To quaife or not to quaife? This is the question.

[petew]

Got a 75' swing trans on the way to being rebuilt. Want to use the car for motorkhanas on dirt and wet tarmac with the odd track day.

I've got a few options;
1. Stock late swingaxle diff (2 spider)
2. Super diff (4 spider)
3. Quaife

Yes, I know I could get a ZF LSD from Mr Tweddle, but really. 50yo LSD centre and hard to get parts. And then there is the cost. Hmm, I think not.

I've used a superdiff/turning brake setup before. Very effective, but I'd like to be able to drive the car with the throttle like a regularly sports car. The motor going in the car is an EFI blown 1600. Not super high power but 9PSI of boost and plenty of torque I reckon.

So, I like people's input. What have you used for these sorts of events? What did you learn? Thoughts?

[petew]

P.s. if you know a dealer who can do me a killer price on a Quaife centre and shipping then let me know about that too pls.

[Jadewombat]

Go for it. I converted 1 car and it was well worth it.

[petew]

can you give me a little more feedback on it?

[Jadewombat]

This was a FWD VW Golf, but after I put the Quaife in the car was a real handful accelerating through sharp corners. The car felt like it would just sink in and pull through, it was a very different feeling, almost like more turn-in was available. Even going through a sweeping turn with steady throttle the car felt more planted and stable. It's the same hp you're dealing with obviously it just seemed like more effective use of it.

[sideshow]

I put one in my IRS daily driver, loads more traction in the yard (dirt/inclines/wet grass), much more predictable than a plate type

[buildabiggerboxer]

Limited slip diffs are not the magic bullet they are cracked up to be, there are pro's and cons and VW's don't really need one, VW traction is very good if the car is set up properly, the common mistake that kills traction is over springing at the rear, a heavy 300 hp bug in road trim with all the seats and creatures comforts fitted MAY possibly gain something from having one, my race bug has 200 hp in 750kg and a free diff, I don't suffer greatly, and race with and beat other bugs with quaife diffs and I can't see were they have any advantage over my car, it's good in the rain too.
The rule really is a Torsen diff for front wheel drive and a plate diff for rear wheel drive or rear engine, Torsen diffs have no over run locking, plate diffs do, and it can be adjusted by changing the ramp angles,
Over run locking control is a vital tool in all out racing for good behaviour from the rear axle when trail braking down into any turns that require it, all the good guys do it without any thought, and the diff action augments the technique.
For a low power swing axle competition car on stock 22mm torsions, I would recommend a Z bar over a lim slip, these offer improved corner exit traction by there action, but can cause understeer or push, so then you will need to add castor and camber and find additional front wheel load, battery relocation is a start.
In 3 weeks time, I have to race a customers car that has a quaife and a 2.3 motor on track day tyres, I will be intrigued to see how it compares to my car, but I have not seen any improvement in lap time by this car since the quaife went in, I know this because I monitor it for obvious reasons.
That's as I see things, just be sure you REALLY need one, but I would go with the Z bar shimmed up solid, For what you want to do it will help you, an expensive diff may not...

[buildabiggerboxer]

Opps, double.

[Jadewombat]

Yeah, but going back to the OP he is talking about doing mostly rallycross where traction is a whole different necessity than Autocross or track days or anything on pavement that has little wheel slippage.

The "feel" is of course up to the driver as always, and yes a better driver will be a better car anyday. Build, you're also talking about bugs that have waaay more power available than stock. In class limited racing where you can't modify the engine much, LSD diffs. are the norm. to take advantage of all available stockish hp.

Pete, go here and start reading and report back:

viewtopic.php?f=50&t=128682&hilit=locker&start=75
http://www.pistonheads.com/gassing/topi ... ferentials

And yes, I've heard of Porsche owners pulling the factory LSD out of their G50 trans. or Jeep owners pulling out lockers to make things more interesting, etc. The argument of whether or not it is a performance gain is different though.

My favorite example, and in NO WAY is this meant to compare a VW bug designed in the 1930s with or without LSD, was an article in Car and Driver, maybe Road and Track, I don't remember but about 4-5 years ago then ran a brand Nissan Z and Mitsu. Evo. at the time through a road course--kind of like a dragon race. On paper the Z was better, 200lbs. lighter, lower, 20? more hp, and well it's more of a sports car that the Evo.

Guess who won? Yep. They credited it to the advanced engineering of the Evos AWD system and diff. control.

[Piledriver]

I hate to suggest this, bit it must be said:
The ~$400 Chinese torsen type sold by OCD or whatever their name is looks rough but has great reviews by folks who are using them. Theeeey make them for T1s, but folks have put the in 914s and adapted to other cars.
(not referring to the Phantom slip joke)

[petew]

Piledriver can you send me a link or something? Very interested to see what you're talking about.

BABB; I get what you're saying. However, I've raced a buggy with an open diff and steering brakes and while it was nice, I really always wanted an LSD of some sort. The driving style is totally different and more akin to the sports car experience of driving the car on the throttle, which is what I want. I could buy a plate ZF, but it's about $500 more than a Quaife, it's also very old. Modena engineering in Aust quoted me $2.5k for a plate style diff they'd built. So really the quaife is a cheap, axle friendly option for me.

The other thing is... transaxles share diff and gearbox oil. Do I want my gearoil full of clutch metal from the plate LSD? I think not. Do I want to have to pull the trans every 12 months to have the diff reset again? No.

My current setup is stock Oval torsion bars and a camber compensator with 185's on the back. The car is getting a blown 1600 soon too. With any sort of LSD it's a recipe for sideways fun on the skidpan.

[Piledriver]

OBX makes them, about a million his on Google, IIRC some discussion here on the STF and TOS.
(OBX: the same folks who make $200 knockoff 304 SS 914 Kerry Hunter headers and cheap Chinese turbos.)

I have seen positive comments from folks who have adapted them for many uses.
Have not read many (really none at all) failure reports from folks who have actually used one.

Did find quite a few folks complaining about poor finish, dubious hardware with early units etc.

I have never seen one myself.

[buildabiggerboxer]

Yes, clutch type diffs are high and expensive maintenance for racing, I did say there is no magic bullet and you asked for information, I've used both types and also solid axles on various disciplines but it's your decision as to if it's a plus for you, I use a ZF in my T25 towing bus and it's done ten years hard graft, but is now noisy and needs a re build, for towing in and out of grassy parking areas with a trailer, it can't be beat. But I still say for swing axle use, start with a proper Z bar, set up well and working full time they increase traction hugely to surpass a wrongly set up chassis even with a slipper diff, a wheel in the air ain't driving nothing, incidentally , the quaife diffs never lock.
We have a swing over here to the "Detroit locker" diffs, wether these are Chinese repros or not I don't know, Pile has a good point and it is closer to home , however I will explore more into the Detroit locker, tho I believe they are a pawl/ratchet type action, and either locked or free, with nothing in between. Regards, BBB.

[petew]

Sorry BBB, you're right. Sorry if I was off hand.

I guess the issue is, like you say, there isn't an easy answer to the issue.

I've sent Bruce Tweddle a question re replacement parts for the swing ZF, but IIRC the clutch plates he uses to rebuilt them are super rare and NOS. I just can't justify putting something so expensive in when I know it a. wears out, and b. has no replacement parts available.

The quaife isn't a lot cheaper, but at least they still make them and they're largely maintainence free. I'm struggling to think of a situation in this car when one wheel would be in the air. I could see it in my old buggy, but not in the current car.

I've looked into Z bars extensively and 2 things stop me. a. the car is a 56' and has no way to mount one, b. all the info I've read seems to say compensators do much the same thing but in a slightly different way. Can you tell me why you think the Z bar is better?

Looked into the OBX. Can't find em to fit an aircooled car, just FWDs and Subarus.

Re detroit lockers, I wouldn't mind one actually. I know it's not progressive, but on a wet skidpan or a dirt track, it would be fine. You don't know of anyone making for swingaxle do you?

[Steve Arndt]

I didn't know OBX made a cheap dif that fits T1 transaxles. More info!