How do the C-clip eliminator kits available for stock axles work? I assumed it provided a beefier, less sloppy clamping action but at the same location on the axle shaft.
Torsen done
- Thread starter Softballer77
- Start date
I spoke with Birdoc last week. You are correct...he is running a spool now; however, when his torsen went out he put a wavetrac in and said he was running 1200hp on it and had zero issues. Also, the wavetrac comes with a lifetime warranty and cost me the same as another Torsen would cost. So, that's why i went Wavetrac. On a side-note I really appreciate Mark being so approachable still. He is leagues ahead of us now with that wicked build...but still took the time to chat with me a bit on his differential experience. Just another reason why everyone likes Van just as much. Good things.
You guys are right in saying 33 spline would be better. I am still running my 31 spline mosers though. Will see how it does. It's easy to say ya might as well do this and that while i'm in there. At the same time, I wasn't a fan of replacing my mosers with another set already that are perfectly fine, and if this one doesn't hold up, a 9" is going in. I'd love to be able to give a great experience on a path not so much followed. I'm a fan of efficiency, and if simply tossing in a Wavetrac and nothing else greatly helps the torsen issue, it can save people money in the long run. These vehicles are already money mongers as it is. (I say this 4 clutches in...)
After the thorough research, i learned that while the Torsen is an excellent track LSD, it's main killers are high horsepower launches in heavy vehicles with slicks or DRs. I'm not pushing 1000hp, but i do go to the track a LOT when I'm home. So, i'm sure that's what did it in. Strangely, under normal driving i don't notice it being an issue and it lays 2 strips of rubber on the pavement with normal street tires. However, I think it was when things got sticky tire wise that it was enabling it to not work correctly, like the burnout box or on prepped 4k launches. I could certainly feel something not right, and witnesses said they noticed one side smoking and the other playing catch-up. To add, at speeds over 100mph, i began noticing a low pitch noise and a strange vibration in the rear. Was this the torsen going? I have no idea. But will no when it's completed today and after a little break-in period.
I will let you all know how it works out. First big test will be at the track in Fontana for NMCA West on the 17th (if i don't have to work). The plan is to run it there.
You guys are right in saying 33 spline would be better. I am still running my 31 spline mosers though. Will see how it does. It's easy to say ya might as well do this and that while i'm in there. At the same time, I wasn't a fan of replacing my mosers with another set already that are perfectly fine, and if this one doesn't hold up, a 9" is going in. I'd love to be able to give a great experience on a path not so much followed. I'm a fan of efficiency, and if simply tossing in a Wavetrac and nothing else greatly helps the torsen issue, it can save people money in the long run. These vehicles are already money mongers as it is. (I say this 4 clutches in...)
After the thorough research, i learned that while the Torsen is an excellent track LSD, it's main killers are high horsepower launches in heavy vehicles with slicks or DRs. I'm not pushing 1000hp, but i do go to the track a LOT when I'm home. So, i'm sure that's what did it in. Strangely, under normal driving i don't notice it being an issue and it lays 2 strips of rubber on the pavement with normal street tires. However, I think it was when things got sticky tire wise that it was enabling it to not work correctly, like the burnout box or on prepped 4k launches. I could certainly feel something not right, and witnesses said they noticed one side smoking and the other playing catch-up. To add, at speeds over 100mph, i began noticing a low pitch noise and a strange vibration in the rear. Was this the torsen going? I have no idea. But will no when it's completed today and after a little break-in period.
I will let you all know how it works out. First big test will be at the track in Fontana for NMCA West on the 17th (if i don't have to work). The plan is to run it there.
These are strictly designed as a way to meet the NHRA rules for axle retention and are located at the wheel bearing end of the axle shafts. They are prone to gear oil leakage in a street application. Also the Torsen differential needs to retain the center bearing block whether you remove the C-clips or not to keep the torque biasing gears in place inside the differential.
The 33 spline Wavetrac doesn't have the center bearing block to control axle end play or have C-clips. So it is structurally much stronger internally. Regardless of the fact that you are eliminating the C-clips to retain the axles.
I'm not giving you a hard time over whether or not you use a 31 spline versus a 33 spline. I made my choice strictly on what I've seen happen 40 years ago with the old 10 and 12 bolt Chevy rears at the drag strips when a C-clip retained axle broke. Back in those days the rear axles had drum brakes. When you broke an axle, the axle, tire and brake drum left the car with catastrophic results. Today you don't see these types of failures due the fact modern cars have disc brakes. The rear disc brake rotor and caliper in of itself retains the axle in the car even if you shear an axle at the splines in the differential. So those safety issues have disappeared as the brakes have changed. The NHRA has never bothered to update the rules to reflect this when it comes to a C-clip retained axle, because there are too many older cars still raced to this day with the factory drum brakes of yesteryear.
Now on to the Wavetrac. To get a good launch with this differential........you must do a good burnout. Why? Because you need to achieve the same axle RPM per side. Once you are done with the burnout the Wavetrac will be locked in the similar manner as a spool. But and here is the BIG BUT. If for any reason you come out of the burn out and have to make any steering correction that causes the diff to unlock for torque bias from left to the right side of the axle. You need to do a dry hop where you spin the rear tires for at least 6 inches to lock the diff as you pull up to the beams square. If you make any major steering corrections to line yourself up in the main grove of rubber as you approach the beams. The diff will not be locked until you leave the line and the Wavetrac senses a speed differential between the left and right side after the launch. It usually takes 6 inches of car movement and the axle speed differential before the Wavetrac fully locks up if you didn't set the car up properly as you come out of the burnout and into the beams.
Not many people know this. I found this out from AutoTech the manufacturer of the Wavetrac.
Also don't purchase any off the shelf synthetic 75W-90 gear oil from you local auto parts store. 99.9% of them have a friction modifier in them from the oil company to work in a clutch style posi unit. This inhibits the way a Wavetrac works. Purchase the high $$$$$$ Motorcraft gear oil specifically designed to work with the Torsen, as it is friction modifier free. I'm not 100% sure of this, but I believe the only other synthetic gear oil without friction modifiers for a clutch style posi available is from Amsoil
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Both seem stay locked better than the torsen for spirited street/strip type driving in my car. I also thought the behavior of the rear axle during wheelspin from hard acceleration was at times unpredictable to me. Say you want to execute a burnout, and when the tires spin up the rear feels like its floating to one side plus the car doesn't feel like it respond to steering inputs the way it "should." But that's only some of the time. The detroit locker locker and eaton posi do not seem to do whatever is causing that.
The detroit locker is very aggressive which will potentially wear you down driving it on the street a lot. It can jerk the car around a little bit during turns, and will talk to you with a few thunks and clunks that aren't terribly loud, with an occasional huge bang happening once in a great while lol.
The eaton posi I think is an often overlooked option on this forum, but I think it's probably potentially a good choice for a lot of guys. It doesn't make any noise, it never chatters in turns, it doesn't one wheel, its half the cost of a torsen, and it's fully rebuildable and there are a number of different choices available for both the preload springs and the clutch pack to adjust the amount of preload that resists the tires from turning at different speeds.
The detroit locker is very aggressive which will potentially wear you down driving it on the street a lot. It can jerk the car around a little bit during turns, and will talk to you with a few thunks and clunks that aren't terribly loud, with an occasional huge bang happening once in a great while lol.
The eaton posi I think is an often overlooked option on this forum, but I think it's probably potentially a good choice for a lot of guys. It doesn't make any noise, it never chatters in turns, it doesn't one wheel, its half the cost of a torsen, and it's fully rebuildable and there are a number of different choices available for both the preload springs and the clutch pack to adjust the amount of preload that resists the tires from turning at different speeds.
I was referred to this, obviously old information to several here;
http://www.spohn.net/support/questi...+different+center+section+differential+types?
http://www.spohn.net/support/questi...+different+center+section+differential+types?
Oh I know you weren't giving me a hard time. Personally I wish I had 33 splined axles. Just hated after purchasing 31 Mosers not long ago having to upgrade once again. The 31 splined Wavetrac option worked out for me.
I have about 300 miles on it. Just been taking it easy so far. The installer (GTR HiPo) mentioned it was super tight in getting Wavetrac's special style clips in. I ordered in what Wavetrac recommended as far as fluid which was Motul 75W-140. They did mention that friction modifiers can do their job to well on the wavetrac and to use something that didn't have them. I just used what they recommended. Also, since I do high speed rallys on top of recreational drags and such, they recommended the 140 weight over the 90.
Thanks for the additional info for the launch. I will have to remember that! I'll re-update after a day at the drags this Saturday on how things were affected with this new LSD.
Kurt--I have the 35 spline Strange S-trac 8.8. Do you know if it locks/unlocks in a similar fashion to the Wavetrac? Thanks for the info... very helpful!
Wavetrac gives you a life time warranty, if you ever break it, pay the difference between the two and upgrade to the 33 spline. You'll have to buy new axles, plus the 9" axle bearing housings to do this. Doing the 33 spline and welding the axle tubes with the 9' ends, according to Mike the shop foreman at Moser, the complete 8.8 axle assembly will handle 1000-1100 RWHP without any issues. Going any higher in power would require a spool from what he told me or a complete 9" rear axle assembly.
I don't know much about this differential, from what little I've read it is similar to the Torsen in how it works internally as far as torque bias left to right. So again no gear lubricants with friction modifiers added for a clutch style posi differential.
Unfortunately this style of torque biasing differential needs both wheels to retain traction for a positively locked diff. If one wheel is completely without traction, the diff will send the power to that wheel. The Wavetrac has the advantage on this point, but it isn't quite as strong as the 35 spline S-Trac. A lot of people don't realize that if one wheel is completely without traction that this style of torque biasing differential will react in the same manner as an open differential. Fortunately at a race track this condition will not happen as long as each tire retains similar traction it will stay locked
As far as following the same burnout procedures as the Wavetrac and lining up on the beams with the S-Trac it isn't critical. Since this is a torque biasing diff with gears inside of it, it strictly relies on how each tire is gripping the track to sense how to respond internally and whether to lock up or not. I would also imagine that Strange built this rear with a higher torque bias than Gleason did for the Torsen. Unfortunately Strange hasn't released much information about the S-Trac differentials since they introduced them 4-5 years ago for the Dana 60 and 9" rears originally.
I have a 9" s-track. It's designed like the true track but with twice the side gears, better metal, serial numbered, rebuildable, preload (so it's locked until you reach 100 (?) Ftlb torque differential... like a clutch style, but just interference fit in the center between the axle gears). Best of all worlds I figure, until you need a locker.
Currie sent 9+ axle lube with the axle. Not sure who makes it, but it leaves 2 thick black lines.
Currie sent 9+ axle lube with the axle. Not sure who makes it, but it leaves 2 thick black lines.
You sure about that Heinzy?
[video=youtube;lkxSlYYKMlE]https://www.youtube.com/watch?v=lkxSlYYKMlE[/video]
You still did well with the #'s of times you've ran your 2010 car and the diff lasting as long as it did.
So I don't see the stock Torsion diff mentioned in the link above. Which diff mentioned is similiar to the design of the Torsion?
Wow. At least that happened off the line and not while going 100+ down the track...
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Okay I did a little more research. This post is to talk strictly about the 33 spline Wavetrac versus the 35 spline Strange S-Trac. The 31 spline Wavetrac is NOT built in the same manner, since it has C-clips to retain the axles.
The Wavetrac and the S-Trac use the same material and number of worm gears internally inside the case. So in this area they're structurally very similar. Now between the axle gears the Wavetrac has the additional locking feature of its design or as they say their "patented device" that sits between each axle gear to over come a single wheel no traction condition.
Both differentials are of a torque biasing gear designs. Now the Wavetrac can be disassembled to modify its torque bias, whereas the S-trac from what I can find any information about this can't
Now what does torque bias mean in this application.
These rears are built to sense a difference in available traction at each tire and use a torque bias ratio to determine which tire gets the most power from the engine. Typically this bias ratio is 2.5 to 1, or 2.5:1
This means if the wheel with the least amount of grip can handle 400 lb-ft of torque that the wheel with the most traction will receive 1000 lb-ft of torque. Now most of you are looking at the difference and thinking oh WOW, that equals 1400 lb-ft of torque, so each axle will spin at the same speed as I proceed down the track, because my engine is only producing 1000 lb-ft of torque at its peak.
Every gear from the engine to the tire is a multiplier of torque
Transmission first gear is a 2.66:1 ratio
Rear axle ring and pinion is a 3.73:1 ration
1000 lb-ft of peak engine torque is going to be multiplied by each of this different gear ratios
1000 lb-ft of peak engine torque x 2.66:1 first gear x 3.73:1 rear axle gear ratio equals 9921.8 lb-ft of torque being applied to the tires.
Now any torque biasing differential will stay locked and turn both axles at the exact same speed, if and only if each tire can support applying 4960.9 lb-ft of torque to the pavement in this example.
Now here is where the problem arises with a torque biasing differential. If lets say one tire can only support 2500 lb-ft of torque, the differential then comes into play to split it with a torque bias to maintain the same axle speeds. Again lets use a 2.5:1 torque bias ratio in the differential center section. So we have a tire that can only handle 2500 lb-ft with a torque bias of 2.5:1. This means that the other tire must have a capability to handle 6250 lb-ft of torque at the tire. Okay, so we add 2500 lb-ft + 6250 lb-ft = 8750 lb-ft. This is what the total will be of the total torque of grip the 2 tires can handle to maintain the same axle speeds. Unfortunately this does exceed our earlier math equation of engine torque x first gear ratio and rear axle ratio equaling 9921.8 lb-ft.......so both tires aren't going to maintain the same speed as the differential splits the torque. The axles will not be turning the same speed as the differential splits the torque. Both axles will be receiving power, but it isn't an equal amount of power and an axle speed differential will come into play as the one tire loses grip.
Now for the good news, I doubt any track you're racing at would have that significant of a difference in available traction or surface grip from the left to right tire in any situation, unless you're driving in your own fluids leaking from your car at the moment.
Now where is the Wavetrac different in this type of situation. Is it not only is torque biasing, it has their "patented device" between the axle gears to lock the two axles at the same speed once one of the tires losses traction beyond the point of the limits of lb-ft of grip available to a particular tire. So in our earlier example where a Tosen, TruTrac or S-Trac would have had a difference in axle speeds, the Wavetrac won't. Now that doesn't mean it will grip the track any better. Why? Because in the first math equation we have 9921.8 lb-ft of torque being applied to the tires. In the second math equation we showed an available grip of 8750 lb-ft. So we are now spinning both tires, only at equal speeds. Whereas with the other torque biasing differentials there will be a difference in axle speeds.
Now lets say the track does have significant difference in grip between the left and right tires and the total of that grip can handle 10,000 lb-ft of torque. Which differential has the advantage? Now we have more total grip than our engine output, but we have a significant difference in the left to right side. To me this really isn't a good situation no matter which rear differential you have, including a spool. Why? Because the car is going to try to turn in the direction of the wheel with the least amount of grip regardless of the differential in the rear axle.
I like the idea of the 33 spline axle Wavetrac in a street driven car, because of the fact it is not only torque biasing. It is also going to lock up under situation where a tire has zero grip. Now they also come with a life time warranty. They also can be taken apart and serviced. They can also be taken apart to change the torque bias ratio to your preferences. If you want a 4.0:1 torque bias versus a 2.5:1 this can be changed in a Wavetrac
All the others are exactly that torque biasing. What does this mean. This means if for any reason a tire has 0 lb-ft of torque application to the ground surface that is the tire that will get 100% of all of the available torque from the engine. Why? Lets says the differential has the standard torque bias of 2.5:1
2.5 x 0 = what?
ZERO!
All of the power is going to go to the tire that has zero traction. This is exactly what happens with an open or non-posi differential.
Now the Strange S-trac has an advantage in axle size. Why? It is 35 spline axle versus 33 spline axle. To add the 2 extra splines to the axle, the diameter of the axle was increased in size. As the axle diameter increased, so did the axles strength to handle torque. Now the disadvantage to this is the larger diameter axle is they weigh more. This is more rotating mass to get moving on the start. It is more mass to stop, but it is also more unsprung weight if you're thinking more along the lines of a car that you want to handle on a road course versus a straight line car on the drag strip. Now can you buy a 35 spline light weight axle? I'm sure you can, but it will probably be for drag race only applications. It won't have the capabilities to be used in a street/strip application where potholes or other hard knocks of street driving can bend or break the light weight 35 spline drag race axle.
There are advantages and disadvantages to everything. You have to decide which suits your needs better.
BIRDDOC was going to run a 9" 35 spline Wavetrac for Drag Week, but he changed to a spool. Why? He felt the Wavetrac wasn't capable of handling the torque his car produced for the days he would be at the track versus the advantages of driving the car on the street between each track event the Wavetrac would give him. So he felt that the extra effort required to steer the car and the fact it would chew tires up for the 1000 miles of driving was worth the extra strength a spool would net him to launch the car without fear of breaking rear axle components.
Everybody has to weigh these options and decide what works best for their situation and final use of the car.
An Eaton/Detroit TruTrac, Gleasen Torsen, Strange S-Trac and a Wavetrac are all torque biasing gear differentials. The Torsen can be bought in 3 different configurations for the 8.8 rear axle. The T2 version from the 13/14 GT500 are structurally stronger than the a standard one. The Ford Racing version M-4204-T31H for road racing is the T2 with a high torque bias ratio.
The main difference is what materials are they built with and how many worm gears are inside the case. The Wavetrac and Strange S-Trac have a higher number of worm gears to spread the torque load out, plus use a higher grade of materials for a higher structural strength.
Great info BC, total next level as usual.
I do think you can get gun drilled lightened 35 spline axles.
I built the best street/strip 8.8 at the time and used a 33-spline Trutrac, if I were doing it today, it would get a 35-spline S-trac. The weight and torque our manual trans Shelbys can deliver is unique in many ways, my chassis shop wanted 35 splines if possible.
He actually recommended a 9" swap, and if I did it again today, I'd have taken that advice based on gear whine.
I haven't launched on my redone fully braced 33-spline 8.8, but if it whines I'm going 9"
-J
:beer:
I do think you can get gun drilled lightened 35 spline axles.
I built the best street/strip 8.8 at the time and used a 33-spline Trutrac, if I were doing it today, it would get a 35-spline S-trac. The weight and torque our manual trans Shelbys can deliver is unique in many ways, my chassis shop wanted 35 splines if possible.
He actually recommended a 9" swap, and if I did it again today, I'd have taken that advice based on gear whine.
I haven't launched on my redone fully braced 33-spline 8.8, but if it whines I'm going 9"
-J
:beer:
Heinz never broke the carrier section in his 2010 Shelby, He did however break the ring and pinion X2 (Motive gear set) but that was with 1000 passes or so on the car........
thats accurate........
yes im sure bud, little do you know that i never broke a diff....just the f888390 twice....same diff everytime put in the stronger f988390 which i suggested you do and never had an issue again...diff was stock 2010 and stock factory 31spline axels...and for your info that diff had around 1200 passes total....but to each there own. cheers!
Well, the weekend didn't go as planned...
My first run, I launched at 4k rpm expecting tire spin but wanted to feel if there was any difference in my old Torsen and the new Wavetrac. It bit so hard I bogged! Same tires as last drag meet, similar hot conditions, 18psi. No tire spin at all. So, obviously, i'm like...this is gonna be a good day! So, next time up I decide to launch at 4500 with same tire pressure. Boom!
I have a video of it, but as soon as the light changed I released the clutch...it bit hard, then an explosion and a sound like someone tossed a handful of nuts and bolts into a blender. It hasn't been opened up yet, but will tomorrow. I will keep you all posted on what we find. Have a feeling the gear set broke (3.90 Motive as well....
)But, my initial feeling was that things were vastly improved over the last meet on the Torsen with the new Wavetrac....unless I find it's the Wavetrac that gave way. Anyways, enough guessing till tomorrow...
https://youtu.be/BKCXiMM8ick
My first run, I launched at 4k rpm expecting tire spin but wanted to feel if there was any difference in my old Torsen and the new Wavetrac. It bit so hard I bogged! Same tires as last drag meet, similar hot conditions, 18psi. No tire spin at all. So, obviously, i'm like...this is gonna be a good day! So, next time up I decide to launch at 4500 with same tire pressure. Boom!
I have a video of it, but as soon as the light changed I released the clutch...it bit hard, then an explosion and a sound like someone tossed a handful of nuts and bolts into a blender. It hasn't been opened up yet, but will tomorrow. I will keep you all posted on what we find. Have a feeling the gear set broke (3.90 Motive as well....
)But, my initial feeling was that things were vastly improved over the last meet on the Torsen with the new Wavetrac....unless I find it's the Wavetrac that gave way. Anyways, enough guessing till tomorrow...https://youtu.be/BKCXiMM8ick
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