Question for LSD guru

YokoAE86
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Question for LSD guru

Postby YokoAE86 » Thu Mar 28, 2013 1:55 am

Hey Guys

Has anyone has experience of TRD 2 way LSD and the Cusco RS 2 way LSD. Which one is better. My existing OEM LSD is fooked and i don't want to repair it with the WEIR kit. TRD are telling me that their 2 way is discountinued.

Can anyone with some real experience give me some feedback. Which one is harsher on the axle? Which one is noiseier? Which one locks faster or better?

thanks

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gotzoom?
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Re: Question for LSD guru

Postby gotzoom? » Thu Mar 28, 2013 8:42 am

I have a TRD 2-way and a Tomei T-traxx. Between the two, the Tomei works vastly better. It hooks up better and makes the car turn better. Both allow me to spin up the inside wheel if I am running too much rear swaybar, though, so if you're expecting spool-like lockup, you're not going to get it. I have no experience with the Cusco, but at nearly half the price, the Tomei is a good way to go, imo. Chatter and noise are all about the gear oil you use. I have run a variety of oils in diffs over the years and the one I found to work the best on clutch diffs is Motul 90PA. I had a lot of chatter when I first got the Tomei diff and used the gear oil that came with it. After changing to the Motul oil, I have no chattering at all.

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Re: Question for LSD guru

Postby Deuce Cam » Thu Mar 28, 2013 11:29 am

The Tomei unit is the least expensive and it's basically the same as the kaaz and cusco units.

I have a cusco 1.5 rs and it works great and locks hard, but it's also obnoxiously loud. I wouldn't recommend it for a street car.

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Re: Question for LSD guru

Postby kouki1986 » Thu Mar 28, 2013 11:55 am

Kaaz is bearable noise and their also cheaper.
Cusco a bit higher on price and it is as noisy as kaaz but a little better performance in my opinion.
Tomei is good for over all performance but is not comfortable for daily drive.
OS Giken is the most quiet compare to those 3 brands above, also better over all performance and not a problem for daily is like having a stock lsd. But, the down side is, their very expensive.
I've never experience the TRD so I can't tell you about them all I do know is that they are rare and if something's go wrong parts is not going to be available.

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Re: Question for LSD guru

Postby chohdog » Thu Mar 28, 2013 1:16 pm

It hooks up better and makes the car turn better. Both allow me to spin up the inside wheel if I am running too much rear swaybar, though, so if you're expecting spool-like lockup, you're not going to get it.

Doesn't that mean your LSD isn't working? You're not supposed to just spin the inside wheel without the outside wheel spinning too. There shouldn't be that big of a differential in torque application if the LSD is functioning.

Purchase what it easier to service according to your location, budget, and access to resources. Cusco has very good support in the USA, and rebuild kits are very easy to get. TRD in theory has dealer support, but it really depends on your parts guy. Some are sympathetic to your cause, others don't care about you unless you're buying oil filters in bulk.

Since you're asking specifically about Cusco and TRD, here's my take on both. Cusco will last longer, has a more technologically advanced design and overall is the better LSD. Just about the only thing that is a con, is that the entry price is very high.

TRD is the most used LSD for AE86 ever. It has more competition usage under its belt, is tried and true, and is technically less aggressive on drivetrain components. Its also discontinued by TRD but very cheap on the used market. Watch old and new option video, and chances are if there is an AE86 drifting, road racing, ice racing or whatever, its using a TRD (even though the other brands were available at that time). The downside, is that it has the least amount of clutch plates within to wear, causing increased wear rate which means rebuilds at a more frequent rate. TRD rebuild kits are also harder to come by.

With that being said, one of my best friends has Cusco, and he loves it. He also taught me most of what I know about the AE86. He's had his for like 10 years and only had to rebuild it once. I have TRD, bought i used, and had to rebuild it once. Since the rebuild however, it hasn't skipped a beat. This was 6 years ago, but I also cryo treated the clutch plates for a reduction in operating temperature which, in theory, reduces the amount of service needed. I have access to TRD very easily though.

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Re: Question for LSD guru

Postby Deuce Cam » Thu Mar 28, 2013 1:51 pm

Another thing to consider is that the aftermarket clutch lsd's can be adjusted for different lockup rates. They're set at 100% lockup from the factory, but I know at least the cusco unit can also be set at 60% or 80% lockup which won't be as hard on the drivetrain as the default setting. The only downside is the lsd unit has to be disassembled to make the adjustments.

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Re: Question for LSD guru

Postby gotzoom? » Thu Mar 28, 2013 3:56 pm

chohdog wrote:Doesn't that mean your LSD isn't working? You're not supposed to just spin the inside wheel without the outside wheel spinning too. There shouldn't be that big of a differential in torque application if the LSD is functioning.


Nope. It's functioning perfectly and has less than 1500 miles on it. It's much easier to unload a live axle inside rear than it is a car with an independent rear suspension. ALL limited slip diffs will spin the inside rear if you take enough weight off of them. If it doesn't do that, it's no longer called a diff, it's called a spool. Having a Whiteline adjustable rear swaybar allows you to tune it out of the car, though.

I also disagree that the Tomei, at least, isn't suitable for daily driving. It makes no noise whatsoever that I can hear. It does make the car a lot more fun to drive, so I guess it would be easier to get a ticket for doing something dumb. I think the TRD diff was the business 30 years ago when it was designed, but the newer designs are vastly superior in peformance.

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Re: Question for LSD guru

Postby Yosuke » Thu Mar 28, 2013 11:14 pm

Deuce Cam wrote:The Tomei unit is the least expensive and it's basically the same as the kaaz and cusco units.

I have a cusco 1.5 rs and it works great and locks hard, but it's also obnoxiously loud. I wouldn't recommend it for a street car.


The Tomei Technical Trax LSD uses the same casing as the Kaaz but both come setup with different initial torque rating from the factory. These both along with the TRD have a cone spring on the outside of the clutch plates which acts as a spring when torque is activated. (LSD activation is out to in)

Unlike other LSD manufacturers, keep in mind that Cusco has 5~6 different LSD models available. The Cusco Type RS unit has small internal springs inside the pressure plates. (LSD activation is in to out)

What you're saying being the same as Tomei and Kaaz is the Cusco Type MZ. This one structurally similar to the TRD, Tomei, Kaaz, & ATS which has cone springs on the outside of the clutch plates. (LSD activation is out to in)

I also agree with you Deuce Cam, the Tomei unit is one of the best diffs out of the box that i have used without having to open it up and adjust. And their prices are outrageously good for still being made in Japan.
And about your diff, you can adjust your Cusco Type RS LSD locking rate by rearranging the clutch plate combinations to allow only 60~80% lock. There are also flat friction plates available too; which are clutch plates without any grooves on them to allow slippage.

But then again, all mechanical LSDs react VERY differently with the type of gear oils out there, and there are many brands that are on the market as well as friction modifier agents. These fluids change LSD characteristics dramatically, so its best to set it up mechanically the way you like it, and use the manufacturer suggested fluids.
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Re: Question for LSD guru

Postby Deuce Cam » Thu Mar 28, 2013 11:30 pm

Thanks for your post Yosuke. Your insight is welcome.

Perhaps my "basically the same" comment was too much of a generalization as I'm no expert. I was hoping someone more knowledgeable would elaborate and post specifics, thank you.

In all fairness for the cusco unit, I probably should have used the cusco 80w-140 oil from the get go per the manufacturer's recommendation. I was deterred by the price though. Initially I tried Motul 90pa - no good, then Motul 90pa with 1 bottle of motorcraft friction modifier - slightly better but still not good, then Valvoline 85w-140 ns with 1 bottle of motorcraft friction modifier - better yet, but still very intense. I have yet to try anything else.

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Re: Question for LSD guru

Postby siman » Fri Mar 29, 2013 4:50 am

I have a group run of the new kaaz lsd in my mr2 its much quieter than the normal kaaz was. Its worth looking into if you want a better,quieter, performance lsd. I just dont think they have the over counter one available yet. O they also say the rebuild interval is much longer than the normal kaaz was but i haven't needed to do mine yet

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Re: Question for LSD guru

Postby siman » Fri Mar 29, 2013 4:53 am

siman wrote:I have a group run of the new kaaz lsd in my mr2 its much quieter than the normal kaaz was. Its worth looking into if you want a better,quieter, performance lsd. I just dont think they have the over counter one available yet. O they also say the rebuild interval is much longer than the normal kaaz was but i haven't needed to do mine yet


Update its called the superq

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Re: Question for LSD guru

Postby YokoAE86 » Sun Mar 31, 2013 12:50 am

Thanks everyone for your feedback. Thanks Yosuke.

I'm going to look at the Tomei LSD as another option now. Does anyone know whetether the Tomei LSD can be adjusted to 60 or 80% lockup like the Cusco RS one?

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Re: Question for LSD guru

Postby Deuce Cam » Sun Mar 31, 2013 1:11 am

There's a bunch of info on the Tomei USA website. They indication that initial tq. can be increased from the default setting so they may not have it at 100% from the factory. It's probably best to contact them directly for specifics.

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Re: Question for LSD guru

Postby Yosuke » Sun Mar 31, 2013 4:27 pm

YokoAE86 wrote:Thanks everyone for your feedback. Thanks Yosuke.

I'm going to look at the Tomei LSD as another option now. Does anyone know whetether the Tomei LSD can be adjusted to 60 or 80% lockup like the Cusco RS one?

Higher the initial Tq, higher response characteristics
Higher the cam angle degree, faster lockup response

Tomei LSD
Initial Tq: 5.0~6.0kg.m
Cam angle: (2way) 45 x 45

Cusco Type RS LSD
Initial Tq: 7~9 kg.m
Cam angle: (1.5 way) 55 x 20, (2 way) 55 x 55

Cusco Type MZ LSD
Initial Tq: 10~12 kg.m
Cam angle: (1.5 way) 55 x 20, (2 way) 55 x 55

Not too sure but I believe Tomei may have theirs set 100% from factory so yeah, best to contact them and ask. I know as an option that they have a thicker cone spring to slightly increase the initial tq for the AE86 applications.

*Also, in some cases dropping the lockup rating from 100% to 80% may not have much effect on some vehicles. Note that there are other factors to consider like the type of LSD, suspension setting, turn radius, tire compound, and overall- engine power output.

The info above is based on LSDs equipped with metal clutch plates, Carbon clutch plates have a different effect in terms of "feeling" despite what their numbers indicate.
Last edited by Yosuke on Sun Mar 31, 2013 4:32 pm, edited 1 time in total.
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Re: Question for LSD guru

Postby Yosuke » Sun Mar 31, 2013 4:30 pm

siman wrote:
siman wrote:I have a group run of the new kaaz lsd in my mr2 its much quieter than the normal kaaz was. Its worth looking into if you want a better,quieter, performance lsd. I just dont think they have the over counter one available yet. O they also say the rebuild interval is much longer than the normal kaaz was but i haven't needed to do mine yet


Update its called the superq


Kaaz Super Q, as in Super Quiet? lol This may be another great choice for those who street their cars.
http://www.kaazusa.com/superq/
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Re: Question for LSD guru

Postby 16v Justice » Sun Mar 31, 2013 5:43 pm

I have a TRD LSD, it's a pretty smooth operating LSD. It's as quiet as stock, and lockup is smooth and linear. It's not super aggressive feeling, but it works great and is a great choice for a street driven car.
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