PhantomGrip LSD's

C

craig bryant

Well-known member
I'm looking for some information from anyone who has had experience with the PhantomGrip Limited Slip Differential conversion kits. Any opinions whether positive or negative, would be greatly appreciated. Thanks in advance.

Craig
 
Junk. stay away unless it's your ONLY alternative.
it's basically a block of metal wedged between spider gears and then holds spring pressure against them. not what I'd call a brilliant idea..
 
I've had a bit of luck with them in the past in autocross cars - they kinda work, but really only useful on cars under 100 hp in my experience. Once you start making any power, you can't even tell they are there :think:
 
Ditto, they're junk. Bad idea.

Mazda switched over from the Torsen to these things somewhere along the way in Miata Land - I think 03. They are super cheap used online if you have a miata and want to try it. Otherwise stay away.
 
blamkin86":32zw7x6d said:
Ditto, they're junk. Bad idea.

Mazda switched over from the Torsen to these things somewhere along the way in Miata Land - I think 03. They are super cheap used online if you have a miata and want to try it. Otherwise stay away.
Click to expand...

Are you sure about that? I have built more diffs than I care to remember and have never seen a PG in a Miata, much less factory. Could you be more specific?
 
Scroll to the bottom:

http://www.miata.net/garage/diffguide/

TOCHIGI FUJI SUPER LSD

For ’03 NB and subsequent, into the NC models the limited slip differential was changed to a Tochigi Fuji Super LSD (What appears to be an adjective, “Super”, is part of the brand name).
Click to expand...

Maybe that's not the same as a PG but I thought it was. Definitely not a torsen.
 
Got ya. Definitely not a torsen. It is a clutch style with a pressure assembly, but the packs are just a tapered cone disk that sits behind the side gear. They work for a while, but as soon as they get a little wear they bottom on the gear and lose all grip. This is the same setup as used in the early RX8's we ran in Grand Am. Keep in mind the second gen RX7 clutch pack is a bolt in for the 1.8 miata until you go to the MX5, then it is the same as TT, RX8, etc.

I will not comment on the PG. :D
 
BTW.......I purchased and tested a Quaife LSD for my RWD 100 HP Sprite car and deemed it a useless POS. I sold it to an autocrosser. I then upgraded to plate type salisbury design diff and after loosening up the preload from stock I eventually felt it was a slightly useful device for a low HP car. Unfortunately quite a bit of $$ , machine time (Quaiffe didn't have a unit to fit the Sprite at the time so I had to modify the heat treated carrier pilot and bolt holes.....no fun), and labor (install, test, pull it out, reshim, install test several times).

Not at all sure the whole exercize was worth it for a low hp car. Now if you have some grunt behind you....that's a different deal.
 
I used a Phantom Grip for about 2 years and it worked OK for a car with less than 100 HP. When installing the unit you'll have some machining on the side gears (they say you can use a file --don't believe it -you'd be there till this time next year) so it doesn't slip right in. I recently went to a welded diff - cost me $20.00 and it will work better.
 
craig bryant":36huybbe said:
I'm looking for some information from anyone who has had experience with the PhantomGrip Limited Slip Differential conversion kits. Any opinions whether positive or negative, would be greatly appreciated. Thanks in advance.

Craig
Click to expand...

Id say this covers it:

phan·tom also fan·tom
n.
1.
a. Something apparently seen, heard, or sensed, but having no physical reality; a ghost or an apparition.
b. Something elusive or delusive.
2. An image that appears only in the mind; an illusion.
3. Something dreaded or despised.

You will wonder where your grip is and your money went. Just weld it. :wink:
 
The other extreme would be the Detroit Locker. Would twist an axle before it disengaged and would shake the car violently with a twitch when re-engaging.

Almost usable on 3.5 wide ****** ***** (think early '60s) that would slip, but unusable with 8.0 wide race rubber.

Have one in a Spridget 4.55 if anyone's interested.

RJS
 
I ran a Detroit locker for many years and once up to speed had no issues with it. That is on a dry track. I found it does not work well on a wet track because the engagement is a little to harsh and can result in a loss of rear traction if any power at all is used in a corner.
 
When I started sharing my Dad's HP Sprite, we had a 4.55 Detroit Locker that we used at most tracks. It's all I knew and it seemed OK. We would measure the circumference of the tires and try to match the rears the best we could. Not sure if that helped, but it didn't seem as evil as it's been described on this board previously (not just in this thread). I will say that the first time I used a Tran-X at Sears Point in the hairpins, it was amazing.
 
Craig:

We've used the PG in our vintage MGB for a few years now (we're actually on our second set of springs). Helps somewhat, but still does not really stop slippage.

Rick
 
I had a PG in my Spridget for one race weekend. Spun out three times, which is more than I had done the previous two seasons. Went back to a welded diff.
 
http://mycomputerninja.com/?p=440
Diagram #3 shows PG blocks.
Diagram #4 shows PG brown blocks, blue seperation springs, green gear fixed to axle. Green gear touches each green block. Depends on friction between PG brown blocks and green axle gears.

L/S (clutch discs friction), PG (spring blocks friction small area) and Detroit locker (like dog rings being ramped out/open for faster tire) are IMHJ 3 totally different differentials. Never did the PG or Detroit locker, but from viewing the mechanicals, I'd continue with a clutch L/S in my car, even if I had a choice.
 
I know little about them, but check out "Wavetrac". Used in big H.P. cars; may not be available for imports. Locks up under power, slips with no load. May not be suitable when getting back on power at apex.

RJS
 
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