1LE TORSEN same axle fluid as clutch diff? Need friction modifier?

[Ragnar]

[QUOTE=NinoSS;8649181]Forum bickering... Always entertaining... [/QUOTE

[Mark T]

The 1LE does have a unique set of axles in the rear. (where they should be lol).

But they are larger than the standard SS and not as beefy as the ZL1. Dont know about the Z28 though.

[B73]

Going to have to admit to learning something new as well, I honestly thought my 1LE had a torsen diff in it too. Was sure I had read it somewhere before buying it, not disputing, just always thought it was too

[X25]

I think mine is one of the few 1LEs in the country with open diff, well at least it operates like that.

The clutch type diff on SS cars works admirably, but mine is no longer locking. When I put one of my rear tires up in the air, I no longer have any forward thrust. In a way, it 'acts like a Torsen' now

Instead of trying a fluid with less friction modifier, etc., I just purchased an Eaton helical (Torsen type) unit. Torsen is not the best type of diff for track use, but at least it does not wear out, so it provides consistent performance. Do you guys know how it compares to what comes with the Z/28? What is the max torque multiplication of the Z/28 unit? Is it preloaded by any chance?

Looking forward to trying it out at the track, but it's usually very hard to understand the difference, since you might attribute that little improvement in turn in to better tires or colder ambient; who knows.

[Dropspeed]

Originally Posted by X25

I think mine is one of the few 1LEs in the country with open diff, well at least it operates like that.

The clutch type diff on SS cars works admirably, but mine is no longer locking. When I put one of my rear tires up in the air, I no longer have any forward thrust. In a way, it 'acts like a Torsen' now

Instead of trying a fluid with less friction modifier, etc., I just purchased an Eaton helical (Torsen type) unit. Torsen is not the best type of diff for track use, but at least it does not wear out, so it provides consistent performance. Do you guys know how it compares to what comes with the Z/28? What is the max torque multiplication of the Z/28 unit? Is it preloaded by any chance?

Looking forward to trying it out at the track, but it's usually very hard to understand the difference, since you might attribute that little improvement in turn in to better tires or colder ambient; who knows.

If you look at my build thread in in my sig you will see I mentioned the diff opening up when the car was brand new in 2013. As it got some miles on it is seemed to get better........Until I had the diff fluid changed at the dealer about a month ago. I immediately noticed the inside tire would spin on the street in a spirited corner. On track this past weekend I confirmed it was an issue (see photos). I had to "pedal" it in corners to get power down. For scientific purpose I stayed in it just to lay this "peg-leg" single track as proof positive.

My theory is that the friction modifier is the issue and broke down overtime when the car was new. With the fresh fluid and modifier the problem came right back. A: I can drain the fluid and not install friction modifier. B: Install the Eaton Tru-Trac (Helical) diff, which has been in the plans for a while....

Matt

[GONIF]

What type is best for the drag strip or street is not always best for road racing. GM had to end up with the best over all compromise for a street driven vehicle . Here is an interesting and very informative read on the subject .
http://www.google.com/url?sa=t&rct=j...6bLnadyElwIQ2w

[White_SS/RS]

My diff always opens up on track as well. I also plan on going with a helical diff when funding allows.

[GONIF]

For those who want to know what a Torsen is http://www.google.com/url?sa=t&rct=j...03388427,d.cGU

[X25]

Originally Posted by Dropspeed

If you look at my build thread in in my sig you will see I mentioned the diff opening up when the car was brand new in 2013. As it got some miles on it is seemed to get better........Until I had the diff fluid changed at the dealer about a month ago. I immediately noticed the inside tire would spin on the street in a spirited corner. On track this past weekend I confirmed it was an issue (see photos). I had to "pedal" it in corners to get power down. For scientific purpose I stayed in it just to lay this "peg-leg" single track as proof positive.

My theory is that the friction modifier is the issue and broke down overtime when the car was new. With the fresh fluid and modifier the problem came right back. A: I can drain the fluid and not install friction modifier. B: Install the Eaton Tru-Trac (Helical) diff, which has been in the plans for a while....

Matt

Originally Posted by White_SS/RS

My diff always opens up on track as well. I also plan on going with a helical diff when funding allows.

In a way, I'm glad to see that I'm not being paranoid. The funny thing is, I changed the fluid a few months back with Amsoil diff fluid, so it doesn't take much to brake down the fluid.

It's promising that it started working again once you changed the fluid, but it's clear that we need a better solution than changing nasty diff fluid every other track day.

I hope to get the Eaton helical unit + Z/28 cooler installed this Friday. If you don't want to go all the way, perhaps getting the cooler installed first might also be a major mitigation since I'm sure overheating the fluid has a lot to do with fluid breaking down.

[X25]

Originally Posted by GONIF

What type is best for the drag strip or street is not always best for road racing. GM had to end up with the best over all compromise for a street driven vehicle . Here is an interesting and very informative read on the subject .
http://www.google.com/url?sa=t&rct=j...6bLnadyElwIQ2w

Thanks for sharing, that was a better read than I thought! I like the comments from the racing point of view.

[White_SS/RS]

I'm sure most of the fluid break down is from the diff opening up and slipping like crazy. That's a lot of oil shearing and friction that would generate lots of heat. I suppose the z28 cooler would help but probably just best to eliminate the slip all together. I know I lose a lot of time where I could be back on the throttle because my diff does open up on those tighter corners. Not sure I will run the cooler at first though.

[X25]

Originally Posted by White_SS/RS

I'm sure most of the fluid break down is from the diff opening up and slipping like crazy. That's a lot of oil shearing and friction that would generate lots of heat. I suppose the z28 cooler would help but probably just best to eliminate the slip all together. I know I lose a lot of time where I could be back on the throttle because my diff does open up on those tighter corners. Not sure I will run the cooler at first though.

Makes sense. I'll hopefully have both installed by end of this week. I might try it on October 10th track day. Hopefully this concludes my car build for the time being... Until I get fed up with Recaros

[Dropspeed]

Originally Posted by X25

In a way, I'm glad to see that I'm not being paranoid. The funny thing is, I changed the fluid a few months back with Amsoil diff fluid, so it doesn't take much to brake down the fluid.

It's promising that it started working again once you changed the fluid, but it's clear that we need a better solution than changing nasty diff fluid every other track day.

I hope to get the Eaton helical unit + Z/28 cooler installed this Friday. If you don't want to go all the way, perhaps getting the cooler installed first might also be a major mitigation since I'm sure overheating the fluid has a lot to do with fluid breaking down.

To clarify. The diff worked better with dirty fluid. As soon as it was changed to new fluid with new friction modifier it started to open up again.

[X25]

Originally Posted by Dropspeed

To clarify. The diff worked better with dirty fluid. As soon as it was changed to new fluid with new friction modifier it started to open up again.

Hmm in my case it's the other way around. I think my fluid is toast.

If you won't change the diff in a while, you guys should also consider Redline 75W-90 NS. Since it has no friction modifier, it will hook up the clutches, no problem. You can then add a little bit of fiction modifier to tune it to your liking. I thought about testing this out first since I already had the fluid for the Quaiffe diff I have for the Miata, but the Eaton unit was too cheap to pass on!