Limited slip diffs

jonhill · 26 Jan 2005, 10:31 (Ref:1210194)

Hello

Does anyone have views or experience of the differences between gear type LSD's (e.g. Quaife) and plate type (e.g. Gripper). Its for a fwd saloon car (pug 205) that'll be racing on 1A road tyres. I dont have power steering, so I want something managable.

My feeling is that the plate type may be technically superior but are less friendly to drive with and require more setup and maintenance work (occasional rebuilds and the like). I'm leaning towards Quaife at the moment as I'm happy with 90% performance if its easier to live with.

Let me know what you think

jon

Anuauto · 26 Jan 2005, 15:05 (Ref:1210394)

The Quaife ATB is not an LSD. The manufacturer takes care never to call it one but some retailers are not so careful. Lots of FWD and RWD IRS users swear by them. Those of us with live rear axles mostly swear at the money we wasted.

Chris Griffin · 26 Jan 2005, 15:58 (Ref:1210428)

Ive never raced a fwd car, but from what i've read the Quaife ATB diff suits them well. However I have raced a rwd Dolomite Sprint for many seasons with firstly a "Detriot Locker" diff, then a Quaife, then a salisbury plate diff. The Quaife was bloody awful. It directly resulted in causing two offs for me. Most rwd race saloon cars need to be driven through corners with a slight tail-out attitude, the Quaife hated this and would constantly change the bias from side to side. It made life very difficult.

graham bahr · 26 Jan 2005, 17:11 (Ref:1210481)

with the quaife ATB its vital to keep both driving wheels well and truly in contact with the tarmac or you'll have no drive. personally i'd go with a plate type every time

jonhill · 26 Jan 2005, 17:26 (Ref:1210503)

mmm.... but with a fwd, its not often that i'll lift a front wheel - really only if i launch off a kerb or something. If it's rallying on **** surfaces i can see this being important, but does it really make a difference on tarmac?

I guess i'd like to weigh it against the the "downsides" of rougher drive and maintenaince of the plate types.

this should be easy

imull · 26 Jan 2005, 22:55 (Ref:1210782)

quaife diffs dont lock, so should you break a shaft you will be stuck ~ just ask the boys who do forrest rallying.

Gripper diffs can be a bit vicious. Lots of snapped shafts when powering out of tight corners. Again thats on forest stages where there isnt as much grip to put force back through the system...

Plate diff by far the best option technically. Easily worked with and can be set up pretty easily from what mates say. Personally what I would go for. As most roundy roundy stuff seems to be only a few laps, surely you could learn to cope with teh added work easily enough.

1200Datto27 · 26 Jan 2005, 23:22 (Ref:1210794)

I agree with the ATB comments, great drive out of the corners (IRS Westfield) and stable under braking/turnin, until you unweight a rear wheel, and then it all goes haywire. Or if you break a driveshaft

then you go no where.

Chucky · 27 Jan 2005, 00:40 (Ref:1210822)

Yeah, I've used the Torsen which is very similar to the Quaife and had excellent results but that was with a car with serious downforce. It would be a handful if you unloaded a tyre. They also degrade in performance over time as the gears start to wear and they are quite heavy in rotational mass.

Plate diffs are good and can be tuned very precisely. However, it can be more work. Not a problem if it's easy to get to. You should find a setup that works on most tracks which will cut out the work.

greenamex2 · 27 Jan 2005, 08:19 (Ref:1210957)

All the XR2's I haved raced against have complained about the ATB diff, with many of them replacing it.

No personal experience though. I use a plate type diff in a RWD Corolla.

Kev_205 · 27 Jan 2005, 13:37 (Ref:1211186)

Ive driven a 205 with the quaife diff and had no problems with it at all. A definete improvement over standard. Was fantastic to drive on the tighter bends.
Personally Im going for a plate-diff though for my racecar, though having never driven a car with one I cant compare. I just can get a better price on one though

imull · 27 Jan 2005, 19:02 (Ref:1211369)

the other option is a cam and pawl diff. Which I am led to believe is open until a predetermined amount of slip is experienced then it slams shut... I think the real F1 cars (60's,70's) used these.

MGDavid · 27 Jan 2005, 19:23 (Ref:1211398)

There's another type too - made by an outfit stateside called Phantom Grip, a Google search will turn it up. I have one for the Midget but as yet untried.

coln72 · 27 Jan 2005, 21:42 (Ref:1211516)

Or you could just weld the stocker. 100% drive no matter what until it goes bang (approx. every 3 years in my case). Might be a bit nasty in a FWD.............

Chucky · 28 Jan 2005, 08:00 (Ref:1211800)

If you ever want a balanced car that actually turns in, forget spools and welded lockers. Cam and pawl's are a bit rare these days. They only lock about 80% and that's only when brand new.

1200Datto27 · 28 Jan 2005, 12:13 (Ref:1211972)

Spools will only really work in a powerful RWD car, that can be setup to allow the inside rear wheel to be unweighted, so as to minimse the push caused by the diff.

coln72 · 30 Jan 2005, 21:45 (Ref:1213371)

I didn't say it would be quick with a locker, but in a RWD they can be a lot of fun

**dtype38** · 31 Jan 2005, 09:17 (Ref:1213600)

Not sure of the technical term but if you've got a big rwd car you could try what Jaguar call a "power-lock" diff. It has a wet multi-plate clutch inside and basically does what it says... its limited slip on over-run and no load, but it locks solid when power is applied. Makes for excellent gettaways from the line because of the locking thing, err, but you don't want to be trying to turn into a corner with the power on!! Half way round a corner like Gerrads at Mallory, you can actually play with the under- and oversteer with your right foot to get the best of the grip

Al Weyman · 31 Jan 2005, 21:06 (Ref:1214086)

Funny eough on my IROC racer I am renovatig (not the one in my avatar but a real ex-Penske one) according to an article in Road & Track featuring my car in IROC they use a spool (totally locked) on the road courses (race circuits to us) and a Detroit Locker on the ovals and I always thought it would be the other way round. I have always been tempted to try a spool in my Camaros but have bottled out.

Chucky · 1 Feb 2005, 00:36 (Ref:1214234)

Wasn't the power-lok another form of a detroit locker? Although your description sounds more like a Salisbury/PowerFlo clutch pack style LSD.

**dtype38** · 1 Feb 2005, 09:51 (Ref:1214419)

Quote:

Originally Posted by Chucky

Wasn't the power-lok another form of a detroit locker? Although your description sounds more like a Salisbury/PowerFlo clutch pack style LSD.

I think the Salisbury was a predecessor of the PowerLock and they overlapped in production so it's probably just a refinement or a trade-named version. Not my specialist field... can anyone out there shed more light?

carsreunited · 2 Feb 2005, 00:13 (Ref:1215090)

"Power-Lok are made in the UK by Salisbury under licence from a Thornton axle company USA patent"

Auto performance May 1983

Don't know if that is of any use to the thread...

Scott

graham bahr · 4 Feb 2005, 20:43 (Ref:1217703)

and i though i was the only one that remembers auto performance!

Chucky · 4 Feb 2005, 21:08 (Ref:1217755)

I can't fathom why they would have used a Detroit Locker on an oval. Thay have a terrible tendency to ratchet on and off through long sweeping turns.

You're right. I would have thought it to be the other way around.

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