Speed Freaks USA group buy for OS Giken LSD
#17
I have been wanting to make the jump to OS Giken in my own car for a while after talking to friends/customers who have them and driving a couple different cars with them. My factory torsen is officially trashed after 65,000 miles and countless track days so now I have an excuse and even I will be jumping in on this
All PMs replied!
-Matt M.
Last edited by SpeedFreaksUSA; 03-05-15 at 11:04 PM.
#19
Tech Info Resource
iTrader: (2)
If you want this done right, go to a shop specializing in truck driveline repair who will work on automotive projects. The trucking industry has very high expertise in differential set up. Going to a "tuner" shop would likely be disappointing at best.
#25
Updated the OP.
We are so close to the maximum discount level! We are still waiting to hear back from a few people and are finalizing pricing with our diff builder so we can provide a service to those who would like to have us do the rebuild. Because of this we have decided to extend the group buy until this Friday (March 13). Once the group buy is closed we will ask for deposits from those on the list and we will have an official discount level once all the deposits are in. *If you are not on the list by Friday, you will not be eligible for the group buy pricing*
We are so close to the maximum discount level! We are still waiting to hear back from a few people and are finalizing pricing with our diff builder so we can provide a service to those who would like to have us do the rebuild. Because of this we have decided to extend the group buy until this Friday (March 13). Once the group buy is closed we will ask for deposits from those on the list and we will have an official discount level once all the deposits are in. *If you are not on the list by Friday, you will not be eligible for the group buy pricing*
#28
As a Toyota/Lexus performance enthusiast and an OS Giken TCD owner, I'm hoping to see many IS-F owners take the plunge by upgrading to the OS Giken TCD with this group buy. Considering that the majority of IS-Fs are the 08-09 model equipped with an open differential (which is the weakest link of the vehicle), adding a competition-grade clutch differential like the OS Giken TCD unit will help make a significant improvement to your lap time (via allowing much faster cornering speeds) if you like taking your IS-F to the track as well as overall spirited driving enjoyment during your daily drives.
From talking with OS Giken reps over the past two years, I've learned that the Lexus IS-F and IS350 are some of the few models which are lucky enough to have BOTH the full 28 clutch-pack set-up (other OS Giken LSDs tend to have less clutch packs due to the size of the smaller differential housing) as well as having the option of the higher-performance TCD model (most models only have the original Super Lock LSD as their sole choice).
If you need more convincing on how well the OS Giken TCD performs, take a look at this video and blog entry from Cobbs Motorsports which used the same 28 clutch plate OS Giken TCD for their 800awhp track GT-R:
From talking with OS Giken reps over the past two years, I've learned that the Lexus IS-F and IS350 are some of the few models which are lucky enough to have BOTH the full 28 clutch-pack set-up (other OS Giken LSDs tend to have less clutch packs due to the size of the smaller differential housing) as well as having the option of the higher-performance TCD model (most models only have the original Super Lock LSD as their sole choice).
If you need more convincing on how well the OS Giken TCD performs, take a look at this video and blog entry from Cobbs Motorsports which used the same 28 clutch plate OS Giken TCD for their 800awhp track GT-R:
Originally Posted by Cobbs Motorsports
http://blogs.cobbtuning.com/2010/03/...iken-rear-lsd/
The COBB Tuning Motorsports team and I just got back from our first weekend of testing at California Speedway with the new OS Giken TCD rear Limited Slip Differential (LSD) upgrade for our GT-R. With nearly 800HP available at the wheels, I had been experiencing significant rear wheel spin on corner exit that was obviously hurting the car’s ability to put power down coming out of the turns and hurting our lap times.
During the install the OS Giken LSD looked quite a bit beefier than the stock part it was replacing. Probably because it has a grand total of 28 friction plates inside! These plates can be configured to provide progressive locking up to 100% and with that many plates there are quite a lot of tuning options for us to fine tune the amount of lock-up we want.
My first impression was “WOW!” What a difference the TCD LSD made! As I started my first hot laps I could feel the difference in the rear of the car. Now the chassis just seemed to hunch down in the back and squirt out of the corners with no rear inside wheel spin at all. Plus it was much easier to use the throttle to help steer the car out of the corners. With the inside wheel spin gone, I could easily modulate rear slip angle with my right foot, encouraging corner exit rotation by feeding in just a bit more throttle.
As they say, the proof is in the data, and we have data. In this first screen shot is data from last year with the stock rear differential. Focus on the section where throttle position begins to increase and look at the difference in rear wheel speeds. At some points there is as much as a 14 mph difference between the rear wheels. And this was on super sticky Hoosier R100 slick racing tires!
This next screen shot is from data recorded during our test day with the OS Giken TCD LSD installed. Looking at the wheel speeds you can see they are much closer together and how much the rear differential is working. It allows a small amount of slip under deceleration, and locks up 100% under acceleration. In fact you can see that for most of the graph the left and right rear wheel speeds are so close they are indistinguishable from each other. What makes this even more impressive is that we were running on Toyo RA1 DOT racing tires. DOT race tires are not nearly as sticky as the pure racing slicks we used last year, so it is clear to see how effective the OS Giken rear diff is, even with much less traction from the tires.
http://blogs.cobbtuning.com/2010/03/...iken-rear-lsd/
The COBB Tuning Motorsports team and I just got back from our first weekend of testing at California Speedway with the new OS Giken TCD rear Limited Slip Differential (LSD) upgrade for our GT-R. With nearly 800HP available at the wheels, I had been experiencing significant rear wheel spin on corner exit that was obviously hurting the car’s ability to put power down coming out of the turns and hurting our lap times.
During the install the OS Giken LSD looked quite a bit beefier than the stock part it was replacing. Probably because it has a grand total of 28 friction plates inside! These plates can be configured to provide progressive locking up to 100% and with that many plates there are quite a lot of tuning options for us to fine tune the amount of lock-up we want.
My first impression was “WOW!” What a difference the TCD LSD made! As I started my first hot laps I could feel the difference in the rear of the car. Now the chassis just seemed to hunch down in the back and squirt out of the corners with no rear inside wheel spin at all. Plus it was much easier to use the throttle to help steer the car out of the corners. With the inside wheel spin gone, I could easily modulate rear slip angle with my right foot, encouraging corner exit rotation by feeding in just a bit more throttle.
As they say, the proof is in the data, and we have data. In this first screen shot is data from last year with the stock rear differential. Focus on the section where throttle position begins to increase and look at the difference in rear wheel speeds. At some points there is as much as a 14 mph difference between the rear wheels. And this was on super sticky Hoosier R100 slick racing tires!
This next screen shot is from data recorded during our test day with the OS Giken TCD LSD installed. Looking at the wheel speeds you can see they are much closer together and how much the rear differential is working. It allows a small amount of slip under deceleration, and locks up 100% under acceleration. In fact you can see that for most of the graph the left and right rear wheel speeds are so close they are indistinguishable from each other. What makes this even more impressive is that we were running on Toyo RA1 DOT racing tires. DOT race tires are not nearly as sticky as the pure racing slicks we used last year, so it is clear to see how effective the OS Giken rear diff is, even with much less traction from the tires.
Last edited by redspencer; 03-11-15 at 06:26 AM.
#29
Pole Position
^^^^You gotta love the power that those modified GTR's put down! Seen a few around here at a local car meet that were putting down 900-1100 hp to the wheel!!
Great endorsement for the OS Giken LSD
I wonder what the heck he was chasing down on the road course, whatever it was it was quick!
Great endorsement for the OS Giken LSD
I wonder what the heck he was chasing down on the road course, whatever it was it was quick!