Installing an LSD

Old Feb 26, 2008 | 09:10 AM
  #16  
atomic80's Avatar
Registered User
Joined: Oct 2005
Posts: 7,057
From: inside someone warm
Rep Power: 382
atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !
+1 on Cantrell. They're a standup shop...they definitely stand behind their work! What suspension are you having done?
 
Old Feb 26, 2008 | 10:45 AM
  #17  
vincentdds's Avatar
Registered User
15 Year Member
Joined: Oct 2005
Posts: 5,522
From: NW
Rep Power: 275
vincentdds has a reputation beyond reputevincentdds has a reputation beyond reputevincentdds has a reputation beyond reputevincentdds has a reputation beyond reputevincentdds has a reputation beyond reputevincentdds has a reputation beyond reputevincentdds has a reputation beyond reputevincentdds has a reputation beyond reputevincentdds has a reputation beyond reputevincentdds has a reputation beyond reputevincentdds has a reputation beyond repute
Installing LSD is not easy. Cantrell and Fordalh outsource it out to a guy in Oregon. You're looking at $1500 lalor. Everyone in Porsche Motorsports uses Guard LSD and that's what I had in installed in my GT2. Quaife is not up nearly as good as Guard.
 
Old Feb 26, 2008 | 11:21 PM
  #18  
Jeffhay's Avatar
Thread Starter
|
Registered User
Joined: Sep 2007
Posts: 148
From: Seattle, WA
Rep Power: 33
Jeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to behold
JIC Cross suspension.

I know Guard is "better" and is a true LSD, not TBD. They are apparently the race part. Quaife is supposed to require less maintenance and is more friendly on the street. $1500 sounds pretty steep.
 
Old Mar 8, 2008 | 09:36 PM
  #19  
Zippy's Avatar
Registered User
20 Year Member
Joined: Aug 2003
Posts: 3,787
From: Edmonton, Alberta
Rep Power: 209
Zippy has a reputation beyond reputeZippy has a reputation beyond reputeZippy has a reputation beyond reputeZippy has a reputation beyond reputeZippy has a reputation beyond reputeZippy has a reputation beyond reputeZippy has a reputation beyond reputeZippy has a reputation beyond reputeZippy has a reputation beyond reputeZippy has a reputation beyond reputeZippy has a reputation beyond repute
I'm seriously considering a guard LSD and new gear ratios. I think, for me, a true LSD is a better idea than a TB-LSD. Just have to try and figure out what lock up ratios to get.

http://www.guardtransmission.com/lsd_info.htm

Generally speaking, this is what most customers opt for:
(a) Street / autocross - Torque-biasing
(b) Street / track - Torque-biasing if light-duty track use, with stock suspension. 40% limited-slip if car has stiff suspension or power upgrades.
(c) Track only - 80% limited-slip differential or spool.
Limited-slip differentials provide lock-up on both acceleration and deceleration. The amount of lock-up on accel and decel can be adjusted by selection of the internal plate sequence. Lock-up on deceleration allows aggressive entry into a turn and late braking, reasons why all Pro race teams (that we are aware of) utilize LSDs, rather than TBDs.
Torque-biasing differentials provide lock-up on acceleration only. The amount of lock-up (5-80%) increases as the amount of torque increases. On deceleration, lock-up is negligible, making the TBD the ideal diff for the slower speed turns of autocross. (In the same slower-speed turns, an 80% LSD would most certainly cause understeer.)
A torque-biasing differential performs like an open diff whenever one of the two drive wheels lifts off the ground. Lock-up and traction are lost until both drive wheels are again planted firmly on the ground.
There seem to be two very distinct groups, one favoring the use of LSD, and the other favoring the use of TBDs. We at Guard Transmission try to avoid making the decision for the customer. We would rather our customer confer with the race shop or transmission builder performing the installation, in order to make an informed choice.
Our primary role is simply to provide the marketplace with the highest quality examples of each and every differential type, all backed with a full 100% money-back guarantee.
Thank you for your interest --
Paul Guard
 
Old Mar 21, 2008 | 09:32 PM
  #20  
Jeffhay's Avatar
Thread Starter
|
Registered User
Joined: Sep 2007
Posts: 148
From: Seattle, WA
Rep Power: 33
Jeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to behold
Just got back from the track today. The suspension rocks!

I met Chris of Chris' German Auto Service while there. A couple people said his shop would be a good one for installing a differential. What do we know about him?

He did say that if I'm tracking with any regularity that a Guard LSD would be better than the Quaife TBD. But I only track 6-10 times a year and I got a hell of a deal on the Quaife from a friend. So I guess I'll just not lock up when I decelerate. In any case, I gotta get the thing installed.
 
Old Mar 21, 2008 | 10:02 PM
  #21  
mitchelrl's Avatar
Registered User
Joined: Oct 2006
Posts: 1,309
From: Seattle, WA
Rep Power: 72
mitchelrl is infamous around these parts
Jeff,

Could you take a picture from under your car, where the halfshafts go into the diff housing?

Are you going to stick with the stock gearing as well? Because if you change your ring gear, you also need to change your pinion gear.
 
Old Mar 21, 2008 | 10:24 PM
  #22  
Jeffhay's Avatar
Thread Starter
|
Registered User
Joined: Sep 2007
Posts: 148
From: Seattle, WA
Rep Power: 33
Jeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to behold
Uh, maybe? I don't really know what I'm doing under there. If you just want to see what it looks like, there's a great article on doing exactly this on CC.Net http://www.caymanclub.net/reviews/sh...duct=119&cat=4

This is far beyond my mechanical capabilities.

I'm keeping the stock gearing. I am secure in my pinionhood.
 
Old Mar 21, 2008 | 11:53 PM
  #23  
atomic80's Avatar
Registered User
Joined: Oct 2005
Posts: 7,057
From: inside someone warm
Rep Power: 382
atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !
Just how much of a price difference is there between the Guards and the Quaife LSD? I would not short change things in a car like a Porsche. I'd wait until you can afford the Guards if I were you.
 
Old Mar 22, 2008 | 12:50 AM
  #24  
mitchelrl's Avatar
Registered User
Joined: Oct 2006
Posts: 1,309
From: Seattle, WA
Rep Power: 72
mitchelrl is infamous around these parts
Can't go wrong with Quaife honestly, they're top knotch.

The install doesn't look too bad, I'd offer to do it for free if I had a lift. Once you have the halfshaft off, it looks like there's plenty of access to it. Those guys should give out the torque specs though.

Here's what my diff looked like before I installed my new one.. (you're looking at the pinion gear)
 
Old Mar 22, 2008 | 01:06 AM
  #25  
19000rpm's Avatar
Registered User
Joined: Dec 2006
Posts: 764
From: Bellevue WA
Rep Power: 72
19000rpm has a reputation beyond repute19000rpm has a reputation beyond repute19000rpm has a reputation beyond repute19000rpm has a reputation beyond repute19000rpm has a reputation beyond repute19000rpm has a reputation beyond repute19000rpm has a reputation beyond repute19000rpm has a reputation beyond repute19000rpm has a reputation beyond repute19000rpm has a reputation beyond repute19000rpm has a reputation beyond repute
What’s left of it anyways. That must have made an interesting noise.
 
Old Mar 22, 2008 | 08:59 AM
  #26  
atomic80's Avatar
Registered User
Joined: Oct 2005
Posts: 7,057
From: inside someone warm
Rep Power: 382
atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !atomic80 Is a GOD !
Quaife works great for BMWs but Guards is really the best for Porsches based on years of proven use.
 
Old Mar 22, 2008 | 09:21 AM
  #27  
HUMMM 3's Avatar
Registered User
Joined: Nov 2006
Posts: 939
From: Bellevue, WA
Rep Power: 69
HUMMM 3 has much to be proud ofHUMMM 3 has much to be proud ofHUMMM 3 has much to be proud ofHUMMM 3 has much to be proud ofHUMMM 3 has much to be proud ofHUMMM 3 has much to be proud ofHUMMM 3 has much to be proud ofHUMMM 3 has much to be proud ofHUMMM 3 has much to be proud of
Originally Posted by Zippy
I'm seriously considering a guard LSD and new gear ratios. I think, for me, a true LSD is a better idea than a TB-LSD. Just have to try and figure out what lock up ratios to get.

http://www.guardtransmission.com/lsd_info.htm

Generally speaking, this is what most customers opt for:
(a) Street / autocross - Torque-biasing
(b) Street / track - Torque-biasing if light-duty track use, with stock suspension. 40% limited-slip if car has stiff suspension or power upgrades.
(c) Track only - 80% limited-slip differential or spool.
Limited-slip differentials provide lock-up on both acceleration and deceleration. The amount of lock-up on accel and decel can be adjusted by selection of the internal plate sequence. Lock-up on deceleration allows aggressive entry into a turn and late braking, reasons why all Pro race teams (that we are aware of) utilize LSDs, rather than TBDs.
Torque-biasing differentials provide lock-up on acceleration only. The amount of lock-up (5-80%) increases as the amount of torque increases. On deceleration, lock-up is negligible, making the TBD the ideal diff for the slower speed turns of autocross. (In the same slower-speed turns, an 80% LSD would most certainly cause understeer.)
A torque-biasing differential performs like an open diff whenever one of the two drive wheels lifts off the ground. Lock-up and traction are lost until both drive wheels are again planted firmly on the ground.
There seem to be two very distinct groups, one favoring the use of LSD, and the other favoring the use of TBDs. We at Guard Transmission try to avoid making the decision for the customer. We would rather our customer confer with the race shop or transmission builder performing the installation, in order to make an informed choice.
Our primary role is simply to provide the marketplace with the highest quality examples of each and every differential type, all backed with a full 100% money-back guarantee.
Thank you for your interest --
Paul Guard
So I have a question. If the 997 turbo has the optional LSD what sort of lock up percentage does it have?
 
Old Mar 22, 2008 | 11:06 AM
  #28  
detailjohn's Avatar
Former Vendor
Joined: Feb 2008
Posts: 1,460
From: Bellevue
Rep Power: 0
detailjohn is a splendid one to beholddetailjohn is a splendid one to beholddetailjohn is a splendid one to beholddetailjohn is a splendid one to beholddetailjohn is a splendid one to beholddetailjohn is a splendid one to beholddetailjohn is a splendid one to behold
Fordahl
 
Old Mar 22, 2008 | 12:11 PM
  #29  
Jeffhay's Avatar
Thread Starter
|
Registered User
Joined: Sep 2007
Posts: 148
From: Seattle, WA
Rep Power: 33
Jeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to beholdJeffhay is a splendid one to behold
Well, there's "afford" and then there's "makes sense". A Quaife is about $1450 shipped from the UK. Guard is ~$2500 + shipping. The way I understand it, there isn't a quality difference between Quaife and Guard, its functionality. The difference being "Do you want to pay nearly twice as much for the Guard to have some diff lock on deceleration, and have to have it serviced every few years, or not?" Yes, ultimately, the Guard is better for track use. But I go to the track less than 10 times a year and got the Quaife for a quarter of what the Guard costs.

So, I'm keeping it. I seriously need to find a local shop to install it. Thanks Mitchel and no offense, but Cantrell ships this kind of work out because he "doesn't have the right tools....". There are things like "backlash" and "tolerances" and other mechanical terms I don't completely grasp, to be dealt with. I'd prefer to have it done somewhere I'd have some recourse should the job go badly. Chris' seems like a pretty serious outfit. They were doing Motec tuning on their race car at the track. JR from Proformance works at their shop and said they'd be great. I don't know anything about Fordahl, but their site looks about as bad as a MySpace.
 
Old Mar 22, 2008 | 07:51 PM
  #30  
mitchelrl's Avatar
Registered User
Joined: Oct 2006
Posts: 1,309
From: Seattle, WA
Rep Power: 72
mitchelrl is infamous around these parts
Originally Posted by Jeffhay
Well, there's "afford" and then there's "makes sense". A Quaife is about $1450 shipped from the UK. Guard is ~$2500 + shipping. The way I understand it, there isn't a quality difference between Quaife and Guard, its functionality. The difference being "Do you want to pay nearly twice as much for the Guard to have some diff lock on deceleration, and have to have it serviced every few years, or not?" Yes, ultimately, the Guard is better for track use. But I go to the track less than 10 times a year and got the Quaife for a quarter of what the Guard costs.

So, I'm keeping it. I seriously need to find a local shop to install it. Thanks Mitchel and no offense, but Cantrell ships this kind of work out because he "doesn't have the right tools....". There are things like "backlash" and "tolerances" and other mechanical terms I don't completely grasp, to be dealt with. I'd prefer to have it done somewhere I'd have some recourse should the job go badly. Chris' seems like a pretty serious outfit. They were doing Motec tuning on their race car at the track. JR from Proformance works at their shop and said they'd be great. I don't know anything about Fordahl, but their site looks about as bad as a MySpace.
hehe, no offense taken.

If you got a new carrier bearing, you could do this in your own garage. I'd recommend a new ring gear and carrier bearing regardless of who does what, so it would be easier to swap in your open diff, should you ever sell it or trade it in.

After all of the work that Cantrell does on Porsches, I'm shocked that they haven't tackled something as simple as this install.
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
eclip5e
Automobiles For Sale
6
Jul 29, 2019 11:13 AM
orbelo
996 Turbo / GT2
30
Aug 30, 2015 12:26 PM
JMon
Automobiles For Sale
1
Aug 21, 2015 08:20 AM
TrackOne
Automobiles For Sale
0
Aug 20, 2015 12:56 PM


Thread Tools
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -6. The time now is 01:43 PM.