Which LSD?

[steve_pugh]

What are my options for getting both my wheels to work at the same time without going all out for a spool?
LSD.. Even if I found a good stock one, is it worth fitting?  or would I be better off fitting something stronger / aftermarket?

Gearbox is an AH 1302s IRS.

[Steve D.]

Two options for IRS, original ZF diff or Quaife torque biasing diff.

Quaife- don't know of the availability of these anymore, contact a good trans shop about this.

ZF- do yourself a favor and just buy one from Bruce Tweddle- he scours Central America to find them, digs them out of rotting cars, brings them back to Canada, and goes through them so they are PERFECT when you buy one.  Even if you are able to find one, you're rolling the dice on it being good.  I have one in my old type 1 trans with many years/miles/dragstrip passes on it and never had an issue with it.

Hope this was some help.

[Lee.C]

Hmmmmm I seem to remember there being a rather good thread on here while back on this very subject......

Please don't quote me here but I think the "Best type" is the kind that act as an "LSD" on Acceleration BUT acts as a "Normal" diff under deceleration.....

I am sure others will give much better details 

[JIMP]

Steve

you could contact Jussi here on the lounge or www.kuplapaja.com, he has the "old" version limited slip with discs but in all new construction, both for 33 or 37 splines, cheers

Friendly

Dimitrios

[steve_pugh]

Two options for IRS, original ZF diff or Quaife torque biasing diff.

Quaife- don't know of the availability of these anymore, contact a good trans shop about this.

ZF- do yourself a favor and just buy one from Bruce Tweddle- he scours Central America to find them, digs them out of rotting cars, brings them back to Canada, and goes through them so they are PERFECT when you buy one.  Even if you are able to find one, you're rolling the dice on it being good.  I have one in my old type 1 trans with many years/miles/dragstrip passes on it and never had an issue with it.

Hope this was some help.

Thanks for this.   Just been looking and a Quaife is avail on their own site:
http://quaife.co.uk/shop/search/results/taxonomy:488
It is gonna cost... but they do offer a lifetime warranty..    Sounds dubious but if true (Says subject to Ts&Cs..), then it's suddenly NOT that expensive.   
Their FAQ seems to hint that once bought, then everything around it will break but the Diff will take "just about as much horsepower as you can throw at it. In almost any given transmission or rear axle, the QUAIFE ATB Differential will not be the limiting factor."


I keep hearing that eventually I'll break my diff and a Super Diff will help that as it has 4 spider gears.
What does a Super Diff give me other than 2 extra spider gears for strength?   will it still not deliver the power in the correct fashion and end up spinning one wheel?

you could contact Jussi here on the lounge or www.kuplapaja.com, he has the "old" version limited slip with discs but in all new construction, both for 33 or 37 splines, cheers

Friendly  Dimitrios

I just tried to look on that website and it's all in Finnish..  My finnish is limited to Zero..   :-)  I did find it amusing tho' that they also own a Herbie.   Just like my car is.   


Also, How do I contact Bruce Tweddle?   I'm interested to see how much a rebuilt ZF will cost against the Quaife.    Obviously the downside to that style is the plates will wear and it needs servicing but a Quaife is a Fit and forget item.   

Tho' I like the idea of the 37 spline so the larger CVs can be used, but does this mean it will only fit a T2 box?  or will it fit inside a 1302/1303 box?   

[glenn]

Bruce rebuilt my IRS ZF LSD. The clutch discs were shot so he sourced some Porsche 904GT discs and it works great.

[ibg]

Steve, i have a quaife and a jusse diff. both are available with beetle or bus output splines but fit in T1 boxs. Everything else is T1 except the splines. Bus splines are stronger, and can use a bus (T2) or T4 CV, both stronger than a beetle CV.
The quaife style evens the power out on acceleration but under brakes behaves as an open diff. the Jussi/ZF clutch style balances the power to the wheels on accel and will try to prevent one wheel stopping under brakes. On the other hand Quife is maintenance free (no clutch plates) and has a very smooth action. At the top end of road racing 'most' prefer a plate style LSD (Jussi, ZF) rather than a Torque sensing diff (Quaife)
a super diff is stronger than a stock diff but has no LSD characteristics. and with high milage often suffer from oil starvation.
A ZF for a T1 box was only made with beetle splines. i can't comment from personal experience on the strength of the splines.
Jussi can be found through the ads here and replies very well in English  

[JIMP]

Hello Steve

his phone nr +358400657728, you can call him on this he speaks english. Yes the 37 spline will fit T1 transmission with proper modifications,

Friendly

Dimitrios

[steve_pugh]

Steve, i have a quaife and a jusse diff. both are available with beetle or bus output splines but fit in T1 boxs. Everything else is T1 except the splines. Bus splines are stronger, and can use a bus (T2) or T4 CV, both stronger than a beetle CV.
The quaife style evens the power out on acceleration but under brakes behaves as an open diff. the Jussi/ZF clutch style balances the power to the wheels on accel and will try to prevent one wheel stopping under brakes. On the other hand Quife is maintenance free (no clutch plates) and has a very smooth action. At the top end of road racing 'most' prefer a plate style LSD (Jussi, ZF) rather than a Torque sensing diff (Quaife)
a super diff is stronger than a stock diff but has no LSD characteristics. and with high milage often suffer from oil starvation.
A ZF for a T1 box was only made with beetle splines. i can't comment from personal experience on the strength of the splines.
Jussi can be found through the ads here and replies very well in English  

I do like the idea of having the Bus splines as I do want to change the flanges for Bus and run larger CVs anyway.   
You say the top end of Road Racing prefer a plate LSD.  What is better for Drag Racing?    I'm probably not going to be entering a whole lot of circuit racing...

Hello Steve

his phone nr +358400657728, you can call him on this he speaks english. Yes the 37 spline will fit T1 transmission with proper modifications,

Friendly

Dimitrios

Cool.  I might just give him a call or an email then.   We have a Herbie in common and I'd like to know how his costs stack up against the Quaife and how much it'd be to rebuild it if/when the plates wear out.
 
What IS the life of Diff Plates?

[Andy Sykes]

LSD and TBD are different beasties  I know two persons with a quaife that has given it no mercy in a heavy 1303 that runs 11s for years and it still lives and full weight oval that get no days off when it comes to being tested

[steve_pugh]

LSD and TBD are different beasties  I know two persons with a quaife that has given it no mercy in a heavy 1303 that runs 11s for years and it still lives and full weight oval that get no days off when it comes to being tested

TBD would be the way to go then if long lasting bullet proofness is desired with abuse?

What is the advantage/disadvantage with a TBD acting like an open diff on deceleration? 
(My limited research is that the at TBD are a gear driven design, the gears only transmit power 1 way and so they only work on acceleration and act as an open diff under deceleration.  Besides limiting wheel spin an important function of a LSD is to stabilize the car under braking, TBD does not accomplish this, only a plate type does ).