3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.
Sponsored by:

Clutch pack diffs for FDs

Thread Tools
 
Search this Thread
 
Old 01-09-23, 08:06 PM
  #1  
Eats, Sleeps, Dreams Rotary

Thread Starter
 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,732
Received 88 Likes on 64 Posts
Clutch pack diffs for FDs

Can anyone point me in the right direction for what brand, type, and initial torque setting will make my FD as fast as possible on the track without too much understeer?
Old 01-09-23, 08:42 PM
  #2  
rotary amuse

iTrader: (12)
 
ZumSpeedRX-7's Avatar
 
Join Date: May 2003
Location: Massachusetts
Posts: 2,878
Received 237 Likes on 124 Posts
I haven't played around with it much to make it the fastest setup as possible, but I have had good success on track with my Cusco RS 1.5way set to 100% torque setting.


You'll have some reading to do, but this should be a good guide to get you going

https://www.cusco.co.jp/en/pdf/LSD%20Guide%20Final.pdf
Old 01-09-23, 10:37 PM
  #3  
Eats, Sleeps, Dreams Rotary

Thread Starter
 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,732
Received 88 Likes on 64 Posts
Originally Posted by ZumSpeedRX-7
I haven't played around with it much to make it the fastest setup as possible, but I have had good success on track with my Cusco RS 1.5way set to 100% torque setting.


You'll have some reading to do, but this should be a good guide to get you going

https://www.cusco.co.jp/en/pdf/LSD%20Guide%20Final.pdf
Did you not measure the initial torque before installing it?
Old 01-10-23, 07:20 AM
  #4  
rotary amuse

iTrader: (12)
 
ZumSpeedRX-7's Avatar
 
Join Date: May 2003
Location: Massachusetts
Posts: 2,878
Received 237 Likes on 124 Posts
Installed back in 2005, I don't have the measurements before install. I am generally good with documentation but not that good

To get you in the ballpark, the initial torque setting on the RS 1.5way is a range of 51-65 ft-lbs
Old 01-10-23, 02:57 PM
  #5  
Full Member

 
Billj747's Avatar
 
Join Date: Oct 2006
Location: SoCal
Posts: 210
Received 122 Likes on 64 Posts
Never go full lock on these japanese LSDs.

Some good info here:

https://motoiq.com/project-nsx-part-...-differential/

https://motoiq.com/watch-how-the-os-...ow-to-tune-it/
Old 01-10-23, 06:21 PM
  #6  
Eats, Sleeps, Dreams Rotary

Thread Starter
 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,732
Received 88 Likes on 64 Posts
Originally Posted by ZumSpeedRX-7
Installed back in 2005, I don't have the measurements before install. I am generally good with documentation but not that good

To get you in the ballpark, the initial torque setting on the RS 1.5way is a range of 51-65 ft-lbs
Fair enough, it does require an SST.
There's a used 1/2-way Kaaz I could snag for about $300 about an hour away, but I wonder if I wouldn't regret it after pulling the thing apart for a rebuild, given that labor will cost more than the diff itself.
A new one would cost about $700-800, and in that case I would get a 1.5-way.
Old 01-10-23, 07:15 PM
  #7  
Rotary Motoring

iTrader: (9)
 
BLUE TII's Avatar
 
Join Date: Mar 2001
Location: CA
Posts: 8,214
Received 764 Likes on 506 Posts
The accepted ultimate is OS Giken Super Lock LSD and we in usa purchase the usa locking spec part number for our style driving (less drift biased).

The OS Giken super lock has the highest # of clutch platesof any diff so it can operate in the "grey" area (not fully locked) the best.

My experience-
I hated my FC stock clutch type because it locked hard and gave on throttle understeer unless you powered over into oversteer.
I swapped it out for an FD Torsen for autox. That worked well at 300ftlbs torque, but when I went EFR and 400ftlbs torque the bias ratio was not high enough and it drove like an open diff. Which would kick to the less loaded side on the freeway- sketch.

So for my FD, I put usa spec OS Giken super lock in. It is amazing. One can get on the gas before the apex and drive through the corner with no understeer. Very controllable throttle steer.

I hate understeer and carefully tune my FD so it never understeers.
My FD specs are 0 toe F/R, -2.5 deg F camber, - 1.4 R. Stock R1 rear swaybar, lightest available Tripoint F bar (they told me it is lower rate than stock R1 bar), ohlins 11k/11k and 295-315 front tire 9n 18x11 +45 and same rear.

With OS Giken I will have to add some rear camber now because you get full power to the rear wheel still on the ground (when you are 2 wheeling transitions) instead of the torsen bias ratio slip limiting rear weight transfer/accel.
The following users liked this post:
jkstill (02-10-23)
Old 01-10-23, 08:22 PM
  #8  
Eats, Sleeps, Dreams Rotary

Thread Starter
 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,732
Received 88 Likes on 64 Posts
Originally Posted by BLUE TII
The accepted ultimate is OS Giken Super Lock LSD and we in usa purchase the usa locking spec part number for our style driving (less drift biased).

The OS Giken super lock has the highest # of clutch platesof any diff so it can operate in the "grey" area (not fully locked) the best.

My experience-
I hated my FC stock clutch type because it locked hard and gave on throttle understeer unless you powered over into oversteer.
I swapped it out for an FD Torsen for autox. That worked well at 300ftlbs torque, but when I went EFR and 400ftlbs torque the bias ratio was not high enough and it drove like an open diff. Which would kick to the less loaded side on the freeway- sketch.

So for my FD, I put usa spec OS Giken super lock in. It is amazing. One can get on the gas before the apex and drive through the corner with no understeer. Very controllable throttle steer.

I hate understeer and carefully tune my FD so it never understeers.
My FD specs are 0 toe F/R, -2.5 deg F camber, - 1.4 R. Stock R1 rear swaybar, lightest available Tripoint F bar (they told me it is lower rate than stock R1 bar), ohlins 11k/11k and 295-315 front tire 9n 18x11 +45 and same rear.

With OS Giken I will have to add some rear camber now because you get full power to the rear wheel still on the ground (when you are 2 wheeling transitions) instead of the torsen bias ratio slip limiting rear weight transfer/accel.
The only problem is that the Giken unit costs twice as much as Kaaz...
Old 01-11-23, 03:23 AM
  #9  
Rotary Freak

 
billyboy's Avatar
 
Join Date: Jun 2005
Location: sydney
Posts: 1,533
Received 261 Likes on 199 Posts
What's a 1/2 way, understood there's 1, 1 1/2 and 2 ways? Kazz units are probably the most popular over here for circuit work - mainly due to local support - less an issue there I'm sure!

I see a 1 1/2 out of a late car is on yahoo now and has dropped about 7k yen in the last week or two after having no takers for months. We bought one for 24k some years ago, plates were fine....if predominantly used by boy racers on the street as most of them are, might be worth a punt.
Old 01-11-23, 05:11 AM
  #10  
Eats, Sleeps, Dreams Rotary

Thread Starter
 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,732
Received 88 Likes on 64 Posts
Originally Posted by billyboy
What's a 1/2 way, understood there's 1, 1 1/2 and 2 ways? Kazz units are probably the most popular over here for circuit work - mainly due to local support - less an issue there I'm sure!

I see a 1 1/2 out of a late car is on yahoo now and has dropped about 7k yen in the last week or two after having no takers for months. We bought one for 24k some years ago, plates were fine....if predominantly used by boy racers on the street as most of them are, might be worth a punt.
1-way or 2-way
Old 01-11-23, 06:07 AM
  #11  
Rotor or no motor

iTrader: (24)
 
R-R-Rx7's Avatar
 
Join Date: Oct 2006
Location: Limassol, CYPRUS
Posts: 3,339
Received 369 Likes on 223 Posts
Originally Posted by Valkyrie
The only problem is that the Giken unit costs twice as much as Kaaz...
if you get one from japan now the currency exchange works in your favor

Old 01-11-23, 06:09 AM
  #12  
Rotor or no motor

iTrader: (24)
 
R-R-Rx7's Avatar
 
Join Date: Oct 2006
Location: Limassol, CYPRUS
Posts: 3,339
Received 369 Likes on 223 Posts
Originally Posted by BLUE TII
The accepted ultimate is OS Giken Super Lock LSD and we in usa purchase the usa locking spec part number for our style driving (less drift biased).

The OS Giken super lock has the highest # of clutch platesof any diff so it can operate in the "grey" area (not fully locked) the best.

My experience-
I hated my FC stock clutch type because it locked hard and gave on throttle understeer unless you powered over into oversteer.
I swapped it out for an FD Torsen for autox. That worked well at 300ftlbs torque, but when I went EFR and 400ftlbs torque the bias ratio was not high enough and it drove like an open diff. Which would kick to the less loaded side on the freeway- sketch.

So for my FD, I put usa spec OS Giken super lock in. It is amazing. One can get on the gas before the apex and drive through the corner with no understeer. Very controllable throttle steer.

I hate understeer and carefully tune my FD so it never understeers.
My FD specs are 0 toe F/R, -2.5 deg F camber, - 1.4 R. Stock R1 rear swaybar, lightest available Tripoint F bar (they told me it is lower rate than stock R1 bar), ohlins 11k/11k and 295-315 front tire 9n 18x11 +45 and same rear.

With OS Giken I will have to add some rear camber now because you get full power to the rear wheel still on the ground (when you are 2 wheeling transitions) instead of the torsen bias ratio slip limiting rear weight transfer/accel.
+1 on the os giken. I absolutely loved it. i recently switched to the carbonetics and i did initially regret it and i ordered a brand new os giken from japan. it seems that the carbonetics though has been quiet lately. i guess its that break in period
Old 01-11-23, 08:42 AM
  #13  
RotorRocket

iTrader: (9)
 
Venom-X1's Avatar
 
Join Date: Jul 2004
Location: Austin, TX
Posts: 233
Received 8 Likes on 6 Posts
How noisy is the OS Giken?

I've had my Tomei 1.5 set at full lock since install and it has always been a pain on the street and I've regretted going with it.
I'm even considering going back to the stock torsen for now.
Old 01-11-23, 08:44 AM
  #14  
Rotor or no motor

iTrader: (24)
 
R-R-Rx7's Avatar
 
Join Date: Oct 2006
Location: Limassol, CYPRUS
Posts: 3,339
Received 369 Likes on 223 Posts
not at all. feels like an oem LSD in terms of noise/clunking
The following users liked this post:
Venom-X1 (01-11-23)
Old 01-11-23, 10:32 AM
  #15  
Full Member

 
Billj747's Avatar
 
Join Date: Oct 2006
Location: SoCal
Posts: 210
Received 122 Likes on 64 Posts
OSG and Carbonetics are more steeetable and "clunk" significantly less than Kaaz, Cusco, Tomei. All of which should be set and have at least one set of clutch plates deactivated to reduce lock for road course and especially street use.
Old 01-11-23, 11:17 AM
  #16  
Rotor or no motor

iTrader: (24)
 
R-R-Rx7's Avatar
 
Join Date: Oct 2006
Location: Limassol, CYPRUS
Posts: 3,339
Received 369 Likes on 223 Posts
the carbonetics (carbon lsd) is not as streetable as the os giken even though over time it is quieting down
Old 01-11-23, 11:38 AM
  #17  
Full Member

 
Billj747's Avatar
 
Join Date: Oct 2006
Location: SoCal
Posts: 210
Received 122 Likes on 64 Posts
Originally Posted by R-R-Rx7
the carbonetics (carbon lsd) is not as streetable as the os giken even though over time it is quieting down
Is this on your personal car? How many miles do you have on your LSD? While they can vary, almost every Carbonetics I've driven is as quiet or quieter than OSG.
Old 01-11-23, 04:06 PM
  #18  
Rotor or no motor

iTrader: (24)
 
R-R-Rx7's Avatar
 
Join Date: Oct 2006
Location: Limassol, CYPRUS
Posts: 3,339
Received 369 Likes on 223 Posts
Originally Posted by Billj747
Is this on your personal car? How many miles do you have on your LSD? While they can vary, almost every Carbonetics I've driven is as quiet or quieter than OSG.
i just switched from the osg to the carbonetics after 15 solid years.
Shortly after switching to the carbonetics i ordered an osg and i am currently planning to install it soon. The carbonetics has been on the car for about 4 months.
i hope that answers your question
Old 01-11-23, 04:10 PM
  #19  
Full Member

 
Billj747's Avatar
 
Join Date: Oct 2006
Location: SoCal
Posts: 210
Received 122 Likes on 64 Posts
What diff fluid are you using? That makes a big difference in the chatter of any LSD, but especially Carbonetics.
Old 01-11-23, 04:20 PM
  #20  
Rotor or no motor

iTrader: (24)
 
R-R-Rx7's Avatar
 
Join Date: Oct 2006
Location: Limassol, CYPRUS
Posts: 3,339
Received 369 Likes on 223 Posts
I have been using the redline 80w-140 the green one. I had originally imported the 80w-250 from os giken.

first time i cracked the pumpkin os giken usa suggested the redline as the os giken oil is only available in japan
Old 01-11-23, 05:28 PM
  #21  
Full Member

 
Billj747's Avatar
 
Join Date: Oct 2006
Location: SoCal
Posts: 210
Received 122 Likes on 64 Posts
How many miles is 4 months and have you changed the fluid after you broke in the Carbonetics?

iirc, carbonetics recommends their 80W90 or similar weight for the initial break-in, and many people have had success with Motul Limited Slip 90PA.

Theyve been quieter than OSG in many S2000, 350Z and RSXs that I've driven.


Last edited by Billj747; 01-11-23 at 05:31 PM.
Old 01-11-23, 08:04 PM
  #22  
Eats, Sleeps, Dreams Rotary

Thread Starter
 
Valkyrie's Avatar
 
Join Date: Oct 2004
Location: Japanabama
Posts: 4,732
Received 88 Likes on 64 Posts
Originally Posted by R-R-Rx7
if you get one from japan now the currency exchange works in your favor
lol
Old 01-11-23, 10:21 PM
  #23  
Rotary Motoring

iTrader: (9)
 
BLUE TII's Avatar
 
Join Date: Mar 2001
Location: CA
Posts: 8,214
Received 764 Likes on 506 Posts
I was going to say, if you think the os giken diff is expensive wait till you have to buy the os giken diff fluid. And you do have to buy it.

I originally installed my os giken with motul as that is what came with it and os giken says you can use it in a pinch (2nd hand diff, but new/unused in box).

TeamRX8 pointed out how superior the os giken fluid spec is for viscocity with heat and all those clutch plates generate a lot of heat.

It drove better with OS Giken fluid, it had a stronger lsd feel.


How noisy is the OS Giken?

When I back out of a parking spot with the steering wheel turned hard one way it does clunk and frienda say the inside wheel locks/unlocks.

Other than that there are no noises/downsides. Nothing in forward gears.
Old 01-12-23, 03:54 AM
  #24  
Rotor or no motor

iTrader: (24)
 
R-R-Rx7's Avatar
 
Join Date: Oct 2006
Location: Limassol, CYPRUS
Posts: 3,339
Received 369 Likes on 223 Posts
Originally Posted by Valkyrie
lol
whats so funny?
getting it from japan costs less than 1050 usd shipped

vs

over 1500 locally + shipping
Old 01-12-23, 01:57 PM
  #25  
Rotary Motoring

iTrader: (9)
 
BLUE TII's Avatar
 
Join Date: Mar 2001
Location: CA
Posts: 8,214
Received 764 Likes on 506 Posts
MB

Location: Japanabama


Quick Reply: Clutch pack diffs for FDs



All times are GMT -5. The time now is 08:55 AM.