Curious how much are limited slip diffs and where can one find one? Does it require dropping of tranny to install one?

$1500..!!

alot, and yes, big labor to install and set up. Contract Brad Mayuer. He may be able to help with price and install labor.

$1000 - $1800 low end if you are lucky.

Tranny comes out, LSD is fitted to your Ring. Then the Pinon to Ring gear backlash has to be set & the Side Cover Pre-load has to be set. The backlash and pre-load require placing the proper shims behind the Diff Bearings. Unless you use a set of old bearings that have been opened up to just fit the shaft - the bearings have to be removed with a puller and pressed back on each time a shim is changed.

Ken

last I checked...GPR had the Quaife for 1250. There's not much markup on them....Factory ones are a bit more.

i think i called carquip and its about 500 bucks to set up the ring grar backlash and shimming of the diff....


so about 2 G installed...

That price isn't too far off getting an LSD for a truck installed.

but the actual diff for the porsche costs a ton mo money......

[/quote]

i think i called carquip and its about 500 bucks to set up the ring grar backlash and shimming of the diff....

[/quote]

Plus shipping the tranny (both ways) to CO.

Ken

[quote name='KenH' date='Apr 30 2006, 04:37 PM' post='671565']
[/quote]

i think i called carquip and its about 500 bucks to set up the ring grar backlash and shimming of the diff....

[/quote]

Plus shipping the tranny (both ways) to CO.

Ken
[/quote]
thats another 150......

ken - dodnt you get one installed recently?

Installed it myself.

Its not hard, just takes time.

Helps if you take the Jerry Woods transmission class. (he knows 101 tricks to make things simple)

If anybody is interested I would be glad to help.

Ken

Stock 901 LSDs are pricing at just under 5 Gs. (at least at Pelican and AA.)

Quaife are definitely the best price alternative and as I understand them, they do not have the added cost of worn disks to replace somewhere way down the road.

i remeber paul guard has his own line of torsen style IIRC...

there are Guard, ZF's and Quaifes IIRC......

I paid about $1400.00 plus shipping for a 40% Guard Transmission LSD. I bought it directly from Guard.

Remember you can convert a 915 Fine Spline LSD to the 901 Coarse Splines with some Guard Transmission parts. LSD carriers are all the same.

Ken

i searched for that article you wrote..... cant find it.

you need different bolts right?

Yes - buy them from your Porsche dealer.

Ken

So this sounds like a good project to include with close ratio transmission build at the end of this year. Appreciate the info.

This is the first 914 I have owned that has enough power to need an LSD. Very cool!

Hi Grant,

I've heard alot of folks who dual drive LSD's in AX and Track go for the 40% versus the 80%. That being said, I installed an 80% unit in my 901 for $1400 from Paul Guard. I had a shop do it. I can't remember the install price but I know I got a good deal. Since I was more track oriented, I decided on the 80%. But I didn't seem to have a problem with the push in the car from the LSD. I'd just tap the gas pedal!

Bill P.

Definitely a thing to do while your inside the box for other reasons...
(or vica versa)

Interestingly...
I had a discussion with a quaife dealer last week.
He said EXACTLY the same thing that Paul Guard admitted to me.
For a 911 the zf style is recommended track and the Torque Bias for Autox...

Buttttt.....
both the dealer and Paul himself admitted that this isn't absolutely true for a mid engined car. The Torque biasing can out perform the clutch-pack on the TRACK in a 50/50 balanced mid-engined car.

so do your reasearch before you drop that cash next winter.
brant

I am running a stock 2.0 and the LSD has been a significant improvment.

There is a big improvment in how the car gets "out of trouble".

The ZF works in both acceleration and de-acceleration (torque-bias does not).

This translates into having both rear wheels have equal traction and straightens the car out much faster than WO a LSD.

I feel it almost as much when "off the throttle" as "on the throttle".

It is very hard to put in to words.

I am sure the LSD can do more with higher HP, but it works well with 100HP.

Mine is at 80% and not very good for A/X if the turns are really sharp. The lightly loaded rear wheel scrubs and if it does hold traction the LSD "growles". 40% would be better for A/X.

Ken

Ken are you sure yours locks up on decell???????

The stock ZF units don't have the ramps setup to do this, The Gaurd units can and will do this. That is unless you have purchased a late model ZF unit from a GT1, GT3, or euro RS. But still the Guard's are better at this than even those.

I am also curious, I am thinking of using a true LSD and not a torque biased unit, why because the setup I run, I worry about wheel lift. It is good to lift a wheel with my Jetta, but not my 914. What sort of suspension setup are you running, shocks, springs, swaybars etc.... I am worried about push, and not oversteer. Love the oversteer.

I would assume if you lifted a wheel on the 914 it would more likely be the inside front.

I guess I will have to see for myself but I would just think lsd on a 914 wouldn't really do a whole lot. You got plenty of weight on the back tires already. Have to have some serious power to break the inside loose.

cars running rear swaybars have a tendancy to lift the "rear" .....you know what they say when you "assume" anything ????

don't let the <100hp rating fool you....besides going around a corner, not all the weight is on "both" wheels.....

Serious power for 914's starts at about 125 hp. I'm substainitally above that mark. I'm probably close to 175 hp with my 2.4. I find with just weight transfer that inside rear will lose traction without LSD in some corners. No need to completely lift the wheel when you have some real power.

I have an early stock ZF with the clutch pack. It works in both directions. I understand there may be two types of ZFs but I only know about mine.

22mm Front Torsion Bars, 22mm Front Sway Bar, Koni 8610 Front Shocks/Shortened Shock Housings, 210# Rear Springs, 16mm Rear Sway Bar. Koni Rear Shocks/Adj. Coil-overs, Kumho 205-50/15 V710s @ 28psi.

Again - the LSD does not need to be used with a high HP motor the be an effective improvment in the way the car handles. Example, when you take your foot off the throttle, both rear wheels want to turn at the same speed, therefore the rear tries to straighten itself out. Just one example.

Ken

My car will definitely spin the inside rear around virtually any tight corner. The stiffer the rear suspension, the more likely the inside rear would come loose (22mm front t-bars, stock front sway, 200# rear springs, adjustable Welt rear swaybar set to full soft) The situation got bad enough that I have disconnected the rear sway for very tight courses. The sway would lift the inside wheel as the weight transfered to the outside and the suspension compressed.

My short experience with a stock LSD MSX geared box cured that problem as both sides hooked up pretty much identically. Great for getting the power down, but you better be pointed where you want to go when you hit the go pedal. I had to adjust my driving a bit as the LSD produced understeer under acceleration.

Now I have to figure out what style of locking diff I would prefer. Gotta keep collecting info

The deal with the old Porsche OEM LSDs (ZF-type) was that the lockup was the same power on and trailing throttle. Somewheres in the late era (around the 993-996 design) the OEM LSDs were setup so that the trailing throttle lockup was higher than power on lockup. The Guard LSDs are like the later model versions in that the power on and trailing throttle lock up could be different (like 40% power, 80% trailing). Either new or old, the ZF-type is gonna give you locking on decel as well.

I just installed an LSD (OE ZF-type) in my 944S2. All I can say after that experience is that the 914 is getting one this winter (along with a 915 conversion). The conversion on the '44 was about $800 in labor and worth twice that inperformance gains IMO.

Regards,
Kevin

Hey Brant:

Why do you think that is?

On a close-tight turn circuit like an AX I can see where there could be advantages of TBD over LSD. On a bigger course like a road course the TBD advantage would seem to go away but you'd still get the advantage of locking on decel with LSD helping your turn-in. I've never driven a car with a TBD but wonder if you can feel it working shifting the torque from side to side. Obviously the LSD is completely transparent in operation like 99% of the time.

Regards,
Kevin

I haven't driven the TB yet so hard to say.
I'm guessing its because with small displacement your wasting less HP on turn in, and power out. (tire slip/heat = eating hp)

I theorize that above some HP level (300 is my guess and when I threw out that number to power haus they didn't argue) the rules change.

but the reason I started asking around is because my guru (whom I trust emphatically) said that they did back to back with the same car and produced quicker 914 lap times with the TB over the LSD on the same track...
(I know for a fact that his -4banger is 205hp at the rear wheels and used that number as a baseline to run the test)

So then I asked Paul Guard... he said the same thing for a 914

so then I ask at PowerhausII... Roger said the same thing for a 914

makes you want to rethink the standard dribble....
I'll be taking out my locker soon and trying the TB
wanted to use the Guard TB, but they've been on back order for 4-5 months and I'm sick of waiting...

will report after seat time.
brant

Sounds like there is some interest here. But is it SERIOUS ($$$) interest? I would count myself as "serious". Should I contact Dave at GPR and see about a Quaife group buy? Can we get 6-8 guys with real green money to make this work? I'm one of the guys with real green money. Anyone else?

only speaking for myself...
but I already paid my money to my race shop.
so he will be buying it with my money, but I won't be in for the group buy as a result.

brant

Well, I've got the green but I'm not in on the TBD yet. I need to do some more research on TBD vs. LSD. I lean towards LSD since that's all I've experienced thus far.

Regards,
Kevin

This

http://cgi.ebay.com/ebaymotors/Porsche-911...sspagenameZWDVW

and

$300 worth of Guard parts and you will have an 901 LSD. Most Ebay unit go for about this price.

Ken

I paid 1500.00 for my unit from Guard.

It's an 80% fine spline unit in my 915 trans.


Step up to the plate, Spend big



Ron

Herb,

I think you can reduce a lot of your wheel spin problems by going to a stiffer front sway bar. I run a similar setup (21mm torsion, 200# coils, 22mm front bar, no rear bar), and have had little or no wheel spin problems. The stiffer front bar will help control weight transfer at the rear. Adding a rear bar actually can make wheel spin issues worse as you couple the the trailing arms and wind up lifting that inside rear because the outside rear is compressing.

Then again, I have a stock 2.0L, so more power will make that problem more noticeable...

-Josh2