Which differential is best?

[speedo140]

I know this questions is up to your specific set up. But I have an option of a Viscous LSD from an S13, or a Helical LSD from an S15. I know you guys know lots. Or would you guys recommend another one that would be better in mechanics. I am sure you guys have had a lot of experience trying these units, so your opinion is valuable. My intentions for this car, an '89 with an sr20, will be mostly street. (some track)

[shift_SRDETuser]

MOst peps wi

I know this questions is up to your specific set up. But I have an option of a Viscous LSD from an S13, or a Helical LSD from an S15. I know you guys know lots. Or would you guys recommend another one that would be better in mechanics. I am sure you guys have had a lot of experience trying these units, so your opinion is valuable. My intentions for this car, an '89 with an sr20, will be mostly street. (some track)

most peps will tell you that the s15 heli is best and it probably is. I have 170,000 miles on my Vlsd from a 1996 Nissan 240sx auto and it locks up like new.

[Kalypso]

^ an s15 is smashing

especially if its new and well priced.

[kentuckyslider]

I just swapped out my USDM J30 with 3.91 R&P for a HRC skyline 4.36 out of a R32 4 door from Jhot. I love the lower gear for the SR, It bolts up with solid mounts vs. the J30/Z32 snout which requires a bushing kit. It makes each gear about 10mph shorter and keeps you in the boost. I paid $220 shipped for it and it is the best bang for the buck mod I have on my car. I haven't raced it yet but it's going to come out hard with the 2 step launch control.

[Tulsa_S-13]

I just swapped out my USDM J30 with 3.91 R&P for a HRC skyline 4.36 out of a R32 4 door from Jhot. I love the lower gear for the SR, It bolts up with solid mounts vs. the J30/Z32 snout which requires a bushing kit. It makes each gear about 10mph shorter and keeps you in the boost.

Same here, I'm running a 4.36:1 FD out of the HCR32. The gearing feels great, even with my relatively weak setup.

I also got mine from JHOT

[kentuckyslider]

I got the idea from you!

[supreamS14]

Professor HOY GLAYVIN

[Kalypso]

I have a j30 vlsd on my coupe. from a '96 but it isnt runnign yet so I havent had a chance to test it.

what is the range of gear ratios on various LSD's and what are there characteristics?

im new to this

[carmo]

Helical would be batter for track duty so I hear. Hehe i said doodie. But not so much for drifting. Viscous may be better if your no sure where you want the project to end up. drifter or road course. I say get a Kaaz 2way or better yet, weld the diff and tell your wife to get her own damn tampons.....but im single.

[Hijacker]

Neither viscous nor helical are ideal for drag/drift. You really want a clutch pack or some other form of locked diff for those.

I would pick HLSD any day of the week over VLSD. Primarily due to service life, ability to apply power to both wheels as needed (so long as one wheel isn't on something that prevents traction like ice).

I've been running a VLSD for about 3-4 years now, and if I could have done it all over again, I would have gone HLSD. The viscous unit is good for an entry level diff. If you occassionally auto-x your car, you won't do wrong with a viscous diff.

But in the end, if I had the choice of HLSD or VLSD and they were identical in price, I would go HLSD in a heartbeat.

[jr_ss]

A helical works great for drag racing... It constantly shifts power back and forth between wheels providing the best grip. Although a welded diff would work much better.

If you are going to be sliding, you want a 1.5/2 way diff, or a welded differential. Something that locks hard...

I love my Helical and I'm glad I went that route, rather than the VLSD

[speedo140]

You guys have been great. The Helical sounds like the better of the two. I have two more questions:

1. Is there a better option at this "money" level?2. What parts are required for the Helical swap? I hear the drive shaft has to be from a KA. I have an sr20 on an '89. I bought the car as is, and don't know if it carries a KA drive shaft, or one from the SR. I have heard the half shafts need to be replaced, but I haven't heard anything about the drive shaft. The helical will come from an S15. Thanks.