Limited Slip

[ITA Racer]

Has any one heard of the Phantom limited slip diff? Is it any good. It is reasonably priced. Much cheaper than a quaiff diff.

[Andy Bettencourt]

For every one posative, I have heard 9 negative.

For the rigors of racing, don't throw good money away. I would ask all the drivers of the brand of your car what provides the best value...you may get a few different answers but it will save you $ in the long run.

AB

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Andy Bettencourt
New England Region, R188967
ITA project SM
www.flatout-motorsports.com

[Chris Wire]

You'll never go wrong with a Torsen, which range from $400 used to almost $700 new.

You can use an OEM diff from the 86-88 models with decent success, if you shim it properly to tighten it up a bit.

Stay away from the vicous-style 89-91 OEM diff, as it will quickly give up under the rigors of racing. Some of the FB guys weld up the factory unit with mixed results, but I haven't heard of anyone using one in a FC.

Andy is right. Don't waste your money on unknowns when it comes to the diff. A full blown Torsen 5.12 will run you $1500-$2000, but it will last you many years when properly maintained.

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Chris Wire
Team Wire Racing
ITS Mazda RX7 #35
[email protected]

[Greg Amy]

ITA Racer (what's your real name?),

The Phantom Grip is nothing more than a preload device. They are springs that are added behind the side covers of your R&P to exert preload on the spider gears. By doing so you're effectively binding up the gears, reducing their ability to spin.

As you can imagine, this induces some extreme loads on the gears, bearings, and side covers. While a little preload is not bad (such as what VW did with the Rabbit GTi) a lot of preload will quickly wear or break expensive components. Get enough wear material in the transaxle and you could be looking at needing a new one.

At best it will be ineffective long-term; at worst it will damage your transaxle. Either way, you are much better off spending smart money and doing it correctly.

Greg Amy

[gran racing]

Wow! 1,500 - 2,000? That is pretty darn expensive.

I'm getting the OPM LSD this offseason which will run $700 plus $300 for them to instal.

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Dave Gran
NER ITB #13
'87 Honda Prelude si

[ShelbyRacer]

Well, I have a PG in my street car (98 Neon SOHC with a few mods), and I can tell you that it basically does nothing. Now, I had my trans apart anyway when I installed it, but I'm glad I didn't spend any money on it really. At this point with both front wheels off the ground, I can grab one and spin it quickly, and the mass of the other one is enough that it won't spin right away. If I do it slowly, both spin together. I figure that's a breakaway torque of about 50 ft.lbs. on the old estimometer.

If you want to make something and you can't afford a torsen, get some tool steel blocks machined up and use high pressure machine springs between them. It'll help a lot to machine the spider gears down so as to have a larger, flatter surface for the block to push against. Just remember, this is using friction to do something where there shouldn't be much friction, so your wear *may* (read-will) increase. Just inspect it regularly and you'll *probably* catch any problems before too much damage is done...

BTW- the above idea should NOT be attempted by anyone who actually can get the correct setup LS for their car. For the rest of us that are screwed, it's all we've got...


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Matt Green
"Ain't nothin' improved about Improved Touring..."

[Richy Gonzalez]

Originally posted by gran racing:
Wow! 1,500 - 2,000? That is pretty darn expensive.

I'm getting the OPM LSD this offseason which will run $700 plus $300 for them to instal.

Everyone that I've ever known with the OPM unit has been satisfied with them. They work good and last pretty long. But at 700 bucks, it is by far the cheapest in the good unit arena. Look at Quaife, Kaaz, Mugen and you'll see the price difference.

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Richy Gonzalez
GB Racing<A HREF="http://groups.msn.com/TheGonzalezFamilyRichySheilaandNyah/projectitacrx.msnw" TARGET=_blank>
#24 ITA CRX For Sale $7500.00 FIRM + $1000.00 with Trailer</A>
LAMIN-X Protective Films

[joeg]

I have a PG, a Quaife, a welded diff and an open diff.

The PG and open are real close in performance. The PG generates more metal filings in the differential fluid, however.

The Quaife works very nicely but it is HEAVY.

This heaviness must have some negative performance aspects.

The welded diff works great on a dry track, at speed.

Everywhere else it is a PITA and it will break CV joints just tooling around in the paddock.

An open is not bad, just slow.

Cheers.

[Tom Blaney]

I have decided that my posts aren't really worth much on this board anymore.

If anybody want's real straight information for someone who had built and won races, they can e-mail me at [email protected]

Have a nice time

[This message has been edited by Tom Blaney (edited December 30, 2004).]

[Knestis]

There's just no way around the fact that a good dif is both expensive and valuable. I'm of the opinion that gears and traction are cheaper time found on the track than just about any other improvement, though - particularly a 'built' engine.

I'm a huge fan of clutch-type diffs and have ordered one of the Kaaz-built units for the Golf, from our friends at Bildon. I've also heard good things from people I trust about the OPM part.

A Quaife unit WILL spin an unloaded tire. If I were building a street car, I'd go that route but I want something a tad more positive for racing use.

K

[gran racing]

Why do you say that Tom?? I think you'd find that many of us disagree with your statement about your posts not meaning much.

(Yes, I realize we all may have discussed this topic some time ago.)

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Dave Gran
NER ITB #13
'87 Honda Prelude si

[JeffYoung]

I have a Quaiffe, since I have limited options for my car. Kirk is right, it will spin an unloaded tire. On smooth tracks this is not an issue. On bumpier ones, or when touching curbing, it can be.

[apr67]

I've driven a welded dif in my own Rabbit GTI (since gone) and Chris Albins Golf.

I don't find that it breaks CV's (you just can't turn the steering wheel more than about half a turn in the paddock). I like it in the wet as well as the dry. In the wet, it stops front wheel lockup when one tire is in a puddle and the other isn't. Either both wheels lock, or neither.

If your choice is open, phantom grip, or welded then Welded is generally going to be the fastest.

[ITA Racer]

Thanks for the replys everyone. I learned one one thing realy important from this post for shure. Build a safe and reliable car this year and spend my money ontrack time then add all the expensive gofast stuff latter.

[zooracer]

Do not waste your money on a phantom grip. If you do, you are throwing money away. Instead send it to me and I will spend it.
I cannot stress this enough. I have one on my ITB car, as does my friend on his ITB swift. I got the stiffest springs (green), but this didnt make any difference. I honestly cannot tell the difference from an open diff.
I get inside wheelspin in some FOURTH gear corners! And I'm making about 85 ft lbs of torque.
Wait, save your money, and buy whatever the fast guys are running.
matt

[seamus88]

Phantom Grips are also known to fail and take the entire trans and case with them.
http://homepage.mac.com/dgiessel/.Pictures...r/phantom_grip/

[This message has been edited by seamus88 (edited January 17, 2005).]

[Knestis]

AAAAH! It's the blob - run!



That's just freakin' awful.

K

[This message has been edited by Knestis (edited January 17, 2005).]

[grjones1]

ITA,
I've used the same Quaife since 1991 in my Fiesta (which still wins a few races). It cost $1200 + installation. But it works and it doesn't break, and it doesn't break other drive train components. It gets me through the Carousel at Summit as quick as anyone and I experience no inside wheel spin. In my humble estimation, it was money well spent.
GRJ

[joeg]

I have seen similar metal shavings on the tranny magnet in my PG Transaxle.
However, my Quaife box is in the car, so I am not worried.

As for messes, nothing beat the times I exploded tranny cases on my Ice racer. Ugh!!

I bet that tranny in the pics still worked, at least to drive the car onto the trailer.

[gsbaker]

Originally posted by Knestis:
AAAAH! It's the blob - run!

a.k.a. aluminum soup.

G