OS Giken - Is it worth it??

Looking for info on benefits of OS Giken diff. Running HPF stage 2.5. I know that Mike (Mspired) has indicated that it works well, looking for views of others, particularly any significant advantage for straight pulls. (Mike, I sent you a PM, call me!!)
TKS

I've enjoyed mine thus far. The only thing you might want to think about getting done before install is have OSG tighten up the gears inside. The stock OSG diff is set run for cars with I think it's either 700hp or 800hp and down. You might think it won't effect you but it might. What happens is when go to press the gas when you stomp or press ing the gas with moderate pressure after the car is coasting for a few seconds. It feels like something bumps the back of the car. The gears just have a little play in them. Just need to be tighten. Easier to do before you put it in. Ask me how I know.

I just got the OS Giken TCD which is apparently better than there Super lock version but I won't be able to test it out until next season but I will let SP know what you said Maverick thanks for the tip

Perhaps look into a Quaife or Torsen LSD. These use a series of worm gears, and thus have no clutch plates to grow concerned about as the plates wear down from use.

Hey Jake,

when I first changed from stock to OSGiken diff, I felt it had changed my car substantially. I used to go always sideways (towards the left side) on every pull and that was on ST2 p+m so I HIGHLY feel it improved the car.
The second major change that helped the car quite a bit for highway pulls was to open up the diff again and move to 3.91. The car feels like it's in the power all the time I feel like driving a bit spirited ... the only down side to it it that you have have to change to 5th for 60-130 pulls, at least for me...

The clutch plates are claimed to be virtually wear proof. They are not a typical item that ever needs replacing.

In a recent press release from the OS Giken team,it was stated that “since released to the public in 2000, there have been ZERO failures of a production unit, and ZERO rebuilds necessary at any level, from street use to professional racing.”

There is none better as far as I have been able to find out.

Originally Posted by MaverickM3

I've enjoyed mine thus far. The only thing you might want to think about getting done before install is have OSG tighten up the gears inside. The stock OSG diff is set run for cars with I think it's either 700hp or 800hp and down. You might think it won't effect you but it might. What happens is when go to press the gas when you stomp or press ing the gas with moderate pressure after the car is coasting for a few seconds. It feels like something bumps the back of the car. The gears just have a little play in them. Just need to be tighten. Easier to do before you put it in. Ask me how I know.

Factory does this also a bit, maybe cuz I have solid everything in the rear its more noticable. however it doesnt FEEL anything just hear, so with the OS you actually feel it?

Thanks!! Really appreciate all the feedback!

Originally Posted by MaverickM3

I've enjoyed mine thus far. The only thing you might want to think about getting done before install is have OSG tighten up the gears inside. The stock OSG diff is set run for cars with I think it's either 700hp or 800hp and down. You might think it won't effect you but it might. What happens is when go to press the gas when you stomp or press ing the gas with moderate pressure after the car is coasting for a few seconds. It feels like something bumps the back of the car. The gears just have a little play in them. Just need to be tighten. Easier to do before you put it in. Ask me how I know.

So the pinion depth was off? I'm confused by this statement, horsepower has little to do with the tolerances of a diff. Maybe I'm wrong here. What did the manufacture say they did? Or claim to do to fix the issue? Someone please learn me on this.

First let me say there is nothing wrong with the Stock OSG diff. It's just not set from the factory(OSG) to handle 900+ hp. It absolutely can handle the power though! I love mine. Period. Call and ask them about it(OSG).

:Edit: Will draw picture later showing what I'm talking about. To hard to try and describe thus fully at 8:30 in the morning. Lol

Originally Posted by MaverickM3

First let me say there is nothing wrong with the Stock OSG diff. It's just not set from the factory(OSG) to handle 900+ hp. It absolutely can handle the power though! I love mine. Period. Call and ask them about it(OSG).

You didn't inquire what the issue was? I don't really have enough information to make a phone on your behalf. I wonder what they change to allow it to handle 900hp+

Originally Posted by xixixi

You didn't inquire what the issue was? I don't really have enough information to make a phone on your behalf. I wonder what they change to allow it to handle 900hp+

It sounds like only a minor adjsutment. As it sits the OSG canhandle HUGE amounts of power. I will find out just what the limit is. Beyond what any of us have I am sure.

- Lock progression timing can be adjusted by using stiffer / weaker pressure ring springs.

This is what Maverick is talking about. Evidently MINOR changes can be made simply by tightening some things up. My installers did this. I just asked them.

Lock progression is how fast the lock up comes. On some of our builds, the sheer POWER and torque may cause the OSG LSD lock up to come a little too FAST in the set up OUT OF THE BOX, which will result in a noise(clunk) and maybe a shudder, especially if you have solid mounting of your sub frame or the stiff AKG BLACK polys for bushings. Not to worry. There are ALL sorts of ways to set up the OSG super lock up specifically to your build.

It is a simple matter to send a dyno sheet to OSG and tell them how well your tires grip. I would give them the compound, size etc...as much info as you can to aid them. In turn they will set their LSD to optimum lock up SPEED so you dont get any clunk or shudder by having a too fast/too loose a set up. I dont think anything radical needs to be done. Only minor tweaking.

I urge you to read their website. I dont think they fabricate their testimonials.

BTW, I posted a similar inquiry thread (a while back)when I was considering spending the sizable fee to buy their Super Lock Up LSD. I bought it in VERY good faith after extensive research and listening to owners' feedback.

try these links:

http://www.osgiken.net/products.php?product=lsd
http://www.osgiken.net/racing.php

I felt that the OSG website was far more than a sales pitch. I found it full of explanations to questions I had not even thought to ask. I carefully read every single testimonial as well. Very interesting reading. It is an awesome website. Take your time. There is a LOT of information.

And yes. The OSG is designed to help a lot at the drag strip, HPDE and on the street too!

I emailed OSG with a link to this thread so they can address ALL the concerns very accurately. I have spoken to them many times. I never felt at any time they were blowing smoke. So, give it a few days and I will post their replies.

BTW, yes, I have felt at sometimes a few OTHER manufactures of aftermarket BMW performance products were not 100% forth coming. Rare. Most companies are just plain good at what they make and are honest with their replies. I will give you a copy and paste reply from OSG, so you can make up your own minds.

Originally Posted by MaverickM3

First let me say there is nothing wrong with the Stock OSG diff. It's just not set from the factory(OSG) to handle 900+ hp. It absolutely can handle the power though! I love mine. Period. Call and ask them about it(OSG).

:Edit: Will draw picture later showing what I'm talking about. To hard to try and describe thus fully at 8:30 in the morning. Lol

Originally Posted by dragosid

Hey Jake,

when I first changed from stock to OSGiken diff, I felt it had changed my car substantially. I used to go always sideways (towards the left side) on every pull and that was on ST2 p+m so I HIGHLY feel it improved the car.
The second major change that helped the car quite a bit for highway pulls was to open up the diff again and move to 3.91. The car feels like it's in the power all the time I feel like driving a bit spirited ... the only down side to it it that you have have to change to 5th for 60-130 pulls, at least for me...

Thanks for this. So, my stage 2.5 makes 750whp and almost never goes sideways, just straight spin. I am running 305 DR's and have full traction in 3rd usually, but limited in 2nd. Mspired, seemed to indicate that he had full traction in 2nd. What I'm trying to get a view on is if anyone can comment on specifically improving traction in 2nd. If I can obtain significant improvement in 2nd gear traction then probably worth it to me, otherwise going to probably pass. Any thoughts appreciated.
TKS

Originally Posted by JakeR

Thanks for this. So, my stage 2.5 makes 750whp and almost never goes sideways, just straight spin. I am running 305 DR's and have full traction in 3rd usually, but limited in 2nd. Mspired, seemed to indicate that he had full traction in 2nd. What I'm trying to get a view on is if anyone can comment on specifically improving traction in 2nd. If I can obtain significant improvement in 2nd gear traction then probably worth it to me, otherwise going to probably pass. Any thoughts appreciated.
TKS

Mspired has the old turbo, with the older turbo i easily made traction in second with the MT's which I believe he has and is referring to when he talks about traction, correct me if im wrong. however with the new 67 and the way the power comes on its alot different. I have had both turbos, and ran with my MT's on each, made traction in second on old turbo, not so well on new turbo. Now my clutch is toast and im in the process of refreshing it, I had a little over 30k miles on my clutch.

Originally Posted by InDiGlOM3

Mspired has the old turbo, with the older turbo i easily made traction in second with the MT's which I believe he has and is referring to when he talks about traction, correct me if im wrong. however with the new 67 and the way the power comes on its alot different. I have had both turbos, and ran with my MT's on each, made traction in second on old turbo, not so well on new turbo. Now my clutch is toast and im in the process of refreshing it, I had a little over 30k miles on my clutch.

So, if you assume primary reason for purchase was to improve traction in 2nd gear, would you spend the money. I dont need full traction in 2nd, but how would you rate the improvement in 2nd gear traction ..... minimal, moderate, substantial....
TKS

Originally Posted by 02black330ci

Holy GRAIL did you just hit the nail in the head

I think you guys are going off into the wrong direction, the 2nd post is full of the same. A diff needed adjustments to run more hp? No information related to the topic has been brought to light. I am all for stoning people, lets be indiscriminate. Does hp effect the tolerances within a differential, my opinion is no. If you wanna nail people to the cross from a technical POV, I'll bring the hammer. What was the fix mav? What did they do? What was the reason behind what they had to do. What tolerances were to loose to run 900hp vs 750hp. Anything? Maybe the dealers are willing to provide this information to their potential stage 4+ customers. Maybe hp has nothing to do with the tolerances in your diff, maybe no one knows. Educate us!

I believe Mav was referencing the activation of extra clutches inside the diff from the factory...regardless it's been a while since he was told that info by HPF and who knows what info they had referenced him on the subject.

Originally Posted by Commanderwiggin

I believe Mav was referencing the activation of extra clutches inside the diff from the factory...regardless it's been a while since he was told that info by HPF and who knows what info they had referenced him on the subject.

I have not had mine tightened but I have driven mavericks car with the extra clutch packs tightened and mine with doesn't have them tightened and the difference is pretty big. Like described.. It's a little thunk when getting on the gas, sounds like gear lash but it's the clutch packs. I would definitely recommend sending it in to OS Giken before installing.

Both Chris and I have given the OS Giken a serious beating and it's held up phenomenally.

Here are some fun facts...OSG will be better for straight line accel because it locks up quicker than OEM...on cornering or before the corner this will also lock up the rear so if you track the car it may not be what you want. IMO the OSG isn't needed.

Was mavericks car tightened by hpf or is giken? I am going to email the rep at OSG I'm dealing with to see if the TCD diff is the same

Originally Posted by MarcusLSB

I have not had mine tightened but I have driven mavericks car with the extra clutch packs tightened and mine with doesn't have them tightened and the difference is pretty big. Like described.. It's a little thunk when getting on the gas, sounds like gear lash but it's the clutch packs. I would definitely recommend sending it in to OS Giken before installing.

Both Chris and I have given the OS Giken a serious beating and it's held up phenomenally.

Read about the TCD diff OSG offers you may change your post

Originally Posted by Commanderwiggin

Here are some fun facts...OSG will be better for straight line accel because it locks up quicker than OEM...on cornering or before the corner this will also lock up the rear so if you track the car it may not be what you want. IMO the OSG isn't needed.