Limited Slip Differential facts
12-27-11, 06:30 AM
#46
Driver School Candidate
Lmao
I posted in the LS section how my (and many other) Lexus LS, GS and SCs seem to have Limited Slip Differentials (LSD's) even though none of these cars had one installed from the factory.
In answering the responses and reviewing our Open Differentials (OD's) in the factory repair manuals I can make the controversial although ACCURATE statement that over time the 1990-2004 stock OD's will slowly become actual LSD's. This is due to the internal parts slowly wearing into each other and creating more and more internal friction.
Further, in reading the manual it appears that it is likely that we could actually build the stock unit to be an LSD using stock parts. This seems hard to believe but the evidence is overwhelming.
When new the mentioned cars would spin ONLY one tire when doing a burnout. This is normal OD operation. An OD provides equal torque to both tires UNTIL one tire looses traction and then transfers up to 100% of the engine torque to the tire without traction. This is why one tire smokes.
LSD's are designed just like OD's except they have friction increasing parts that restrict the torque from overpowering one tire. This keeps equal torque going to each tire and is why LSD equipped cars smoke both tires when doing a burnout.
The LSD's friction increasing parts are designed to SLIP when cornering because the outside tire needs to rotate faster than the inside tire. So this SLIP allows the differential to do its work and allow a differential tire speed. This is the reason for the name Limited Slip.
Torsen differentials such as installed on Supra Turbos are not limited slip. They keep torque applied to both tires by an ingenius gearing system. They will also spin both tires in a burnout and will allow differential action but there is no slipping of friction materials so they are not limited slip even though they are commonly called LSD's.
My dragstrip times in my sig were done around 50k miles. At that time my car would easily smoke just the passenger side tire.
Also, the OD in my car is identical to the GS400 and GS430 through 2004. It would be interesting to have members test their cars traction and report back if they smoke one or both tires and how many miles they have on their car.
Here is my STOCK OD 1999 LS400 showing my LSD function due to increased internal friction with 170k miles. I am guessing somewhere around 100k this will become the norm for the cars mentioned. It is probably helpful NOT to change the diff fluid as specified.
In answering the responses and reviewing our Open Differentials (OD's) in the factory repair manuals I can make the controversial although ACCURATE statement that over time the 1990-2004 stock OD's will slowly become actual LSD's. This is due to the internal parts slowly wearing into each other and creating more and more internal friction.
Further, in reading the manual it appears that it is likely that we could actually build the stock unit to be an LSD using stock parts. This seems hard to believe but the evidence is overwhelming.
When new the mentioned cars would spin ONLY one tire when doing a burnout. This is normal OD operation. An OD provides equal torque to both tires UNTIL one tire looses traction and then transfers up to 100% of the engine torque to the tire without traction. This is why one tire smokes.
LSD's are designed just like OD's except they have friction increasing parts that restrict the torque from overpowering one tire. This keeps equal torque going to each tire and is why LSD equipped cars smoke both tires when doing a burnout.
The LSD's friction increasing parts are designed to SLIP when cornering because the outside tire needs to rotate faster than the inside tire. So this SLIP allows the differential to do its work and allow a differential tire speed. This is the reason for the name Limited Slip.
Torsen differentials such as installed on Supra Turbos are not limited slip. They keep torque applied to both tires by an ingenius gearing system. They will also spin both tires in a burnout and will allow differential action but there is no slipping of friction materials so they are not limited slip even though they are commonly called LSD's.
My dragstrip times in my sig were done around 50k miles. At that time my car would easily smoke just the passenger side tire.
Also, the OD in my car is identical to the GS400 and GS430 through 2004. It would be interesting to have members test their cars traction and report back if they smoke one or both tires and how many miles they have on their car.
Here is my STOCK OD 1999 LS400 showing my LSD function due to increased internal friction with 170k miles. I am guessing somewhere around 100k this will become the norm for the cars mentioned. It is probably helpful NOT to change the diff fluid as specified.
Well, you start with an "apology" for coming off as rude. So I can assume your next paragraph is an intentional insult. You may or may not do that face to face. I would rather hope you would not.
Your second paragraph is condescending but finishes with a "thank you".
I do not know you and you have limited posts for one to draw a more balanced perspective on your motives. From your limited effort I can only guess that by taking a self rightous attitude and calling me out without explaining your differences you are not interested in the discussion but rather in self aggrandizement.
So, even though it may fall on deaf ears... care to explain how my statements may lead to "someone less experienced damaging their vehicle" ???
Your second paragraph is condescending but finishes with a "thank you".
I do not know you and you have limited posts for one to draw a more balanced perspective on your motives. From your limited effort I can only guess that by taking a self rightous attitude and calling me out without explaining your differences you are not interested in the discussion but rather in self aggrandizement.
So, even though it may fall on deaf ears... care to explain how my statements may lead to "someone less experienced damaging their vehicle" ???
LOL It's been a while.. simple operational principles, old oil will deteriorate and loose some of it''s lubrication properties, will increase friction, increased load (ergo, Drag Launches, and along with power upgrades) will put more strain on the diff, leading to a very probable premature failure...
this will be may my last post on this thread you have, single handedly blown holes in your own "opinions" as well as proved your-self wrong. you have your statements but i hope you learned a thing or two since my last post...
either way this was quite a laugh, and thank you for being so eloquent in your defenses.
Oh before i go... the main reason I haven't posted much is because i have nothing important to contribute at the moment. i may make a build thread, or throw around some ideas concerning CNC, design and styling to gain different perspectives and new ideas. but a the moment my vehicle is sitting, waiting on engine to be overhauled.
I'm Active duty military, where condescending is a way of life, and bluntness and form of respect.
I have a lot of things to do as i'm currently deployed, so excuse me if i don't always post consistently, it's not like i'm in war zone or anything.
you sir, have simply got on my bad side w/ your ignorance using . had you not attempted to circumvent the simple truths, and disregard pertinent information, well i would have simply passed the thread without a second whim... Chow
12-27-11, 09:25 PM
#47
Lexus Champion
Thread Starter
jrowedem,
Taking you at your word, Thank You for Your Service
Anyone in active duty, God forbid a war zone, that get's any enjoyment out of whatever is going on here... one way or another... is welcome to it.
That your condensending bluntness may be a form of respect? If so, thank you.
Stay safe.
Taking you at your word, Thank You for Your Service
Anyone in active duty, God forbid a war zone, that get's any enjoyment out of whatever is going on here... one way or another... is welcome to it.
That your condensending bluntness may be a form of respect? If so, thank you.
Stay safe.
Last edited by JBrady; 12-28-11 at 08:02 AM.
01-04-12, 12:58 AM
#48
BANNED for ripping off other members
iTrader: (-1)
Join Date: Jan 2009
Location: ny
Posts: 434
Likes: 0
Received 0 Likes
on
0 Posts
we must consider the differences:
1 way, 1.5, and 2 way LSD. only 1 and 2 way have been discussed.
If the ramps are symmetrical, the LSD is 2 way. If they are saw toothed (i.e. one side of the ramp is vertical), the LSD is 1 way. If both sides are sloped, but are asymmetric, the LSD is 1.5 way.
i remember years ago, in high school, we had a v6 95' mustang. in wet asphalt, the damn thing, at all attempts, would only spin one tire = 1 way lsd
do the same on a gs and both will spin = 1.5 way
1 way, 1.5, and 2 way LSD. only 1 and 2 way have been discussed.
If the ramps are symmetrical, the LSD is 2 way. If they are saw toothed (i.e. one side of the ramp is vertical), the LSD is 1 way. If both sides are sloped, but are asymmetric, the LSD is 1.5 way.
i remember years ago, in high school, we had a v6 95' mustang. in wet asphalt, the damn thing, at all attempts, would only spin one tire = 1 way lsd
do the same on a gs and both will spin = 1.5 way
01-04-12, 05:21 AM
#49
we must consider the differences:
1 way, 1.5, and 2 way LSD. only 1 and 2 way have been discussed.
If the ramps are symmetrical, the LSD is 2 way. If they are saw toothed (i.e. one side of the ramp is vertical), the LSD is 1 way. If both sides are sloped, but are asymmetric, the LSD is 1.5 way.
i remember years ago, in high school, we had a v6 95' mustang. in wet asphalt, the damn thing, at all attempts, would only spin one tire = 1 way lsd
do the same on a gs and both will spin = 1.5 way
1 way, 1.5, and 2 way LSD. only 1 and 2 way have been discussed.
If the ramps are symmetrical, the LSD is 2 way. If they are saw toothed (i.e. one side of the ramp is vertical), the LSD is 1 way. If both sides are sloped, but are asymmetric, the LSD is 1.5 way.
i remember years ago, in high school, we had a v6 95' mustang. in wet asphalt, the damn thing, at all attempts, would only spin one tire = 1 way lsd
do the same on a gs and both will spin = 1.5 way
1 way LSD = only LSD effect on acceleration, none on deceleration
2 way LSD = full LSD effect on acceleration and on deceleration
1.5 way LSD = full LSD effect on acceleration, ~some~ on deceleration
Neither of those cars you listed have LSD's, they both have fully open differentials...
03-06-12, 05:11 AM
#51
I posted in the LS section how my (and many other) Lexus LS, GS and SCs seem to have Limited Slip Differentials (LSD's) even though none of these cars had one installed from the factory.
In answering the responses and reviewing our Open Differentials (OD's) in the factory repair manuals I can make the controversial although ACCURATE statement that over time the 1990-2004 stock OD's will slowly become actual LSD's. This is due to the internal parts slowly wearing into each other and creating more and more internal friction.
Further, in reading the manual it appears that it is likely that we could actually build the stock unit to be an LSD using stock parts. This seems hard to believe but the evidence is overwhelming.
When new the mentioned cars would spin ONLY one tire when doing a burnout. This is normal OD operation. An OD provides equal torque to both tires UNTIL one tire looses traction and then transfers up to 100% of the engine torque to the tire without traction. This is why one tire smokes.
LSD's are designed just like OD's except they have friction increasing parts that restrict the torque from overpowering one tire. This keeps equal torque going to each tire and is why LSD equipped cars smoke both tires when doing a burnout.
The LSD's friction increasing parts are designed to SLIP when cornering because the outside tire needs to rotate faster than the inside tire. So this SLIP allows the differential to do its work and allow a differential tire speed. This is the reason for the name Limited Slip.
Torsen differentials such as installed on Supra Turbos are not limited slip. They keep torque applied to both tires by an ingenius gearing system. They will also spin both tires in a burnout and will allow differential action but there is no slipping of friction materials so they are not limited slip even though they are commonly called LSD's.
My dragstrip times in my sig were done around 50k miles. At that time my car would easily smoke just the passenger side tire.
Also, the OD in my car is identical to the GS400 and GS430 through 2004. It would be interesting to have members test their cars traction and report back if they smoke one or both tires and how many miles they have on their car.
Here is my STOCK OD 1999 LS400 showing my LSD function due to increased internal friction with 170k miles. I am guessing somewhere around 100k this will become the norm for the cars mentioned. It is probably helpful NOT to change the diff fluid as specified.
In answering the responses and reviewing our Open Differentials (OD's) in the factory repair manuals I can make the controversial although ACCURATE statement that over time the 1990-2004 stock OD's will slowly become actual LSD's. This is due to the internal parts slowly wearing into each other and creating more and more internal friction.
Further, in reading the manual it appears that it is likely that we could actually build the stock unit to be an LSD using stock parts. This seems hard to believe but the evidence is overwhelming.
When new the mentioned cars would spin ONLY one tire when doing a burnout. This is normal OD operation. An OD provides equal torque to both tires UNTIL one tire looses traction and then transfers up to 100% of the engine torque to the tire without traction. This is why one tire smokes.
LSD's are designed just like OD's except they have friction increasing parts that restrict the torque from overpowering one tire. This keeps equal torque going to each tire and is why LSD equipped cars smoke both tires when doing a burnout.
The LSD's friction increasing parts are designed to SLIP when cornering because the outside tire needs to rotate faster than the inside tire. So this SLIP allows the differential to do its work and allow a differential tire speed. This is the reason for the name Limited Slip.
Torsen differentials such as installed on Supra Turbos are not limited slip. They keep torque applied to both tires by an ingenius gearing system. They will also spin both tires in a burnout and will allow differential action but there is no slipping of friction materials so they are not limited slip even though they are commonly called LSD's.
My dragstrip times in my sig were done around 50k miles. At that time my car would easily smoke just the passenger side tire.
Also, the OD in my car is identical to the GS400 and GS430 through 2004. It would be interesting to have members test their cars traction and report back if they smoke one or both tires and how many miles they have on their car.
Here is my STOCK OD 1999 LS400 showing my LSD function due to increased internal friction with 170k miles. I am guessing somewhere around 100k this will become the norm for the cars mentioned. It is probably helpful NOT to change the diff fluid as specified.
03-06-12, 05:55 AM
#52
I know this has been beat to death, but any open diff with equal traction on the tires will do a LSD like burnout.
With IRS rears that we have it is much easier, an open diff in a live axle wants to lift the right wheel and then do peg leg burnouts. IRS won't try to lift a tire (right) off the ground. So overall there is more traction with a IRS is improved.
With live axle cars you can put airbags in the right side (unless reverse rotation driveline as in circle track racing) and improve the right side psi from the tire to the ground and have near LSD like burnouts.
The REAL advantage in a LSD is the speed at which you can come out of a corner. A LSD will put the power to the INSIDE tire where an OPEN diff will put the power to the outside tire.
I went from 3.42's (open with traction control) to 3.08's (LSD) in my 94 Fleetwood and it was VERY noticeable the power in cornering.
With IRS rears that we have it is much easier, an open diff in a live axle wants to lift the right wheel and then do peg leg burnouts. IRS won't try to lift a tire (right) off the ground. So overall there is more traction with a IRS is improved.
With live axle cars you can put airbags in the right side (unless reverse rotation driveline as in circle track racing) and improve the right side psi from the tire to the ground and have near LSD like burnouts.
The REAL advantage in a LSD is the speed at which you can come out of a corner. A LSD will put the power to the INSIDE tire where an OPEN diff will put the power to the outside tire.
I went from 3.42's (open with traction control) to 3.08's (LSD) in my 94 Fleetwood and it was VERY noticeable the power in cornering.
01-11-18, 03:43 AM
#53
Pole Position
Id like to add something to a potentially old thread. Nor have I had the time to read the whole thing. Has anyone considered that we may in fact have a viscous lsd fitted? I say this because twice now Ive laid a thick black pair of railway tracks with my LS430 with the diff stone cold and thick fluid in the viscous clutch packs, causing it to lock under hard load. But warm that fluid up and the thing single pegs like a V6 Holden Commodore on a Friday night in Penrith. It also explains why my LS decided to chuck me right round exiting a roundabout one day in the wet with no VSC, the diff spun one and then decided to spin both and it was all over from there. Worn out viscous lsds have a tendency to be unpredictable like that, and I have like 140,000 odd miles on my car. I will add that the burnouts were done with some sticky Toyo 225 wide tyres and on the brakes, so I gave it every reason to peg leg
Thread
Thread Starter
Forum
Replies
Last Post
JBrady
LS - 1st and 2nd Gen (1990-2000)
40
12-26-20 11:05 AM
