Rear gearing - 3.73 or 3.55??

[Mopar Boy]

So, about a year and a bit ago I wanted to change my rear ratio. I spoke with a few people and I decided upon 3.55's. When at my dealer, I told them what I wanted and they said the only good ones you should go with is the Mopar ring and pinions. They told me they had done many customers cars and they said they had tried other brands but for various reasons (two of them being strength and noise), they and the owners were not happy with the aftermarkets gear sets so they ended up removing them.

So with this info I agreed Mopar was the way to go. So being that Mopar only still offered 3.73's, I went with those as it was still better than the 3.07's.

So, now that you know the HISStory I have a few questions.

1 - How much of a difference will I notice between the two gear sets?
2 - Has anyone had both and can give a detailed account as to what they preffered?
3 - Are there other good brands of ring and pinions
4 - Is it worth swapping out gears for a set of 3.55's??

I ask as the car is great in town, but on the freeway, it really howles over 70MPH and is starting to eratate me a bit revving so high!

Thoughts. Opinions. Suggestions. Let me have em!

Thanks!

Robert
P.S. Ahhh, The wonderful benifits of being in the VCA and having access to these boards BEFORE you go to change your gearset. The first time!!

 

[zracer196]

Mine revs at about 2000 at 80 mph in 6th. Comfy to me.

But this is my first Viper...AND I have nothing else to compare it to. It came with these gears.

Good luck!

 

[Martin2000GTS]

i would think with your 20 in rears and other wise stock power you would be happy with the 3.73's. I had the stock 3.07 with 19" wheels on my 2000, Had Tator do the 3.73 and I love it. I have a pretty much stock engine and plan on keeping it that way, if your looking at big power adders you might want to look at swapping out, traction would be tough off the line, what are you running rpm wise at 80 mph, im at about 2000 rpm.

 

[Steve 00RT/10]

So, about a year and a bit ago I wanted to change my rear ratio. I spoke with a few people and I decided upon 3.55's. When at my dealer, I told them what I wanted and they said the only good ones you should go with is the Mopar ring and pinions. They told me they had done many customers cars and they said they had tried other brands but for various reasons (two of them being strength and noise), they and the owners were not happy with the aftermarkets gear sets so they ended up removing them.

So with this info I agreed Mopar was the way to go. So being that Mopar only still offered 3.73's, I went with those as it was still better than the 3.07's.

So, now that you know the HISStory I have a few questions.

1 - How much of a difference will I notice between the two gear sets?
2 - Has anyone had both and can give a detailed account as to what they preffered?
3 - Are there other good brands of ring and pinions
4 - Is it worth swapping out gears for a set of 3.55's??

I ask as the car is great in town, but on the freeway, it really howles over 70MPH and is starting to eratate me a bit revving so high!

Thoughts. Opinions. Suggestions. Let me have em!

Thanks!

Robert
P.S. Ahhh, The wonderful benifits of being in the VCA and having access to these boards BEFORE you go to change your gearset. The first time!!

Hi Robert,

With 20" wheels, you likely have an effective ratio of around 3.35 to 3.45 now. To me that's a good place to be. There are numerous gear calc sites to figure it out exactly.
Here's one: Gear Design Equations Formulas Calculator Effective Gear Ratio 3.55s will drop you lower towards the stock 3.07. I quick plugged a 28.4" tire for you and it showed a 3.26 effective ratio.

Measure the OD of your 20" wheel. A stock 18" OEM MPS tire is 26.1". Our bumblebee, with 19" wheel package (27.4" MPS), has an effective ratio of 2.92, noticeably different from the 3.45s in the 18" wheeled car.

Steve

 

[Canyon707]

I have both and the 3:07 Question 1 the 3:73 are the quickest lots more feeing of power down low. The 3:55 set I liked a lot and it was one less shift in the 1/4 mile So as much as I like the 3:73 which I have in my car now I think the 3:55 set is my preference. Dodge no longer makes the 3:55 and I went unitrax for the gears. I tried to break them in properly but they made so much noise I had to remove them. There now sitting in my garage diff and all. So I don't know which brand is better or not better I have heard that the Quaife is the best but not sure on the break in or noise. Maybe someone could put some insight in on Quaife. The 3:73 should have a diff cooler installed if your going to push the car as the oil surely heats up more than the rest of the gear sets. Your best bet is to talk to John ( I prefer emailing him) he pretty much knows the pros and cons on most Viper issues. I would not think the gears are seated correctly I had the same problem. I agree with the mopar gears but I understand there no longer available. Correct me if I am wrong on this. Good luck.

 

[PhoenixGTS]

With the Gen III height rear tires on a Gen II 3.73 gears will have the effective ratio that 3.55 gears have with stock height Gen II rear tires. I have stock height Gen II rear tires and 3.55 gears with about 525 crank horsepower and love this gearing. Along with my shorter 5th and 6th ratios this is how the car SHOULD have come from the factory. It is pretty sad when a car like the CTS-V comes with more appropriate ratios than a Viper.

 

[Mopar Boy]

By the sounds of it, I should be staying with the 3.73 as I already have a technical 3.55 (well, counting the rims).

Canyon - I appreciate the detailed comparison since you have had both. Thank you!

Steve - Thanks for the info and the link!! I played for awhile on there!

Martin - I am not 100% sure what RPM I am at 80MPH but I believe I was in the 1600 RPM range at 60ish and 2000ish at 80. Was it VERY high revving, no. I was just thinking it was a little high compared to how I was pictuing a 3.55 to be.

I guess more than anything, I have just been second guessing my gear choice. Granted, by the sound of it, I lucked out especially not getting Non-Mopar gears!

Thanks again folks!! It is so worth having these boards!!

Robert

 

[JonB]

......... When at my dealer, I told them what I wanted and they said the only good ones you should go with is the Mopar ring and pinions. They told me they had done many customers cars and they said they had tried other brands but for various reasons .........So with this info I agreed Mopar was the way to go. So being that Mopar only still offered 3.73's, I went with those as it was still better than the 3.07's.
P.S. Ahhh, The wonderful benifits of being in the VCA and having access to these boards BEFORE you go to change your gearset. The first time!!

Unfortunately, it sounds like you bought a gearset and only THEN turned here for advice?

This is funny: Dealer choice is BEST because its the only choice he offers?!? Best for HIM!
If the mopar part # ends in 7022, its a lot WEAKER in fact than the '01+ kits.

You should know that the spec on the 2001+ MoPar gearsets are the exact same part # of Spicer-Dana gears as used by PartsRack and Unitrax. But in addition, we cryogenically harden those same gears, and micro-polish them to make them stronger, quieter, and cooler. So our afttermarket product is "BETTER" as well as less costly. And we sell to many dealers.

Why is the dealer out of 3:55? I know: because when Mopar announced a closed out /discontinued the 355s a while back, PartsRack bought all 220+ sets they had left! Every One. We shipped almost all of them to Unitrax for improvement with cryo-polish-setup.

I have used 355 and 373 in my own personal Vipers. The HP and PLANNED MODS matter.
Driving venues matter. Sticky Tires matter. My personal opinion is like the Goldilocks fable: 3:55 is "JUST RIGHT" Howling gears are almost always setup related. The more aggressive cuts of 3:73 are more prone to noise than 3:55, esp if setup less-carefully.

Canyon: I bet Unitrax sold you the gears, but SOMEONE ELSE did the noisy setup? Experience matters...

 

[Mopar Boy]

Unfortunately, it sounds like you bought a gearset and only THEN turned here for advice?
.

Yes Jon, very true unfortunetally. I was looking for help with the choice but did not know where to go and as I did not get my membership confirmation saying I could officially use the boards, I just went with what was recommended to me.

The issue was I had signed up but my info was lost for 6 months!! The day I got my VIN into my name (April 07) I faxed the info in to VCA Headquarters. You will notice my start date says November. That is why. I finally contacted my Chapter president in November stating being part of the VCA is not very fun. I got no emails, no welcome, no invites to any events, heck, I did not even go anywhere the first summer with my car as I thought I was alone! Nabil eventually got everything in order and then I signed up on here.

Before I got the car, I did not know you could be a part of the webboards and not be part of the VCA. And as I gathered you had to have a Viper to be part of the VCA as it is a Viper OWNERS club, I just lurked here for many months before I got the Viper because I thought that was all I was allowed to do! Boy was I wrong!!

Oh well. Live and learn......

Robert

 

[JonB]

A 3:55 CAN BE INSTALLED in your carrier if that is your preference......I assume you have a speedo re-calibrator? (Dodge-MoPar does NOT offer this item for 92-02) If you change, We can tell you how to recalibrate it....

 

[Mopar Boy]

Thanks Jon for the info.

I do have a Unitrax speedo re-calibrater for the car. Works awesome!

Glad to know the 3.55 can still be done if I do want to go that route. I think for now I need to do some thinking on if I still want to go that route, or if I will just leave it as is.

Tough question.

Thanks again! You always seem to have an answer for these things!

Robert