OS Giken Differential in Viper

[Cop Magnet]

The closer your Viper gets to becoming a race car, the further it gets away from being a comfortable daily driver.

Truer words have never been spoken.

 

[Cop Magnet]

Love my Giken. I think I made the right choice on this. once in awhile I do get it right. Great on the drag strip straight runs, strong, no wheel hop.

What setting are you using? Factory recommended or for some other application? How much street, strip, and roadcourse useage are we talking about? Thanks for your input on this subject.

 

[Bobpantax]

My Giken arrived at the dealer today. We had it adjusted before they shipped it based on the following criteria;

1. Primary use: street.
2. Secondary use: occasional road course and standing mile events.
3. Tires to be used: PS2s and possibly the ACR sport cups ( my first pair are too hard ( too many heat cycles) and I am not sure that I am going to replace them.)

So, if you are going to get the Giken, it is important to tell them your intended use and the type of tires that you are going to use so they can adjust the piece to your needs.

Once it is installed ( probably sometime next week) and I test it, I will report back.

 

[eucharistos]

looking fwd to your report

congrats on your upgrade

 

[Canyon707]

What setting are you using? Factory recommended or for some other application? How much street, strip, and roadcourse useage are we talking about? Thanks for your input on this subject.

Sorry for the delay getting back to you. Up in Bellevue Washington visiting family. I and Nader are probably some of the first Giken users and I had Devin at Unitrax set it up for Street and drag racing. Not sure exacty what he did to it but, I always trusted his judgement based on his knowledge of the Giken. I have run several times at the strip and have found that this Diff is nearly bullet proof ( I know better) I hooks up evenly, no wheel hoping, and with my M&H drag radials it bites down hard. I currently and using a BBG twin disk carbon fiber clutch and that adds to the excitement since it is such a positive grip on the flywheel. It did take some getting use to and some seat adjusting since it comes in higer that thes stock clutch. I also added a launch light. a shift light and a shift beeper since I do bracket racing against a lot of automatics. I am planning to go out again the first week of Nov and see how it it runs. As for the OS Giken I love it but, I only can compare it against the stock Viper diff.

 

[dave6666]

Just an FYI i have about 4000 miles on my Giken now and yes I do get popping from it after very hard driving on the track. The heat generated in that situation will swell the disc's and create more preload. There is very tight tolerances in the Giken and extreme use will produce this. What I "think" it could be is the fact that there are so many clutches in the diff that some never have to move under normal use. Then when tolerances tighten they are engaged more and "pop" loose, maybe for the very first time in a long time. I did not experience any of this when the unit was new and did NOT do any type of break in, hard running right out of the box.

I loved my Quaife till my erratic driving style started slowing me down. I am too old to change my balls out driving style so I bought the Giken, and will never look back. That said I think the Quaife is the obvious choice and offer it to 85% of my customers "based on the actual use and drivers style" all questions I ask about anything I offer. You should never "tell" someone what they want or need, you should talk with them and find out what they need!

Although one person I've talked has said it's a cold phenomena, mine is a more frequent popper when hot like you've said. I guess all the chatter on this thread has awoke mine again. Hadn't popped in a while, and did it twice last week. No triple bangs, just the single gimme a wedgie pop.

One benefit that should be reminded of - OSG versus the Q - is the amount of machining to the stub axles from one diff versus another. At least in regards to the Gen 2 like I have, reportedly there is way less machine work required when installing the OSG. Less machine work resulting in a stronger axle at the end of the day.

 

[Bobpantax]

I picked up the car today. In addition to the Giken, I had the compression on the Motons moved up a notch and new PS2s put on. ( MY old PS2s were also heat cycled out like the ACR tires.). We also tightened up a few bolts here and there that were not quite torqued to spec. I periodically have same checked just to be on the safe side.

I am going to allow a 3 or 4 hundred mile break in period. It did not pop from the time I left the dealership to the time I got off the highway about 35 miles later. The highway driving would have heated up the whole drivetrain a bit. It popped a couple of times when I turned after getting off the highway. I then stopped at a meeting for a bit more than one hour. After I got back in the car, it did not pop on the way back to my office.

The only other thing I have observed so far is that the diff feels stronger but I do not know whether this feeling is real or a psychological effect based on what I have read about the Giken. I will have to wait until after the break in to put her through her paces and see what's what. For now, it feels good to have my Viper back.

 

[treesnake]

I picked up the car today. In addition to the Giken, I had the compression on the Motons moved up a notch and new PS2s put on. ( MY old PS2s were also heat cycled out like the ACR tires.). We also tightened up a few bolts here and there that were not quite torqued to spec. I periodically have same checked just to be on the safe side.

I am going to allow a 3 or 4 hundred mile break in period. It did not pop from the time I left the dealership to the time I got off the highway about 35 miles later. The highway driving would have heated up the whole drivetrain a bit. It popped a couple of times when I turned after gwetting off the highway. I then stopped at a meeting for a bit more than one hour. After I got back in the car, it did not pop on the way back to my office.

The only other thing I have observed so far is that the diff feels stronger but I do not know whether this feeling is real or a psychological effect base on what I have read about the Giken. I will have to wait until after the break in to put her through her paces and see what's what. For now, it feels good to have my Viper back.

 

[Canyon707]

It is stronger.

 

[97snk]

I picked up the car today. In addition to the Giken, I had the compression on the Motons moved up a notch and new PS2s put on. ( MY old PS2s were also heat cycled out like the ACR tires.). We also tightened up a few bolts here and there that were not quite torqued to spec. I periodically have same checked just to be on the safe side.

I am going to allow a 3 or 4 hundred mile break in period. It did not pop from the time I left the dealership to the time I got off the highway about 35 miles later. The highway driving would have heated up the whole drivetrain a bit. It popped a couple of times when I turned after getting off the highway. I then stopped at a meeting for a bit more than one hour. After I got back in the car, it did not pop on the way back to my office.

The only other thing I have observed so far is that the diff feels stronger but I do not know whether this feeling is real or a psychological effect based on what I have read about the Giken. I will have to wait until after the break in to put her through her paces and see what's what. For now, it feels good to have my Viper back.

It's been quiet a few weeks now...I m awaiting your feedback before placing my order...

 

[treesnake]

It's been quiet a few weeks now...I m awaiting your feedback before placing my order...

Same here. Talked to Mark J. yesterday...
Probably going to replace my Quaiffe in track car with one.

 

[Bobpantax]

I have not yet tested it under spirited conditions so I do not have anything significant to report yet in that context. ( I have been driving my Jeep and my Challenger more lately.) I can say that for normal, everyday road use I have not had any issues. At the beginning there were a few occasional sounds from it which I understand are from the action of the internal clutches while breaking in but that went away almost immediately. It does feel more robust. The only reason I put it in was that it is robust enough to deal with my power level in different contexts over a long period of time but for a stock power level and DD use with occasional spirited driving I would say that the Gen IV differential is fine. The stock Gen III differential is an inferior piece. For stock power level with DD use and track days, the quaife, as I understand it from reviewing posts here, is a good choice. If I remember correctly Dan Cragin from DC Performance has now decided that the Giken is his preferred choice. See post number #110 above. Mark Jorgensen from Woodhouse has also made a detailed post on this subject comparing and contrasting the Giken and the Quaife which I found useful before I made my choice. See post #117 above. Mark also now prefers the Giken. The Giken is more money but is easier to install.

You should note that my Vipertech, a fanatic about Vipers and an exceptionally knowledgeable and talented mechanic (Ray at University Dodge in Davie, Florida), who is familiar with all of the different types of differentials available for Vipers, thinks that the Giken is an extraordinary piece. When he looked at it before installation, he looked like a child looking at his favorite Christmas gift and grinned from ear to ear.

I hope the above helps you with your decision.

 

[Bobpantax]

I did a little testing today limited to the performance scenarios below. The Giken was superior to the stock Gen IV differential in each case. Since I have no personal experience with the Quaife, I cannot comment on the difference between the Giken and the Quaife. All testing was done under safe and lawful conditions.

1. Full throttle in first from a stop. RPM at about 1200 at launch.
2. Full throttle after car obtained a speed of 15 mph.
3. Spirited shift from first to second.
4. Full throttle in second from 50 MPH.
5. A few quick left hand turns with acceleration out of the turns.

Knowing that the Giken is a very robust piece that can handle considerably more power than my car produces ( 685 RWHP) is a psychological plus. It made a difference with respect to the subjective driving experience.

 

[brianmeeks]

Just got a Black 04 with 13,000 miles on it and rearend doesn't hold for anything. The car runs great other than that with no rearend noice, chatter, or rattle. After reading some of the posts and talking to a friend, this rear-diff sounds like it may be my problem?

 

[97snk]

Just got a Black 04 with 13,000 miles on it and rearend doesn't hold for anything. The car runs great other than that with no rearend noice, chatter, or rattle. After reading some of the posts and talking to a friend, this rear-diff sounds like it may be my problem?

problem or solution?

 

[AZTVR]

Just got a Black 04 with 13,000 miles on it and rearend doesn't hold for anything. The car runs great other than that with no rearend noice, chatter, or rattle. After reading some of the posts and talking to a friend, this rear-diff sounds like it may be my problem?

Stock power? 6-7 year old, run flat tires ?

 

[10 BANGER]

From what I see I'm thinking a Giken unit would be over kill for a stock Gen 3 that's only street driven. I Haven't had any problems since the upgrade to the Gen 4 Viscolok unit installed by unitrax along with the 3.55's
Do you guys think my stock Gen 3 would benefit from it? Would I be able to tell the difference on daily driving use?

 

[Bobpantax]

It would be a waste of money for you.

From what I see I'm thinking a Giken unit would be over kill for a stock Gen 3 that's only street driven. I Haven't had any problems since the upgrade to the Gen 4 Viscolok unit installed by unitrax along with the 3.55's
Do you guys think my stock Gen 3 would benefit from it? Would I be able to tell the difference on daily driving use?

 

[Mopar Boy]

When one says the third gen rears are crap, in what way?

 

[JonB]

Just got a Black 04 with 13,000 miles on it and rearend doesn't hold for anything. The car runs great other than that with no rearend noice, chatter, or rattle. After reading some of the posts and talking to a friend, this rear-diff sounds like it may be my problem?

Hold?

If you have 13k miles on OE RunCrap tires, THAT is the grip-hold issue for sure.

But an OSGiken will be a bullet-proof addition if you plan to drag or track your car, the Gen 3 diff is probably the 'worst' ever in a Viper for track use.

 

[JonB]

From what I see I'm thinking a Giken unit would be over kill for a stock Gen 3 that's only street driven. I Haven't had any problems since the upgrade to the Gen 4 Viscolok unit installed by unitrax along with the 3.55's
Do you guys think my stock Gen 3 would benefit from it? Would I be able to tell the difference on daily driving use?

You should be fine as-is...... the G4 diff and your driving style are ideal as set up.

 

[JonB]

When one says the third gen rears are crap, in what way?

Short answer - Cannot handle abuse.

Trivia: When the SRT10 debuted at VOI-Nashville in 2002, it first came to the V10- nationals at Bowling Green drag strip 1 day before. 4 cars. SRT drivers. TWO REAR ENDS BROKE that day, on the early runs, and SRT had to scramble to get em fixed. [ All of which cars Owners could drive in the Autocross the next 2 days.] It foretold the future a bit.

More trivia: When we left BG Drags, about 70+ Vipers buzzed the Vette Museum lot nearby enroute to VOI !

 

[Dan Cragin]

More Triva:
The early 03 SRT's had an issue with breaking the pin that holds the spider gears. A running change was a new pin that was heat treated with a new process. That was the issue at Bowling green.

The Hydro-lock used on the 03-06 Models does not fair well on gear changes. The posi-cannot handle the torque. if you change the gears, change the posi.

If you have any grabbing issues with your 08-10 Visco-lock- you need to change the oil and add fiction modifier. Seen numerous with grabbing issues.

Hope this helps.

 

[Mopar Boy]

Interesting. Thanks.

Was just curious. Seems like it was a backwards step. 2nd gen rears were decent (minus 1/2 shafts) then the 3rd gens come along.....

 

[venomred]

Dan...What are 'grabbing' issues w/ the Visco-Loc diff? What are the symptoms and affect on performance?? What happens??

 

[VicTxV10]

Dan...What are 'grabbing' issues w/ the Visco-Loc diff? What are the symptoms and affect on performance?? What happens??

Maybe this...

http://forums.viperclub.org/srt10-srt10-coupe-discussions/642001-rear-end-noise-sharp-turns.html

 

[Nadine UK GTS]

I've run many Quaifes in Gen2 and never looked for anything better. Gen 3 Street and Comp Coupe the Giken is a big improvement in how you can drive the car out of a corner, end of story, this is the best!

 

[GONABITE]

Unitrax just completed installing the Giken for my GEN 3 as well as upgrading the half shafts. They are being sent back to me as of now and I will be installing next week. Unfortunately there is over a foot of snow on the ground here in NY so I wont get to drive the car anytime soon. :-(

 

[WCKDVPR]

Thanks for all the information. Now that some time has passed, is there any additional input that owners of the Giken and or Quaife have at this time - especially those who have experience with both? I am looking at replacing the the posi unit in my track only (road course), Hoosiers/slicks, 645 hp, Gen 2. Really looking at these two diffs and staying with the 3.07 (due to transmission ratios) but upgrading the ring and pinon to the later model ones with larger ring gear bolts.

Thanks you for your feedback.

Best regards and happy holidays.

 

[Garron]

Wow old posts.

The wavetrac diff is the latest now. I am still doing a lot of reading because I want to get rid of my stock gen 3 diff and like you I am not really sure what to replace it with.