Rear diff LSD question

[Dephective]

I have a very basic understanding of how the different types of differentials work, and I can see the evidence of ours in the form of two black rubber stripes left on the pavement when I hit the go pedal.

But, since I'm significantly lowered, I have to do the sideways entry to steep driveways, especially those with a gutter. When I do this, and one wheel is off the ground, the car just spins the loose tire, not the one with all the grip, causing me to be stationary until I every so slightly catch grip and fling forward. With a 1 way, the power should be applied to the wheel with all the traction, not sent to the wheel in the air, correct? Id really like to figure this out. TIA!

[aCab]

Originally Posted by Dephective

I have a very basic understanding of how the different types of differentials work, and I can see the evidence of ours in the form of two black rubber stripes left on the pavement when I hit the go pedal.

But, since I'm significantly lowered, I have to do the sideways entry to steep driveways, especially those with a gutter. When I do this, and one wheel is off the ground, the car just spins the loose tire, not the one with all the grip, causing me to be stationary until I every so slightly catch grip and fling forward. With a 1 way, the power should be applied to the wheel with all the traction, not sent to the wheel in the air, correct? Id really like to figure this out. TIA!

A Torsen diff like our cars have factory acts as an open diff when one wheel is in the air. A clutch type (rather than torsen) does not have this issue.

[ZDan]

Yes, the torsen opens up with one wheel off the ground.
The torsen T2R does have some breakaway torque, but not the "regular" T2.

With a clutch-type 1-way (or 1.5- or 2-way), how much it can deliver to the side with grip depends on the preload/breakaway torque in the diff.

My personal preference for clutch-type diffs is to have the kind with ramps that increases clamping load with torque, and to have minimal breakaway torque.

I don't think I'd go to the time/money/hassle of a new diff for this particular problem, maybe you can just approach with a bit more speed to carry you over the dip?

[aCab]

You may solve the problem disconnecting your rear sway bar as well. If you're just driving the car like a normal person, having the read sway disconnected shouldn't be much of an issue. These cars have so little suspension droop its not even funny.

[Dephective]

Lol no go on the increase in speed. It's not a huge issue, was just wondering the root cause is all. I'm waiting to see if it's worth it to wait for the '15 to see if it's worth it before I do something so drastic as a new diff. I had a clutch type in my FD so I never had this problem, and my MS6 was AWD and also clutch type. my first Torsen!

[RallySport Direct]

You should be able to use the E-brake to help keep load on both side of the diff, which should give the tire on the ground some power. I have never tried this personally, but in my head it makes sense haha.

Also I have a very steep driveway and with traction control on, when the wheel lifts, I swear I can hear/feel the brakes being applied and it carries me forward up my driveway.

Hope this helps.
Thanks,
Rick

[mike the snake]

Torsen (Torque Sensing) diffs work off a gear ratio, and apply torque to the non-spinning wheel at a ratio of torque sensed from the spinning wheel's resistance.

So, if one wheel is spinning in the mud, the diff senses how much torque is applied to spin that wheel, and applies torque to the non spinning wheel at whatever ratio the diff happens to be, like 4 to 1 or 5 to 1.

If the spinning wheel is in the air, then no torque is being applied to spin that wheel, so no torque gets applied to the non-spinning wheel.

Regular LSD's need to be serviced and rebuilt at some point, whereas Torsen diffs work off of gears and resistance and do not need rebuilding from what I have gathered.

The two diffs apply their LSD action differently in turns. From what I've read, Torsen diffs work well, and seem to be fine for street applications, whereas regular LSD diffs are preferred for track use.

[topazsparrow]

Originally Posted by aCab

You may solve the problem disconnecting your rear sway bar as well. If you're just driving the car like a normal person, having the read sway disconnected shouldn't be much of an issue. These cars have so little suspension droop its not even funny.

Riding the brake will work well also and won't require modifying the handling characteristics of the car.

[Dephective]

I'll try the E-brake method and see if that works out for me. Theoretically, it should like Rick said.

[ZDan]

aside: It always amuses me when people talk about the *rear* diff on these cars, S2000, 240SX, RX-7, 240Zs, virtually every car I've owned.

Strictly rwd, what other diff *is* there?!

[rice_classic]

What? Your 86 doesn't have a front diff too? Dude, you need to complain to the dealership, you got robbed!

So now, with that covered, I'm off to replaced the power steering fluid on my FRS.

[topazsparrow]

Originally Posted by rice_classic

What? Your 86 doesn't have a front diff too? Dude, you need to complain to the dealership, you got robbed!

So now, with that covered, I'm off to replaced the power steering fluid on my FRS.

Whats the deal with the PS fluid?

[Nightbringer]

Originally Posted by topazsparrow

Whats the deal with the PS fluid?

He's joking. It's electric steering... just like the front diff. You've been trolled, sir.

[anthros]

Whoosh.

The joke here is that just as the 86 twins don't have a front differential, neither do they have power steering fluid. The PS on these cars is electric, not hydraulic.

Cheers,

Jason