lsd question

[driftoy]

im not sure if this has been posted already but....

what is the difference between helical and viscous lsd's. i just recently got an "lsd" from someone's 97 240. how can i tell which diff is which?

[Dryftyn850]

The viscous lsd came oem in the the se's. Viscous is also a liquid based lsd. I believe under high horse power these type seem to not work so well. Just my 2 cents

[skydragoness]

Helical's also do not have any wear parts that need to be replaced. IMO, the best OEM lsd you can get... now if people would just stopping raping others for them in price...

[DjPantsSpecR]

yep, yours is viscous. viscous has "snot" that heats up when two plates run against it. The spinning plates cause enough of a temperature difference that the snot thickens and thickens until the plates can't spin and the diff behaves like an lsd. viscous isn't just bad for high horsepower, its also bad when the viscous fluid is too old or worn out

helical refers to the kind of gears used. they are cut with helical teeth and as they recieve more and more spinning torque they start to push away from each other and they push the plates together causing the locking effect

helical rules, but im pretty sure it only came in the S15 or the S chassis, and getting an S15 diff to work is a lotta work, however, its quite searchable

[deviousKA]

s15 hlsd will go into an s13 easily, using the s13 case. You need the s15 output shafts is all. The ring gear from the s13 works on the hlsd.

Good thing about the vlsd and hlsd is that regular gear oil can be used, unlike an expensive clutch type that requires expensive oil change just about every time your change your engine oil, if your truly "using" it anyways. Clutch type also wear much faster and need to be maintained.

vlsd like others said, is so-so, although ive never had one in my car.

Thats why I have an s15 hlsd Well worth it compared to a name brand qualf/quife however its spelled, those run like $2500?

Edit: that picture of your diff, not a s15 hlsd. Must be a vlsd but I dont really know.

[DjPantsSpecR]

lol, sorry to entirely jack this thread, but i gotta on two accounts..

1st) quaife is what you wanted to say, but you said "quife" which where i come from is when you discharge some air from your vag with a hilerious high pictched squeek. Could also be caused by sticking something in and out of there reapeatedly....

and for the thread jack part... SorryDevious i have an ECU that says 3C, and is from my 95 motor. It's quite useless to me, but i'll trade it to you if you promise to hook me up with a DE stage 3 tune when you get done with it....

[deviousKA]

Lmao, quife, yeah, I didnt realize i typed that vaginal fart, er good times.

Hm stage 3 NA de eh, should be done soon after some more A/F tweaking. Ill keep that in mind, I will have another batch of daughterboards coming in so should have stock on those for quite some time.

I need the s14 ecu to reverse engineer the daughterboard.

[DjPantsSpecR]

I see.

i remember seeing something a while back about a list for ECU identification, but searching to find that is a *****. However, i'm quite positive this is from a 95 motor, and i thought it was OBD1, but things have me thinking otherwise..

but like i said, its free, for you

[deviousKA]

To continue off topic.

I have been getting a bit frustrated or "fed up" with ecu rom tuning lately, well sort of. Trying to figure out all of the formulas and locations in 32k of code that is difficult to understand, just to find a single feature (ie. TP maptracing, real map trace not calculated like others do). I really wish more smart people that knew a lot about embedded microcontrollers were into it, the few that are arent very nice or work with other nissan ecus.

In other words, I may or may not be interested in designing a d-board for the s14 ecu, thats all I would need it for as I run standalone, hacking nissan ecus for the hell of it.

Anyways, to create a better NA tune for the de it is rather simple. Find a good stock or slightly modified KA dyno sheet, with A/F log along with it. Decide what A/F change you would like at any given point and it can be easily modified. If you would like the JWT NA tune it is already available, although rather basic and could be taken a step further.

Im going to order some more parts up to finish the rest of my daughterboards for s13 de, If you wanted you could send me your ecu and I could install with tune, in exchange for your s14 ecu. In order to tune the s13 ecu the original code must be dumped first and then the tune applied to it.

I think Justin (glacier985) will by dynoing the sohc stage 3 tune here shortly, not sure though.

-end rant.

[skydragoness]

Anyways, to create a better NA tune for the de it is rather simple. Find a good stock or slightly modified KA dyno sheet, with A/F log along with it. Decide what A/F change you would like at any given point and it can be easily modified. If you would like the JWT NA tune it is already available, although rather basic and could be taken a step further.

Im going to order some more parts up to finish the rest of my daughterboards for s13 de, If you wanted you could send me your ecu and I could install with tune, in exchange for your s14 ecu. In order to tune the s13 ecu the original code must be dumped first and then the tune applied to it.

If i'm reading your right, are you saying there is a way to do all the stuff that the JWT stage 1 ECU does without too much trouble? Doesn't the stage 1 get rid of that 'tip-in retard' crap. I hate that most of all. It drives me insane.

[driftoy]

woww! u guys been writin like crazy!!!

yeah hey thanx for the info. i thought it was vlsd. gee a helical would be nice too. is there any proceedures i should go through to keep good care of my diff? like oil, or if i need to change seals when i swapped, even if they dont leak. would stock axel be able to "keep up" with this diff?

yall said something about this diff wont withstand alot of power. well how much power can it work with.