helical vs. 2-way LSD?

[r34 gtr]

ryan, you should be able to help me out a whole lot with this. ive got a 300zx TT vlsd in my garage but cannot find the correct output shafts or a pair of z32TT axles for anything less than a fortune. its been about a year and i want a friggin lsd in my car already! my dilemma is that im not sure which type would better suit my needs. i would like to be able to slide the car around if i felt so inclined, but i dont want it to be locking up every time i pull into my driveway or something. i do significantly more tearing a$s down/up mountain roads than i do sliding the car, so i was thinking a helical unit might be more appropriate. seeing as i can find both for about $600 and its on my parents' wallet (w00t! birthday/christmas owns!!) i want to make sure im gonna get the right one.

on a side note, my car is leaking a large amount of oil from the back of the engine. im not sure exactly where its coming from but it has managed to coat the firewall, o2 sensor, steering shaft, steering rack and transmission in a thick layer of oil. ive had enough so im pulling the engine next week. ive also got to re-do the oil return line for the turbo (its rubbing against the steering rack) so it doesnt get a hole in it. any idea what could be causing it to leak so badly? other than the infamous rear main seal? i used all new OEM gaskets for the whole engine only 6 months ago, so it shouldnt be leaking but this is MY car we're talking about so anything is possible. i was thinking of dropping in some forged slugs at the same time but dont know if its even remotely necessary. let me know what you think, and sorry about the long post!

- Tim

[c-rad]

ryan, you should be able to help me out a whole lot with this. ive got a 300zx TT vlsd in my garage but cannot find the correct output shafts or a pair of z32TT axles for anything less than a fortune. its been about a year and i want a friggin lsd in my car already! my dilemma is that im not sure which type would better suit my needs.

- Tim

First off, the Z32 TT LSD is an R230V. It's physically too big to fit. Second, even if it were, the axles are too long. If you were to use a Z32 NON-turbo LSD, you could get the axles from a J30 and that WOULD work.

That d!ck mx*83 whatever on ebay sells the S15 diffs with BRAND new output shafts for $679. And they are the 6-bolt output shafts too so it bolts right in. We just installed one in my friends S14 and it was pretty simple.

As for 2-ways, some people claim they are a little dangerous when decellerating in the rain, but others say they have no problem. I've never driven with a 2-way, so I can't comment.

[sdtouge]

2way:)

[slownslurious]

helical for grip in the dry, 2 way clutch for drifting/rally, 1.5 way clutch for decent all around use, 1 way clutch for drag.

helical isn't a true lsd, they can get unstable in the wet or in the snow.

2 way sucks on wet roads, lots of guys here in town have been spinning out with welded diffs in the wet lately, several totalled cars...

[float_6969]

helical isn't a true lsd, they can get unstable in the wet or in the snow.

That's the most ridiculous statement I've ever heard. If a helical isn't a Limited Slip, then WHAT IS a limited slip by YOUR definition? If you don't like the way a helical acts in the wet or snow, set the ebrake a click or 2. The only reason they CAN stop functioning on the wet or snow is because they need some traction to work. They sense the amount of torque going to the wheels, if one wheel has less ability to hold torque than the other, than it transferes the torque to the wheel with the ability to hold more. The only time that is a problem is if you have ZERO traction. The only happens when you've one one wheel in the air, or in the wet or snow, and aren't using proper tires.

But in comparison to a 2way in bad weather, I'd still take a helical. At least when I helical isn't working, it just acts like an open diff. Kind of a pain, but you're not having problems controlling the rear end either. A 1.5way is better, but I think they're getting hard to actually get a hold of. A lot of manufacturers will still list it as available, but you can't actually get it. The same goes for the 1 way. Everyone and their mother thinks they wanna be a drifter and so you can't find any decent clutch types anymore. At least ones that don't act like a welded diff. It is true though that you can play with the plates in the diff and get it to not lock up so much, but that requires A LOT of removal, dissassembly, reassembly, and installation.

I got a Helical. I did A LOT of research before I made that decision. If you plan on drifting or drag racing at the track with any sort of frequency, the helical may not be the best decision. AutoX, road racing, daily driving, occasional street racing, or drifting, the helical is the way to go.

That is, of course, my opinion. And as they say, opinions are like azzholes, everbodys got one, and everybody but your own stinks...

[slownslurious]

yeah but a helical is not a limited slip. it doesn't limit slip. If you drive someplace where it snows and one tire hits a patch of ice, with a 2 way the tires will stay locked for more or less predictable handling, with an open diff the tire on the ice will just spin... but with a helical it can jerk the back end out as the diff tries to bias torque. its not MY definition.. its THE definition of a limited slip differential.

[r34 gtr]

well, i guess im gonna keep my eyes peeled for a nice 1.5 way limited slip. stability in bad weather is kinda important to me as ive had plenty of bad experiences in my car when it was so much as damp outside (before i got new wheels i was driving on completely bald falken azenis sports). ive had about enough of taking turns nice and slow only to find myself doing a 720 across the front yard of a church (done it 4 times now! wheee!). whatever i end up getting though i'll probably just learn to deal with it.

- tim

[slownslurious]

no matter what diff you get you are still doing to have to slow down considerably in inclement weather, and no diff will substitute having good tires. Having driven on bald azenis sports daily for a while myself I have to say that they are less than ideal for wet conditions. You also need to remember that event a 1.5 way applies locking force during braking, which can make the back end step out quicker in low traction surfaces (although at the same time it also makes handling more preditcable, so if you are comfortable with a more tail happy setup it CAN make it safer to drive in those conditions... but if you aren't ready to catch the tail end it can be dangerous).

[biosehnsucht]

a helical limits the slip between the two wheels, thts what a LSD does. LSD doesn't keep your wheels from slipping on the road. sure it doesnt' limit in some conditions, but neither does a 1 way clutch diff, and its a LSD!

saying a helical LSD isn't a LSD is going against essentially the entire industry's definition. you're free to think that but you are, by "everyone" else's definition, wrong.

[slownslurious]

incorrect.

[c-rad]

I'll end this....

http://en.wikipedia.org/wiki/L...ntial

[iliketocrash]

and if there was any confusion.. this means that yes... the HLSD is a type of LSD

[slownslurious]

and if there was any confusion.. this means that yes... the HLSD is a type of LSD

Read the following, realize you are wrong, then stop arguing:

"In a helical differential like the Quaife, the reaction force shoves the sun and planet gears sideways, where they rub against the ends of their housings. This rubbing encourages both wheels to turn together.

The reaction force only happens if there's some resistance to your shove, though. If there was no resistance in our door latch example, the doorframe would just fall over. If there's no resistance from the other gear, it will just turn. This is why, technically, a helical limited slip isn't really a limited slip. Put one wheel on ice and the other on pavement, and there won't be enough resistance to prevent all the power from going to the ice.

This is why Quaife prefers the term "torque-biasing differential.""

~taken from:http://www.sportcompactcarweb....livia/

OMG, so an ENGINEER is explaining how a helical diff works, how its not a limited slip, and then explains that this why THE LARGEST MANUFACTURER OF DIFFS SAYS THEY ARE NOT LIMITED SLIP DIFFERENTIALS BUT TORQUE BIASING DIFFS.

You guys have the right to your OPINIONS but for the sake of spreading misinformation please keep them to yourselves in threads requesting FACTS.

[redamnavit]

well, i guess im gonna keep my eyes peeled for a nice 1.5 way limited slip.

The CUSCO LSDs seem like a good way to go. I think its the RS type (they make RS and MZ, and my work web filter won't let me go looking for which one) that can have its internal springs rearranged to be either 1.5 or 2-way. Set it up as a 1.5 and if you ever decide you want a tail-happy car you can make it 2-way.

[r34 gtr]

cool, thanks!

and for the record, i really dont care what the technical definition of a helical differential is. i was just wondering which unit would better suit my needs. my car will never see ice and snow so the fact that the helical unit wouldnt do its job under certain extreme conditions doesnt matter in the least bit.

ill be on the lookout for a good 1.5 or 2 way LSD but may still opt for the helical unit since i have yet to discuss it with my dad, and he's the one paying for it (christmas! yeeeeeeah!!!!).

has anyone seen that cusco 1-way unit thats one ebay right now? was just wondering if anyone had tried one and what their opinions on it were. thanks!

- Tim

[r34 gtr]

ok, ok. found some interesting information and it looks like im gonna go with a cusco unit if at all possible. ALL cusco limited slips can be set to 1, 1.5 or 2 way operation with no additional parts. the only difference in the RS and MZ is that the RS has lower initial torque because it doesnt use the "cone plates" that the type MZ uses. all this is available at the cusco website.

- Tim

[Badfish]

Read the following, realize you are wrong, then stop arguing:

"In a helical differential like the Quaife, the reaction force shoves the sun and planet gears sideways, where they rub against the ends of their housings. This rubbing encourages both wheels to turn together.

The reaction force only happens if there's some resistance to your shove, though. If there was no resistance in our door latch example, the doorframe would just fall over. If there's no resistance from the other gear, it will just turn. This is why, technically, a helical limited slip isn't really a limited slip. Put one wheel on ice and the other on pavement, and there won't be enough resistance to prevent all the power from going to the ice.

This is why Quaife prefers the term "torque-biasing differential.""

~taken from:http://www.sportcompactcarweb....livia/

OMG, so an ENGINEER is explaining how a helical diff works, how its not a limited slip, and then explains that this why THE LARGEST MANUFACTURER OF DIFFS SAYS THEY ARE NOT LIMITED SLIP DIFFERENTIALS BUT TORQUE BIASING DIFFS.

Please dont go around taking whats said in Sport Compact Car as the be-all-end-all of car knowledge. You'll save yourself a lot of trouble in the long run.

You guys have the right to your OPINIONS but for the sake of spreading misinformation please keep them to yourselves in threads requesting FACTS.

This applies to you as well. You might want to do some more technical reading on the subject.

[iliketocrash]

This is why Quaife prefers the term "torque-biasing differential."

exactly. they "prefer" to call it such. That doesn't make it so. and yes i like disrupting threads occasionally and straying from the main topic for the sake of an interesting argument.

[float_6969]

OK, then. How about this? By slownslurious's definition, it merely depends on which MODEL of helical we're talking about. You see, if you do a little MORE research, you'll find that their latest version includes pre-load on the planetary gears via an internal spring. This eliminates/greatly reduces the "open diff" scenario in 0 traction conditions.

http://www.torsen.com/general/...20air

NOW is it a LSD?

[r34 gtr]

easy there boys.

- tim

[float_6969]

Shutup Tim. Don't make me get the hose....