Differential gearing gen 2???

[James430]

Have the car in the shop now getting some more performance mods done and while it was in there I was thinking about changing the gearing.Need some advice on which way to go.there is 3.33,3.45,3.55 gearing don't want to go any higher than that ,I don't put a lot of highway miles on it but once in awhile will take a trip,so mileage is and isn't an issue....Any experience would be a big help from everyone.

Thanks

[BlknBlu]

I have had my RT/10 for about 3 months and love the 355's in it. Drove it to Detroit from Omaha and got 24 MPG, really fun around town too. I like this gear ratio.

Bruce

[James430]

That's a good positive....I'm running right at 1350 rpm's @ 70 mph with stock gears have you noticed what your rpm's are at 70 with the 355's??

[Vprbite]

I had 3.55s in my 02 GTS. I loved em. In fact, I am going to do them on my gen 3 ASAP. Gotta put some money together and do a few things at once, otherwise wild have them in already.. I can't remember exactly what my rpms were at when doin 70 in 6th but I feel like right around where yours are now. Maybe 1500 but I doubt higher than that. I mean, cruising down the highway felt like not much more than idle but with acceleration available. I could cruise up mt Lemmon in 5th and accelerate if desired.

I also found myself using 5th around town. If driving on a stretch at 45 or 50 for a while, just pop it in 5th for the mpg. I think the way to describe the 3:55 gears is "snappy." It's almost like if your driveshaft was 15 feet long and had to go through 2 differentials and you took half of it out and one of the differentials, so now all of the engine power goes right to the wheels instead of getting lost. A bit of a clunky analogy but really, it almost feels like the gas pedal is squishy without them.

On the same token, I have no idea how some guys are runnin 373s or higher. That sounds like a nightmare to me unless you are running 21s to bring the total effective gearing back down. Though I believe Gen 2s require a speedo recalibrator piece. Or use a GPS and see by what percentage you are off and always do the math. I recommend the speedo recalibrator method. Jon B can send the whole shebang in one box. I think as diffs go, it's pretty easy. Any good differential shop or even 4x4 shop should be able to handle it no prob from everything I have been told. I hear the Gen IVs are tricky and have to be done early into ownership IIRC.

P.S. perhaps the people who know more about these can give you more detail but as I understand it, I wouldn't mess around with 333, or 345, because you would get less "oomph" and only be saving yourself maybe 100RPMs at freeway speed. Just get the oomph and you will never notice the 100 RPMs at 70. I have also heard that 02 GTS Vipers on a closed course in Mexico can do 165/170 with 3:55s (possibly more) so IMO no concern with top speed loss either. There really isn't anywhere you can go that fast and if you are building a car to take on standing mile competitions then you are into an entirely different build ballpark.

Do it and don't look back. You will be glad you did.

[BlknBlu]

At 80 MPH i was at about 1800 RPM and it purred like...... well a snake

Bruce

[James430]

Thanks everyone......Sounds like the 355 is the way to go....This is a quote from Jonb site,I guess I need to call him frst....
Other downsides: Your tranny and rear end will run marginally warmer with a 3.55.

Very little factor here, eliminated by simply increasing the frequency of fluid swaps to 25% sooner than normal. Vipers already pushed to 700HP or beyond might choose a 3:33 instead.....a mere with 8% rear torque boost, but easier to control the massive wheelspin that will otherwise develop. At 550 HP, the gear "feels" like 82 more HP. What about 3.73? Or 4.11? Don't Go

Mine should be pushing over the 700 hp mark with th SC and it's already hot enough here in Tx....I'll see if he recommends the 333's

[JonB ~ PartsRack]

The "Ideal" pick of a 3:33 for 700HP is tempered by a total 3:33 availability of ZERO. I have spent many many hours scouring for even a used 3:33.

Do the 3:55, and NOT the much-weaker 3:45. The diff heat is a factor if you track your car.............

Thanks everyone......Sounds like the 355 is the way to go....This is a quote from Jonb site,I guess I need to call him frst....
Other downsides: Your tranny and rear end will run marginally warmer with a 3.55.

Very little factor here, eliminated by simply increasing the frequency of fluid swaps to 25% sooner than normal. Vipers already pushed to 700HP or beyond might choose a 3:33 instead.....a mere 8% rear torque boost, but easier to control the massive wheelspin that will otherwise develop. At 550 HP, the gear "feels" like 82 more HP. What about 3.73? Or 4.11? Don't Go

Mine should be pushing over the 700 hp mark and it's already hot enough here in Tx....I'll see if he recommends the 333's

[JonB ~ PartsRack]

Thanks John,as per our phone conversation I will get a set when I find someone to install it....everybody I call says no on the install around here so far...

Yur better off with a Dana-44 Jeep-Vette specialist who's done 100+ Dana 44s than a 'Viper Tech' who's done 4-5.

[ACR_VP]

Yur better off with a Dana-44 Jeep-Vette specialist who's done 100+ Dana 44s than a 'Viper Tech' who's done 4-5.

I agree on this completely... I've personally put lockers in 3 different dana 44's in Wranglers, as well as a 3.55 rear end in my viper, it's the same thing. There are plenty of guys out there that can do the work with their eyes closed.

With that said, I'm at about 630 crank horsepower, and I with the tires hot (PS2's) you can feel the rear slightly letting loose in second... First is impossible not to break loose at nearly any speed. But I'd be willing to get it's still better than the stock 3.07's.

[JonB ~ PartsRack]

Yep ! Its not rocket science, but it IS technically challenging to achieve balance (lash) on 3 axes at thousandths of an inch.

Get it wrong, and it will wwWWHHIINEE on 1, 2, or all 3 axes.

[James430]

Thanks.....Read about 50 different posts on the forums and with the HP I will have 700 + @ crank everybody is losing traction badly and a lot are switching back to the stock setup....Got a Pm from a guy who has a brand new polished and shot peened hardened 3.45's for a good price.Have to do some thinking.......Probably need to drive it a little with the SC and see how she acts before deciding..

[JonB ~ PartsRack]

Which one would you want in Your diff? "Size matters"
RingGearComparo.jpgBe careful on "GM" 3:45s.... the hardening is good, and needed at 700HP. But the size of the carrier bolts matters too. The later-year fittments are much meatier gears. Vs smaller, sleeved bolts. Your 01-02 came with the larger set as seen on top. The 3:55s we offer are as the top set, shot-peen hardened.

[Vprbite]

Jon, what do you think about the mopar 3:55 gear set for Gen 3s? Also, for the uneducated among us (Me), can you tell us what shot peen hardened means? Thanks Jon for your help, as always.

Sorry if this is thread hijacking. If so, please let me know and I will remove. I thought it germane to the issue at hand though.

[JonB ~ PartsRack]

3:55s are the "Goldilocks, Just Right" gearset for MOST Vipers. When SRT decided to test 3:55 in the first G5 mule cars, PartsRack was proud to provide the first 12 sets..... (sworn to secrecy of course.) The exact-same gearsets are now OE in all Gen 5s.


Shot-Peening is a metallurgy process that "hammers-blasts" small BB-like particles against a metal surface, 'denting' and hardening those surfaces that will see friction in their life. This 'stress' extends the life, resists wear. The media, speed, density, and duration of the blasting matters. A quick google search will tell you more than you could ever want to know.

[Vprbite]

Gen Vs come with 3:55s?

What do you think about the Mopar gear set? I assume they are quality. Do you recommend?

[JonB ~ PartsRack]

All Gen 5s come with a Spicer-Dana 3:55 Ring-Pinion. {Badged as Mopar.} Same exact gear PartsRack (and Unitrax) offers for many more years, and for much less $$$ than Mopar offers it.

Mopar Builds NOTHING. Mopar is a giant middle-man, contracting and re-badging the products of others.

[PittsburghRT]

Loving the 3:55's in my Gen2 and I actually use 6th gear now.

[Uncle Paul]

I had 3:55's in my Gen III and loved them. Then put on a Paxton and "Wow...what a Rush!"

That car was a handful. Actually slower in the 1/4 as I could not keep the stock tires from spinning.

Same on the road course. Lots of power out of the corners, and down the straight, but was really working the steering, brakes and shifter like mad to keep up with th e power rush. When the extra power finally blew out the rear end, I switched back to the original, and far stronger stock 3:07.

The car then settled down. I was able to have the car in one gear long enough to get some forward momentum. It pulled like the proverbial freight train, and the chassis felt more in tune with the car. The pulls turned into powerful lunges, and I was able to far better control the longer thrust from the motor.

The rear end settled down, and was no longer so squirrley. Was better able to put the power down and enjoy the rush. Not so frantic, but much more controllable.

Summary. The 3:54 was great fun, but mostly on the ragged edge of control. The 3:07 made the whole Paxton package more useable, and while not at much fun, actually put down better numbers as the tires were no longer being overwhelmed.

Better tires might have changed the equation, but with street tires the 3:07 ended up being better with the additional horsepower.

[Vprbite]

I loved my 3;55s I my Gen II. As I understand it, the heat generated is higher but can be fixed by changing fluids more often. Unless you are a track rat, in which case you need a diff cooler, I would thnk you are fine with occasional track use.

[Vipermann]

Which one would you want in Your diff? "Size matters"
RingGearComparo.jpgBe careful on "GM" 3:45s.... the hardening is good, and needed at 700HP. But the size of the carrier bolts matters too. The later-year fittments are much meatier gears. Vs smaller, sleeved bolts. Your 01-02 came with the larger set as seen on top. The 3:55s we offer are as the top set, shot-peen hardened.

JonB, are you saying that Corvette 3.33 gears, if you can find a set - even used, are thinner like the 3.45s as well?

[Sybil TF]

I have 3:73's in my 96 GTS and it's a ball buster.

[72hemi]

I had 3.55 installed in my 01 ACR and they were already installed in my 96 when I picked it up, if they hadn't I would have installed them because they make such a huge difference in the car!

[ultradriver10000]

I have 3:73's and she is still slow! lol Feels way better then the 3:07s though.

[Vprbite]

I am gonna start a business transporting vehicles to Mexico. I would think that is the hardest part about making these videos.


I still haven't seen a hellcat in the wild.

[Vprbite]

And I will say it again, on the Gen II, 3:55 is the way to go. Yes you can go taller as some people do but that seems pretty intense to me. I think 3:55 is the sweet spot. I wouldn't do 3:33 unless you were SuperCharging and if you are gonna do 3:45, just do the 3:55s instead. It will get you more oomph and only cost you a few RPMs.