LSD of choice?

[sscguy]

My brother and I are building an SR20-powered S13 240SX, and among other things we're looking into a better LSD than the stock viscuous unit. This will be used primarily for HPDEs/autoxing, but for now no competition will be involved. Autox class doesn't need to be considered, because that too will be for the learning experience and not winning or anything, so even if that bumps us up to SM or something, I could care less. Anyway, what LSDs do you all have/prefer and which did you not like? I've heard contradictory things about what types of clutches are best for track duty, which for strip runs, etc., and I'm trying to get something acceptable without making a $900 mistake.

[JasonNagra]

Kaaz. Direct bolt in for USDM S13. Everyone who has driven my car (drift) LOVES it and always tells me it rocks. Nuff said.

[Matt240SE]

geltabs and liquid

[zero.counter]

KAAZ 2-WAY

[JasonNagra]

Originally posted by zero.counter
KAAZ 2-WAY

Word.

[sscguy]

I've heard the 2-way diff is good for drifting and the 1.5-way is good for roadracing. Anyone confirm?

[Dousan_PG]

NO!

Nismo SSS

why? Nismo SSS is 1.5 AND 2 way LSD. disassemble LSD and resassemble to be either 1.5 or 2 way

its ALSO 3 way torque breakaway adjustable

soft, medium and hard

means how fast the LSD will engage

its perfect for a road racer/autoxer OR drifter

you can tune the LSD to the track conditions or driver or type of racing.

how to change the torque breakaway:

drop LSD, remove one out put shaft, change torque w/ torque wrench and 19mm socket

KAAZ requires LSD guts disassembly to change the torque breakaway

also look into NISMO GTPRO its like the SSS but with larger cluch plates and more (sss is 16 and GT pro is 20)

good luck!!

[sscguy]

Thanks all for the help, I appreciate it. Dousan, where could I get the Nismo one, and how much would it cost?

[fooddude]

Geltabs haha.:eek3:

[Halz]

Torsen differentials have been used with great success in road racing.

[Dousan_PG]

oh yeah, as HALZ mentioned, torsen/helical is great for road race too. check out QUAIFE it has lifetime warranty too

NISMO can be ordered from Nissan dealer. ask for the SSS or the GT PRO lsd (like upgraded SSS).

good luck!
oh check out nismo.co.jp site for info on GT PRO/SSS comparison. use altavista babblefish to translate it to english :)

[TBreu007]

Phantom Grip is the best HA :D

Everyone I know that actually road races a 240 says get a Quaife or you will be disappointed. I'm sure the viscous, Kaaz, Nismo, etc. is fine for most, but the Quaife is the most race worthy.
I run the Quaife in my race car.

[nokeone]

Kaaz 2-way is all i have experience with personally and i think it is awesome...:)

although from what i read Dousan's is the better overall..:doh: . but quite a bit more $$$

[sscguy]

I've heard just the opposite about the Quaife, that it's better for drag racing rather than road racing. I really don't know enough about how the two work, so I can't say for myself. Any particular reason for this idea?

[nokeone]

Originally posted by sscguy
I've heard just the opposite about the Quaife, that it's better for drag racing rather than road racing. I really don't know enough about how the two work, so I can't say for myself. Any particular reason for this idea?

i actually heard the same thing...i heard it was great for straight line acceleration but when using it to track/autoX/etc it can be a little dissapointing because it will release if you lift a tire off the ground...

but this could have just been heresay...

anyone know?

[sykikchimp]

Torsen/helical diffs are better for road racing. period. It is in their ability to feather power back and forth b/w the wheels as necessary to afford as much traction as possible. Quaife calls it "Automatic Torque Biasing" or ATB.

With a Torsen diff, as you apply power exiting a corner it will not just lock the two wheel together. It will apply a percentage of the power to each wheel, as a function of grip at that wheel.

Clutch diff, on corner exit, will simply lock the two wheels together, and you will scrub the outside tire, and reduce possible traction. Great for drift, ok for road race, but hard to get used to.

Viscous is better for road race than clutch in that it engages much smoother than the clutch diff, but still eventually locks the wheels together, and is a bit laggy

The last two are on/off switched, the first is a continuously variable percentage.

For Helical diffs your options are

1. Quaife - Perfect fit for the R200 diff from a 300zx app. and I believe it uses the 300zx output shafts.
2. S15 SpecR HLSD unit - Need Stock S15 output shafts. Also the ring gear flange bolt holes are 13mm. The stock 240sx ring gear has 12mm bolt holes. SO.. you either cope with a bit of slack, or if your anal, get 1/2mm wall thickness sleeves made to take up the slack. I opted for getting the sleeves made sense I'm Anal.

[sykikchimp]

Originally posted by nokeone
i actually heard the same thing...i heard it was great for straight line acceleration but when using it to track/autoX/etc it can be a little dissapointing because it will release if you lift a tire off the ground...

but this could have just been heresay...

anyone know?

Thats correct. On deceleration, or situations where 1 wheel has NO resistance, the Torsen diff acts as an Open Diff. This is one of the things that makes it work so well though.

When Entering a corner, if you have a clutch diff, the 2 rear tires are locked together.. this causes the vehicle to be unstable in trail braking situation b/c of the scrubbing action.

Viscous, same deal, but acts a bit later.

Helical, and Open diffs on decel don't lock the wheels together, so they are free to operate at different speeds.. this is absolutely necessary during turning situations to afford the best stability. Especially when trailbraking.


Honestly, how often are you going to lift a DRIVE wheel in a RWD car with a properly stiffened chassis, and stiff springs? next to never.

[nokeone]

Originally posted by sykikchimp
Thats correct. On deceleration, or situations where 1 wheel has NO resistance, the Torsen diff acts as an Open Diff. This is one of the things that makes it work so well though.

When Entering a corner, if you have a clutch diff, the 2 rear tires are locked together.. this causes the vehicle to be unstable in trail braking situation b/c of the scrubbing action.

Viscous, same deal, but acts a bit later.

Helical, and Open diffs on decel don't lock the wheels together, so they are free to operate at different speeds.. this is absolutely necessary during turning situations to afford the best stability. Especially when trailbraking.


Honestly, how often are you going to lift a DRIVE wheel in a RWD car with a properly stiffened chassis, and stiff springs? next to never.

very cool..thanks for the info..:D

[sscguy]

Maybe the complaints about the quaife came from FWD cars? VWs or something? I have seen them lift drive wheels at autoxes, but never at a track (though that's a recipe for disaster, I'd think). Thanks for the explanation sykikchimp, that clears up a lot of confusion. Would you consider the quaife LSD better for a beginner then?

[LanceS13]

Someone mentioned it earlier. Does anybody have any experience with the Phantom Grip? At $350, it's cheaper than even a good used VLSD...but is it worth it? At any rate, I would guess it's better than an open diff.

[TBreu007]

Great, informative post sykikchimp!

Just to add a bit..if someone pulling a drive wheel off the ground, they're running too much bar and should probably go up in spring rate and soften the bar.

The Quaife is a bolt in (with propper shims, setting preload etc.)
The output shafts from my '92 slid right into the diff. carrier. No need for "Z" output shafts.

Don't waste your time with a Phantom Grip. From what I've heard, it's pretty much worthless...especially with any track driving. Save your money and buy a R200V if the $1000 Quaife, Nismo, or Kaaz is too much $$$ for you.

[sykikchimp]

Open diffs are better for beginners. They are much more forgiving to excessive throttle inputs, but a Torsen is by far the best all around LSD you can buy.


yeah, the phantom grip is a clutch type. I hear its good for drag racing, but not much else.

just FYI - If you look, you can find Spec-R LSD's on ebay all the time. After my escapade of asking every friggin online retailed to get the output shafts, I actually see them all the time now.


I paid $500 for mine shipped. So a good bit cheaper than the quaife, and it only had 500km on it.

[sscguy]

Yes, we'll be starting with an open diff, but will definitely be moving up to an LSD eventually. I'll have to consider the Spec R, that sounds like a good deal, as long as it's a good diff.

[240racer]

Originally posted by sykikchimp


Honestly, how often are you going to lift a DRIVE wheel in a RWD car with a properly stiffened chassis, and stiff springs? next to never.

only when you do some thing wrong like hit a curb or an ice patch :-)
Actaully it is pretty funny to see pictures of people with lifted tires when they are roadracing or auto-x, everybody thinks that they are going fast, but I just think they aren't getting much grip and could be going a whole lot faster if they put that tire back on the ground with suspension adjustments or driving style.

Also, the torque percentage is based on the lower traction of the two wheels, it forces the other tire to have 35% (or whatever it is adjusted to) of the torque it can support. that is why when you lift a tire (or get on ice) 35% of 0 is 0 and now you have no torque transfer. So if one tire can hold 500ft-lbs of torque in a certain situation, the torsen diff makes the other tire receive at least 175ft-lbs. in an open diff, the other tire would recieve no torque

[sykikchimp]

Adam H. on FA, recently posted a picture of his car pulling a front inside tire off the ground.
http://www.turbo240sx.ca/ddttrackwheeloff.jpg
I don't think he should be though. He's on level ground, or it would appear to even be elevating just a bit. I think that picture demonstrates a weak point in the chassis stiffness on the 240sx. The firewall is a pretty flimsy spot on out cars, and stock, you can flex it upwards quite a bit. If he had proper fender/firewall bracing, then you wouldn't see that. Of course, his race class doesn't allow such bracing.

If I wasn't concerned about resale value, I would run a roll cage point through the firewall for each side, and connect them to the front strut towers. that would be in my theoritical 10-point cage though. Not really legal in most classes b/c they have rules about running bars through the firewall. I guess the NAMS Fender bars could be a fair street replacement. It's definately on my list of "one days"

[Dousan_PG]

sykikchimp: check out the NAMS product for the one that bolts from the firewall to the strut tower. top quality peice, i handled it and examined it up close. it was VERY nice.

[sykikchimp]

Are you talking about the Fender Brace? Like the one on SPLParts? If so, thats the one I'm talking about.

[Dousan_PG]

nah brah, totally different
think of the firewall
bolts form there and will sit under your strut tower bolts from suspension (bolts in).

its like that!!
you mentioned about a 10pt thru firewall, this could be a nice way around that ;)

pics..er...ehh...check the names site

[Dousan_PG]

here ya go:

http://www.nagisa-auto.com./nagisa/shiyakito-011.jpg


http://www.nagisa-auto.com./nagisa/nams-shilyakitpureeto.html

[TBreu007]

By simply triangulating the front strut tower brace to the firewall, it helps a ton for stiffness.

Still, there is a such thing as too much sway bar, and an effect of running too stiff a bar (or not setting preload properly) is pulling inside wheels.

[Night Slide Josh]

yo dousan..
where can i actually buy those?
and do you know where i can pick up some nismo front and rear lca's

also i like ats..
kaaz is tooo quiet..
we got a 24 disk in the 350z and its quiet...

[s14falcon]

Can anyone give me any info about the tomei technical trax 2 way lsd? I haven't seen it talked about here, and I was wondering how it would compare to these other ones.

[LanceS13]

"I've heard" and "From what I hear" = "experience"?
Wow! j/k :p

So I guess no one's actually driven with one?

What exactly do you need to get the Spec R to work in an open-dif S13?

[Dousan_PG]

you need s15 output shafts

[sykikchimp]

Originally posted by LanceS13
"I've heard" and "From what I hear" = "experience"?
Wow! j/k :p

So I guess no one's actually driven with one?

What exactly do you need to get the Spec R to work in an open-dif S13?

Somebody needs to reread a few posts. Like Prego, "it's in there"

[Stee Flo]

Well is there any diff that would work well for both grip and drift? I see that various diffs are optimal for grip(torsen/helical) and others for drift(2 way clutch), but is there a good compromise for someone that would like to do both?

[nokeone]

i would go with one more designed for grip...then use it for drift as well...should work just fine as rear wheels generally are not lifted mid drift which would cause it to lose it's LSD characteristics...as opposed to a heavy duty one designed for drift which would almost be more hurtful then helpful on a tight, technical, grip circuit/autoX...

but yeah..i dunno..lol

[sykikchimp]

a basic vlsd is a great compromise diff.

I've read complaints that helical lsd's can be a bit unpredictable while drifting. Probably due to the fact that resistance on each wheel changes constantly..

[RBS14]

^^^^^^^

Exactly.

I've heard that drifting a helical diff equipped car is like really weird. It it harder to kick out the rear and once you do the attitude of the car is constantly changing because of the diff. speeding up, slowing down, more sever angles, less sever angles out of nowhere. It does this cause when the suspension is reacting it is putting different loads on each wheel which in turn makes the diff react accordingly and feel very unpredictable.

Palabra.

[tsunami0ne]

Originally posted by s14falcon
Can anyone give me any info about the tomei technical trax 2 way lsd? I haven't seen it talked about here, and I was wondering how it would compare to these other ones.

The tomei technical trax is the same as the kaaz unit I think.

[RBS14]

^^^^^

Werd. I also heard lately that Kaaz actually makes Tomei's diffs for them. so Kaaz = Tomei from what i've heard.

[nokeone]

Originally posted by RBS14
^^^^^

Werd. I also heard lately that Kaaz actually makes Tomei's diffs for them. so Kaaz = Tomei from what i've heard.

concur..

[kaazlsd]

Kaaz = Tomei! CONFIRMED

Tomei units are supplied by Kaaz.

:D

Kaaz USA 888-522-KAAZ(5229)

[jmauld]

I have a quaife in my FWD car. It's true that when you lift a drive wheel it will put all of the power to that wheel. What they don't mention is that if you get anywhere close to lifting a wheel it will send power to it. In other words it doesn't need to reach 0 grip to send all of the power to that wheel.

As for lifting wheels in a corner. There are advantages to that. For example, RWD cars can be setup to lift a front wheel in corners. This transfers more weight to the rear tires and allows the driver to use more throttle. The same thing is true for a FWD car when it lifts a rear tire, just not to the same degree as a RWD car.

[DS 240R]

I also have a Quaife in my FWD racecar. I really like the feel of it, but there's not much practical difference between in and new NISMO clutch pack diff. I think the clutch-type diffs are usually cheaper, so unless you are racing I'd go with one of those. If you are racing, then there's a trade off between the Quaife and clutch diff- a little more corner entry understeer with the clutch diffs, but on tight off-camber turns the clutch diff gets out of the hole a little better. FWD anyway.

I would definitely recommend against a viscous unit- under heavy use conditions my vlsd would heat up and lose viscosity. After a few years, it was spent.

[Vatche]

ok my one question is.....s15 hlsd vs quaiffe..... 1200 bucks for quaife vs i dont know how much and i dont know how much work either one is.....now is it worth digging around for all the parts i would need to install the s15 and how hard it is....are these lsd's even comparable in how good they are.....and how hard is it to install the quaife into my car too....what do you all think any info would be nice, i think im deciding between the two now....i dont thnk they have any other competition do they?

[sykikchimp]

I have the s15 LSD in my car. Installed it myself.

Install on either diff will be the same. Spec-R S15's are considered to be some of the best handling vehicles in the world. In large part due to the LSD.

The ONLY things you need to install the S15 diff is the Diff unit itself, and the output shafts. If you find the right seller, you can likely get them together.

I bought mine for ~$500. Japandy had one for sale recently for about ~$250 WITH output shafts.

MUCH cheaper than Quaiffe, and I promise it'll work just as good, if not better.

I love mine.

[Vatche]

any idea how to shop for them.. used obviously do they go bad or anything, im more interested in the s15 lsd cuz its cheaper....need to know where to look other then ebay?

[sykikchimp]

yahoo japan auctions?

no they never go bad. you could break one, but that's possible with any diff.

[Akuma Trueno]

Originally posted by Matt240SE
geltabs and liquid

I just wanted to warn everybody not to use the brown blotter... it's bad!:rawk: :rawk: :rawk: :rawk:



no really, go for KAAZ it is the best option.


heh heh, I said "option":D

[Akuma Trueno]

Originally posted by RBS14
^^^^^^^

Exactly.

I've heard that drifting a helical diff equipped car is like really weird. It it harder to kick out the rear and once you do the attitude of the car is constantly changing because of the diff. speeding up, slowing down, more sever angles, less sever angles out of nowhere. It does this cause when the suspension is reacting it is putting different loads on each wheel which in turn makes the diff react accordingly and feel very unpredictable.

Palabra.

This is the TRUTH!! Queefe is no good for drifting. You want to have good response from rear end then you most likely need to use a clutch type diff.

[98sr20ve]

He said from the start that he was doing HPDE's and autocrossing. Get either the 1.5 way clutch type or the Quaife. I would get the Quaife. I have one in my FWD Sentra. Works very well. Lifting a wheel does cause it to go open but that does not last long and its ussually only a problem if you hop curbs a lot. For autocrossing the Quaife is clearly the best choice. It will be easier to drive and more predictable. Clutch type will require a different setup then a Torsen/Quaife. Keep that in mind. Clutch type on the RWD car will be more likely to oversteer under power. For drag racing the best is a clutch. It will lock up much more solidly then the Quaife. I have a question. Is the S15 LSD a Torsen type?

[thelinja]

Yes, S15 diff is Quaife/Torsen/Helical/awesome beyond belief

[WilloW]

Sykikchimp, thanks for the great info man. I know which LSD I want now.

[Def]

RWD cars pick up their front inside wheel due to the large roll moment a typical MacPherson strut based suspension sees when lowered. The roll center of the suspension moves farther away from the center of gravity, thus the theoretical lever arm affecting the rolling force the front suspension sees is much greater than with a stock based car generating the same level of lateral grip.

I also see RWD cars "lifting" rear wheels all the time. Look at anybody on the track termed a "curb hopper" and you're bound to see some drive wheel aerial liberation when they get on it. Straights out the corner a bit, and tends to really thrash the car.


My 2 cents on the LSD issue(having driven all three types) - go with either a clutch type or torsen style. Torsen's have no adjustability, but assuming the engineer was smart(Quaife's are), the forces it puts out are pretty optimal. Clutch type diffs can be made to work just fine if you put some effort into tuning them. Keep in mind that wear will affect their performance and characteristics over time. Major downfalls of a clutch type diff are that you tend to increase understeer on corner entry to varying degrees depending on the setup(rear wheels are locked together and don't want to start spinning at different speeds = pushes car forward when you want to turn). They also tend to have a brief moment of throttle-on understeer when the rear wheels lock up under power. Lifting does help the nose tuck in nicely by uncoupling the rear wheels.

My E36 M3 has a factory clutch type diff and I find it works just dandy on the track. You just have to get on the gas early and stay on it through the corner.


One question though - has anybody found a place that sells Quaife's at reasonable prices? Honda diffs can be had for around $750-800, while a quick search for the R200 shows ~$1300-1400(ouch!). Seems a bit steep considering some 240SX's aren't even worth that much total.

[DS 240R]

Honda diffs can be had for around $750-800, while a quick search for the R200 shows ~$1300-1400(ouch!). Seems a bit steep considering some 240SX's aren't even worth that much total.

Welcome to having a Nissan and getting raped on price of everything.

[sykikchimp]

I think Nopi sells it for around $1200.

[sscguy]

Why are diffs more expensive but cams cheaper? (to Honda/Nissan price comparison).

[MadScientist]

OK wow this has alot of info and gets a bit off topic but lets see what I can offer...

Nismo GT LSD is the big brother to the SSS which is discontinued.
Nismo GT has 3 Options available!!
1. GT 1.5 or 2 way, non adjustable
2. GT Pro, adjustable 1.5 and 2 way w/ 65deg. plate angel.
3. GT Pro TT, adjustable 1.5 and 2 way, with 55deg. plate angel.

Plate angle helps cornering speed... the TT has a faster corner speed... very simple logic.

Fender Braces by URAS, Tanabe, Silk Road, etc... are all made by Silk Road (a.k.a. Section) basically the logic of attaching the cab area to the engine area by brace improves chasis rigidity. When Installing this item you will see how the stock chasis seems to be week in this area.

Firewall Brace... as Sykikchimp mentioned the Fireway is thin and will flex theirfore by attaching the strongest part of the firewall (Top) to the Strut tower you have reduced flexablity.

Both items are very different but perform very similar... if you get one, its good to get the other as well (just like sways and strut tower) deffinatly a good idea for drifting... check with your sanctioning race holders for legal use in autocross.

[DS 240R]

Why are diffs more expensive but cams cheaper? (to Honda/Nissan price comparison).

Most Honda cams are vtec cams which are harder to grind than single lobe Nissan cams.