Benefits Of Slippy Diff

[djinuk 2]

, just wondering on the benefits of a slippy diff , and cost.. at the moment i have a 1.9 gti , avo coilovers, spax rears, very low, runs veyr nice though , 4 branch manifold etc, and just interested really on what benefits a diff will hold, i will most likely swap the gearbox at the same time to a mi16 box.

[welshpug 1,657]

benefits, more grip

[DanteICE 72]

reduced understeer

[perry318888 0]

the car will feel a lot stickier to the road as the engine and box will have more to play in the grip side of things as they will - in effect - be controlling 2 wheels instead of just 1!. also should be quicker if your changing the ratio?

[DanteICE 72]

What diff did you have in mind, because apparently LSD's do need rebuilding every so often.

 

However a quaife ATB diff does not. But I have heard that the quaife can be a bit twitchy for road use, but again I have never tried it so I don't really know. The Focus RS (original one at least) has a quaife diff and clarkson said it was a little twitchy on normal roads but superb when your leathering it. However I reckon its just he's not used to it, because he will probably never have driven a FWD car with an LSD before and its bound to have different tendancies!

 

Geoff

[alync406 4]

I would be thinking that another benefit would be that it won't break up and come out through the side of the box.

[taylorspug 7]

From what ive heard the best thing you can do with those Focus RS's is throw the Quaiffe in the bin and fit a nice plate diff, apparently cures the pulling problem straight away...

[DanteICE 72]

Can you explain what the problem is? (with the focus rs diff that is)

 

Also does the quaife diff work ok on a 205 or is it the same problem as the Focus RS?

[taylorspug 7]

The diffs on the focus and the 205 work on the same principle as far as im aware. From what i know, the problem with the Quaife seems to lie with the 'torque biasing' aspect of it, which switches the amount of torque it transfers from one wheel to the other far too much, causing the car to snatch and pull all over the road. In all honesty its not actually a 'proper' LSD, more a halfway hose between an open diff and an LSD. Also if you have one wheel off the ground with the Quaife diff, neither wheel will be driven (again due to this 'torque biasing' thing). A plate diff delivers the same amount of drive to each wheel all the time, depending on its settings.

 

Id imagine the big wide wheels on the Focus dont help, although a few people i think have had similar problems on the 205. The few ive driven with them fitted seemed fine though in all honesty.

[tom_m 0]

quaifes are tame compared to proper plate diffs

[SurGie 54]

The diffs on the focus and the 205 work on the same principle as far as im aware. From what i know, the problem with the Quaife seems to lie with the 'torque biasing' aspect of it, which switches the amount of torque it transfers from one wheel to the other far too much, causing the car to snatch and pull all over the road. In all honesty its not actually a 'proper' LSD, more a halfway hose between an open diff and an LSD. Also if you have one wheel off the ground with the Quaife diff, neither wheel will be driven (again due to this 'torque biasing' thing). A plate diff delivers the same amount of drive to each wheel all the time, depending on its settings.

 

Id imagine the big wide wheels on the Focus dont help, although a few people i think have had similar problems on the 205. The few ive driven with them fitted seemed fine though in all honesty.

 

 

Sorry to jump in but what are your views on gripper diff's? Cheers

[Sandy 191]

It depends on your suspension geometry and power, as to how good or bad a Quaife gear type diff is to use. With moderate power and good geometry, the improvement in traction can seem to work wonders. However, it relies largely on grip to work, if you have enough power to break traction with it or if the suspension geometry makes the car follow cambers/whitelines etc, it can be horrible to use and I mean really horrible, dangerous torque steer!

Plate type diffs like the Gripper work brilliantly with the right settings on a range of surfaces. They can be (but not always) noisy at slow speed turning etc and if subjected to a large amount of "tight" use such as that, can need rebuilding sooner, but they work so much better, personally I'm prepared to live with that.

On the competition cars I'm involved with, the Quaifes have been no more reliable than plate types, but on the road, a Quaife is likely to last longer.

Edited September 30, 2008 by Sandy

[jackherer 543]

Its interesting you mention geometry Sandy, I put a new steering rack on a 205 with a Quaife yesterday and drove it to get the tracking set after roughly setting it by eye. With the tracking not right it drove like it had an open diff, I gave it a bit of power in first to get out of a junction into a small gap and it instantly span up with awful torque steer which really took me by surprise, when its aligned correctly it has loads of grip.

[kyepan 291]

I've got a quaife in my MI, and under full acceleration it accentuates any tendancy to tram line as it searches for grip. Coupled with my neutral track and -ve camber front set up, it's lively to say the least. If your coming out of a slow corner, or off a tight roundabout and give it death, both hands need to be on the wheel.

 

From what I understand, plate diffs can be tamed by adjusting the ramp angle of the plates, so they engage more gently and when greater slip is detected.

 

Would also say you have to modify your driving style after fitting a Quaife Diff to get the best out of it, point and squirt doesn't work so well, because if you can light up the wheels, the diff doesn't help.

 

Driving through the corner on the power works very well, because whilst the car is in grip you get drive through the corner not under steer, so you have to adopt a steady in fast out attitude.

 

This sounds like I'm not a fan of the Quaife, which in fact I am, it's certainly made the MI's power accessible and turned it from a slightly unruly car that feels overpowered to a quick planted car. It alters the vehicle dynamics and makes you drive slightly differently to get the best out of the available grip, which i don't think is a Disavantage.. Because if you're hooliganing it everywhere lighting up the fronts.. you're either driving like a tit, or rallying, and need a plate diff.

 

Personally, not having to take the box off every time it needs a rebuild is reason enough to get one. Also it seemed to improve the braking performance too.. ask batfink, he likes my brakes.

[SurGie 54]

It depends on your suspension geometry and power, as to how good or bad a Quaife gear type diff is to use. With moderate power and good geometry, the improvement in traction can seem to work wonders. However, it relies largely on grip to work, if you have enough power to break traction with it or if the suspension geometry makes the car follow cambers/whitelines etc, it can be horrible to use and I mean really horrible, dangerous torque steer!

Plate type diffs like the Gripper work brilliantly with the right settings on a range of surfaces. They can be (but not always) noisy at slow speed turning etc and if subjected to a large amount of "tight" use such as that, can need rebuilding sooner, but they work so much better, personally I'm prepared to live with that.

On the competition cars I'm involved with, the Quaifes have been no more reliable than plate types, but on the road, a Quaife is likely to last longer.

 

 

Ok then well im having koni coilovers, 309 full legs anti roll bars etc, 250 BHP GTI 6 180 lbf torque, lowered to approx 30mm back to 35-40 at the front. With

around -2 neg camber at front and -1.2 neg camber at the rear. Also having silicone bush set all round and gp A for rear etc.

Im already having the gripper diff but didnt know they will need rebuilding when on road use, do you know what kind of

price that would be? Il also have NOS fitted at a later date for drag racing.

Edited September 30, 2008 by SurGie9

[dirtdog 4]

However I reckon its just he's not used to it, because he will probably never have driven a FWD car with an LSD before and its bound to have different tendancies!

 

Geoff

 

 

The RS focus wasn't the first front wheel car to come with a LSD. Pretty sure some rovers used to have them way before the ford focus..(?)

 

 

 

Surgie...why are you drag racing your 205 if your putting all those suspension mods on? If your going to drag race just spend the ££ on the engine as you won't need the car to turn good?

[Sandy 191]

The Accord and Integra Type R have gear type LSDs and both are considered paragons of FWD handling, however they have excellent geometric stability at the front and moderate torque.

[SurGie 54]

The RS focus wasn't the first front wheel car to come with a LSD. Pretty sure some rovers used to have them way before the ford focus..(?)

 

 

 

Surgie...why are you drag racing your 205 if your putting all those suspension mods on? If your going to drag race just spend the ££ on the engine as you won't need the car to turn good?

 

 

The car will be muli purpose, part track/fast road/drag till i can afford a sh+t looking 205 and then put a GTI6 in it for all day track action,

il put differant wheels on to help stop the traction grip it may cause, im having 6.75 width alloys for road track then my GT alloys

for drag fun, they are about 5 width and smaller about 13 inch. It will be experimental.