S15 HLSD Diff question, yes I've searched.

[SixSpeedSleuth]

I've searched and read just about everything I can find on the S15 Type R HLSD Diff compared to other diffs including the VLSD 180SX diff; and a stock S13 welded diff.

Currently I'm running the OEM 180sx VLSD. From what I've read the S15 HLSD would offer the best GRIP as far as diffs are concerned. Is that true?

For example, I'm running 400whp with a VLSD. Lets say I keep all things equal and just switch the diff to a S15 HLSD. Are the gains in traction going to be noticeable? I'm on the fence about buying a S15 HLSD and my goal is MAXIMUM grip from an LSD. Bottom line is would the S15 HLSD give me that? Thanks for any input!

[luftrofl]

Originally Posted by SixSpeedSleuth

I've searched and read just about everything I can find on the S15 Type R HLSD Diff compared to other diffs including the VLSD 180SX diff; and a stock S13 welded diff.

Currently I'm running the OEM 180sx VLSD. From what I've read the S15 HLSD would offer the best GRIP as far as diffs are concerned. Is that true?

For example, I'm running 400whp with a VLSD. Lets say I keep all things equal and just switch the diff to a S15 HLSD. Are the gains in traction going to be noticeable? I'm on the fence about buying a S15 HLSD and my goal is MAXIMUM grip from an LSD. Bottom line is would the S15 HLSD give me that? Thanks for any input!

Do you mean which one locks harder? They don't give you more grip

The HLSD will better, especially considering that the VLSD needs to heat up to really lock and is probably worn out depending on how old it is.

[drift freaq]

Originally Posted by luftrofl

Do you mean which one locks harder? They don't give you more grip

The HLSD will better, especially considering that the VLSD needs to heat up to really lock and is probably worn out depending on how old it is.

I think what he is asking about is actual traction. If your going to do AutoX or track stuff and not drift then the HLSD is the way to go. Drag racing? That's a debate.

[clark]

Originally Posted by SixSpeedSleuth

I've searched and read just about everything I can find on the S15 Type R HLSD Diff compared to other diffs including the VLSD 180SX diff; and a stock S13 welded diff.

Currently I'm running the OEM 180sx VLSD. From what I've read the S15 HLSD would offer the best GRIP as far as diffs are concerned. Is that true?

For example, I'm running 400whp with a VLSD. Lets say I keep all things equal and just switch the diff to a S15 HLSD. Are the gains in traction going to be noticeable? I'm on the fence about buying a S15 HLSD and my goal is MAXIMUM grip from an LSD. Bottom line is would the S15 HLSD give me that? Thanks for any input!

i did alot of research on HLSD. they're a highly sougth after upgrade on any track car. when i was into vdubs, peloquin and quaiffe made after market diffs for our cars, quaiffe makes a 350z helical diff that costs ~$1300!!!

i persoanlly have recently installed an S15 HLSD diff into my R200 pumpkin myself, which i DON'T recommend you do, as the very nature of differentials is advanced and precise. i'm a dick and made shims out of sheet metal, and didn't really make it tight enough in there.

i now have to go to a diff shop and get it adjusted. it works just great, i just didn't shim properly and there's vibrations, but here are my driving impressions

1. AWESOME!!!, if you drop the clutch, it locks right up.
2. anyone who says you can't drift with one of these obviosly never drove one (i don't drift, but i do ocasionally have some fun on empty streets). it's just that a clutch type is better for drfiting because it can maintain a locked status, however the torsen or HLSD will tone it down and provide the most power tot he wheel with more grip

3. acceleration out of turns is awesome
4. off the line, great accesleration, 5. it's stricly mechanical, basically, will last forver, if of course the owner takes care of it.

misc notes:

-get new axle seals when doing it
-i got mine for ~600 on ebay with the corresponding axle shafts, let me know, i'll give you the ebay sellers name, i'm absolutely satisfied.
-you don't need the special nismo bolts for the ring gear, but i got them anyway cuz i had some extra cash (special bolts have a 13mm shank, but 12mm thread body)

[murda-c]

It does not bias torque equally, that's what an open does.

It multiplies torque so the wheel with more grip gets more torque.

[clark]

Originally Posted by murda-c

It does not bias torque equally, that's what an open does.

It multiplies torque so the wheel with more grip gets more torque.

you're right, i got a little overzealous, edited!

in addition, i know there are several members running the S15 HLSD on here, i say you sift through the old HLSD threads to find more input, or pray they chime in.

[murda-c]

Wasn't there a guy who used the obx lsd and it worked out well?

[silnismo]

Originally Posted by murda-c

Wasn't there a guy who used the obx lsd and it worked out well?

http://zilvia.net/f/chat/101109-obx-...-review-4.html

Yea, he has updated in a while though...

The s15 diff is truely an amazing upgrade with excellent DD qualities.

If its your DD you can't go wrong. Full track car, go for the 1.5.

[SixSpeedSleuth]

Originally Posted by drift freaq

I think what he is asking about is actual traction. If your going to do AutoX or track stuff and not drift then the HLSD is the way to go. Drag racing? That's a debate.

Yes, you are correct. I'm talking about what diff will give me the best traction/power to the ground. The cars purpose is street/strip setup. Thanks for those who have responded so far. There will be no drifting with this setup. I should have asked if the S15 HLSD would benefit me better than the 180sx VLSD for drag racing, which from reading the previous posts, it appears if it will. Thanks.

[BigVinnie]

I use the OBX HLSD.
I don't see much difference between the OBX or hitachi R200 type accept that the OBX was built on a cheaper more horrendous chinese production assembly.
Helicals make the rear end much more manuverable for auto x. For drifting you would have to keep your rev much higher because of the way the torque bias is designed from stock, (you can always change the pre load washers)... As far as reliability you can rebuild a helical, you would have to throw away a viscous type. Parts for the helical are also cheap and you can also manipulate and change the torque bias ratio with the way you set pre load washers (by thickness, and offset).
Personal opinion...... I like my HLSD mostly because I drive on the street often, and track it about only 5 or 6 times out of the year. Braking responce for the rear is much better than most clutch locking types that are 1.5 or 2 way, and even most viscous types. Also the helical diff is a quiet diff it doesn't make any noise at all if you've done the proper steps to set gear lash...
Depending on how you set pre load washers from stock you can make a helical lock up much faster with less torque than a 1.5 way clutch type or viscous type diff. Only concerns you should worry about on the helical is wheel lift, or wheel hop which can temporarily throw off the torque bias, and have a wheel spining around like a open diff. That would have more to do with how your suspension is set up and designed.

[g6civcx]

Originally Posted by SixSpeedSleuth

From what I've read the S15 HLSD would offer the best GRIP as far as diffs are concerned. Is that true?

What is "GRIP"? Roadracing? Autocross? I assume you mean roadracing.

Originally Posted by SixSpeedSleuth

For example, I'm running 400whp with a VLSD. Lets say I keep all things equal and just switch the diff to a S15 HLSD. Are the gains in traction going to be noticeable? I'm on the fence about buying a S15 HLSD and my goal is MAXIMUM grip from an LSD. Bottom line is would the S15 HLSD give me that?

This topic is discussed at least once a month. I have always maintained the following position.

For roadracing:

welded < open < vlsd < hlsd < 1.5 < 2

Do what you want.

</end thread>

[SixSpeedSleuth]

Originally Posted by g6civcx

What is "GRIP"? Roadracing? Autocross? I assume you mean roadracing.



This topic is discussed at least once a month. I have always maintained the following position.

For roadracing:

welded < open < vlsd < hlsd < 1.5 < 2

Do what you want.

</end thread>

I've read through approximately 16 threads using the search function concerning this matter but have not found somebody wanting absolute maximum mechanical grip for drag racing, and what diff to use in the process. I'm not worried about drifting, road racing, or autocross. I want my car to hook the best it possibly can IN A STRAIGHT LINE. I did not see that topic discussed in any of those threads, Hence my New thread about the subject. I, however thank you for your input to this matter, it has been valuable.

[g6civcx]

Originally Posted by SixSpeedSleuth

I want my car to hook the best it possibly can IN A STRAIGHT LINE.

Say what you mean then. Generally around here "grip" = roadracing, not drag.

In that case, open < vlsd < welded < hlsd < 2 < 1.5

[S14DB]

Originally Posted by SixSpeedSleuth

I've read through approximately 16 threads using the search function concerning this matter but have not found somebody wanting absolute maximum mechanical grip for drag racing, and what diff to use in the process. I'm not worried about drifting, road racing, or autocross. I want my car to hook the best it possibly can IN A STRAIGHT LINE. I did not see that topic discussed in any of those threads, Hence my New thread about the subject. I, however thank you for your input to this matter, it has been valuable.

Get a Spool. If you are cheap, weld an open diff.

[s13dan]

KAAZ 1.5 =800$ but iv heard they are great, buy it once and be done with it.

[soreballz]

Drag racing? Thats it?

Welded/Spool, done. Either way... Whichever is friendliest on your wallet.

[SixSpeedSleuth]

Originally Posted by soreballz

Drag racing? Thats it?

Welded/Spool, done. Either way... Whichever is friendliest on your wallet.

I had never head of "Spool" until reading this thread. I did some quick reading and it appears to have started with the V8 crowd wanting traction. Is it a particular insert I put in the diff housing?

[soreballz]

Its a piece that goes between the gears to lock them together. It does the same thing a welded diff does, but for a different price. lol

[S14DB]

Originally Posted by soreballz

Its a piece that goes between the gears to lock them together. It does the same thing a welded diff does, but for a different price. lol

Spool replaces the Center Diff all together. Swap the ring gear and bearings like any other diff swap.

Mini-Spool. Replaces the gears with a sold piece. Pull the pins. Drop the gears out. install the mini. reinstall the pins. Easier, but you can still break the pins.

[coolcatracing]

If you're drag racing a clutch type or spool is going to be the best. You can make the S15 an open real quick if you lose traction on one wheel. I've picked up wheels plenty of times in corners with HLSD's and you lose all traction. With some preload you still have some but its still not what you would have with a clutch type. Helicals are made for cornering and to be quiet, if you're not going to do that then don't buy one. From what you're saying you're best bet is with any one of the clutch type diffs since you really only need a 1.5 and they'll all do that.

[952jz240sxr]

i have the s15 hlsd installed in a 3.54 q45 diff, and it is not wat i thought it would be. basically im putting down 640hp at the wheels and i feel like i have an open diff in second gear and thats with sticky bfg drag radials (295/35r18).

[g6civcx]

Originally Posted by 952jz240sxr

i have the s15 hlsd installed in a 3.54 q45 diff, and it is not wat i thought it would be. basically im putting down 640hp at the wheels and i feel like i have an open diff in second gear and thats with sticky bfg drag radials (295/35r18).

Too much power for the 3.54. Go with a Pathfinder 3.133 and swap in your S15 HLSD and axle flanges.

[952jz240sxr]

is that a bolt in affair?

[g6civcx]

Originally Posted by 952jz240sxr

is that a bolt in affair?

Yes. May need a new driveshaft if you're stock. Shouldn't be stock with that much power any way. Search my posts.