4.777 and LSD
 

Hey Guys,

BACKGROUND
I just had the OEM 4.777 diff installed. To avoid having my car in the shop for a couple of days, I had them install it on a back end they had in stock at their shop and we just swapped back ends after the diff was installed.

When they cracked open the back end of the one they had in stock, the LSD was shot and could not be repaired with a new part -- too far gone. The LSD did not seem heavy duty, when looking at it, and after doing some research, it seems that many 8's blow it i out, so maybe my existing one was shot to??? Anyways I told them to proceed and if I didn't like it, I could just go back to my exisiting rear end and diff.

DECISION
So it turns out that I LOVE the 4.777 gearing and my former diff had a functional LSD. So if I hit a corner hard now, the back end will slide out -- not a big issue as a DD but am worried about what will happen at the track (track day coming up soon). So the decision I need to make is...

1. Do I get them to put the 4.777 gear into my old rear end to restore the OEM LSD functionality

(or)

2. Upgrade LSD to an after market one for better performance. My concern here from what I have read so far is added noise and more frequent maintenance. Founded? Which LSD is best?

I am looking for better performance but I only track 3 to 4 times a summer and otherwise it is used as a DD in the summer only (winter stored). As such, I don't want a solution that is good for the track only, it has to be an excellent choice for DD as well.

Thoughts?

Kaaz is the way to go for the LSD if you were to upgrade.

Imo 1!

Here we go again.

Nevermore. :lol:

If you are planning to track the car then get a new LSD. As for increased maintenance and proper function steer away from differentials with carbon discs. They have different temperature ranges and way too frequent maintenance.

I don't think that Kaaz differentials are bad at all but you might want to look what carbonetics has got to offer as well as cusco.
Then you should clear your mind on what diff. to buy. 1, 1.5 or 2 ways? :)

No I was going to elaborate on personal experiences from the past but what do I know...I am just ignoring the part in an engaging conversation with you.

It is rather old.

Continue.

Like BSE said it comes down to preferences and I just had a really good exp with Kaaz.

Sure but I wouldn't push the Kaaz if I didn't believe in it. My Margin on it is less than 10% anyway. More of a convenience when you do a complete swap/rebuild.

The Car that I drove that had the Kaaz was a GSR so it wasn't an RX-8 per say. But, when I drove it on the course when it was upgraded was night and day as I had driven his car before and was very pleased with the end result.

I will be doing a Kaaz upgrade on my car, I will post my feedback then when it is complete along with my 5 speed swap in the not so distant future I will post more.

I have the Feed 4.777 + the Kaaz 2way and they work very well, are great for track and for drift use.

:yesnod:

Thanks for the perspective Brice. As I understand it, Kaaz recommends it's own oil, correct? How often does that need to be changed, do you know?

Any particular reason that you went 2 way as opposed to 1.5?

How noisy do you find it for DD?

It is perfect for drifting, at least in my opinion.

And yes, it is a bit noisy when you maneuver to park the car or when you turn very slow, etc. The more angle the more noise you get, I mean if you are slow and steering a lot you get a lof of difference of speed between the wheels, so more noise. (oh my horrible english!!!!sorry)

Yes they do but that is their recommendations. As for how often that I am unsure about.

I thought your English was good, being that you are from Spain.

Scott, the noise factor you will get over, you don't get into a diff and be concerned about noise it is just one of those things. Being that this is a daily driver it may be a challenge for you to over come that concern.

IMO if you track the car in anyway, well worth the money.

The noise can be annoying, true, but in the end both the 4.777 ring and pinion and the LSD are upgrades that are strictly track\"fun" aimed so you can't have the best of both worlds.

The 2 way diff is real fun to drift with, for other types of drive styles i would like to keep it 1 way or 1.5 but that's just personal preference. I don't like 2 way diffs that are too hard while decelerating. Beside from my own preference though a 1 or 1.5 way diff. might be slightly safer to operate in traffic, like when you get out of a turn on a rainy day and find a traffic light or a traffic jam :p

Dumb question but what does the LSD do versus traction control?

http://en.wikipedia.org/wiki/Limited_slip_differential here you go for the differential. It is fairly complete even if i wouldn't take it as definitive :)

I ran a Kaaz 1.5 way on my Miata, then switched to a true 2 way diff from OS Giken later.

2 way is pretty much crap for DD. I would not recommend it to anyone that plans to drive their car on the streets. When the roads get slick from rain, you have to REALLY watch yourself with a 2 way LSD. 15-20 mph right handers almost always turn into a steer-throttle modulation-correct affair.

The 1.5 way from Kaaz was definitely a good compromise between a full 2 way and a stock Torsen.

be advised that the KAAZ comes setup up from the factory at 100% differential, but can have the clutchpack discs swapped around to also provide 65% or 35%, you can specify this when ordering it and KAAZ USA will make the change for a small fee (was $25 several years ago)

100% - drifting
65% - track & autox competition/high performance applications
35% - street cars

this is likely the cause of the rain issue, not 1.5 way vs 2 way, believe I posted the clutch pack orientation information in PDF format on the website previously

KAAZ also offers a special "WPC" clutchpack friction-surface treatment as an option, I would recommend this for competition vehicles

Anyone know anything about the Carbon vs metal LSD's? Info here too.

The carbon diff. is absolutely not meant for street use in my opinion.
The clutches work at a different operating range, maintenance must be done often and only proper oils can be used. You should do an oil change every 3000km or so, depending on the use.

Team, could you be so kind to point us out to that pdf for, as far as you say that it has nothing to do with 1.5 vs 2 way diffs i'd still prefer a 1.5 over a 2ways one at the track and would like to read more.

It's on my other computer, I'll post it the next time I fire it up, you can always call and talk to Ray @ KAAZ USA

Team, no feedback on carbon LSD's?

see attached