Quaife vs. OS-Super-Lock vs. 3.73's vs. steering

[dave6666]

I've been working with Parts Rack on a new differential package for my '01, and of course there are some choices to be made. I'm already set on a 3.73 gear which will net me at 3.45 with my 20's, but I'm concerned about making the right decision on the diff. I did read this thread BTW. Very good stuff.

http://forums.viperclub.org/srt10-srt10-coupe-discussions/625381-os-giken-differential-viper.html

The obvious diff choices are:

-> stock

-> Quaife

-> OS-Super-Lock

My desire is to reduce the car swinging the rear to the side upon acceleration. Not drag strip launching but street type driving. I use a PS2 and don't plan on changing that.

The post I linked above mentions concerns about steering under both heavy acceleration AND a slippage with the OS. Not so much with the Q. I otherwise like what I've read about the OS.

Any recommendations or suggestions about the diff or new comments about my hood vents? BTW my car is lightly modded N/A. Will probably never see more than 500 at the wheels if that.

 

[Steve-Indy]

You pose an interesting dilema...and I'm sure that many of us are interested is the recommendations that will be forth coming.

Oh, by the way, you could haul your Asp out of that hot, dusty State and bring it to the green, wooded, lush Putnam Park Road Course on August 8th and 9th...and talk the situation over with The-Pro's-Who-Know at the Open Track Sessions.

You might just see some folks that you know!!

 

[Tom F&L GoR]

I suggest you find someone that autocrosses a Viper. Their service might be very representative.

 

[VIPER BAZ UK]

I got the Eaton Trutrac from DC and so far very pleased with it.......

 

[JST2CRZY]

I have a Quaife w/3:33's. Very impressive. I can punch it at about 30-40 mph in any gear but first and wheel spin or not the car stays straight. Also had the stock unit w/3:07's and would not go back.

 

[dave6666]

The concern that was pointed out in the SRT thread I linked to was that if the diff has locked AND you get sideways a bit, then correcting your direction of travel requires not just steering input with the front wheels but also feathering the throttle to get the back end to cooperate too.

I fully understand the concept of how that all works. But just like I rely on my ABS to assist me during rapid deceleration, I'm relying on my brain here to make a smart choice on driveability of my car without graduating from drifting champions school.

Back to the SRT thread, it was also pointed out that this "steering" matter would be more pronounced in high hp cars. I do not consider mine nor do I plan to make it a "high hp" car, but there are sections of straight highway pavement that I've had traction issues at 80 - 90 mph with my 3.07's.

With the 3.73 ratio (3.45 net) I'm going to do that will make the ability to break traction even better I assume. Don't want to find out while aimed at the guard rail at 90 mph that my parts choice was really not the best one. Nor are there any closed course facilities in this area that replicate straight line highway driving, if I wanted to do some car control training on this exact subject. Trying to get this one right, pretty much straight out of the box.

Reasonably experienced driver + good diff = predictable and manageable car... is the goal.

 

[Jack B]

The concern that was pointed out in the SRT thread I linked to was that if the diff has locked AND you get sideways a bit, then correcting your direction of travel requires not just steering input with the front wheels but also feathering the throttle to get the back end to cooperate too.

I fully understand the concept of how that all works. But just like I rely on my ABS to assist me during rapid deceleration, I'm relying on my brain here to make a smart choice on driveability of my car without graduating from drifting champions school.

Back to the SRT thread, it was also pointed out that this "steering" matter would be more pronounced in high hp cars. I do not consider mine nor do I plan to make it a "high hp" car, but there are sections of straight highway pavement that I've had traction issues at 80 - 90 mph with my 3.07's.

With the 3.73 ratio (3.45 net) I'm going to do that will make the ability to break traction even better I assume. Don't want to find out while aimed at the guard rail at 90 mph that my parts choice was really not the best one. Nor are there any closed course facilities in this area that replicate straight line highway driving, if I wanted to do some car control training on this exact subject. Trying to get this one right, pretty much straight out of the box.

Reasonably experienced driver + good diff = predictable and manageable car... is the goal.

I have run the Quaife for about four years with 3.33's. On the bottle I am over 850 rwhp and it tracks straight. All the other schemes use some type of locking mechanism, the Quaife is a torque bias whcih means it is supplying all the torque possible to each tire dependent on traction and does such in a continual transition, no abrupt changes in torque.

If you get it done make sure you have the ring gear bolts drilled and wired. If you are going up in hp you should have the ring gear drilled and tapped for the next larger size bolt. I believe it goes from 7/16 to 1/2.

 

[2MANYTOYS]

I have run the Quaife for about four years with 3.33's. On the bottle I am over 850 rwhp and it tracks straight. All the other schemes use some type of locking mechanism, the Quaife is a torque bias whcih means it is supplying all the torque possible to each tire dependent on traction and does such in a continual transition, no abrupt changes in torque.

If you get it done make sure you have the ring gear bolts drilled and wired. If you are going up in hp you should have the ring gear drilled and tapped for the next larger size bolt. I believe it goes from 7/16 to 1/2.

I agree. the Quaife is probably the best mod I've ever had on my car. Should have done it sooner.

 

[Canyon707]

It sure would be nice to have them side by side. I hear the OS Giken is good I hear the Quaife is good. I understand that the OS is not even available for a couple more months.

 

[dave6666]

I understand that the OS is not even available for a couple more months.

Jon didn't mention that when quoting me on the diff package. I think it might be just the Gen 3 unit that is being delayed; different stub axles.

 

[Canyon707]

That might be, I spoke with Devin at Unitrax last week and thats what I was told. It sure would be nice to have one in hand. I am sure Jon knows the scoop.

 

[ViperGeorge]

I've been thinking about a diff swap in my high HP Gen 3. Would the choice of diff vary based on car use? In other words is one better for the street, another one better for the drag strip, and yet another better for a road course. I used to drive a high HP Mustang on a road course with a Detroit Locker, scared the crap out of me. When you put the power down coming out of a corner the damn thing would want to drive you straight off the road and into the nearest wall. Switched it to an Auburn High Torque Posi and liked it much much better. I suppose on a drag strip the Detroit Locker would have been the ticket but definitely not for me on a road course.

 

[dave6666]

First off, just spoke to Devin at Unitrax and they are expecting a handful of Gen 3 OS units by the end of the week. Gen 2's are in stock now.

Regarding the driving type or style, Devin made some interesting comments on that as each diff may have a suitability for one type of driving versus another. But a starting point in that is, that until recently only the Q was available. So that made your choice for you right there - get the Q because that's all there is. Anyway, the OS has just been hitting the shores here and the pool of available opinions from the Viper guys is limited. Devin did recommend reading this info from OS's testimonial page:

Testimonies | OS GIKEN

Devin also made it clear that the OS is not a locker, and will also run cooler than the Q because of it's design.

I'll call my driving type for this car performance street driving. Maybe kind of a hybrid mix of strip/road course in their lighter sense. Devin did recommend the OS for both those driving types.

I could be about $3500 away from being a test dummy.

I've been thinking about a diff swap in my high HP Gen 3. Would the choice of diff vary based on car use? In other words is one better for the street, another one better for the drag strip, and yet another better for a road course. I used to drive a high HP Mustang on a road course with a Detroit Locker, scared the crap out of me. When you put the power down coming out of a corner the damn thing would want to drive you straight off the road and into the nearest wall. Switched it to an Auburn High Torque Posi and liked it much much better. I suppose on a drag strip the Detroit Locker would have been the ticket but definitely not for me on a road course.

 

[ViperGeorge]

First off, just spoke to Devin at Unitrax and they are expecting a handful of Gen 3 OS units by the end of the week. Gen 2's are in stock now.

Regarding the driving type or style, Devin made some interesting comments on that as each diff may have a suitability for one type of driving versus another. But a starting point in that is, that until recently only the Q was available. So that made your choice for you right there - get the Q because that's all there is. Anyway, the OS has just been hitting the shores here and the pool of available opinions from the Viper guys is limited. Devin did recommend reading this info from OS's testimonial page:

Testimonies | OS GIKEN

Devin also made it clear that the OS is not a locker, and will also run cooler than the Q because of it's design.

I'll call my driving type for this car performance street driving. Maybe kind of a hybrid mix of strip/road course in their lighter sense. Devin did recommend the OS for both those driving types.

I could be about $3500 away from being a test dummy.

I seem to remember somewhere some posts about installing a Gen 4 diff in a Gen 3. Don't know if it would fit a Gen 2 (probably not). Wonder what the advantages of that swap might be over an OS or a Q. This diff stuff is getting complicated. Seems like the only way to know which way to go is to try one but its a lot of $$ if you guess wrong.

 

[JonB]

The G4 antislip has a better system, a Visco-Loc vs the G3 Hydra-Lock. The G3 hydra is weak, and a straightswap G4 is an upgrade. But if you install a Q or an OS in a G3 or a G4, either way you REPLACE the stock OE anti-slip......its gone, so does not matter.

The OS requires less machining (weakening) of axles and case..... Crazy Swede Sam Hubinette used the OS extensively in his Drift championships and recent competitions....his mechanics report a LOT more dependability in the OS due in large part to cooler operation

OS for G2 like D666 has is available. [ 2 sets] . Gen 3-4 is still 9-14 days

 

[ViperGeorge]

JonB, but would a Gen 4 diff be a better option in a Gen 3 than a Q or OS?

 

[JonB]

JonB, but would a Gen 4 diff be a better option in a Gen 3 than a Q or OS?

Better? no way! Either the Quaife or the OS would be dramatically better than the G3 or G4. The CASE does not matter. The guts of the differential becomes the Quaife or the OS Super.

 

[dave6666]

Jon... Contrary to your statement the the OS takes less machining than the Q, Devin at Unitrax sez that ain't so. They are both about the same.

Might be trivial to many as long as the damn thing works and don't break, but if one of the selling points for the OS is stronger stub axles due to less material being removed, then like I said Devin disagrees with that.

 

[JonB]

Jon... Contrary to your statement the the OS takes less machining than the Q, Devin at Unitrax sez that ain't so. They are both about the same.

Might be trivial to many as long as the damn thing works and don't break, but if one of the selling points for the OS is stronger stub axles due to less material being removed, then like I said Devin disagrees with that....

George's question and my reply was Gen 3-4......The Year Matters.....Gen III-IV is the one that requires much less machining for an OS vs a Quaife.

 

[dave6666]

George's question and my reply was Gen 3-4......The Year Matters.....Gen III-IV is the one that requires much less machining

Your statement I referred to was in a recent email conversing about the diff options for my '01, not in this thread.

But you know what happens when me and you start arguing Jon. I'm willing to just give the machining issue a big whatever! Because it really doesn't matter to me how they fit the parts in.

Anyway, I do have a few more items to get answered as I've been making some notes along the way. I'll pop you an email again. I'm ready for them gears...