Guys, I am curious to get some info regarding Viper Rears. In a recent Car and Driver mag someone wrote in the letter to the editor section that the issue with the Viper being able to really beat a new Z06 centered around the Viper's stock rear. If the Viper had a 3.73 rear given it's torque it would be a serious contender to beat the new Z. Not being technical, whats the deal with the rear and what are different rear end options? How does that "help" the Viper perform? Which is the best rear, are they difficult to install and what about the cost? I sure appreciate any insight you can provide. Thanks
Viper Rears
- Thread starter Turbo63
- Start date
First, a stock SRT Viper can beat a Z, if driven well ... and vice versa.
As for the gears, 3.73 is too high (vs. the stock 3.07 rear gear) IMO. The higher gear helps the motor move the car faster through the rpm range, but the trade-off is that you have to shift sooner and more often (not necessarily a bad thing). I run a 3.45 gear and it feels pretty good on my normally aspirated car, but cars with huge HP (blowers) don't need any help through the rpm range, so a higher gear is unnecessary. The 3.45 is no longer in production, but there may be a few still floating around. There is a 3.55 available, and that is the very highest I would ever go (IMO). A 3.33 rear gear is the Unicorn of Viper rear gears ... perfect ... but nowhere to be found.
The Z06 Vette runs a 3.42 rear gear (I believe) and also has slightly smaller rear tires, which also affect the rear gearing.
As for the gears, 3.73 is too high (vs. the stock 3.07 rear gear) IMO. The higher gear helps the motor move the car faster through the rpm range, but the trade-off is that you have to shift sooner and more often (not necessarily a bad thing). I run a 3.45 gear and it feels pretty good on my normally aspirated car, but cars with huge HP (blowers) don't need any help through the rpm range, so a higher gear is unnecessary. The 3.45 is no longer in production, but there may be a few still floating around. There is a 3.55 available, and that is the very highest I would ever go (IMO). A 3.33 rear gear is the Unicorn of Viper rear gears ... perfect ... but nowhere to be found.
The Z06 Vette runs a 3.42 rear gear (I believe) and also has slightly smaller rear tires, which also affect the rear gearing.
vincent_esq
Viper Owner
I was about to post the same question. So is it advisable to go with te 3.55 now, that 3.33 and 3.45 aren't available? I get lots of wheel hop already with the 3.07. Wouldn't changing to 3.55 make wheel hop even worse? It would be too expensive for me to do the gears AND QUAIFFE differential. What are your opinions, guys? Paxton is my dream come true, but the wifey isn't buying it. 
PhoenixGTS
Enthusiast
If you do the math and compare the Gen II height rear tire to the taller Gen III height rear tire the difference in the gearing from the tires alone is worth about 0.20 of ratio. In other words, a 3.73 gear in a Gen III is the same "effective" ratio as a 3.55 in a Gen II (with stock height tires). If you visit the Gen II board you will see that for a bolt-on horsepower car as opposed to a blown car a lot of us LOVE our 3.55 gears (see link below to recent post). I think my Gen II with shorter 5th and 6th gear ratios and 3.55s out back is perfectly geared given my lower pwer level (6,000 rpm in 6th = 200 mph), and driving in at parking garage speeds is SO much nicer with short gears. 3.73 sounds like what a Gen III needs to me.
The biggest secret though is traction. I have said before (many disagree) that if Kumho came out with a V700 that fit both the C6 Zo6 and Gen III Viper that the Viper would finally be able to use all its torque and would benefit more than the Vette (even more so with shorter gears).
Gen II gear post
The biggest secret though is traction. I have said before (many disagree) that if Kumho came out with a V700 that fit both the C6 Zo6 and Gen III Viper that the Viper would finally be able to use all its torque and would benefit more than the Vette (even more so with shorter gears).
Gen II gear post
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