Vance, it's not that I disagree with your caution, I think it is well
placed. But Quaife doesn't sell them or make them because they ARE
selling LSD's for @$1,000. Why should they make a product that would
undermine their existing product while selling for less money. Besides,
I think most of their R&D time is being spent on their rocket box
sequential transmissions, or electronically controlled differentials.
Not mechanical LSD's.
Now wouldn't a six speed sequential gearbox be fun? :-)
I wouldn't discount the effectiveness of the PG until there has been
some more investigation. You raised several good questions that should
be satisfied with good answers. After all, once in awhile, a better
mousetrap does get built. New ideas challenge old ones etc...
Shawn Loseke
1972 TR6
Fort Collins, CO
http://www.loseke.net/shawn
On Thursday, September 12, 2002, at 12:32 PM, Navarrette, Vance wrote:
> Kai:
>
> I have done a little studying on them, and I have concluded
> they are the worst sort of ghetto hack. Mind you, I have not actually
> tried one, so you would have no trouble making me look like an idiot
> by trying it and reporting positive results. After shooting my mouth
> off for years, I have learned to eat lots of crow. =:-o
> There are several different ways to build an LSD, all of them
> with different tradeoffs of cost, reliability, effectiveness, etc.
> The Phantom Grip is of the "Clutch" variety, where a pre-loaded clutch
> is used to lock the two axles together. When enough torque difference
> between the two axles occurs, the clutch slips allowing the wheels to
> rotate at different speeds.
> The problem I see with the PG is that there is no clutch, in
> effect. The device relies on the friction between a spring loaded
> steel block, and the edge of your axle gears. The shape of the
> gear edge is not well controlled (after all, it is not the
> actual gear teeth, but merely an adjacent face never intended to be
> load bearing). In some applications, the PG uses only a rough machined
> gear face as the clutch. Tell me how that is going to work!
> I would expect the actual results to vary wildly, depending
> on the shape and surface area of the gear face. In addition,
> because the gear face was never intended to be used as a clutch
> surface, wear would be unpredictable, depending on which part of
> the gear was hardened, and how deep that hardening goes.
> In a regular clutch LSD, there is a stack of clutches to
> distribute the load and wear over a large area. These designs
> require special friction oil additives to make the slippage
> predictable. The PG has none of this. What do they know
> that everyone else doesn't? Quaife sells an LSD for $1,000. Is
> Quaife stupid? Why can't Quaife create a PG? They do LSDs for a
> living...
> In addition, I have had a dickens of time finding any
> testimonials in chat rooms, etc. Everyone seems to know "a friend
> of a friend" who had great results, but the one or two cases
> where the testimonial is in the first person, all they do is
> gripe about how it doesn't work, or it worked for a few weeks
> and then quit.
> So I remain unconvinced that this is anything but another
> "Split Fire" spark plug, that offers better gas mileage, lower
> emissions, and higher horsepower, yet no one is able to
> substantiate their claims. In other words, it's all marketing
> hype and unprovable claims.
>
> Someone should probably try one just for the heck of it,
> but it won't be me. Kai, the question you have to ask yourself
> is "Do I feel lucky?". Well....?
>
> Waiting to be revealed as the village idiot,
>
> Vance
>
>
> ------------------------------
> 1974 Mimosa Yellow Triumph TR6
> Cogito Ergo Zoom
> (I think, therefore I go fast)
>
>
>
> -----Original Message-----
> From: Kai M. Radicke [mailto:kai@radiohead.net]
> Sent: Thursday, September 12, 2002 8:48 AM
> To: 6-Pack
> Subject: Phantom Grip LSD - the catch?
>
>
> Undoubtedly anyone seriously active or interested in British sports car
> racing has seen these Phantom Grip LSD units being advertised lately
> with
> greater and greater penetration into magazines and also now known
> suppliers
> of quality racing components are beginning to stock them. For those
> that
> haven't seen them yet:
>
> http://www.phantomgrip.com/
>
> A Phantom Grip LSD conversion for your TR6 is listed at $349 from the
> manufacturer, and I've seen them as low as $296 from distributors. So
> if no
> one has used one yet, who is going to be the bold guinea pig who tries
> one
> first? (or have I just volunteered myself)
>
> Kai
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