3:55 Vs 3:73

[ElDiablo Viper]

What would make more sense? I also road race in the summer once per month.

 

[Vipermed 97.01]

I personally prefer 3.73 but if you are road racing with that gear be prepared to shift alot

 

[onerareviper]

I prefer the 3.73's as well. They rip!!!! That being said, you will need to shift a bit more than with the 3.55's, and a lot more than with the 3.07. Hence, I would look into an aftermarket shifter unit (not just the shift knob). I could be way off, but I think they cost around $300. Should make down shifts more 'positive' as well.

Also will need to practice 'restraint' with the gas pedal coming out of a turn. If memory serves, the torque is 21% greater with the 3.73 gears over OEM.

*** These links will help with your decision:


http://www.viperclub.org/faq/techgears.html

http://www.socalviper.org/techtips/gears.html

 

[ElDiablo Viper]

Thanks, I have the Ripper installed from day one.

 

[Snakester]

I had 4.10 gears installed in my last Corvette, and they made a huge difference, with 5th gear actually being usable afterwards, and the car definitely feeling more frisky. But around town I found myself shifting quite a bit more than with the stock 3.42 gears.

I'm installing gears on my Viper next week and I chose 3.55s.

I only have light (better breathing) mods, but I also have a NX N20 setup in my garage that I'm still debating on installing (I'm looking for a good progressive controller), and I think that the 3.55s will give me a noticable improvement over the stock 3.07s, but I won't have to swap the gears back if I decide to upgrade the power later.

Plus, I can easily get wheelspin already in first and second gears when I punch it, and I don't want to lose that much more actual acceleration by spinning the tires with toasty 3.73 or 4.10 gears.

-Dean.

 

[v8huntr]

i have complete DTS 3.73 with speedo calibrator. e mail me if you are interested. [email protected]

 

[ElDiablo Viper]

Here is a great IM with info from Paolo Castellano:

El Diablo, you will definitely be able to hit the exact same speed with 3.73 rear end gear and .8 5th and .62 6th. This is what Dodge should have done with the Viper. Paolo

Here are some charts.

Tires size (nominal dia inches)
Differential gear
1st gear 2.66
2nd gear 1.78
3rd gear 1.30
4th gear 1.00
5th gear .74
6th gear .50

Max RPM/Max Velocity (MPH)



Chart: Gear/RPM -- Velocity (MPH)

RPM 1st 2nd 3rd 4th 5th 6th
2000 19 28 38 49 67 98
2250 21 31 43 55 75 111
2500 23 35 47 62 83 123
2750 25 38 52 68 91 135
3000 28 41 57 74 100 148
3250 30 45 62 80 108 160
3500 32 48 66 86 116 172
3750 35 52 71 92 125 185
4000 37 55 76 98 133 197
4250 39 59 80 105 141 209
4500 42 62 85 111 150 222
4750 44 66 90 117 158 234
5000 46 69 95 123 166 246
5250 49 73 99 129 175
5500 51 76 104 135 183
5750 53 80 109 142 191
6000 56 83 114 148 200
6250 58 86 118 154 208

Viper Gear Calculator

Tires size (nominal dia inches)
Differential gear
1st gear 2.66
2nd gear 1.78
3rd gear 1.30
4th gear 1.00
5th gear .80
6th gear .62

Max RPM/Max Velocity (MPH)



Chart: Gear/RPM -- Velocity (MPH)

RPM 1st 2nd 3rd 4th 5th 6th
2000 15 23 31 41 51 65
2250 17 26 35 46 57 74
2500 19 28 39 51 63 82
2750 21 31 43 56 70 90
3000 23 34 47 61 76 98
3250 25 37 51 66 82 106
3500 27 40 55 71 89 114
3750 29 43 58 76 95 123
4000 30 46 62 81 101 131
4250 32 48 66 86 108 139
4500 34 51 70 91 114 147
4750 36 54 74 96 120 155
5000 38 57 78 101 127 163
5250 40 60 82 106 133 172
5500 42 63 86 111 139 180
5750 44 65 90 116 146 188
6000 46 68 94 122 152 196
6250 48 71 97 127 158 204

El Diablo, here. 3.73/.62 6th is 188 MPH @5750 RPM. This is 3 MPH different than stock 5th/3.07 rear end gear. Effectively, for road racing, you would be adding another gear, you would shift more but would be in the power range in each gear less time, but in the overall sense you would spend a greater amount of area under the curve in the powerband of the car. Just like the F-1 cars with 7 speed gear boxes. By going 3.73 and .8/.62, you are shortening the spacing between the gears and you would definitely be more like the F-1 cars taking only a few seconds to go through each gear. The only drawback will be trying to consistently launch the car on the street in a drag race situation.

El Diablo, I have a good idea for you for road racing and the 3.73 gear. You can change 5th and 6th to .8 and .62. ==>3.73 X .62 = 2.3126. ==> 3.07 X .74 = 2.2718. If you go to 3.73 for road racing you would normally lose top speed capability as 3.73 in .74 5th will be less than 170 MPH. With what I am suggesting, you would have 21 % more hp and torque multiplication throughout the gears. Since the final ratio between .74 3.07 5th and .62 3.73 6th, you have almost identical final drive which would be adding essentially another gear to the Viper transmission. 3.73 is not that good for out of the hole, but for the road course, I would imagine, as long as you can shift well, that would be the way to go.