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Got to get a Giken - The ONLY LSD to have.

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Old 10-21-2009, 02:06 AM
  #16  
DocTock993
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kicking up their heels on an exotic beach with an umbrella drink in each hand and some big titted blondes frolicking around
Damn! And I was hoping the aftermarket P-car parts biz was going to be my ticket into this kind of life...
Old 10-21-2009, 02:10 AM
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race911
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Originally Posted by DocTock993
Damn! And I was hoping the aftermarket P-car parts biz was going to be my ticket into this kind of life...
Give it a shot! That was me in the mid-'80's. Except I was sitting on a folding chair in the Arizona desert with a soft drink..............but I did have a rather well proportioned blonde for a girlfriend!
Old 10-21-2009, 01:10 PM
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I don't think it's pissing and moaning, just lamenting the fact that 1) our cars did not come with what we now understand to be ideal gears for the way we want to drive, and b) that Porsche parts, as well engineered that they surely are, are so much more expensive than other less exotic parts, and III) I can't think of a third thing but I wanted to use roman numeral three.
Old 10-21-2009, 01:58 PM
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Originally Posted by brucec59
I don't think it's pissing and moaning, just lamenting the fact that 1) our cars did not come with what we now understand to be ideal gears for the way we want to drive, and b) that Porsche parts, as well engineered that they surely are, are so much more expensive than other less exotic parts, and III) I can't think of a third thing but I wanted to use roman numeral three.
Usually:
III) ???
IV) profit
Old 10-21-2009, 02:05 PM
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jdistefa
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Originally Posted by race911
Give it a shot! That was me in the mid-'80's. Except I was sitting on a folding chair in the Arizona desert with a soft drink..............but I did have a rather well proportioned blonde for a girlfriend!
Pictures my friend, pictures....!
Old 10-21-2009, 07:29 PM
  #21  
race911
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Originally Posted by jdistefa
Pictures my friend, pictures....!
From the '80's? That was when you had to buy film and get it developed! Not to mention I was nearly broke from putting all my spare money into my shop or racing. The pictures I have are almost all of race cars on the track.
Old 10-22-2009, 12:46 PM
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Originally Posted by race911
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...........
Hmmm, maybe I need to review my goals in life?? I'm working in an underlit shop fighting with the wiring loom on a 964, it's so cold I have 4 layers of clothing on and it's tipping down with rain outside......

....lack of visualisation is possibly where it all went wrong?
Old 10-22-2009, 02:54 PM
  #23  
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Wow I created a monster with this thread! Guess I'll be sticking with the stock gearing for a while.
Old 10-22-2009, 03:52 PM
  #24  
chris walrod
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Now only if we could create and combine that picture of Ken's 80's hottie girlfriend in Colin's cooooold shop, we'd be all set!!!
Old 10-26-2009, 10:16 PM
  #25  
Paul Guard
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Although I am retired from Guard Transmission, I don’t like hearing that the products I helped develop are being held up in a negative light. Let me correct the inaccuracies that have been excitedly presented as facts.

First of all, only Porsche street cars (intended for street use) come equipped with carbon friction discs. Track use will fry carbon friction discs pretty quickly, which is why all Porsche track cars utilize a far more aggressive friction disc (far more durable and functional than a carbon disc). When I was with Guard Transmission, I would rebuild perhaps 3 or 4 Porsche street LSDs each week, replacing the carbon discs with our own Motorsports style discs (which also require using our harder REM plain plates). This makes a street LSD far more trackable, although certainly not on par with a complete Motorsports LSD (whether that be a Porsche Motorsports or Guard/GT unit).

Given the fact that a good used Porsche street LSD upgraded with Motorsports style friction discs will perform properly for many times longer than any LSD equipped with carbon friction discs (30,000+ miles for street use), no shop should ever talk their customer into replacing an OE street LSD with a less versatile product. And, if they should sell that customer any aftermarket differential without offering him something for his removed OE LSD core (or returning it to him to sell on e-bay), well … that just isn’t right.

Regarding the number of plates in an LSD: In my experience, the number of plates makes little difference in the service interval of any LSD. Service intervals are far more affected by the type of friction material in the unit. (In every street LSD with carbon discs that I’ve rebuilt, the service interval was at least quadrupled by replacing the carbon street discs with Motorsports style friction discs … and as I‘ve already said, performance was greatly enhanced at the same time.) Although my company used to offer an LSD that would accept 24 plates (12 friction + 12 plain), we never had a shop ask even once for this many active discs to be installed. The Porsche engineers (who are pretty smart guys), have never seen a need for more than 8 friction discs (+8 plain plates) in their Cup or GT3RSR race cars.

It’s worth stressing again that a conventional LSD can be set up in any number of ways by varying plate, disc, and belleville washer thickness, number of active friction discs, ramp angles, etc. There is no single set-up that is perfect for every user, so the ability to adjust an LSD to different settings (and the ability to later change those settings) is important to most shops, and certainly to any race team. Set-up versatility in any track LSD is essential. Any Porsche owner who has only an open diff will of course see some level of improvement with almost any LSD or TBD that they choose … but the smart owner who’s interested in aftermarket differentials, will only deal with a mechanic who can intelligently discuss the pros & cons (quality, price, intended usage) of each choice with him.

When it comes to LSD and suspension set-up, BMC&G is by far the most experienced of any shop in the U.S. Since Brian has taken LSD tuning to a new level through his interaction with every U.S. Pro race team as well as Porsche engineers in Weissach, I naturally value his opinion on various LSD types more than any other shop. According to Brian, extensive testing was performed by Porsche Motorsports in which he was the service technician … once in early 2008 with an ’07 GT3RSR, and again in late 2008 with an ’08 GT3RSR. Porsche gathered every different LSD type that they could find … factory LSDs, aftermarket LSDs, high priced LSDs, moderately priced LSDs, and even one low priced LSD. Onto each of these LSDs was installed a ring gear*, bearings, and the required shims. Each LSD was pre-measured and set up to quickly fit into the same transmission. (*Eight R&P sets were selected with identical R factors, because comparative testing had to be performed in a single day.) Different pre-measured internal disc and plate stacks were assembled for each tunable LSD, which would allow for quick changes in stack preload (breakaway torque) during the test period. The drivers were shielded from knowing which unit they were testing or not testing. Each mini test session was comprised of a 5-lap run, with all results being data logged. There was about 20 minutes spent between each test session installing a different LSD.

1) The lowest lap times and highest driver satisfaction were obtained with Ricardo's new viscous type LSD. This is a near perfect LSD for a number of reasons that don’t need to be fully explained here. Suffice it to say that the ultimate in performance does not come cheap. The cost of this LSD is well over $20,000.

2) A group of LSDs virtually tied for a very close 2nd place behind the viscous unit. These LSDs all had high breakaway torque settings, with the only exception being a very high quality German made LSD with zero preload. All of these LSDs had Motorsports type friction discs. While the handling characteristics of the car varied slightly between LSDs, the lap times were virtually identical.

3) Further testing was performed using lower breakaway torque values with any of the above LSDs that would allow such adjustments. In each case, lap times were significantly slower at these reduced pre-load settings.

4) Singled out by its slow lap times and worst exit understeer characteristics was the lowest priced LSD. Porsche actually spent a little more time testing this unit than some of the others, because they were intrigued by the low cost … not because they were impressed with its “counter springs” or the 20+ plates in it. However, each time the driver was sent out with this unit, he returned to the pits with a “thumbs down” in regards to its track performance. Obviously, no Professional Porsche road racing team would ever run one of these LSDs, despite its low cost.

When the day comes that a vendor can truthfully claim that the LSD they retail has replaced Guard’s as standard equipment in every RUF Rt12 Turbo, I will concede that this product is probably as strong as a GT LSD. When that vendor can further claim that their LSD has replaced Porsche’s LSDs in Professional road racing cars, I will also concede that this is the new standard by which LSD comparisons should be made. In the meantime, I feel that I am certainly within my rights to defend any product (that I helped develop) from being unjustly slammed on Rennlist by one of its sponsors.

Paul Guard


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“Remember Jerry … it isn’t a lie, if you believe it.” George Castanza, Seinfeld
Old 10-26-2009, 11:45 PM
  #26  
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Originally Posted by Paul Guard
Although I am retired from Guard Transmission, I don’t like hearing that the products I helped develop are being held up in a negative light. Let me correct the inaccuracies that have been excitedly presented as facts.
.
.
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When the day comes that a vendor can truthfully claim that the LSD they retail has replaced Guard’s as standard equipment in every RUF Rt12 Turbo, I will concede that this product is probably as strong as a GT LSD. When that vendor can further claim that their LSD has replaced Porsche’s LSDs in Professional road racing cars, I will also concede that this is the new standard by which LSD comparisons should be made. In the meantime, I feel that I am certainly within my rights to defend any product (that I helped develop) from being unjustly slammed on Rennlist by one of its sponsors.

Paul Guard
Paul,
Amazingly informative response - thank you for taking the time to post.

Your name and contributions need no introduction...

Regards,
Andreas
Old 10-27-2009, 12:12 AM
  #27  
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Paul,

Fantastic comments, I truly hope that you remain "around the traps" as Porsche tuning needs gentlemen like you. You service to the porsche community is one that is both long and successful and I hope in retirement you enjoy the fruits of your labors.... I am sure you have earned it.

Regards..

PS: I would love to hear more about the Ricardo LSD is you can point me in the right direction (just for interest cannot afford right now...)
Old 10-27-2009, 12:40 AM
  #28  
chris walrod
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Originally Posted by trophy
Paul,

Fantastic comments, I truly hope that you remain "around the traps" as Porsche tuning needs gentlemen like you. You service to the porsche community is one that is both long and successful and I hope in retirement you enjoy the fruits of your labors.... I am sure you have earned it.

Regards..

PS: I would love to hear more about the Ricardo LSD is you can point me in the right direction (just for interest cannot afford right now...)
I have worked with the Ricardo viscous diff, its truly a working diff. Hewland has a similar diff we ran in our late 90's indycar but I wasnt allowed to take it apart -- LOL. Diff performance is a HUGE tuning **** in open wheel cars and important in road cars especially cars with a 60% rear weight bias.
Old 10-27-2009, 11:00 AM
  #29  
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Thanks Chris.....

I take it there is nothing at a cheaper price point for our cars? Does the ricardo basically give seemless lockup from 0 to 100%, without potential transitional issues and the like.

PS OT: How's the rear bushings working out?
Old 10-27-2009, 04:07 PM
  #30  
Erik@GBox
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Well I was really hoping to avoid getting into a pissing contest with you here Paul, so I will try to address your obviously well thought out comments here with some of my own.

First of all, as you very well know I have recommended and sold a great many of the GT differentials in the past, and have always held them to be one of the best differentials on the market. However, your view point of my sales ability has always been a biased one and some of your comments of the past certainly border on being bigoted, and self serving.

Had you been the one to develop this differential, (the OS Giken) and brought it to market, you would not be saying a thing about my comments. But due to the fact that another company has brought out some competition to you now, and due to the fact that I have been fortunate enough to have found this product, you now look to cast not only our company but also me personally and professionally into a poor light. Really? Do you really have nothing better to do in your retirement then to engage in this obvious smear campaign?

It should be noted here that I have nothing but respect for Paul Guard and Guard Transmission, but after having to deal with this for several years now, enough is enough.

I noticed that you refrained from talking too much about what the OS Giken actually brings to the table here. I am guessing that this is due to the fact that you really don't have much space here to criticize.

So let us you and me set the record straight for everyone here. Porsche street differential, as well as Porsche Motorsport differentials, until recently, have been using carbon as the primary friction material in their differentials for years and years. Of this I am sure you will agree, as your prior comments here said that you had in the past been rebuilding and upgrading these differentials with your more aggressive friction and plain plates, replacing the carbon ones.

This has since changed, Porsche now uses a Brass friction material that that is actually quite similar to their synchronizer material, (see pic) The reason behind this is two fold. With the addition of greater HP and Torque the past Carbon plates were simply not holding up under the stress, and maintaining a locked state during track application. This better friction material would allow the Porsche differential to increase it's grip without having the need to completely redesign the internals to allow for more plate internally. Here is the more important consideration though. The main reason for going to a brass friction material is to ensure that as the differential sheds material, which all differentials do a certain degree, that material does not work in a detrimental way to the rest of the gearbox. Brass is soft, and thereby does not create the same amount of detrimental particulate as say, a steel friction disc. As the brass is soft the risk of pushing materials, ie steel from the plain plates, and Moly from the friction discs, into the gear sets and bearings, is minimal.

Paul does make a very good observation here that a upgraded differential with a more aggressive friction material will allow for the differential to last a great deal longer, especially in a street application. His comment regarding a shop, presumably us here, offering a product, to our customers, that would be less versatile to their OEM LSD is almost laughable. Anyone who has done business with us here will attest to the point that we are a quality shop, with the highest levels of customer service and integrity. If anything here, I am trying to educate and share a product here that offers more durability and versatility, NOT less.

Regarding the number of plates in a LSD, and how that number effects the service interval and durability of a differential, I think we will just have to agree to disagree on this point. That you have not seen a differential's service interval increase with the reduction of plates, simply does not follow logical thought. By increasing the number of friction plates and plain plates in a differential, you effectively reduce the amount of work that the differential is required to do, you also reduce the amount of heat generated internally to the differential, due to the balance of work load throughout the greater number of clutches. A greater number of plates also increases the reliability and general operation of the differential to hold a greater amount of HP and Torque during track application.

Here is the real reason why the GT differential, as well as the Porsche Motorsport does not utilize more plates, they have not figured out a way to get the differential to release it's pressure once those plates have locked up to each other. This is the greatest advance that the OS Giken offers in their differential. The ramps on the OS Giken differential have counter springs that effectively allow the differential to re-open when the amount of torque is reduced to the differential. This is in my opinion, the advancement in mechanical differential operation that should be noted and is not available in any other differential. This allows for a very minimal amount of preload to be needed, which allows for greater feel and car control. The car does not need to have to overcome the locking effects of the differential, (which sheds metal and material in the process) when the car is not under heavy torque load.

This allow the car to turn in more accurately, and also allows the differential's durability to increase exponentially. It is effectively not having to continue to work against itself when there is no need, as when in a tight turn.

I would completely agree regarding the point made that no differential is going to be perfect for all users. This is one of things that really made the GT differential worth exploring. The multiple ramp angles cut on to the GT differential, gave the driver the ability to customize the diff to his or her own driving style. Guess what, the OS Giken is completely adjustable, as well.

Paul I will not even discuss with you the differences in our professional abilities, as this will never be something that you and I are ever going to see eye to eye on. The fact that you would even go there in this discussion does not become you.

The idea that the only company competent enough to educate a customer on their options, good, bad etc, as well as the costs involved, is BMC&G and Brian Copans, really says a lot about how you feel about the people that have purchased, installed, and recommended your products for so many years.

Now before this gets out of hand, as well, Brian Copans has certainly earned the respect that he gets, and his list of accomplishments is something for any dedicated Porsche Company to strive for. Saying that he is the only company who can correctly setup a differential, as well as intelligently discuss the differences between differentials, however, pretty arrogant Paul. I would certainly think that there are any number of time tested professionals out there that can offer these services, not just us here at GBox, and to be honest, I find your thoughts on this to be insulting not only to me personally, but to every builder out there who has put in the time.

Lastly here, I doubt that you will ever be able to admit that the GT products have real competition in the market place now. I fully expect that you will continue to cast negative comments on the competition, no matter who they are. Especially so when they are poised to take a great deal of attention away from you.

So be it. I will not continue to compare and contrast your delusions with reality any longer. This dialog has become non-productive and simply does not justify my spending any more time on it with you.


Warmest Regards to you all here and I appreciate your patience today with me.


Erik Johnson
GBox Sales Manager
(303) 440-8899 work
(303) 895-4828 cell


PS sorry the pic would not load.


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