitely should be interesting. You might want to speak with Mark J at Woodhouse about your project since he has done a few automatic cars but not with the Vette tranny.
     
  18. Viper X

    Viper X VCA Member - South

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    Sounds like a very interesting build.

    A few thoughts:

    Have never seen a drive shaft failure yet in a Gen 3 or newer Viper...and I've run a Quaife with drag radials at 18 psi, Unitrax's upgraded 1/2 shafts, John Donato built T-56, stock flywheel and upgraded clutch in a 925 rwhp, 860 rwhp Gen 3 Viper. Paxton car with the factory computer tuned to run 91 octane (CA).

    I did blow 5 diffs trying to get the right one into the car. The Quaife has been bullet proof so far, 40K miles.

    I also lost all the teeth on the second gear input and output shafts once while running quickly over a bumpy section of road.

    A few clutches have bit the dust.

    Would love to have that 8 speed auto in my ACR for the track.....
     
  19. emericr

    emericr Enthusiast

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    Interesting build for sure. Wish the factory would offer that option...
     
  20. JETSTAR

    JETSTAR Enthusiast

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    Once I get done with the Gen 5 the Gen 3-4 cars should be no problem but you will have to go back to the drawing board on the gear ratio I am going with the 3.07 to start with but will offer options depending on the customer.
    I plan to install the trans in my Gen 5 race car and do some heavy R&D track days just to see how strong it is. All the reports I've seen so far have been very positive The ZO6 engine may overheat but very few trans problems
    Thanks
    Wayne
     
    Last edited: Jul 3, 2015
  21. Viper X

    Viper X VCA Member - South

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    Wayne,

    Do you know the rear gear ratio in the new Z06?

    My 09 ACR is also running 3.07.

    Would be an interesting swap. Anxious to hear your results.

    Dan
     
  22. Dave1968

    Dave1968 Enthusiast

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    3:73 with stronger 1/2 shafts?
     
  23. JETSTAR

    JETSTAR Enthusiast

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    2.41
    Model Years Make and Model Final Drive Ratio
    2015–present Cadillac Escalade [2] 3.23
    2015–present Chevrolet Corvette (C7) Stingray [3] 2.41 (std)
    2.73 (Z51)
    2015-current Chevrolet Corvette (C7) Z06 [4] 2.41
    2015–present Chevrolet Silverado/GMC Sierra[5] 3.23 (std.)
    3.42 (Max Trailering Package)
    2015–present GMC Yukon Denali/Denali XL 3.23
    2016–present Cadillac ATS-V 2.85
    2016–present Cadillac CTS-V 2.85
     
  24. JETSTAR

    JETSTAR Enthusiast

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    just a quick update
    The trans has been a challenge to get but should be here next week according to my GM dealer
    Thanks
    Wayne
     
  25. ViperJeff

    ViperJeff VCA Legacy Member - UT/AZ Staff Member

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    Thanks for the update
     
  26. pitdad

    pitdad Enthusiast

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    How's the build going?
     
  27. JETSTAR

    JETSTAR Enthusiast

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    Kind of hit a decision point
    It looks like my best option is to install the entire transmission and rearend from the Vette in the rear of the Viper.
    So I'm looking for the parts
    Thanks
    Wayne
     
  28. pitdad

    pitdad Enthusiast

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    Sounds cool - can't wait to see progress..
     
  29. Viper LP

    Viper LP Enthusiast

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    I would be interested :) will text you today about it...Lou
     
  30. ringram

    ringram Enthusiast

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    Probably better off with the camaro 8 speed? Vette will have torque tube config etc..
     

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