There's a guy advertising in Grassroots Mosports claims he can build limited slips starting @$250.00...........
anyone have any experiance with this guy?

Steve

Must be welded or locked diff's, that is way too cheap for anything else. I have seen one 901 ZF LSD for sale at swap meets in the last 10 years. I kick myself for not buying it at $750.


Geoff

I'm going to call this guy and ask him how he builds them,I can't believe he is welding them or being totally locked.........they wouldn't even work on pavment.
I've seen the 4X4's get away with a welded diff,but that is in the dirt...................

Steve

key word: limited slip, therefore, it cannot be locked.....

Let us know, that sounds too good to be true......I'm thinking the answer will be NO or the price will be 2-3 times more than the advertised price....

"sorry dude, the $250. is only for Hondas....."

I'm afraid you might be right............................

Steve

Anybody have any experience with these? Phantom Grip. They don't seem to make one for 914s, but one might be adapted to work, or maybe if demand was great enough they'd make one.

I have heard of problems with Phantom Grips. Parts of the differential are stressed in ways that they weren't designed to handle. Here is a link to a thread that mentions it. Appareantly it has happened to more than one make of transmission.

http://forums.probetalk.com/showthread.php...ht=phantom+grip

Andrew

A Probe message board! Now I've seen everything!

I got indirectly screwed by the Phantom Grip guys.....tore down a transmission (chipped pinion gear) to send to another shop so that they could send it to PG to use my open diff for R&D....anyways, the story is that they couldn't make one to fit and refused to return it unless I paid for return shipping (heavy sucker)

We footed the bill to get it there in the first place !!!!!

I've seen a 914 with a welded diff. And yes it was on pavement. It was a fast sucker too. It was a race car and yes one wheel would slide any time it wasn't going straight. It was a PITA to push when it didn't run too.

That thing was (I believe) a 2.4 or 2.5 4-cyl.

I have a quafe in mine and I love it on the track. It makes a huge difference in how soon you can get back on the throttle exiting a turn. The inside tire doesn't wildly spin anymore.

I don't think it would be much advantage on the street.

i wonder how many 914 trannies for the european market came with LS ...
with all the snow and stuff over there, you know. it was an option after all ...



Andy

Quite a number of years ago, my instructor at an autoX drove a 914-6 racer (chopped windshield and all!) with a locked diff. Riding in that was an interesting experience!! AutoXes are tight enough that he pretty much had to stomp the throttle and kick the tail end of the car out at every single corner, otherwise the car just would not turn...

Pretty fun, but kinda scary...

--DD

Long ago, I had a 1980 Chevy Malibu. Most unreliable piece of crap I ever drove. But it had a sport-suspension and a V-8. And a limited-slip differential. In the winter time (in Chicago), it was da shiat. There was no snow drift I couldn't get out of. With normal street radial tires. I even towed my friend's 4x4 Jeep out of his driveway when he got plowed in. It made me a believer in L/S differentials. Sadly, my Trooper does not have one, and I get stuck in the dunes about half the time I go out there.

The dune-buggy/sand rail guys just weld them, from what I've been told.

I'm going the other way, from a locked diff to an open diff on my vintage race car. For three years I ran with the locked diff, and couldn't get rid of the horrible understeer in tight corners. I tinkered with all the usual stuff, and now blame it on the lock diff. My car is fairly softly sprung for a race car, so lifting an inside wheel isn't a problem. And with a 2L six, I'm hardly spinning tires coming out of the corners. Most irritating though was pushing the car around - I got REALLY tired of that. Of course, up here it's another two months before I will know if I'm right. Track test report to come...
Gavin
VARAC #58

I'm checking into this as Brad Mayuer has my 901 box apart now. In a short conversation with Brad on Friday, he told me he thought the carriers were the same for the 901 and the 915. At least that's what I took from our conversation...

Or at least they share parts like the carrier housing, spyder gear shaft, etc. Phantom Grip shows a listing for the 915 application, so if the spyder pin shaft and space between the spyder gears are the same it should fit.

If it fits this should save the cost of setting up a Quaife as well as the added cost. It looks like you simply slide the spyder shaft out, insert the PG between the gears, reinstall the pin, and release the safety locks.

As far as the weak spyder shaft in the ford Probe, and other models listed goes, it looks like the company has addressed this problem.

Rick, FWIW I have a Quiafe early 915 in one of my 901 boxes. So yes they can be interchanged.

A LSD for around $250 would be nice. I might buy one at that price.

Need4speed,
I doubt the sandrail guys weld them. I've built one and been around them for a while. We've discussed this but the old guys that have done it say you just can't get them to turn at all with a welded diff. They are so light in the front you have problems with understeer anyway. They use cutting brakes to apply the brakes to the inside rear wheel in a turn to make them turn sharper. Another advantage of cutting brakes is if you have one wheel with no traction you can apply the brakes on that wheel and send the power to the other wheel.

John

I am running a Quiafe LSD with favorable results in my 901.................with a massaged 3.6

I'm running a Peloquin LSD in my daily driven, week-end SCCA, '95 VW Jetta and love it! I noticed when I hit standing water on the highway (one tire on pavement, the other in the puddle or stream) my car doesn't rapidly pull to the puddle side and the rpm don't shoot up. And I can get on the throttle more into corners and exit more quickly...hey, commuter traffic can be a bitch, too

I think an LSD on any sports car should be standard.

Brad has a line on a used Quaife, But it may not materialize. So the Phanton Grip looks like it could be a very low cost option. Doesn't look like anyone here has used one. I may be the test case in a 901.

Unless Mike has some more info about the fitment being a problem.

QUOTE (rick 918-S @ Feb 5 2006, 11:08 AM)

Brad has a line on a used Quaife, But it may not materialize. So the Phanton Grip looks like it could be a very low cost option. Doesn't look like anyone here has used one. I may be the test case in a 901. Unless Mike has some more info about the fitment being a problem.

Hmm, I'd be very interested to see how this works out. I'm not too sure a locker is a good thing though.. seems like it could lead to some mean oversteer.

Gavin,

the only way to cure the understeer on a locked diff is to change your driving style.

took me most of a season to learn this technique with the locked diff.
when I did I picked up 2 seconds a lap at my favorite track (using the same set of tires)

I'm trying something different this season, but have run locked diffs on -4 and -6 race teeners. (both 2.0L)

The style is much more "dukes of hazard" if that makes any sense in the great north. Basically don't even try to get the car to turn into the corner. Throw it into a slide and slide down to the apex and apply throttle when your ready to shoot out of the corner straight.

no kidding 2 seconds a lap, mostly because that using this technique you can increase your entry speed significantly and practically stop using your brakes. You can out brake anyone in the braking zone before the corner.

brant

My taildragger racing friends tell me the biggest improvement gained with the LSD is stability under braking. 911s can be very unstable under braking (ie make sure you are steering straight ahead when you apply brakes or the inner wheel will lose traction and around it goes), but that traction on acceleration is not as problematic due to the rear weight bias.

The 914 does not have as much rear weight bias as a 911 and therefore cannot run as much rear roll stiffness without losing traction on the inner drive wheel. With a LSD, additional rear sway (anti-sway?) bar can be used and therefore maintain better wheel geometry.

I'm attempting to transplant a LSD from a 915 into a 914/901 transaxle. I've been told this sway is feasible using the 915 output flanges netting six bolt flanges to 944 CVs to 914 axles to 944CVs to 911/951 stub axles to 911 hubs with 914 wheel bearings.

I have sourced most of the parts except the stub axles and hubs.

Anybody have any extras they can part with?

Thanks

Eddie

Definitely helps under braking, and also accelerating off the apex, although my car currently doesn't have nearly enough torque or grip to take full advantage of that.

I know of one 914 race car that runs a locked diff... er spool.

The Kirby/Finch 914.

Personally, I don't like them, but obviously they can be fast.

I think I want to add a comment too after re-reading my post.
The locked Diff helps your lap times, more than it does in wheel to wheel.

What I mean is, that in traffic you can't always be where the car needs to be to take advantage of the style of driving necessary with the locked diff.

on open track it was 2 seconds a lap for me.

but in heavy traffic, the compromises to track position can cost the driver from realizing the full benefit. (basically by consuming HP on corner exit)

I ran a 2 hour enduro with around 80 cars on a track that is designed for 25. Needless to say there was little opportunity to take advantage of the differential's strengths

I have been carefully trying to research a theory I am developing about HP% that is used amongst the 4 different styles of differential.

(I think there are really 4 styles, because the guard clutch pack is quite different than a factory ZF)

my theory is that there is a horse power threshold, and that different styles of limited slips are better for different HP applications.

long story.... I'm keeping my locked box... but I'm also building a Torq-biasing box at the moment for next season. My theory is that the TB will be better below 250rwhp than a ZF. This belief is partially based on a converstaion with Paul Gaurd about the differential differences between a 911 and 914.

brant

Several interesting points, but I'm really looking for experiences with the Phantom Grip. I don't have any intension of running a welded or locked diff. My car is much more a driver than a AX'er or track car. Infact my rear tire wear is even. I have no problem kicking the rear out any time I need to. So I'm looking for a low cost improvement without over kill. Anyone have any experience installing and using this type of posi unit?

QUOTE (rick 918-S @ Feb 5 2006, 05:42 PM)

Several interesting points, but I'm really looking for experiences with the Phantom Grip. I don't have any intension of running a welded or locked diff. My car is much more a driver than a AX'er or track car. Infact my rear tire wear is even. I have no problem kicking the rear out any time I need to. So I'm looking for a low cost improvement without over kill. Anyone have any experience installing and using this type of posi unit?

My comment was about the phantom grip.. my understanding is that it locks on acceleration. That would make it just like a spool when you accelerate, which may or may not be desiarable. If you're accelerating gently it could cause understeer, if you're accelerating hard, it could suddenly induce oversteer. It seems to me that it might make it difficult (or maybe even impossible) to find that sweet spot where you're not over or understeering.

Anything that increases resistance in the spider gears is going to equalize the output to the axles, I would say up to a point ,100hp (I dont know) for 250.00 you will feel the diff. More power less effectiveness.
I would like to know how many ft lbs of torque resistance (friction) on the bench this unit creates.

QUOTE (sixnotfour @ Feb 5 2006, 04:54 PM)

Anything that increases resistance in the spider gears is going to equalize the output to the axles, I would say up to a point ,100hp (I dont know) for 250.00 you will feel the diff. More power less effectiveness. I would like to know how many ft lbs of torque resistance (friction) on the bench this unit creates.

Ya, I didn't see any real numbers, but with my car they wouldn't really that accurate. ( more weight, seriously more HP) I would assume HP & weight would cancel some of the effects or some of the locking effect.

per the old manual a ZF with about 200 pounds compression (torqued together) on the multi plate clutch stacks both sides yields what porsche calls 50% limited slip

QUOTE (rick 918-S @ Feb 5 2006, 06:01 PM)

QUOTE (sixnotfour @ Feb 5 2006, 04:54 PM) Anything that increases resistance in the spider gears is going to equalize the output to the axles, I would say up to a point ,100hp (I dont know) for 250.00 you will feel the diff.  More power less effectiveness. I would like to know how many ft lbs of torque resistance (friction) on the bench this unit creates. Ya, I didn't see any real numbers, but with my car they wouldn't really that accurate. ( more weight, seriously more HP) I would assume HP & weight would cancel some of the effects or some of the locking effect.

According to the description, it is only limited slip on cornering and braking. On acceleration it is a NO-slip.

QUOTE

Secondly, the Phantom Grip works as a locker in hard acceleration. The disc plates pivot, locking spiders, causing both wheels to exert equal power to the road, providing less torque steer than an ordinary differential.

That's the bit that worries me. I've never driven a car with a locker, but my understanding was that they're great for drag racing, but not much else.

QUOTE (bondo @ Feb 5 2006, 07:15 PM)

QUOTE (rick 918-S @ Feb 5 2006, 06:01 PM) QUOTE (sixnotfour @ Feb 5 2006, 04:54 PM) Anything that increases resistance in the spider gears is going to equalize the output to the axles, I would say up to a point ,100hp (I dont know) for 250.00 you will feel the diff.  More power less effectiveness. I would like to know how many ft lbs of torque resistance (friction) on the bench this unit creates. Ya, I didn't see any real numbers, but with my car they wouldn't really that accurate. ( more weight, seriously more HP) I would assume HP & weight would cancel some of the effects or some of the locking effect. According to the description, it is only limited slip on cornering and braking. On acceleration it is a NO-slip. QUOTE Secondly, the Phantom Grip works as a locker in hard acceleration. The disc plates pivot, locking spiders, causing both wheels to exert equal power to the road, providing less torque steer than an ordinary differential. That's the bit that worries me. I've never driven a car with a locker, but my understanding was that they're great for drag racing, but not much else.

Are you suggesting the phantom Grip will lock the diff all the time when moving in a straight line? That shouldn't be a problem. As long as it slips when cornering, just enough to keep the inside tire from bucking or chattering.

Does this seem to be a race part only?

Or a possible improvement for a sports car?

I could really use some input from someone that has used one of these in our transaxle.

My understanding is that the wheels lock together as soon as you get on the gas, whether you turning or going in a straight line. I too would like to hear from someone that has used one.

Thanks guys, bump for more input.

bump....

Rick, so I don't think anyone has ever tried one of these phantom brands in a 914 yet.

I don't think they even make one that would fit the box, but maybe mike muellers earlier post proves that wrong.

You might try asking the 911 guys.

My understanding from previous threads and also from import board discussions, was that it was not a great product and had mostly been tried by import tuner guys.

you may want to check with the honda guys?

I'd be a tiny bit leary to pay $500 installation labor for something that was a complete unknown, just because it would be so hard to remove, and would cost another $500 to have taken out.

At that point... if the gamble doesn't pay off... you could buy a GT style diff for the same price.

brant

EDDIE914

All you have to do is buy the Course Spline output Bevel Gears from Gaurd Transmission. All 901 & 915 LSD components are interchangable.

Ken

Rick,

I took apart a good working 901 transmission just for the diff. to send to Phantom (not directly, thru that kid that lived in the desert that had 924's that Sammy is pissed off at for stiffing him on a radio)

According to Phantom, no dice, they couldn't make one to work and on top of that, wouldn't return the diff.....

Really...

That sucks mike.. I really wanted to try this...

QUOTE (Mueller @ Feb 6 2006, 10:37 AM)

Rick, I took apart a good working 901 transmission just for the diff. to send to Phantom (not directly, thru that kid that lived in the desert that had 924's that Sammy is pissed off at for stiffing him on a radio) According to Phantom, no dice, they couldn't make one to work and on top of that, wouldn't return the diff.....

That's wierd.. They list one for the 915.. should be the same...

QUOTE

They list one for the 915..  should be the same...

they are probably not aware that 901s and 915 use some of the same components.

QUOTE (rick 918-S @ Feb 6 2006, 01:15 PM)

QUOTE (Mueller @ Feb 6 2006, 10:37 AM) Rick, I took apart a good working 901 transmission just for the diff. to send to Phantom (not directly, thru that kid that lived in the desert that had 924's that Sammy is pissed off at for stiffing him on a radio) According to Phantom, no dice, they couldn't make one to work and on top of that, wouldn't return the diff..... That's wierd.. They list one for the 915.. should be the same...

dunno, maybe the guy lied to me, I had been told I would get a Phantom diff at cost or less if I supplied the parts for R&D...once he said no dice I left it at that and didn't question anyone about it....

I have a 915 ZF limited slip in my 901 (914-6) gearbox.
You need the entire ring gear carrier, and output flanges form the 915. This mates up with 911 (6 bolt ) inner CV joints. These CV joints have to be taken appart and the ineer ball (spline) section shortened so that it will fit on the 914-6 half shaft spline. Actually using the 911/915 ring gear carrier (901 ring gear bolts right up) off-sets the output flanges by about 10mm. But due to designed in axial in the CV joints, this is no problem. I use Swepco 201 and use a (bilge) pump and tranny oil cooler when om track. The limited slip is preloaded at "80%".
Works very well on the track, in that when in the turn, letting off slightly on the thottle will tighten up the line. all in a very controlable manner. The motor is a hot 2.4 S. I was pleased with the result and teh used 915 ZF was a lot easier to find and less expensive.
Martin Jansen
Agoura Hills SoCal.
70 914-6 GTR (dual purpose car)

Ok, one more time on this thing, Does anyone know if the 901 and 915 OPEN diff use the same carrier?

Q. 1) Can some check part numbers?

Q. 2) Does anyone have both units apart in there shop?

This is what I'm looking for.


Q. 3) I need to know if the space between the spyder gears is the same.


Q. 4) And if the spyder shaft is the same diameter.

QUOTE (rick 918-S @ Feb 8 2006, 11:20 AM)

Ok, one more time on this thing, Does anyone know if the 901 and 915 OPEN diff use the same carrier?

I doubt it.. I have a 914 carrier on the bench at home, and it has a 914 part number. I can post it when I get home.

I suspect the phantom grip will work in a 914 trans, but only if a 915 carrier is used.

QUOTE (marankie @ Feb 6 2006, 01:53 PM)

I have a 915 ZF limited slip in my 901 (914-6) gearbox. You need the entire ring gear carrier, and output flanges form the 915. This mates up with 911 (6 bolt ) inner CV joints. These CV joints have to be taken appart and the ineer ball (spline) section shortened so that it will fit on the 914-6 half shaft spline. Actually using the 911/915 ring gear carrier (901 ring gear bolts right up) off-sets the output flanges by about 10mm. But due to designed in axial in the CV joints, this is no problem. I use Swepco 201 and use a (bilge) pump and tranny oil cooler when om track. The limited slip is preloaded at "80%". Works very well on the track, in that when in the turn, letting off slightly on the thottle will tighten up the line. all in a very controlable manner. The motor is a hot 2.4 S. I was pleased with the result and teh used 915 ZF was a lot easier to find and less expensive. Martin Jansen Agoura Hills SoCal. 70 914-6 GTR (dual purpose car)

How much does a 915 ZF cost?

What pump are you using? I've set up my 901 for a cooler but I have yet to source an affordable (but sufficient) pump. I've been thinking of a convertible top hydraulic pump, but I'm a little worried that they aren't capable of continuous duty.

When you say "offsets the output flanges by about 10mm", do you mean the output flanges end up 10mm farther apart, effectively making the ideal axle length shorter?

QUOTE (bondo @ Feb 8 2006, 10:27 AM)

[ [/QUOTE] I doubt it.. I have a 914 carrier on the bench at home, and it has a 914 part number. I can post it when I get home. I suspect the phantom grip will work in a 914 trans, but only if a 915 carrier is used.

I guess that's why the second part of the question.

If the shaft is the same diameter, and the spacing between the gears is the same, the carrier won't matter.

I'm attempting to save the cost of setting up a different (915) carrier in my case.

QUOTE (rick 918-S @ Feb 8 2006, 11:39 AM)

[QUOTE=bondo,Feb 8 2006, 10:27 AM] [ [/QUOTE] I doubt it.. I have a 914 carrier on the bench at home, and it has a 914 part number. I can post it when I get home. I suspect the phantom grip will work in a 914 trans, but only if a 915 carrier is used. [/QUOTE] I guess that's why the second part of the question. If the shaft is the same diameter, and the spacing between the gears is the same, the carrier won't matter. I'm attempting to save the cost of setting up a different (915) carrier in my case.

Ok, well I'll get you the measurements and part number that I can, and hopefully someone with a 915 can cover that side of things.

QUOTE (bondo @ Feb 8 2006, 10:49 AM)

[QUOTE=rick 918-S,Feb 8 2006, 11:39 AM] [QUOTE=bondo,Feb 8 2006, 10:27 AM] [ [/QUOTE] I doubt it.. I have a 914 carrier on the bench at home, and it has a 914 part number. I can post it when I get home. I suspect the phantom grip will work in a 914 trans, but only if a 915 carrier is used. [/QUOTE] I guess that's why the second part of the question. If the shaft is the same diameter, and the spacing between the gears is the same, the carrier won't matter. I'm attempting to save the cost of setting up a different (915) carrier in my case. [/QUOTE] Ok, well I'll get you the measurements and part number that I can, and hopefully someone with a 915 can cover that side of things.

Thanks,

I think I'll start a new thread to get some more attension.