Very loose rear end (Handling)

[johan]

Originally Posted by Gforce

Helical and Torsen are not the same. Don't you ever get tired of constantly being wrong?

This is true. @Tcoat - that Wikipedia link you posted is wrong.

None of the FWD Honda vehicles in that list have a Torsen LSD, they have a Helical LSD.

I've owned 2 of the Si's you provided the owner's manual excerpt from about the LSD. Honda marketing, owners manuals and service manuals all refer to it as a Helical LSD, not a Torsen.

The only Honda vehicle that I know of that shipped with a Torsen is the S2000, which I've also owned, and was very clearly marketed as coming with a Torsen. If a Torsen is used, it is always part of marketing and clearly denoted anywhere it can be.

Note the following:

Si sales card:
https://image.slidesharecdn.com/2011...?cb=1306109531

I can't find the same thing (something OEM looking) for an S2000 atm, but if I had to prove the point, I could go take a photo of the limited edition S2000 book I have hidden away in the office.

Torsen and Helical are -similar- so similar that people lump them together. But similar is not equal.

[Tcoat]

Originally Posted by johan

This is true. @Tcoat - that Wikipedia link you posted is wrong.

None of the FWD Honda vehicles in that list have a Torsen LSD, they have a Helical LSD.

I've owned 2 of the Si's you provided the owner's manual excerpt from about the LSD. Honda marketing, owners manuals and service manuals all refer to it as a Helical LSD, not a Torsen.

The only Honda vehicle that I know of that shipped with a Torsen is the S2000, which I've also owned, and was very clearly marketed as coming with a Torsen. If a Torsen is used, it is always part of marketing and clearly denoted anywhere it can be.

Note the following:

Si sales card:
https://image.slidesharecdn.com/2011...?cb=1306109531

I can't find the same thing (something OEM looking) for an S2000 atm, but if I had to prove the point, I could go take a photo of the limited edition S2000 book I have hidden away in the office.

Torsen and Helical are -similar- so similar that people lump them together. But similar is not equal.

Thanks. My research was obviously faulty and a response beyond "No you are stupid" is greatly appreciated. My search for what cars have Torsen resulted in that list and I had no reason to doubt it.

[Tcoat]

Originally Posted by Gforce

Helical and Torsen are not the same. Don't you ever get tired of constantly being wrong?

No I don't mind being wrong occasionally. Everybody is wrong occasionally. If my research materials are flawed then shame on me for not digging deeper to confirm them. I had no reason to doubt the source.
I can man up and say I was wrong unlike some that when faced with information that prove them incorrect they just make statements such as "we will agree to disagree".

[ZDan]

The Torsen itself is a helical diff. Minor differences allow Eaton, Quaife, and others to make helical diffs that are functionally equivalent to the Torsen T2, but are not "Torsen".

[Gforce]

Originally Posted by ZDan

C'mon, if it acts as an open diff at all times, it wouldn't do anything to transfer torque.


So, first you say that the Torsen does not lock, then you say that it "locks" completely? WTF?!

The Torsen does lock up PROGRESSIVELY with applied input torque. Also, the clutch type locks up progressively with applied input torque.

Of course with different wheel sizes there is constant slip, and the faster you drive the greater the torque, and consequently the greater the heat and wear due to friction, which is the mechanism by which the Torsen works in the first place...

I respect your posts a great deal. I find them useful and have no doubt others do also.

I do not wish to continue our apparent disagreement. I'm fairly sure we would agree were we to have a working model of each of a Torsen and a clutch type diff on a workbench in front of us and we were discussing them over a beer. Two beers each and that would make that discussion tricky.

I recognize that my descriptions of how the Torsen differs from other differential types are imperfect. Nevertheless, I find them useful to me. I hope those who read my descriptions and do not find them useful enjoy driving their BRZ as much as I do mine.

[Tcoat]

Originally Posted by ZDan

The Torsen itself is a helical diff. Minor differences allow Eaton, Quaife, and others to make helical diffs that are functionally equivalent to the Torsen T2, but are not "Torsen".

In your opinion are they close enough that when the Si owner's manual says "Do not use the spare on the drive wheel or it may cause damage" to still apply?

[ZDan]

Originally Posted by Gforce

I'm fairly sure we would agree were we to have a working model of each of a Torsen and a clutch type diff on a workbench in front of us and we were discussing them over a beer.

Having working models to play with would be helpful...

[ZDan]

Originally Posted by Tcoat

In your opinion are they close enough that when the Si owner's manual says "Do not use the spare on the drive wheel or it may cause damage" to still apply?

In my opinion, yeah, I would have exactly the same concern about heat and wear with any helix-type, be it "Torsen" or other, being continuously operated with different output speeds.

I can't say at exactly what speed or what distance heat or wear would become a serious problem, but whatever type of limited slip I would never run different diameter tires on the drive end of the car.

[Tcoat]

Originally Posted by ZDan

In my opinion, yeah, I would have exactly the same concern about heat and wear with any helix-type, be it "Torsen" or other, being continuously operated with different output speeds.

I can't say at exactly what speed or what distance heat or wear would become a serious problem, but whatever type of limited slip I would never run different diameter tires on the drive end of the car.

Those have been my thoughts throughout this ordeal. Nothing saying it would happen quickly or even at all but the risk is higher than I would find acceptable.

[Gforce]

Originally Posted by ZDan

In my opinion, yeah, I would have exactly the same concern about heat and wear with any helix-type, be it "Torsen" or other, being continuously operated with different output speeds.

I can't say at exactly what speed or what distance heat or wear would become a serious problem, but whatever type of limited slip I would never run different diameter tires on the drive end of the car.

I would never do this regardless of how my car was geared up.

The most amazing thing about this discussion is the absence of discussion about why you should never run a space saver spare of any size anywhere for longer than it might take to get from where you had your flat to a tire repair shop.

Space saver spares are just barely safe for emergency use only. Many, many people just do not understand this important fact. Any time we can remind people about the safety aspects, we ought to.

Space saver wheels are ugly for very good reasons. Transmission or differential wear is not among them. Seriously. I think the limits of those tires are 50 miles at no more than 50 mph.

[Gforce]

Originally Posted by ZDan

Having working models to play with would be helpful...

When I was just a teenager I attended an automotive technician's open house at my local technical college. One exhibit was a cutaway open differential. Two minutes of manipulation by hand was superior to any length of text which might have explained how it worked.

Now lego makes one. Not a Torsen though.

[ZDan]

I might have to get that Lego one. I have a running argument with my local bartender who insists that an open differential is "1-wheel drive". He doesn't believe that it actually provides equal torque to both rear wheels, I can't convince him!

[Tcoat]

Originally Posted by ZDan

I might have to get that Lego one. I have a running argument with my local bartender who insists that an open differential is "1-wheel drive". He doesn't believe that it actually provides equal torque to both rear wheels, I can't convince him!

He should have been with me when the diff on my 64 Impala locked up on me at 70MPH. He would have come away from it knowing that it does indeed provide torque (or in that case very suddenly stop providing torque) to both back wheels.
Both hubcaps shot straight out and took off down the road. The one that cleared the wheel well was never seen again and the one that clipped it went airborne before rolling.
A couple of weeks ago I was cleaning the basement and actually found the cap. You will notice it is no longer round. Why the hell I have hauled it around with me for 30 years I do not know.

[navanodd]

Originally Posted by Gforce

When I was just a teenager I attended an automotive technician's open house at my local technical college. One exhibit was a cutaway open differential. Two minutes of manipulation by hand was superior to any length of text which might have explained how it worked.

Now lego makes one. Not a Torsen though.

We had a Lego Torsen at my school, really helped to understand how it worked.