I have 3.73 rear end?

[Steve737]

I have 3.73 rear end!

Hello by the way my name is Steve. I've been around the viper community for the last few years. I just bought a new to me 04 SRT 10 with a Paxton set up. The car is very clean and had 4500 miles on it. I haven't driven many gen 3's so it took me a while to figure out what was going on. The car is crazy down low say 1-3rd gear. Anyway I had the car down at Tombal Dodge today to change some the fluids and we noticed the diff had been opened up. It has 3.73s I want to change them out. What gears do you think would be best. I'm leaning toward 3.33 a little taller than stock but not to tall like the 3.73. What do you guys think is the best way to go with the Paxton set up.

Thanks Steve

 

[Steve737]

I did find a good thread on the topic. Looks like 3.55 and the 3.33 are the way to go. Any new info to share. I won't track this car so just want to enjoy some spirited street driving. I may make a trip to the local dragstrip every once in a while.

 

[v10viperbox]

I would go with the 3.33 if you have a blower.

I have the 3.55 and its aggressive even with less power then you. If you are going to do the gears though calling unitrax or one of the other vendors on the site and finding a stronger rear end might be in order.

 

[SHEVIPER]

I have 3.33 and a Paxton. I had wanted 3.55, but Doug Levin recommended the 3.33 because of the blower. I track mine, but also drive it on the street quite a bit; and I feel the 3.33 works well for both.

 

[NI-KA]

Why do want to change them?

Are you unhappy with the driving experience?

 

[Nine Ball]

If your engine is still stock, and you are around 650-675 rwhp, then the current 3.73 set should work the best for the drag strip. Your car will likely trap in the 134-136 mph range.

http://www.apexgarage.com/tech/gear_ratios.shtml

Using this gear ratio calculator, 4th gear is 1.0 and that is the finishing gear at the drag strip. With a 6200 rpm limiter, on a 27.5 tall drag tire, your 4th gear is at 136 mph as you cross the finish line. Just about perfect.

You might consider putting some stickier tires on the car first, see if you like the gears then.

Tony

 

[Steve737]

NI-KA I wouldn't say unhappy it's just a lot different then my old GTS. It seems as though I go through the first three gears like rapid fire. It does pull very hard if I can get the tires to stick.

NIne ball good info! I putting the tires you suggested on soon so it hurts nothing to just wait and see ow that goes.

I called the Wizard yesterday and he was thinking for drive ability that the 3.33 or stock would be the way he would go. I'm thinking that the 3.33 would be the way to go for me but I'm keeping an open mind. If I do decide to change them out I was thinking I should go with stronger half shafts since they will be off any way. I was going to get a hold of unitrax and get there advise as well. You guy rock thanks. Steve

 

[beerly]

I don't track mine, but I had 3.73's and hated them. I went back to 3.07 and love it. 5th and 6th are worthless unless doing 120+, but I have just enough length in gears 1-3 so I'm not shifting like an 18 wheeler. Can get to 60 in first. I have a Quaife, Paxton, headers, bigger fuel, and about 660 rwhp. Just my $.02. But if you are tracking, don't listen to me. Weekend spirited driving is my game.

 

[Steve737]

Beerly you said it better than me. Ya I feel like I'm driving my old tractor. I think you can just let the clutch out without throttle on a hill and it will just climb on up. It's a great though to teach my wife how to drive stick! I'm just not a track guy. So I'm like you spirited driving.. Thanks for you input. Steve

 

[pittVIPER]

I have 3.07 with Paxton/headers/Corsa track/fuel upgrade/SCT tune (700rwhp) and could not imagine wanting the gears any shorter. No track or drag for me either-5th and 6th just for quiteing things down and long trips. It is an art to hook things up now even with Invo's; I bet yours seem super short as soon as they light up. Best of luck. Steve

 

[Paul Hawker]

Driving a stock tired, Paxton Viper with 3:73 is like trying to ride a squirrel, on ****, without a saddle.

They are all over the road, with tires spinning madly, and broken driveline parts flinging themselves off the car.

While this can be great fun, the car really is challenged to put down the torque from the supercharged engine.

Stock, or 3:33's allow much longer, and very powerful pulls. You get the chance to enjoy the power, without scaring yourself, and endangering everybody else around you. (Still sounds like fun though)

Paxton Vipers with 3:33's are like magic bullets. While they do not feel as frantically fast, they actually put down much better performance for most circumstances.

If you are setting up for the drag strip, with slicks, a taller gear might make more sense.

 

[Steve737]

Thanks for the advise everyone. I called over to unitrax and we talked for a while and they suggest stock 3.07's because in ther words they are bullet proof. The 3.33 are hard to find. And if i understood them right are not manufactured by them. They have two but one set is spoken for already. The 3.73 are a lot of fun around low 3 rd gear but getting there is a little squirmy. Steve

 

[iownedu]

I'd possibly consider trading you my 3.07 diff. 2004, 15k miles. PM me.

 

[Steve737]

I'm not sure what ill do but I'll keep you in mind. Steve

 

[FLATOUT]

I have 3.73's in mine and love them, but I'm used to driving cars setup for the 1/4 so it feels like my older cars felt.

 

[beerly]

I'd possibly consider trading you my 3.07 diff. 2004, 15k miles. PM me.

iownedu, if you want a set of 3.73s, I still have my ring and pinion, they're polished and only have about 2000 miles on them. I'll sell them for $150+shipping

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[steve911]

I have a bone stock complete'04 diff complete w/bat wings. I bought it as I was going to put 3.33's in it but decided to stay with 3.07's.

I will sell it outright to you or anyone else.

 

[VIPERCON305]

3:55 is the way to go.... The problem with our supercharged cars especially up top or in my case I like to run from a 70 mph roll is that our power band on a supercharged car is from 4,000 rpm to 6,000... And once u shift it drops u out of the power band of the charger and the car feels sluggish... I have worked on this with Doug levin and we have done a couple of things to correct the problem... Which is change the gears so that I can get to my power band quicker... The power of the car is not the problem.. I make 800 to the wheel.. The problem is that the power only comes in at 4,000 not sooner.. On a supercharged viper... I went to a 3:55 and it helped out alot.. Go with a 3:55 and u will be happy...

 

[Steve737]

Thanks I'm going to call Unitrax and order them thanks. That was there advise as well.

 

[VIPERCON305]

Thanks I'm going to call Unitrax and order them thanks. That was there advise as well.

Ya thats where i bought mine from. they are very helpful. and they did tell me that they dont even carry 3.33 gears anymore. so u would have to go to a 3.55 or back to the 3.07

 

[HobokenViper]

Guys, please forgive my ignorance as I'm a new 1st time Viper owner and am soaking up all kinds of great knowledge from people on here and reading through the forums, but can someone explain what the major differences are between all of these bearings and how they feel change the driving experience? I assume that 3.07 is more geared toward higher top speed and you can reach past 60 mph in 1st gear, while the closer you get to 3.73 the taller the gearing is and the lower the top speed is, but the faster you get to redline in each gear thus faster acceleration...? The reason I ask is that the previous owner of my Viper (2008 vert) installed a 3.73 and I don't know what it would feel like otherwise... He said did it so he could have a more usable 6th gear cruising at highway speeds as the old gearing annoyed him he said. What are your thoughts on this and can you explain the distinct differences between the different ratios?

Secondly, the only other major mod on my car is high flow cats, and I was curious if that is going to give me a problem passing my inspection that is due this winter on the car......? It would be a huge pain in the butt to have to get and install the old cats back on the car just to pass inspection, and then pay again to switch them back out right afterwards..... Any thoughts or experiences with this issue?

 

[HobokenViper]

Sorry, auto correct on my iPad said bearings instead of gearings in the first sentence of my post above.

 

[beerly]

your general understanding is right. The 3.73's are sometimes called the poor mans supercharger. they give you a "seat of the pants" feeling of faster acceleration and thus a feeling of more power. But all you are doing is revving the engine to redline faster. Much like a big rig. Some people, myself included get annoyed with the shortness of the first and second gears and when you add more power, such as a supercharger, it can become downright dangerous in these gears, unless you carefully monitor your right foot. Keeping the wheels from spinning takes a lot of work, with street tires. With slicks or drag radials you get more grip but, where the street tires were your break point, half-shafts and other driveline components become targets for weakness. Now the other side of it is you do get use of your 5th and 6th gears at 70-120 mph. For those who care about using 5th and 6th gears, these gears do it. Top end is reduced. At 3.07, the car can do 190 mph, but who needs that? My corvette is geared at 3.42 and I routinely start in 2nd gear, which you may find easier in your gearset. At the end of the day, gearing is a personal preference, most street drivers, and a lot of us that have S/C engines prefer 3.07s up to 3.55's. I personally like the stock ratio. With the S/C, theres plenty of raw power to put to the wheels and I prefer the long pulls between shifts. Then there are those who love 3.73's and even 4.10s, but I'm pretty sure they are trackers and these gears really help on the track, as far as I understand.