Black-Tooth
Tony Natoli
That's the only currency we use in SoCal! nt
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"Limited slip diffs have put food on my table for 17 years..."
- Thread starter Rupunzell
- Start date
rossofozini
True Classic
Some info
Max Medwell competed in local rallies here in Adelaide. Hi said the car was never very quick (595cc and twin carbs!!) but was consistent and rarely ever got bogged. Max competed back in the 50's.
Max and Mary Medwell were invited guests to the Aniversary event at Pt Wakefield. As Max was friends with [FONT=Verdana, Arial, Helvetica, sans-serif]“Possum” Kipling [/FONT]also an old time racer, they and Sir Jack had crossed paths many years earlier. Max and Mary had the honor of driving Sir Jack and lady Brabam back to Adelaide.
I need to get together with Max to copy all the old photos. I will post them when do.
Max's Topolino
http://www.flickr.com/photos/rossfelix/3191301292/sizes/o/in/set-72157604084654674/
More reading
http://www.mgccsa.org.au/FeatureArticles/Back to PT Wakefield.htm
http://www.lagler.com.au/portwakefield.htm
Max Medwell competed in local rallies here in Adelaide. Hi said the car was never very quick (595cc and twin carbs!!) but was consistent and rarely ever got bogged. Max competed back in the 50's.
Max and Mary Medwell were invited guests to the Aniversary event at Pt Wakefield. As Max was friends with [FONT=Verdana, Arial, Helvetica, sans-serif]“Possum” Kipling [/FONT]also an old time racer, they and Sir Jack had crossed paths many years earlier. Max and Mary had the honor of driving Sir Jack and lady Brabam back to Adelaide.
I need to get together with Max to copy all the old photos. I will post them when do.
Max's Topolino
http://www.flickr.com/photos/rossfelix/3191301292/sizes/o/in/set-72157604084654674/
More reading
http://www.mgccsa.org.au/FeatureArticles/Back to PT Wakefield.htm
http://www.lagler.com.au/portwakefield.htm
Paul Valente
Automotive Engineer
Weismann Locker
Don't know how a cut and paste from one of my posts ended-up the subject of the this thread :wacko: but....
I did a lot more with the race-car stuff at my last job (Tractech) than I do now so I havent seen a Weismann Locker in years! Carol Smith really seems to think they are special in his books but they really function very similar to a Detroit Locker only instead of dog-teeth, they use a roller-ramp clutch. Granted they are very smooth relative to a Detroit.
Look-up US patent # 3,383,611 for the details.
The only things I have worked on recently in motorsports are helical diffs for the CORR trucks and Trophy trucks. The OEM world is moving toward active devices with electronic controls. Although there is still some interest in passive devices, the current state-of-the-art is wet-clutches and ECU's. My appologies to Luddites.:wink2:
Don't know how a cut and paste from one of my posts ended-up the subject of the this thread :wacko: but....
I did a lot more with the race-car stuff at my last job (Tractech) than I do now so I havent seen a Weismann Locker in years! Carol Smith really seems to think they are special in his books but they really function very similar to a Detroit Locker only instead of dog-teeth, they use a roller-ramp clutch. Granted they are very smooth relative to a Detroit.
Look-up US patent # 3,383,611 for the details.
The only things I have worked on recently in motorsports are helical diffs for the CORR trucks and Trophy trucks. The OEM world is moving toward active devices with electronic controls. Although there is still some interest in passive devices, the current state-of-the-art is wet-clutches and ECU's. My appologies to Luddites.:wink2:
Rupunzell
Bernice Loui
There is a lot of "crowing" about Wisemann Lockers in Smith books. Biased opinion from back in the days when fewer limited slip diff choices were available or maybe Pete and Carroll were really good buddies?
Since then, electronic diffs have changed the big picture quite a bit making the Wisemann locker a bit dated for "state of the art" race cars today.
I sorta remember Lancia was using electronic diffs back in the 1980's on their Intergrale 4WD rally cars, I'm pretty sure they were not the first to do this.
Since then, electronic diffs have changed the big picture quite a bit making the Wisemann locker a bit dated for "state of the art" race cars today.
I sorta remember Lancia was using electronic diffs back in the 1980's on their Intergrale 4WD rally cars, I'm pretty sure they were not the first to do this.
Rupunzell
Bernice Loui
Thanks Papa for the info.. It did get me thinking about all things with coaxial counter rotation props like the Russian built Kamov helicopter and Hughes XF-11 experimental re-con plane that nearly killed Howard (crashed due to an oil leaking hose/fitting).
Just one way to control angular momentum... I had no idea this was used in boat props.
Anyway, does this mean if we ever visit "Ole Salt" Papa Tony in So Cal, we can go sailing?
Just one way to control angular momentum... I had no idea this was used in boat props.
Anyway, does this mean if we ever visit "Ole Salt" Papa Tony in So Cal, we can go sailing?
Pete Whitstone
True Classic
Doesn't TracTech make a LSD that is...
dunno how to describe this... a sun gear arrangement with 3 planetary gears, each of the planetary gears is a cylinder longer that it is in diameter and has a helical pattern on it. Not as steep in pitch as a worm gear but similar. In normal (straight-line) operation, the worm gears don't turn, they are essentially locked (not by any locking mechanism, they just don't have a force acting on them that would cause them to turn) and just turn the outer "ring" gear. But in a corner they can turn between the sun gear and the outer ring gear.
Seems like a very simple, elegant and strong solution to me. But I have no experience with them. I'd be interested to hear your (and other) opinions on the strengths and weaknesses of this type of unit.
And some help remembering what it's called.
Pete
dunno how to describe this... a sun gear arrangement with 3 planetary gears, each of the planetary gears is a cylinder longer that it is in diameter and has a helical pattern on it. Not as steep in pitch as a worm gear but similar. In normal (straight-line) operation, the worm gears don't turn, they are essentially locked (not by any locking mechanism, they just don't have a force acting on them that would cause them to turn) and just turn the outer "ring" gear. But in a corner they can turn between the sun gear and the outer ring gear.
Seems like a very simple, elegant and strong solution to me. But I have no experience with them. I'd be interested to hear your (and other) opinions on the strengths and weaknesses of this type of unit.
And some help remembering what it's called.
Pete
Black-Tooth
Tony Natoli
Yep... and nope...
Yep to the counter-rotation issues... nope to the sailing.
Yur about 10 years too late.
As I said... We got into catamarans and eventually towed two stacked on one trailer just about everywhere we went. I guess we averaged about twice a month until Thanksgiving, then off until usually mid-February. We must've kept up that routine for about 10 years also.
I can't believe the energy and effort it took to do those things... but it was a lot of fun. Once the kids got into high school they developed their OWN interests and we were off supporting them. I finally sold my last when my granddaughter was about 4 and never got to take her out. Again... I believe that boat sat for about 10 years before I let it go.
Our trip to the Ventura Marina last weekend got me thinking again... but I doubt if I'd ever own a racing cat again... probably would consider joining a yaucht club and rent various and sundry craft. Much easier on the pocketbook! HA!
Thanks for the memories...
Yep to the counter-rotation issues... nope to the sailing.
Yur about 10 years too late.
As I said... We got into catamarans and eventually towed two stacked on one trailer just about everywhere we went. I guess we averaged about twice a month until Thanksgiving, then off until usually mid-February. We must've kept up that routine for about 10 years also.
I can't believe the energy and effort it took to do those things... but it was a lot of fun. Once the kids got into high school they developed their OWN interests and we were off supporting them. I finally sold my last when my granddaughter was about 4 and never got to take her out. Again... I believe that boat sat for about 10 years before I let it go.
Our trip to the Ventura Marina last weekend got me thinking again... but I doubt if I'd ever own a racing cat again... probably would consider joining a yaucht club and rent various and sundry craft. Much easier on the pocketbook! HA!
Thanks for the memories...
ng_randolph
Bjorn H
Torsen?
As in Torque Sensing.
As in Torque Sensing.
Black-Tooth
Tony Natoli
What a great history...
Congrats Ross... and enjoy your new project!
Congrats Ross... and enjoy your new project!
Pete Whitstone
True Classic
I don't think that's it....
I think the term Torsen has been around since, maybe the 60s. This is a newer product that I think appeared in the late 90s or early this decade.
As far as I can tell, it is entirely a passive design, so I don't think there is any "sensing" of torque going on. But then, I'm not sure there's any "sensing" of torque going on in the Torsen design either! But that's only because I'm not familiar with it.
Pete
I think the term Torsen has been around since, maybe the 60s. This is a newer product that I think appeared in the late 90s or early this decade.
As far as I can tell, it is entirely a passive design, so I don't think there is any "sensing" of torque going on. But then, I'm not sure there's any "sensing" of torque going on in the Torsen design either! But that's only because I'm not familiar with it.
Pete
htfx19
Herzel Frenkel
I realy appreciate the offer, Tony
That might shoot me back in time to the 60's and my 20's.
Not doable.
Now I am only 30 min drivr from Irit and 10 from my gandkids. At my age that is a lot.
One has to be happy at home.
One day I still may show up on your front door, so if you move, keep me posted...
That might shoot me back in time to the 60's and my 20's.
Not doable.
Now I am only 30 min drivr from Irit and 10 from my gandkids. At my age that is a lot.
One has to be happy at home.
One day I still may show up on your front door, so if you move, keep me posted...
Paul Valente
Automotive Engineer
Much more than you ever wanted to know about Helical Differentials
Gleasman came out with the first popular one back in the 50's (maybe even the forties) that was a cross-axis style helical now called the Type-A or T1.
It was invented by a guy named Gleasman which is confusing as he sold out to a company calledd Gleason and it was called the Tor-sen for Torque Sensitive. Along the way the way the company has had a lot of parents, Zexel Torsen, Bosch and now JTekt. The Gleasman family has since started another company called Torvec:
http://www.torvec.com/products_ftv.html
Anyhow, in about 1973 TracTech (now owned by Eaton) came out with a parallel-axis helical called the TrueTrac
It has sold well in the aftermarket and was OEM on Ford F450 and F550's when I was with the company. They make them for racing applications (Ford 9", Frankland Quick Change, Winter's axles, etc.) although they are illigal in NASCAR (has to be an open diff or a Detroit Locker last I knew).
:bla:
The paralell axis diff is now basically public domain so there are a bunch of companies that showed-up when the TracTech patents ran out. Torsen makes one (called the Type-B or T2), Quaife, Tochigi Fuji (now part of GKN), and the company I work for now, AAM. We are OEM in the big Dodge trucks 10.5" and 11.5" ring gear axles. And we make a locking version of it for the Dodge Power Wagons and another application due out next year (can't tell yet). We also have it as a center diff in some of the new Audi S5's.
:bla:
It's not really this simple but the deal is that these things all make friction when you put torque into them. That friction supports some amount of torque. An open diff is basicaly 50:50 side to side governed by the worse wheel. With torque-sensitive LSD like these, you are still governed by the worse wheel but since the diff is sort of bound-up, you can transfer more torque to the good wheel by some ratio. Typically, 1.8:1 to 4:1. Even though it looks like a lot going on with all the gears, it really is just making friction like a plate-type diff. Only different is that the friction is generated by the gears thrusting. No differentiation needs to occur to make the friction. You just need to be able to get torque into it. I don't like to plug the competion too much but these guys wrote a nice paper back in 1988 about how the friction is generated in a T1. The parallel style would be calculated similarly.
http://www.torsen.com/files/Traction_Control_Article.pdf
Told you it was more than you wanted to know.
Gleasman came out with the first popular one back in the 50's (maybe even the forties) that was a cross-axis style helical now called the Type-A or T1.
It was invented by a guy named Gleasman which is confusing as he sold out to a company calledd Gleason and it was called the Tor-sen for Torque Sensitive. Along the way the way the company has had a lot of parents, Zexel Torsen, Bosch and now JTekt. The Gleasman family has since started another company called Torvec:
http://www.torvec.com/products_ftv.html
Anyhow, in about 1973 TracTech (now owned by Eaton) came out with a parallel-axis helical called the TrueTrac
It has sold well in the aftermarket and was OEM on Ford F450 and F550's when I was with the company. They make them for racing applications (Ford 9", Frankland Quick Change, Winter's axles, etc.) although they are illigal in NASCAR (has to be an open diff or a Detroit Locker last I knew).
:bla:
The paralell axis diff is now basically public domain so there are a bunch of companies that showed-up when the TracTech patents ran out. Torsen makes one (called the Type-B or T2), Quaife, Tochigi Fuji (now part of GKN), and the company I work for now, AAM. We are OEM in the big Dodge trucks 10.5" and 11.5" ring gear axles. And we make a locking version of it for the Dodge Power Wagons and another application due out next year (can't tell yet). We also have it as a center diff in some of the new Audi S5's.
:bla:
It's not really this simple but the deal is that these things all make friction when you put torque into them. That friction supports some amount of torque. An open diff is basicaly 50:50 side to side governed by the worse wheel. With torque-sensitive LSD like these, you are still governed by the worse wheel but since the diff is sort of bound-up, you can transfer more torque to the good wheel by some ratio. Typically, 1.8:1 to 4:1. Even though it looks like a lot going on with all the gears, it really is just making friction like a plate-type diff. Only different is that the friction is generated by the gears thrusting. No differentiation needs to occur to make the friction. You just need to be able to get torque into it. I don't like to plug the competion too much but these guys wrote a nice paper back in 1988 about how the friction is generated in a T1. The parallel style would be calculated similarly.
http://www.torsen.com/files/Traction_Control_Article.pdf
Told you it was more than you wanted to know.
Pete Whitstone
True Classic
Fascinating Paul, thanks for posting...
I had no idea that the design was that old. Looks like ng_randolph was right on the money.
I look at the cone and clutch setups and such, and can't for the life of me figure out how they work. But the first time I saw this, it was immediately obvious. Very nice design.
Now if only we could get some built for the X!
Pete
I had no idea that the design was that old. Looks like ng_randolph was right on the money.
I look at the cone and clutch setups and such, and can't for the life of me figure out how they work. But the first time I saw this, it was immediately obvious. Very nice design.
Now if only we could get some built for the X!
Pete
Black-Tooth
Tony Natoli
Take care, my friend! nt
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Black-Tooth
Tony Natoli
Dittos Paul, I've heard of True-Trac or Tru-Trac...
... but never really knew of how it was so different.
Thanks for all the info! Good stuff to bore our women with!
HA!
... but never really knew of how it was so different.
Thanks for all the info! Good stuff to bore our women with!
HA!
Paul Valente
Automotive Engineer
One for the X
I could design and source an X1/9 helical but the parts are so expensive in small quantities! It would be something like $5500 for each one. Gears are really a killer on price. The other alternative is to find a Quaif that is close and modify it. It's a long shot as there are so many variables (splines, spline location, ring gear pilot, bearing span, bolt pattern (it goes on and on) but I don't want to say it is impossible. Some diffs are nearly identical. The AMC 20, the old Toyota pick-up truck axle and the Dana 44 are really close. There is (or was) a kit to fit a GM 12-bolt truck differential into Land Rover (or was it a Land Cruiser?) so it is not impossible. Still, Quaife charges a forutune for their diffs ($1200-ish) and you'd have machining costs on top of it.
I could design and source an X1/9 helical but the parts are so expensive in small quantities! It would be something like $5500 for each one. Gears are really a killer on price. The other alternative is to find a Quaif that is close and modify it. It's a long shot as there are so many variables (splines, spline location, ring gear pilot, bearing span, bolt pattern (it goes on and on) but I don't want to say it is impossible. Some diffs are nearly identical. The AMC 20, the old Toyota pick-up truck axle and the Dana 44 are really close. There is (or was) a kit to fit a GM 12-bolt truck differential into Land Rover (or was it a Land Cruiser?) so it is not impossible. Still, Quaife charges a forutune for their diffs ($1200-ish) and you'd have machining costs on top of it.
Paul Valente
Automotive Engineer
Steve Hoelscher
True Classic
Torsen-Gleason and other bland subjects...
Paul,
Thanks for the history lesson. History is always usefull, if not particularly exciting.
Gleason supplied their Torsen diffs to Toyota for the '93-'98 Supra Twin Turbos. I had one in my '98 Supra SE. While these units work effectively in many applications, I hated the unit in the Supra. This is because the Torsen type diffs open up if one wheel looses its resistance. This is because (as I am sure you know) the helical planetary gears require some torque loading to provide enough thrust action to generate the required friction to transfer drive to the other wheel.
The Torsen in the Supra opened up regularly relegating it to open diff status. And once you have one wheel spinning, you have to get completely out of the throttle before it will lock up. I assume this is the reason that TRD offered a standard clutch type diff for the Supra. I switched to that unit and was much happier.
You remarked about the cost of the Quaife unit. Quaife's manufacturing is in England where costs (and taxes) are much higher than the far east or even the US (in some cases). I met with the people from Quaife at the PRI show last year and was very close to closing a deal with them to be a dealer and their US service facility. It is important to know that Quiafe is primarily a manufacturer of racing transmissions but it is there diffs that are better known in the US. I was primarily interested in their sequential shift transmissions. I dropped the plans when a more interesting and exciting opportunity presented itself.
I have rebuilt a number of Quaife diffs, others too, and found it interesting that there is a company (I forget who) that now makes a version of the Torsen diff that uses clutches to provide preload to the planetary gears which solves the Torsen design's biggest short coming. While I haven't tested one, it should be effective, if expensive (the result of combining the parts from both the Torsen and clutch type designs.
Paul,
Thanks for the history lesson. History is always usefull, if not particularly exciting.
Gleason supplied their Torsen diffs to Toyota for the '93-'98 Supra Twin Turbos. I had one in my '98 Supra SE. While these units work effectively in many applications, I hated the unit in the Supra. This is because the Torsen type diffs open up if one wheel looses its resistance. This is because (as I am sure you know) the helical planetary gears require some torque loading to provide enough thrust action to generate the required friction to transfer drive to the other wheel.
The Torsen in the Supra opened up regularly relegating it to open diff status. And once you have one wheel spinning, you have to get completely out of the throttle before it will lock up. I assume this is the reason that TRD offered a standard clutch type diff for the Supra. I switched to that unit and was much happier.
You remarked about the cost of the Quaife unit. Quaife's manufacturing is in England where costs (and taxes) are much higher than the far east or even the US (in some cases). I met with the people from Quaife at the PRI show last year and was very close to closing a deal with them to be a dealer and their US service facility. It is important to know that Quiafe is primarily a manufacturer of racing transmissions but it is there diffs that are better known in the US. I was primarily interested in their sequential shift transmissions. I dropped the plans when a more interesting and exciting opportunity presented itself.
I have rebuilt a number of Quaife diffs, others too, and found it interesting that there is a company (I forget who) that now makes a version of the Torsen diff that uses clutches to provide preload to the planetary gears which solves the Torsen design's biggest short coming. While I haven't tested one, it should be effective, if expensive (the result of combining the parts from both the Torsen and clutch type designs.