New ATB diferential from Quaife

[olin]

Quaife has recently released this differential for Clio 172/182:
http://www.quaife.co.uk/productnews...tle=New Renault Clio 172-182 ATB differential
Is there anybody around there who has tried it ?
I am interrested but also a bit reluctant since ATB differential are not as good as plate differentials.
On the other hand I have talked to the gearbox design team at Renault and they told me that the JC5 gearbox has not been designed to cope with the torque peaks that occur when a plate diff is locking. They say it would beak the gearbox within 10k...
So it seems that ATB differentials would be the only alternative...

I am also surprised to read here:
http://www.quaife.co.uk/catalogue/page4.htm

"Eliminates harsh torque steer and under steering characteristics of other types of LSD"
I'm quite surprised since I thought that ATB diffs where producing quite a lot of understeering effect. Is this bull*** or a new design that makes it better ?

 

[portal172]

Looks promising, the big question is... Quanto dinheiro?? $$

 

[olin]

1000 £ incl vat

 

[portal172]

Note to self: You must read the whole paragraph.

 

[Fred@BTM]

£1K plus fitting

 

[MarkM]

£1K plus fitting

ouch.

Would a decent electronic traction control system be as good for getting the power down or does a mechanical system have benefits?

ie racelogic at half the price.

 

[stu8v]

ouch.

Would a decent electronic traction control system be as good for getting the power down or does a mechanical system have benefits?

ie racelogic at half the price.

A diff is much better proposition than T/C.

 

[MarkM]

A diff is much better proposition than T/C.

why?

 

[stu8v]

You can use the diff to control the cars attitude when cornering etc. it helps handling and traction. T/C cuts power whats the point in that? You can do that yourself with your right foot you dont gain anything from having it.

CCC tested two cars with Racelogic fitted, a Cossie and a GTI both where quicker with it switched off!

 

[MarkM]

so am I right in saying that a diff transfers the power from a sinning wheel to the one with grip therefore you are not cutting power as per the TC you are transferring it?

 

[stu8v]

Taken from Quafes site,

The Quaife Differential powers both drive wheels under nearly all conditions, instead of just one. With an ordinary open differential, standard on most cars, a lot of precious power is wasted during wheelspin under acceleration. This happens because the open differential shifts power to the wheel with less grip (along the path of least resistance). The Quaife, however, does just the opposite. It senses which wheel has the better grip, and biases the power to that wheel. It does this smoothly and constantly, and without ever completely removing power from the other wheel.
In drag-race style, straight-line acceleration runs, this results in a close to ideal 50/50 power split to both drive wheels, resulting in essentially twice the grip of an ordinary differential (they don't call open diffs "peglegs" for nothing).

In cornering, while accelerating out of a turn, the Quaife biases power to the outside wheel, reducing inside-wheel spin. This allows the driver to begin accelerating earlier, exiting the corner at a higher speed.

The Quaife also controls loss of traction when the front wheels are on slippery surfaces such as ice and snow or mud, providing the appropriate biased traction needed to overcome these adverse conditions. The Quaife Differential provides constant and infinitely variable drive. Power is transferred automatically without the use of normal friction pads or plates seen in other limited-slip designs.

The Quaife's unique design offers maximum traction, improves handling and steering, and puts the power where it is needed most. A definite advantage whether on the track or on the street.

The Quaife is extremely strong and durable and since the Quaife is gear operated, it has no plates or clutches that can wear out and need costly replacement.

The Quaife is great for street driving or racing. Racers don't have to put up with locking mechanisms or spools that created unwanted understeer under power, or in the case of front-drive cars, even tear the steering wheel out of their hands when cornering. Because it behaves like an open differential during ordinary driving, street drivers will have trouble telling it's there until pushing the car's limits

 

[MarkM]

cheers stu.

So how much to fit one of these they sound the business.

Does anyone run one and does it make a big difference?

 

[Fred@BTM]

remove/refit gearbox from car = £300ish labour

box rebuild = £300-£500

i'm not sure if this one will require driveshaft moddification or not

 

[MarkM]

remove/refit gearbox from car = £300ish labour

box rebuild = £300-£500

i'm not sure if this one will require driveshaft moddification or not

Not cheap then!

Is it worth it?

 

[Fred@BTM]

"awaiting Beni'manexpertR to comment"

yeah it'll be good, but having being in Yasser's cup with his Gripper diff i'm not sure if i could live with the noise everyday (Quaife's unit might be quieter

 

[stu8v]

cheers stu.

So how much to fit one of these they sound the business.

Does anyone run one and does it make a big difference?

its a gearbox out and rebuild so labour will be expensive.

ATB types do make a big difference i have one in my pug rally car.
It is temting to fit one in the clio in order to stop 2nd gear wheelspin in the wet but i reckon all in you would be looking at £2000-2500 fitted.

A plated option, but will be much more aggresive in action only for competition IMHO.
http://www.racecar.co.uk/gripper/images/diagrm1.gif

They can be set up with varying amounts of preload to suit individual driver preference and particiular conditions. In Rallying they offer the additional advantage that, in the event of failure of other transmission elements, e.g. a broken drive shaft (even at low levels of preload) they may still provide sufficient traction to drive out of a stage. Models are currently available to suit a number of popular applications, based on two sizes of largely standardized internal components.

 

[stu8v]

"awaiting Beni'manexpertR to comment"

yeah it'll be good, but having being in Yasser's cup with his Gripper diff i'm not sure if i could live with the noise everyday (Quaife's unit might be quieter

The quaife acts as std in terms of noise and operation, only better traction and feel.

 

[BenR]

imo, i wouldnt bother with an atb............unless you like understeer. When a diff is always seeking 50/50 torque split, the inside wheel will be pushing you wide all the time.

Every one i know who has driven a plate type, the gone to an ATB, has hated it and gone back to a palte.

As for the JC5 casing not taking it, i've seen plenty of them last, and still last. The only problem with clamp shocks is if your ramp angles and initial torques on the lsd are poorly setup.

 

[stu8v]

imo, i wouldnt bother with an atb............unless you like understeer. When a diff is always seeking 50/50 torque split, the inside wheel will be pushing you wide all the time.

Every one i know who has driven a plate type, the gone to an ATB, has hated it and gone back to a palte.

As for the JC5 casing not taking it, i've seen plenty of them last, and still last. The only problem with clamp shocks is if your ramp angles and initial torques on the lsd are poorly setup.

When a plate type locks it does exactly the same, thats why you can drive with one shaft snapped!

 

[BenR]

plate types will allow a maximum loss/slip, or minimum torque bias, depending on how its setup. If you have, and most people max their diff as a 60/40 then you wont acheive 50/50 understeer heaven. If you want that might aswell weld the diff solid.

And you will carry on driving even with 1 DS becuase you have that maximum 60% torque loss on the open side.

i just cant get on with atb's......maybe rallying on loose surfaces, but tarmac and progressive (most peoples) driving = understeer which can be worse than std.......add bumps and constantly adjusting grip levels and the atb will dart you all over the road.....i just dont like the idea of an 'lsd' which required grip on both wheels to work.

 

[olin]

Thank you Ben, this is also what I was thinking about ATB differentials: understeering in the acceleration phase.
I've seen two Group A Clios explosing the transmission because of a faulty plate type differential ( the unit fitted on the Sadev sequential gearbox )

 

[Andy GDI]

welding diffs........ to the DATcave

 

[y0z2a]

Olin,

are these now a production item, as a few months ago (after autosport) they said to me that they were making them, but were only making 6 or something, all of which were sold and went to rally teams as far as I remember.

?

/y0z