Got to get a Giken - The ONLY LSD to have.
10-20-2009, 06:25 PM
#1
Got to get a Giken - The ONLY LSD to have.
Hey there everyone,
I am still trying to get used to the rules of posting here, so forgive me if I ask to you do more work then you needed to.
I posted a great post about the new OS Giken differential in the Porsche Cup Car forum. You need to check it out if you are going to be changing out your differential this winter.
It is the only differential to have, and I think that if you take a good look at the pic I attached to the post you will be able to see why.
The Porsche Motorsport differential is a 8 plate differential, where as the OS has more then double the amount of plates.
Let me know if you need one of these or anything else that would be gearbox related, as this is what we do.
Warmest Regards,
Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell
I am still trying to get used to the rules of posting here, so forgive me if I ask to you do more work then you needed to.
I posted a great post about the new OS Giken differential in the Porsche Cup Car forum. You need to check it out if you are going to be changing out your differential this winter.
It is the only differential to have, and I think that if you take a good look at the pic I attached to the post you will be able to see why.
The Porsche Motorsport differential is a 8 plate differential, where as the OS has more then double the amount of plates.
Let me know if you need one of these or anything else that would be gearbox related, as this is what we do.
Warmest Regards,
Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell
10-20-2009, 07:20 PM
#3
Rennlist Member
Don't worry, Erik, you're not violating any rules of posting. Thanks for being a Sponsor!!
But just to help you out, we are a very skeptical bunch with very sensitive B.S. detectors. We're a VERY tough crowd. So claiming a product to be the best when there are commonly-accepted outstanding alternatives (e.g. Guards) is ... well, a bit bold.
I look forward to hearing more about your product! I'm due for a rebuild soon.
But just to help you out, we are a very skeptical bunch with very sensitive B.S. detectors. We're a VERY tough crowd. So claiming a product to be the best when there are commonly-accepted outstanding alternatives (e.g. Guards) is ... well, a bit bold.
I look forward to hearing more about your product! I'm due for a rebuild soon.
10-20-2009, 08:04 PM
#4
Believe me I understand where everyone is coming from here, but take a look at the OS Giken here, and I am sure that you are going understand where I am coming from with regard to saying that even the GT differential, which has always been a very good option in the past does not hold a candle to this differential.
A very bold statement I understand. But since it has been now brought up here are some things to consider when comparing these two.
The GT Differential has always had a similar design the Porsche Motorsport differential, that being a plate type ramping differential. It made it's mark here with the ability to custom choose between two different ramp angles within the same differential. Usually 40/60 and 80/80 but certainly a couple of other options as well. It also features 4, 6 or 8 plates internally, that is 2, 3, or 4 plates per side. It also features a more aggressive friction composition to that of the Porsche Motorsport diff.
Here is the rub. The GT differential has on average a 65 to 85 lbs. breakaway preload. This has shown to cause a couple of issues. The first being that as you enter into a tight turn your car has to overcome this preload in the process of turning in. So what right? That should not make much of a difference. Well actually it does. The more preload there is the harder it will be to get the car to turn, but this is not usually much of a problem as you get used to the differential, and modify your driving to compensate. What is a problem is the material that is removed from the plates inside the differential ever time this happens.
The Porsche Motorsport differential utilizes carbon as the primary friction material in their differentials, the GT diff does not. They use a moly blend, which is then plasma sprayed onto the plates to cause a friction material. This material is highly coarse and reacts in a way to not only lock the differential, which is good, but also remove metal from the opposing plates, which is bad. This combination of friction material and removed metal goes where?? Through out the gearbox, very bad. It especially goes directly into the input and pinion bearings, where it begins to cause problems inside of them as well. VERY VERY Bad.
So how is the OS Giken different? If you review the pic here, you will see that on the ramps themselves are counter springs that help you pull the ramps back to neutral when there is no force applied to them. It essentially reduces the breakaway to a very minimal amount, it basically opens the differential up, releasing the plates, so that you do not get unneeded lockup, and as a result unneeded wear. The friction material is again carbon, but due to the amount of plates which is more then double the GT or the PMS, as well as the way the differential works, they do not suffer from premature wear. Nor do they require the rear of the car to overcome excessive lockup in order to turn the rear end. (the difference in speed between the left and right tire.)
I understand that in the past we have all, including me always gone to GT for the strongest best differential made. I have for years recommended only them for racing applications. However with this new offering, as well as the difference in cost between the two differentials, I can not see how anyone could still do this.
GT Differential, $2,400 to $2,800 give or take.
OS Giken Differential $1,790.00
In the nine year that OS Giken has been making differentials, they have exactly ZERO failures. Now to make this completely understood, that is not just in their Porsche diffs, that is for ALL of their differentials across the board. That to me is pretty impressive.
Check out this pic, I think that if you have ever been inside of a Porsche LSD, no matter who built it, you will see, there is no comparison, and for the moment, no competition to this differential.
Warmest Regards,
Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell
A very bold statement I understand. But since it has been now brought up here are some things to consider when comparing these two.
The GT Differential has always had a similar design the Porsche Motorsport differential, that being a plate type ramping differential. It made it's mark here with the ability to custom choose between two different ramp angles within the same differential. Usually 40/60 and 80/80 but certainly a couple of other options as well. It also features 4, 6 or 8 plates internally, that is 2, 3, or 4 plates per side. It also features a more aggressive friction composition to that of the Porsche Motorsport diff.
Here is the rub. The GT differential has on average a 65 to 85 lbs. breakaway preload. This has shown to cause a couple of issues. The first being that as you enter into a tight turn your car has to overcome this preload in the process of turning in. So what right? That should not make much of a difference. Well actually it does. The more preload there is the harder it will be to get the car to turn, but this is not usually much of a problem as you get used to the differential, and modify your driving to compensate. What is a problem is the material that is removed from the plates inside the differential ever time this happens.
The Porsche Motorsport differential utilizes carbon as the primary friction material in their differentials, the GT diff does not. They use a moly blend, which is then plasma sprayed onto the plates to cause a friction material. This material is highly coarse and reacts in a way to not only lock the differential, which is good, but also remove metal from the opposing plates, which is bad. This combination of friction material and removed metal goes where?? Through out the gearbox, very bad. It especially goes directly into the input and pinion bearings, where it begins to cause problems inside of them as well. VERY VERY Bad.
So how is the OS Giken different? If you review the pic here, you will see that on the ramps themselves are counter springs that help you pull the ramps back to neutral when there is no force applied to them. It essentially reduces the breakaway to a very minimal amount, it basically opens the differential up, releasing the plates, so that you do not get unneeded lockup, and as a result unneeded wear. The friction material is again carbon, but due to the amount of plates which is more then double the GT or the PMS, as well as the way the differential works, they do not suffer from premature wear. Nor do they require the rear of the car to overcome excessive lockup in order to turn the rear end. (the difference in speed between the left and right tire.)
I understand that in the past we have all, including me always gone to GT for the strongest best differential made. I have for years recommended only them for racing applications. However with this new offering, as well as the difference in cost between the two differentials, I can not see how anyone could still do this.
GT Differential, $2,400 to $2,800 give or take.
OS Giken Differential $1,790.00
In the nine year that OS Giken has been making differentials, they have exactly ZERO failures. Now to make this completely understood, that is not just in their Porsche diffs, that is for ALL of their differentials across the board. That to me is pretty impressive.
Check out this pic, I think that if you have ever been inside of a Porsche LSD, no matter who built it, you will see, there is no comparison, and for the moment, no competition to this differential.
Warmest Regards,
Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell
Last edited by Erik@GBox; 02-15-2010 at 01:21 PM.
10-20-2009, 08:40 PM
#5
Three Wheelin'
Hi Erik, Nick your neighbor over at Go Motors gave me your card the other day. I've been meaning to have a chat with you guys. Not sure I am going to do anything soon. At one point I was considering modifying my box.
Thanks for the introduction. Oh yea, this can be a rough crowd
Bob-
Thanks for the introduction. Oh yea, this can be a rough crowd
Bob-
10-20-2009, 09:32 PM
#7
Rennlist Member
Believe me I understand where everyone is coming from here, but take a look at the OS Giken here, and I am sure that you are going understand where I am coming from with regard to saying that even the GT differential, which has always been a very good option in the past does not hold a candle to this differential.
A very bold statement I understand. But since it has been now brought up here are some things to consider when comparing these two.
The GT Differential has always had a similar design the Porsche Motorsport differential, that being a plate type ramping differential. It made it's mark here with the ability to custom choose between two different ramp angles within the same differential. Usually 40/60 and 80/80 but certainly a couple of other options as well. It also features 4, 6 or 8 plates internally, that is 2, 3, or 4 plates per side. It also features a more aggressive friction composition to that of the Porsche Motorsport diff.
Here is the rub. The GT differential has on average a 65 to 85 lbs. breakaway preload. This has shown to cause a couple of issues. The first being that as you enter into a tight turn your car has to overcome this preload in the process of turning in. So what right? That should not make much of a difference. Well actually it does. The more preload there is the harder it will be to get the car to turn, but this is not usually much of a problem as you get used to the differential, and modify your driving to compensate. What is a problem is the material that is removed from the plates inside the differential ever time this happens.
The Porsche Motorsport differential utilizes carbon as the primary friction material in their differentials, the GT diff does not. They use a moly blend, which is then plasma sprayed onto the plates to cause a friction material. This material is highly coarse and reacts in a way to not only lock the differential, which is good, but also remove metal from the opposing plates, which is bad. This combination of friction material and removed metal goes where?? Through out the gearbox, very bad. It especially goes directly into the input and pinion bearings, where it begins to cause problems inside of them as well. VERY VERY Bad.
So how is the OS Giken different? If you review the pic here, you will see that on the ramps themselves are counter springs that help you pull the ramps back to neutral when there is no force applied to them. It essentially reduces the breakaway to a very minimal amount, it basically opens the differential up, releasing the plates, so that you do not get unneeded lockup, and as a result unneeded wear. The friction material is again carbon, but due to the amount of plates which is more then double the GT or the PMS, as well as the way the differential works, they do not suffer from premature wear. Nor do they require the rear of the car to overcome excessive lockup in order to turn the rear end. (the difference in speed between the left and right tire.)
I understand that in the past we have all, including me always gone to GT for the strongest best differential made. I have for years recommended only them for racing applications. However with this new offering, as well as the difference in cost between the two differentials, I can not see how anyone could still do this.
GT Differential, $2,400 to $2,800 give or take.
OS Giken Differential $1,790.00
In the nine year that OS Giken has been making differentials, they have exactly ZERO failures. Now to make this completely understood, that is not just in their Porsche diffs, that is for ALL of their differentials across the board. That to me is pretty impressive.
Check out this pic, I think that if you have ever been inside of a Porsche LSD, no matter who built it, you will see, there is no comparison, and for the moment, no competition to this differential.
Warmest Regards,
Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell
A very bold statement I understand. But since it has been now brought up here are some things to consider when comparing these two.
The GT Differential has always had a similar design the Porsche Motorsport differential, that being a plate type ramping differential. It made it's mark here with the ability to custom choose between two different ramp angles within the same differential. Usually 40/60 and 80/80 but certainly a couple of other options as well. It also features 4, 6 or 8 plates internally, that is 2, 3, or 4 plates per side. It also features a more aggressive friction composition to that of the Porsche Motorsport diff.
Here is the rub. The GT differential has on average a 65 to 85 lbs. breakaway preload. This has shown to cause a couple of issues. The first being that as you enter into a tight turn your car has to overcome this preload in the process of turning in. So what right? That should not make much of a difference. Well actually it does. The more preload there is the harder it will be to get the car to turn, but this is not usually much of a problem as you get used to the differential, and modify your driving to compensate. What is a problem is the material that is removed from the plates inside the differential ever time this happens.
The Porsche Motorsport differential utilizes carbon as the primary friction material in their differentials, the GT diff does not. They use a moly blend, which is then plasma sprayed onto the plates to cause a friction material. This material is highly coarse and reacts in a way to not only lock the differential, which is good, but also remove metal from the opposing plates, which is bad. This combination of friction material and removed metal goes where?? Through out the gearbox, very bad. It especially goes directly into the input and pinion bearings, where it begins to cause problems inside of them as well. VERY VERY Bad.
So how is the OS Giken different? If you review the pic here, you will see that on the ramps themselves are counter springs that help you pull the ramps back to neutral when there is no force applied to them. It essentially reduces the breakaway to a very minimal amount, it basically opens the differential up, releasing the plates, so that you do not get unneeded lockup, and as a result unneeded wear. The friction material is again carbon, but due to the amount of plates which is more then double the GT or the PMS, as well as the way the differential works, they do not suffer from premature wear. Nor do they require the rear of the car to overcome excessive lockup in order to turn the rear end. (the difference in speed between the left and right tire.)
I understand that in the past we have all, including me always gone to GT for the strongest best differential made. I have for years recommended only them for racing applications. However with this new offering, as well as the difference in cost between the two differentials, I can not see how anyone could still do this.
GT Differential, $2,400 to $2,800 give or take.
OS Giken Differential $1,790.00
In the nine year that OS Giken has been making differentials, they have exactly ZERO failures. Now to make this completely understood, that is not just in their Porsche diffs, that is for ALL of their differentials across the board. That to me is pretty impressive.
Check out this pic, I think that if you have ever been inside of a Porsche LSD, no matter who built it, you will see, there is no comparison, and for the moment, no competition to this differential.
Warmest Regards,
Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell
Erik,
As it happens I am now in need of a new diff, The stock one finally failed two weeks ago. I will PM you for more details.
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10-20-2009, 10:21 PM
#11
Seared
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10-20-2009, 10:38 PM
#12
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This is, essentially, a negative preload diff. We used these in the late 90's in Indycar. They are effective in battling the yaw damping characteristics of a traditional, or positive preload diff. More preload, more heat, more yaw damping but does kill off, like you mentioned, initial turn-in.
One thing that appears to be excessive is the friction surface count -- there are a lot of them, 32 it appears. That is a lot of heat generation.
One aspect of this number of plates is the steep ramp angles one would need to use as a result. More plates, the steeper the ramp angles. Just seems like a lot of lock up for a rear engined car.
I appreciate the innovation and you sharing it with us!!!
One thing that appears to be excessive is the friction surface count -- there are a lot of them, 32 it appears. That is a lot of heat generation.
One aspect of this number of plates is the steep ramp angles one would need to use as a result. More plates, the steeper the ramp angles. Just seems like a lot of lock up for a rear engined car.
I appreciate the innovation and you sharing it with us!!!
10-20-2009, 10:57 PM
#14
Rennlist Member
How many are presently installed in racing 993/964 chassis? Either stock/prepared or Cup/RS (and clone) variants?
To the hijack of regearing a G50, what exactly are you guys pissing and moaning about? That those with expertise should be working for $1.99/hr to perform the work? Or that there's not someone out there who will reproduce gearsets, ensure they are at least factory quality, and retail them for say $50/ea? I doubt any of the vendors involved with these transaxles are kicking up their heels on an exotic beach with an umbrella drink in each hand and some big titted blondes frolicking around when they make a sale...........
To the hijack of regearing a G50, what exactly are you guys pissing and moaning about? That those with expertise should be working for $1.99/hr to perform the work? Or that there's not someone out there who will reproduce gearsets, ensure they are at least factory quality, and retail them for say $50/ea? I doubt any of the vendors involved with these transaxles are kicking up their heels on an exotic beach with an umbrella drink in each hand and some big titted blondes frolicking around when they make a sale...........
10-20-2009, 11:25 PM
#15
RL Technical Advisor
