BPRacer

iTrader: (1)

I am looking for a good LSD unit for my '03 350Z that I am putting together for STU autocrossing and track use as well. In addition, the car sees some street use on occasion, so good street manners are important as well.

I was wanting to use the OS Giken unit, but the price is a bit steep for my current budget. I had almost decided on the Quaife- I think as long as I keep the inside rear wheel on the ground it would work well for me, and it is good on the road as well- but I then ran across the Tomei 1.5 way LSD at a good price.

I have not been able to find many reviews of the 1.5 way version, only the 2-way. Has anyone here used their 1.5 way? How is it as far as traction, noise, durability, and maintenance required?

Any other options I should consider? Again, budget is a big priority at this time, but I don't want to install something I will end up disappointed with.

Opinions?

Thanks!
Brian Flanagan

dkmura

iTrader: (64)

I haven't used the Tomei unit, so I cannot comment there. My NISMO 1.5 LSD has been a good and durable unit for going on eight years. Using annual fluid changes and Redline friction modifier has extended its service life.

With your choices being severely limited by budget, there's little reason to go into an extended discussion on other LSDs.

travlee

iTrader: (8)

what is your budget, and do you have an open diff now?

guitman32

iTrader: (15)

If street manners are important, absolutely forget about any non-carbon clutch type (Nismo, Cusco). I have a Cusco RS at 80% lock, absolutely loud and clunky no matter what...90PA/75w-140/1or2 bottles friction modifier. Works great, just unruly. And not nearly as clunky as the Nismo unit.

Second on your list will be the carbon clutch types, but those are out of your budget.

Therefore, Quaife is your best option. Plenty of people run torsen type diffs with great success.

BPRacer

iTrader: (1)

My budget is compromised right now by that "real life" obstacle that sometimes gets in the way lol. It's not a definite budget, more just a need to get the most for my money because if I wanna go play right now I've got to stretch the dollars.

I've used a Quaife before, in my old E30. It was so so for autocross (because that car lifted a wheel frequently), good on track, and when I converted it to a stage rally car, it was fantastic in the gravel. My BSP 350z I had a few years back had the Cusco RS- it was great in action but loud as crap. In hindsight, I didn't ever flush the fluid, so that may have been a factor.

I'll probably go with the Quaife, but when I saw the Tomei was several hundred dollars cheaper to purchase, it made me wonder how they were. If it's comparable quality to the Cusco or the OSG, it would be worth trying out. If not, great, just looking to find that out.

In summary: not looking to cheap out, just wondering if the Tomei is good bang for the buck, or if it's crap.

guitman32

iTrader: (15)

I definitely wasnt implying anything like that, totally reasonable to have a budget.

Ive never used a Tomei, but if its a steel clutch type I would expect similar levels of street-ability to other steel plate clutch type diffs.

I keep hearing ruminations about torsen style diffs with a preload feature that will prevent it from opening if you lift a wheel. I had found some material online but honestly have no recollection where...worth looking into.

BPRacer

iTrader: (1)

Oh, I didn't think you were implying anything. I appreciate your input! Interesting thing about the Torsen you mention, I'll have to research it. It was my understanding that the diff coming open when one wheel had no resistance was just a characteristic of the design. It would definitely make a difference if there was a way around that issue.

Toneloc

quaife will fufill 90% of 350z owners needs...the other 10% that only use their z's for track, autocross and drift with little to no street use goes for clutch type (giken, tomei, etc) because of their clunky almost dangerous in rain street use.

Quaife is all mechanical and last a long time, clutch type is just that a clutch that will wear out over time..

Its really your goal with your car and how much you expect to track use it.

guitman32

iTrader: (15)

I found it, this is one of two diff types allowed in Spec Z (the other is the Nismo clutch type unit):
http://www.wavetrac.net/different/

No personal experience, but I knew there was a torsen differential available with this feature.

"The innovative, patent-pending, Wavetrac® device in the center of the diff responds during these exact conditions when zero or near-zero axle-load occurs. At or near zero axle-load, the axles (and therefore each side gear in the diff) start to turn at different speeds.
This speed differential causes the Wavetrac® device to step into action:


Precisely engineered wave profiles are placed on one side gear and its mating preload hub. As the two side gears rotate relative to each other, each wave surface climbs the other, causing them to move apart.
Very quickly, this creates enough internal load within the Wavetrac® to STOP the zero axle-load condition.
The zero axle-load condition is halted, and the drive torque is applied to the wheel on the ground (the gripping wheel)… keeping the power down.
Some gear differentials rely solely on preload springs to combat loss of drive. The drawback is that you can’t add enough preload to prevent loss of drive without creating tremendous handling and wear problems at the same time. So, to avoid these problems, the preload from ordinary spring packs must be reduced to a level that renders them ineffective at preventing loss of drive. The Wavetrac® is the only differential that can automatically add more load internally when it’s required.
In the case where both wheels are on the ground during zero axle load, such as during a transition to deceleration, the Wavetrac® device is able to prepare the drivetrain for when the zero torque condition stops, eliminating the delay seen with ordinary gear diffs.
What this means for you as a driver is that power is delivered to the gripping wheels for more time and in a more constant manner – making you faster and improving stability.
The Wavetrac® truly is different - and its innovative features can make a real difference in your car’s performance."

BPRacer

iTrader: (1)

I have heard a lot of rumblings regarding Wavetrac failures from the Spec Z guys. Not sure of the specifics though.

03threefiftyz

iTrader: (25)

Man up and get the OSG.

/thread.

BPRacer

iTrader: (1)

What do you know about autocross Z's Lane? Lol

Toneloc

Weld spider gears; that's on a budget..."merica"

ZoneMaster

OSG diff is well worth the money. Buttery smooth on the street, and very solid and predictable at the track. I'd wait and save a few more pennies

guitman32

iTrader: (15)

Ive read similar things.

dkmura

iTrader: (64)

The first gen Wavetrac units were the ones that had Spec Z problems. Wavetrac stepped up and rebuilt the units and most reports I've heard are that the second gen Wavetrac LSDs are much improved in terms of durability.

Shane86

iTrader: (1)

I ran the wavetrac V2 in STU this year, no complaints.. has definetly not exploded.
I talked to the guys at Nismo before i ordered it, and they agreed that the problem with the wavetracs exploding were heat disspaiton issues. V2s are better, but if you're not running flat out for sprints, you should be fine.

that being said, i am thinking about a giken.. the wavetrack can be a bit finicky applying power mid corner. Probably not until next year though. we'll see how much of that was just **** shocks.

350z-Helsinki

iTrader: (1)

I got a Quaife diff. It's 1000x better than the stock diff, but sometimes it doesn't lock as strongly as I would want it to. I was 50/50 between OSgiken and Quaife. Quaife was almost half the price (in Europe) and that made the decision for me. Love the fact that it's maintenance free and has a life time warranty. So I'm happy with my decision. Car is really easy to control since there is no abrupt lockup.

Zero lockup is usually only an issue on low grip surfaces. In track driving these situations are extremely rare if your car is setup properly.
Against common "knowledge" you can easily drift with a Quaife diff. Although I admit that clutch type diff is better. Heat becomes a problem when drifting and you need an oil cooler.

In the end both are Quaife and OSgiken are good choices.
Based on your post I would go with Quaife.

Shane86

iTrader: (1)

A Quaife is a Helical, torque biasing diff.. it will never "lock"
It will on the other hand, free wheel if you loose all traction on one side.

That's the strong point of the wavetrac over the Quaife. it can actually lock as there's an additional cam in the middle that twists into place.

350z-Helsinki

iTrader: (1)

I know, I was figuratively speaking. It transfers a multiplier of the torque that is applied to the (inside) wheel that has less traction. But it's kind of irrelevant. Quaife has it's weaknessess, but it's a robust unit that's easy to setup, maintain and enjoy.