Phantom Grip Limited Slip

[RubyRed]

Does anyone out there have experience with the Phantom Grip add-on to convert the diff to limited-slip? It seems like it would be really hard on the spider gears when slip was actually required (a lot of metal-on-metal grinding). It also looks like it would be VERY expensive to install PROPERLY (I know it's way out of my league for DIY).

Anyone who has fitted this to a Cruiser, or any other car, could you share your thoughts? Thanks in advance for any help you can give.

[Ant]

I have done some research on it but have not done an install. From what I have seen, if installed properly, it is very reliable. There is actually a gentleman on the Neon forums who has designed a "grooved, channeled" pin to replace the solid one in the kit. It is supposed to allow better oiling to the spider gears for improved reliability. I have a good amount of experience working on cars but I would not attempt taking apart this electronically controlled Auto tranny. If I had a 5 speed, with the power I have now, I would probably install the Phantom Grip.
Unless you are using the car for some sort of racing (drag, autocross, street ) it is not necessary.

[Gary C]

The Phantom grip LSD uses absolutley nothing more than spring loaded friction plates between the two output shafts. This is not the best setup in my mine, reason being, it's a fixed preload, never locks up, nor disengages and allows for a 'full functional' differentail action like a torque biasing differential, like a quiaffe, or torsion diff would.
THe reason they work for drag is the fixed preload is greater than the typical torque imbalance that will occur when you're spinning the wheels taking off from a stop in a straight line. As long as neither tire has traction, the torque imbalance is low. Such as when your launching from a dead stop and get wheelspin, due to your power overcoming the traction available from the tires on the ground.
Where it (phantom grip_ fails is any unequal traction situation, such as one tire on pavement, the other on wet pavement. The
engine torque multiplied by the gear ratios will overwhelm the preloading of the plates with the spring b/w them which acts on the spider gear in the diff, and thus you will just spin freely with virtually zero power going to the tire with more traction and the tire on ice will spin freely. However.. you will still accelerate, though slowly, as the preload will shunt a bit of torque to the side with more traction, thus making it not completely worthless, just inefficent at what it is supposed to do.
Again, in road racing/auto-x situations where you will want the outside tire *with more weight on it, thus better traction* to get more power than the unweighted inside tire, the phantom grip is virtually worthless as well. The tractino imabalance is high, and your inside tire will still get the majority of power since it has the path of least resistance.

I *personally* prefer a good torque biasing diff, like a quaiffe, or kaaz. Though more expensive, they certainly do a much better job in all situations than the phantom grip does. It's true when it comes to LSD's in that you do get what you pay for. I've driven everything from cars with welded diff's to a phantom grip equiped honda civic (built for SCCA SOLO racing) to driving many a car with quaiffes and the like in them. The phantom works pretty good for drag, but again it's just 2 metal plates with a spring tensioning them that gets placed in the stock open diff and applys pressure to your spider gears... not the best for all situations, but that's just my 2 cents. *shrug*

[Ant]

Originally posted by Gary C
Again, in road racing/auto-x situations where you will want the outside tire *with more weight on it, thus better traction* to get more power than the unweighted inside tire, the phantom grip is virtually worthless as well. The tractino imabalance is high, and your inside tire will still get the majority of power since it has the path of least resistance.

I

You can chose from a # of different weight springs to adjustr the amount of lock up between the gears and the housing. You need to chose them according to what you ulimately use the car for.
Torque transfer is not fixed with the Phantom Grip, it adjusts according to the driving condition. During cornering with neutral throttle the blocks will push up against the spider gears and provide a modest amount of resistance. However, (this is a quote from a tech article as they installed the PG on a Neon):
"as the need the to limit the torque transfer increases, like when 1 wheel really starts to spin, the blocks pivot about the pinion shaft, twisting and wedging hard against the spider gears to to provide more lock up to transfer torque to the tire with more grip. As an added benefit for road racers and autocrossers, this resistance to torque transfer helps keep the inside wheel from locking up and flat spotting when trail braking occurs."
If I had an option I would certainly opt for a Quaife differential. But, the cost is MUCH more and the installation is more technical.

[Gary C]

ah, when i first started playing with the phantom grip it was when they still had just the single weight spring out *as far as we knew at the time.... (going back..oh..about ~3 years give or take if i recall correctly). so take that factor out of the equation then, i was unaware of the different weight springs.
Thanks for the clarification there. They definatly are *GREAT* if your looking for a budget minded solution to the problem at hand.
As for cost, i have purchased LSD's ranging in price from the 895 dollar Pelequin *very similar to a quaiffe* to systems near twice the cost for a Ford 8.8" rear end on my Mustang notchback which definatly is QUITE a bit more than the phantom grip and if they work as good as the guys with the neon are saying they are, I may look into one of those for the time being instead of holding out for a quaiffe or such.

[RubyRed]

Good responses all, I'm interested in a limited-slip for foul-weather traction. I used to own a Ford Aerostar with the 3.0L 6, a 5-speed manual and a 3.73 limited-slip rear. Gee, I never knew I was supposed to race it. Damn, I bet it would pull in the low 20s in the quarter mile! Why did I ever trade it? All I ever used it for was hauling and kiddie transport in all weather conditions... boy, am I a sucker.

Originally posted by Ant
Unless you are using the car for some sort of racing (drag, autocross, street ) it is not necessary.

Seriously, since owning that van I have had 3 cars with electronic traction-control (2 BMW 3-series convertibles and the Cruiser) and can tell you that in the hills and mountains where I live it doesn't come close to the extra go provided by the Aerostar's limited-slip. I ran snow tires on all those vehicles and, truth-be-told, despise the way that traction-control robs you of power just when it is most required. At least BMW will admit its limits and advises that it be turned off in deep-snow situations.

I wanted to get a feel for what kind of expense was involved if I took the plunge. The Phantom Grip seemed like an affordable option. I had already priced quality units like the Quiaffe and the purchase price alone scared me off, not to mention installation.

Again, thanks for the detailed answers, guys.

[Mark1]

I am look to install it as well for the same reasons of bad weather. I have found in my research that it is a great first step. A grat way to get both wheels to pull. But as stated before it is not that great at the extreems. For a retro fit on a daily driver it it worth looking into. Now if i could only get a deal on the install!!