How important is an LSD on this car?

[Allch Chcar]

Originally Posted by ToyotaObsession

Well you don't want a locked up rear end on ice either unless you plan on turning very, very slowly.

You don't want a Locked up Rear on anything that will see turns over 10 MPH.

It works great when you are climbing over rocks at .5 MPH but when turning at speed you have to let the wheels spin at different speeds.

The slower you go with a locked axle on asphalt the harder it is to turn. The differential I mentioned allows for easy on/off from regular LSD(clutch pack) operation to full lock. Another nice option for the auburn units is that they can be set to different locking %. At least from memory I think they do I'll have to reread it again...

For low traction situations with locked/welded/solid axles the slippage for turning comes from the lean of the vehicle in turns and the low traction allows the inside wheels to slip as it loses traction and the power goes to the wheel with more traction not less. I'm sure it could be explained better, needless to say people have DD cars with locked axles, it's just not ideal.

Locked axles, welded axles, or solid axles are generally undesirable for street driving. Welded axles are used on certain race cars and not just for drag racing. Drifting or even certain road racing are other places you might find a locked up axle. If anything imagine go-karts, solid axles but that's not the best example since go-karts aren't the same as cars. I know it's easier for a small car with a short wheelbase to benefit from a locked axle than a heavier and softer sedan .

[Ryephile]

Originally Posted by enc0re

I'm hoping we'll get a torque sensing rather than locking differential.

Any particular reason? You do realize that a good clutch-pack LSD offers greater car control and quicker lap times versus an ATB.

[enc0re]

First of all, I realize locking is the way to go on the track. However torque sensing doesn't need maintenance, gives more assistance on snow/ice (as long as you know to brake while hitting the gas), and are much easier to master.

If they put a locking LSD on a production car it would have to be 1-way or people will kill themselves when it locks under braking in a corner. At that point, I'd rather have ATB.

Reasonable people may disagree with my assessment. At the end of the day, any LSD is better than open.

[Dimman]

Originally Posted by enc0re

First of all, I realize locking is the way to go on the track. However torque sensing doesn't need maintenance, gives more assistance on snow/ice (as long as you know to brake while hitting the gas), and are much easier to master.

If they put a locking LSD on a production car it would have to be 1-way or people will kill themselves when it locks under braking in a corner. At that point, I'd rather have ATB.

Reasonable people may disagree with my assessment. At the end of the day, any LSD is better than open.

Clutchpack is the way to go (also pretty common for OEM). Torsens are sensitive to abuse.

[OldSkoolToys]

Its Toyota, and it's an entry-level low price sports coupe. Clutchpack is what it'll be.

[enc0re]

Civic Si and Mazdaspeed3 use torque sensing. There's hope.

[OldSkoolToys]

Originally Posted by enc0re

Civic Si and Mazdaspeed3 use torque sensing. There's hope.

And Nissan uses Viscous...so I guess you could say there's a chance for viscous?

I realize the IS-F comes with a Torsen diff, but clutch style fits this car's personality and characteristics.

Edit: Just realized you listed off two FF cars talking about Torsen. Yes, there's a reason they use those LSD's...

Honestly, I want to see Clutch type, I could live with Torsen(begrudgingly)...but please, no ABS "LSD" non-sense. Keep that garbage elsewhere.

[Allch Chcar]

Originally Posted by OldSkoolToys

And Nissan uses Viscous...so I guess you could say there's a chance for viscous?

I realize the IS-F comes with a Torsen diff, but clutch style fits this car's personality and characteristics.

Edit: Just realized you listed off two FF cars talking about Torsen. Yes, there's a reason they use those LSD's...

Honestly, I want to see Clutch type, I could live with Torsen(begrudgingly)...but please, no ABS "LSD" non-sense. Keep that garbage elsewhere.

I believe Mazda tends to go with Torsen even on their RWD cars.

I'd take clutch packs, it's not like they're expensive to replace if you DIY. Viscous is the one that needs silicone in the differential fluid right?

[OldSkoolToys]

Originally Posted by Allch Chcar

I believe Mazda tends to go with Torsen even on their RWD cars.

I'd take clutch packs, it's not like they're expensive to replace if you DIY. Viscous is the one that needs silicone in the differential fluid right?

Thats the reason I want clutch packs. In the future, rebuild kits are many times cheaper than an entirely new LSD, and relatively easy to DIY. Even if you don't DIY, it would be cheaper than buying a new LSD and then having someone replace it, instead of buying the rebuild kit and doing the same.

Yes, Viscous uses fluid. The bad thing about viscous is that the 'locking fluid' is in a separate chamber from the actual gear oil, so you can't change the fluid, ever. You have to replace the unit entirely...and if you do that, you might as well just get a real LSD.

[Ryephile]

Originally Posted by enc0re

Civic Si and Mazdaspeed3 use torque sensing. There's hope.

That's because they're front drive, and ATB's are better suited for front drive applications.

Here's a quick guide...

Front Drive:
*Open Diff: one-wheel peel, demands good suspension design
*Clutch-pack LSD: Better than nothing, easy to burn up if abused
*ATB LSD: Ideal for lap times but adds torque steer

Rear Drive:
*Open Diff: one-wheel peel, demands good driving skills
*ATB LSD: Better than nothing, still worthless on ice
*Clutch-pack LSD: Ideal for lap times

In both applications, the more clutch discs the better, however in a front drive you do not want 100% lock like you may in a rear drive. The more lock you opt for in a rear drive, the more drift or drag biased the diff is.

I don't have enough experience with viscous LSD's to be able to accurately place them within the above hierarchy. I would expect them to be mid-pack or slightly better than an open-diff in both applications.

[ToyotaObsession]

Originally Posted by OldSkoolToys

Yes, Viscous uses fluid. The bad thing about viscous is that the 'locking fluid' is in a separate chamber from the actual gear oil, so you can't change the fluid, ever. You have to replace the unit entirely...and if you do that, you might as well just get a real LSD.

Where in the world did you hear that??

I was under the impression that what friction modifiers are for. Turns the Gear oil into that thick snotty crap.

How would they keep the "locking fluid" in a separate chamber?

[Allch Chcar]

Originally Posted by OldSkoolToys

Thats the reason I want clutch packs. In the future, rebuild kits are many times cheaper than an entirely new LSD, and relatively easy to DIY. Even if you don't DIY, it would be cheaper than buying a new LSD and then having someone replace it, instead of buying the rebuild kit and doing the same.

Yes, Viscous uses fluid. The bad thing about viscous is that the 'locking fluid' is in a separate chamber from the actual gear oil, so you can't change the fluid, ever. You have to replace the unit entirely...and if you do that, you might as well just get a real LSD.

I've never heard of that . I've always read that you mix the silicone with the differential gear oil. And it has to be a certain % or it doesn't work or it locks up too much.

[OldSkoolToys]

I was speaking from first hand knowledge on S13 LSD's, where friends were basically forced to buy a new unit when the silicone fluid lost its viscosity. They couldn't change it, only replace the unit. That's all I know of Viscous LSD's...maybe they've changed since then? Wouldn't be surprised.

http://auto.howstuffworks.com/differential5.htm

The viscous coupling has two sets of plates inside a sealed housing that is

The housing is completely sealed off from the rest of the differential, as the sealed housing is where the LSD magic happens in a VLSD. I've never heard of anyone actually changing the fluid inside that chamber. The other part is where the regular gear oil is, doing what gear oil does in any Diff, keeping shit lubricated and cool.

Basically the most common thing for drifters on a budget is to find another VLSD from another 240/300zx in a local yard and replace their worn unit with it. Otherwise, you find a -real- LSD that'll lock regardless of whats going on.

"Snotty" thick stuff? I know I have to use LSD additive in my rear-end (even though the clutches are shot I still do it, rofl). But thats because my diff is clutch style.

[ToyotaObsession]

Originally Posted by OldSkoolToys

"Snotty" thick stuff? I know I have to use LSD additive in my rear-end (even though the clutches are shot I still do it, rofl). But thats because my diff is clutch style.

That's what a VLSD is. It's a very thick fluid that allows a little bit of slippage, but once starts to turn too much the fluid starts to act like glue to transfer more torque to it.

Very inefficient as it's easy to overcome the fluid.