LSD? To Have Or Not To Have

[Larry Andrews]

One thing I haven't seen mentioned is to evaluate the caster setting. It sounds like you've got some sort of suspension binding that's causing issues. But if you're having the same excessive rear body roll problem on both sides - the first place I'd look at is the caster.

Miatae have a good adjustment range - take advantage of it.

[Mako Koiwai]

Isn't Camber typically more important the Caster ... and so I have the Camber bolts maxed out. One uses the same camber bolts to adjust both Camber and Caster on the Miata. I'm not sure what Max. Camber settings do to the the Caster on this car.

[Craig Naylor]

On topic, different question

Posted this hours ago, but it's gone now... oh well, I'll try again

From reviewing Miata.net I have some questions about STS2 and the Miata LSD

'90-'93 Miatas offer a "viscious LSD" as an option on all version except '93 Base
'94-'95 Miatas offer a "torsen LSD type 1" as standard on all but the base models with 5spds
'96-'97 Miatas offer a "torsen LSD Type 2" as standard on all but base & '97 touring models with 5spds

'90-'97 Auto's not available with LSD's of any type.

STS2 rules state "only original equipment viscous limited-slip differentials are legal in STS2" However it specifically lists '90-'97 Miatas as examples of cars included in the class.

So ONLY '94-'97 Base models, and Auto's eligible for STS2?

Also whats the difference between the Type 1 and Type 2 torsen LSD's.

Or am I missing something in the translation. I ask, because I know I have see Hard topped '94-'97 Miatas run in STS2, but base models did not offer that as an option...or were the cars Auto's.

Thanks in advance for any clarification.

[Mako Koiwai]

Checking the Torsen web site ... could it be that the type 2 is the Torsen model T-2R ... which combats the fact that if you have a wheel in the air, the Torsen LSD can't do anything ... by preloading the system?

http://www.torsen.com/general/general_faq.htm

What happens when I have a wheel in the air?
As mentioned above, the Torsen differential is a torque multiplier. The Torsen requires some type of resistance or friction in the system to function properly. A wheel in the air provides zero torque or friction on the system and as the Torsen multiplies the available torque, zero, by its TBR, the end result is still zero. In response to this, we developed the Torsen T-2R with pre-load to combat those wheel in the air situations.

[Mako Koiwai]

Maybe not ... there is a Type 2 and then the Type 2R

Torsen differential products cover a wide range of torque biases and applications in the front, center, and rear of a vehicle!

T-1 (Type A)
This is the original differential that was introduced in the AM General HMMWV (Hummer�) and the Audi Quattro which has seen considerable growth in other worldwide applications. This is our crossed axis helical (Invex™) higher torque bias differential.

T-2 (Type B)
This differential is only a few years old and adds a wide range of torque bias coverage for the Toyoda-Koki Automotive Torsen North America, Inc. product line. This type of differential is referred to as our parallel axis helical (Equvex�) differential which was designed to accommodate Ford and GM C-Clip applications.

T-2R (RaceMaster)
The T-2R is a higher bias T-2 torque sensing parallel axis differential designed for the more performance minded driver. The higher bias found in the T-2R, like the T-1, allows the transfer of more available torque to the wheel that can better use it.

T-3 (Type C)
The newest differential style of the Torsen product line. The T-3 is currently offered in a single or Twin Differential configuration (The twin differential has an open differential surrounded by a Torsen differential!). This versatile unit is ideally suited for center applications and is designed for those hard to package all wheel drive systems. The design of the Type C allows for a torque split other than 50:50 with a majority of available torque designed to go to either the front or rear axle.

[Steve Ekstrand]

Checking the Torsen web site ... could it be that the type 2 is the Torsen model T-2R ..

No.

[Mako Koiwai]

As I said ...

Maybe not ... there is a Type 2 and then the Type 2R

[Bob Beamesderfer]

On topic, different question

Posted this hours ago, but it's gone now... oh well, I'll try again

From reviewing Miata.net I have some questions about STS2 and the Miata LSD

'90-'93 Miatas offer a "viscious LSD" as an option on all version except '93 Base
'94-'95 Miatas offer a "torsen LSD type 1" as standard on all but the base models with 5spds
'96-'97 Miatas offer a "torsen LSD Type 2" as standard on all but base & '97 touring models with 5spds

'90-'97 Auto's not available with LSD's of any type.

STS2 rules state "only original equipment viscous limited-slip differentials are legal in STS2" However it specifically lists '90-'97 Miatas as examples of cars included in the class.

So ONLY '94-'97 Base models, and Auto's eligible for STS2?

Also whats the difference between the Type 1 and Type 2 torsen LSD's.

Or am I missing something in the translation. I ask, because I know I have see Hard topped '94-'97 Miatas run in STS2, but base models did not offer that as an option...or were the cars Auto's.

Thanks in advance for any clarification.

Hardtop was available as a separate option with any model, 90-97, although not all colors all years. [Also came with M edition, 10AE, 91 BRG]. Plus, a lot of hardtops have changed hands over the years.

[Jason Isley BS RX8]

Checking the Torsen web site ... could it be that the type 2 is the Torsen model T-2R ... which combats the fact that if you have a wheel in the air, the Torsen LSD can't do anything ... by preloading the system?

If you had one you would not be legal for stock, they were not OE on a Miata. All this time you have wasted you could have already pulled the diff and looked at it.

[Mako Koiwai]

Obviously the T2-R would not be legal in my car. It does appear to be part of the Shelby Mustang package.

Me pull the Diff ... I don't think so. That would just be making work for my local Mazda shop to fix it. It might come down to having them check it!

[Bob Beamesderfer]

Obviously the T2-R would not be legal in my car. It does appear to be part of the Shelby Mustang package.

Me pull the Diff ... I don't think so. That would just be making work for my local Mazda shop to fix it. It might come down to having them check it!

You took the shocks out, right? Pulling one of the axles isn't any harder than that.

[Jason Isley BS RX8]

Obviously the T2-R would not be legal in my car. It does appear to be part of the Shelby Mustang package.

Me pull the Diff ... I don't think so. That would just be making work for my local Mazda shop to fix it. It might come down to having them check it!

I am not saying pull the guts out of the case, leave that for a pro, but getting the rear out of the car to inspect is easy.

[Mako Koiwai]

Just talked to a techie at the TORSEN Traction company. First off, their web site needs up dating. The T-2R LSD is only in the Mustang FR-500S ... a spec racing model, not street legal ... and not in the Shelby.

So, even the Torsen company says that really you can only tell by pulling an axle stub, if you aren't going to open the case.

From my description of what I saw thru the filler hole, he thought I might have an LSD.

Try to tell by launching on different surfaces doesn't work either because of lots of variables. Independent suspension negates certain things.

[Mike Simanyi]

From reviewing Miata.net I have some questions about STS2 and the Miata LSD

'90-'93 Miatas offer a "viscious [sic] LSD" as an option on all version except '93 Base
'94-'95 Miatas offer a "torsen LSD type 1" as standard on all but the base models with 5spds
'96-'97 Miatas offer a "torsen LSD Type 2" as standard on all but base & '97 touring models with 5spds

'90-'97 Auto's not available with LSD's of any type.

STS2 rules state "only original equipment viscous limited-slip differentials are legal in STS2" However it specifically lists '90-'97 Miatas as examples of cars included in the class.

Craig, you can run a '94+ Miata in STS2 by applying the Stock rules for option packages. You just have to run a Miata that doesn't have the torsen diff.

Does that answer your question?

Mike

[Mako Koiwai]

FINALLY ... found some time between message boards and emails to pull an Axle! (Thanks for the advise Bill and Bob)

We DO have a LSD.

If you see THIS BAR going across, you have an Open Differential:

opendiffbar_small.jpg (4.08 KiB) Viewed 5996 times

But we don't have that bar, ie. LSD

LSD-4-SureSML.jpg (85.42 KiB) Viewed 5996 times