LSD effect on handling

[Igorbio]

the title is quite poly-semantic but we are talking about limited slip differential ;)

never had a chance to drive a FWD car with LSD, how does it change the handling and turn-in tactics? doesn't the car start to understeer and becomes "boring" to drive at the limit? and if so can this be overcame by suspension tuning?

I am considering both - pre-tensioned quife and plate type LSD (which is in favor due to high efficiency).

It's quite expensive mod so I'd like to be sure I will not ruin the handling which is so fun and the best quality in a saxo/106 imo.

[Ross]

Probably the single best mod I have done to my car. Wish I'd done it years ago.
I run a plate diff and once setup correctly for road use, is incredible. Seems like there's 10x the grip (of course there isn't but a LOT more confidence).

Highly recommended.

Is this in an MA gearbox? The BE diff's are somewhat cheaper, and as you probably know, a lot easier to service (something you will need to do every now and then with the plate style diff).

[Igorbio]

Probably the single best mod I have done to my car. Wish I'd done it years ago.
I run a plate diff and once setup correctly for road use, is incredible. Seems like there's 10x the grip (of course there isn't but a LOT more confidence).

Highly recommended.

Is this in an MA gearbox? The BE diff's are somewhat cheaper, and as you probably know, a lot easier to service (something you will need to do every now and then with the plate style diff).

you are talking about grip while accelerating out for corners and what happens on turn-in - does it enter corners with the same willingness and agility as before?

not planning to change the gearbox, many reasons...

[Ross]

i found (and I'm talking only from a "road" perspective, I have no real track experience in the last 15 years) that turn in was very similar, but it was almost as if when you feel understeer you could apply more power and it "drags" you round. It's a hard thing for me to describe.

I think the initial (very first) part of the turn in is a little more resistant as the car does want to stay in a straight line more, but once turning it's very willing. There is perhaps a little more pull (in your hands) to the outside of the bend.

I'm sorry that I'm struggling to explain it well for you, but I really think it greatly improved the car. Obviously the main reason I got it was for the high power handling, but I would get one on an NA car if I bought again :)

[welshpug]

plate = WIN :D

Quaife is stronger than o.e, but that's about only thing going for them.

The need for servicing of a Plate unit varies but they can do several thousands of miles without needing any work.

[sexy_gt]

ive only ever used a quaife on my car. i wasnt impressed at all when i first used it (120bhp), after some tuning (150bhp) other drivers from trackdays would comment how i can get on power way before them.... now im supercharged (220@wheels min) its a must have. the only downside is wondering how much quicker id be with a plated version.

i would love a plated diff but i dont want all the servicing they require to keep them at their best.

plated diffs are going to be much harder on all drivetrain though.

[Gabbastard]

I once built up a box with an ATB Quaife in it, and put the box in my car to test it out. I drove a road I drove a lot, and when I got to the small roundabout that represented the turnaround, I turned in and applied power the way I normally would have. With the Quaife I almost hit the inside kerb as the car seemed to pull itself into the corner a lot harder.

Never tried it on track but would assume the same kind of effect would be there.

[Mr_X]

I'd argue it worsens the handling.

[sexy_gt]

I once built up a box with an ATB Quaife in it, and put the box in my car to test it out. I drove a road I drove a lot, and when I got to the small roundabout that represented the turnaround, I turned in and applied power the way I normally would have. With the Quaife I almost hit the inside kerb as the car seemed to pull itself into the corner a lot harder.

Never tried it on track but would assume the same kind of effect would be there.

ive heard people say it pulls a car closer to the apex. but i wouldnt say that at all.

I'd argue it worsens the handling.

please explain why as i am interested ...

[Dave_P]

I'd argue it worsens the handling.

It depends what your used to...

Any LSD of sorts is an improvement on an open diff...

[Mr_X]

well lsd isnt going to improve handling and the way in which it works can upset handling, with more tendencies to understeer.

So IMO get the car set up properly and there is no need.

[welshpug]

you alter your driving style to suit, it means you can put the power down far earlier, oversteer much safer and controllable with one, no brainer for a car driven hard and one with a tuned engine.

[Mr_X]

you alter your driving style to suit, it means you can put the power down far earlier, oversteer much safer and controllable with one, no brainer for a car driven hard and one with a tuned engine.

I still argue lsd masks the problem of a poorly set up car.

It does have some advantages but imo it's not the wonder people think.

[Regis_92N]

I still argue lsd masks the problem of a poorly set up car.

That will be true for a No roll car (Mc Laren F1, new Mp4 or P1...)

So absolutly not true for a car like 106/saxo and almost every other cars.

And because you have to put power to the ground you need a LSD ;)

[welshpug]

I still argue lsd masks the problem of a poorly set up car.

It does have some advantages but imo it's not the wonder people think.

Why does every race car worth mentioning have one then? Inc f1...

And i bet those that dont, like a roadgoing lotus evora, have the most complex ebd asr tcs systems to do the job of a diff, and more.

[Mr_X]

That will be true for a No roll car (Mc Laren F1, new Mp4 or P1...)

So absolutly not true for a car like 106/saxo and almost every other cars.

And because you have to put power to the ground you need a LSD ;)

Cant say I have great experience of lsd in a saxo :oops:

Why does every race car worth mentioning have one then? Inc f1...

And i bet those that dont, like a roadgoing lotus evora, have the most complex ebd asr tcs systems to do the job of a diff, and more.

I dont know why tbh, but is it for handling sake?

I can say lsd made my car handle worse, It may have allowed me to get on the power earlier out a tight bend... but that isnt handling.

[axsaxoman]

Cant say I have great experience of lsd in a saxo :oops:



I dont know why tbh, but is it for handling sake?

I can say lsd made my car handle worse, It may have allowed me to get on the power earlier out a tight bend... but that isnt handling.

If you find an lsd of any type makes the car handle worse ,then may I suggest you change your driving style .
or take a few driving lessons .
thats not much more one can say every competition car has one for a good reason

[sexy_gt]

I have driven supercharged saxo 200bhp it span wheels through 3rd in the dry with a standard diff.

My current saxo with a quaife would not do that in the dry And its 50 bhp more.

I would say thats a good enough example of one being of good use.

[Mr_X]

If you find an lsd of any type makes the car handle worse ,then may I suggest you change your driving style .
or take a few driving lessons .
thats not much more one can say every competition car has one for a good reason

I've had plenty of training thanks. How exactly does in improve handling? Genuinely interested.

[Mr_X]

Sexy-gt, with a 200bhp saxo, i dont doubt it stops the loss of traction.

[sexy_gt]

I've had plenty of training thanks. How exactly does in improve handling? Genuinely interested.

Sexy-gt, with a 200bhp saxo, i dont doubt it stops the loss of traction.

being able to exit a corner with more power sooner... thats a handling improvement.

[AXracing]

As people have said just about any LSD is an improvement. Different diffs do however have very different affects.

Plate type are very effective but can be aggressive but are however consistent so you can learn to drive very quick with these. Sadly the MA gearbox does not have enough room for as larger plate diff as many higher power guys would like. So the clutches do eventually wear and require replacing.

AP Racing Suretrac type are in my opinion brilliant. Could not really explain how they work but my old one put up with many years of stick and so incredibly easy to drive. I had on several occasions experienced racing drivers get in my car and comment how nice the diff was and how well the car turned in and gripped out the corners. They work by magic. No honestly they do. These only have a relatively low torque rating though so one for the normally aspirated guys perhaps.

The ATB is probably the most common in road and track days cars these days. They are fit and forget and are in almost every situation substantially better then a open diff. They are also very strong so great for the boost guys. Only real down side of them is they are a tad unproblematic. I found the few i have driven would fight me and the car world dart about side to side on the track/road a bit. It was like torque steering but changed its intensity and direction every few seconds. However effect was quite mild so still controllable and only in really slippy conditions I even found it a real problem. I guess on a road car it could become a bit annoying though.

Viscous diffs I always liked on road going FWD cars because there so predictable and very easy to drive. There just like a open diff but better. There low maintenance to boot. However they have lost popularity these days and i don't think any one offers one for the MA box? You many find there is not enough space for one.

[AXracing]

I've had plenty of training thanks. How exactly does in improve handling? Genuinely interested.

If your driving a FWD car as quick as it can go you will be using the throttle to steer it round the bends. With a Open diff its very hard to do this as when the inside wheel lifts you effectively loose drive and spin.

[sexy_gt]

I found the few i have driven would fight me and the car world dart about side to side on the track/road a bit. It was like torque steering but changed its intensity and direction every few seconds. However effect was quite mild so still controllable and only in really slippy conditions I even found it a real problem. I guess on a road car it could become a bit annoying though.



ax racing i agree on the road about this... again its only since going from 150-250bhp...

[Igorbio]

I once built up a box with an ATB Quaife in it, and put the box in my car to test it out. I drove a road I drove a lot, and when I got to the small roundabout that represented the turnaround, I turned in and applied power the way I normally would have. With the Quaife I almost hit the inside kerb as the car seemed to pull itself into the corner a lot harder.

Never tried it on track but would assume the same kind of effect would be there.

It`s clear here, but I presume you were driving pretty far from limit on that roundabout, if you did you wouldn`t be able to open the throttle in the first part of the corner and the car would demonstrate the tendency to go outside. When you accelerate, yes it does pull the car inside - but it dictates a totally different style of driving.
Open diff: trailbraking on turn in or low throttle to help traction on the front, then on the pedal while hitting apex or slightly before it and then pedal to the metal on the exit.
LSD: as the car does not turn-in so well you have to brake harder and turn-in at a slightly lower pace and start accelerating right after the turn-in or even simultaneously...
That`s a whole different story and seems much less "fun" to me. I love the saxo/106/205 for it's agility entering tight bends and being tail-happy and LSD might diminish these qualities significantly...

well lsd isnt going to improve handling and the way in which it works can upset handling, with more tendencies to understeer.

So IMO get the car set up properly and there is no need.

That`s right! I also heard hat a well setup saxo doen't really need one...
But my plan for 2013 is 150-160hp, so it might be usefull especially in the wet, let alone snow/ice racing where LSD lets you dominate all FWD open diff cars even with really fast guys behind the wheel...

you alter your driving style to suit, it means you can put the power down far earlier, oversteer much safer and controllable with one, no brainer for a car driven hard and one with a tuned engine.

Sure one has to alter the driving technique and tactics, one can even drive horribly understeering audis and volvos very fast around a track but it won't be "fun" by any measures...
So the deal is how does it transform the 106/saxo and how does the car react with different LSD setups (pretension, degree of slip etc.)?

Why does every race car worth mentioning have one then? Inc f1...

And i bet those that dont, like a roadgoing lotus evora, have the most complex ebd asr tcs systems to do the job of a diff, and more.

Cuz it helps acceleration especially for very powerful cars, besides most of them are RWD which is a whole different story. And still those really fast racing cars may lack the thrill of a sketchy turn-in and have an understeering character.

Anyway LSD IS AN IMPROVEMENT - no doubts here, but how drastically it alters the handling?

[Igorbio]

As people have said just about any LSD is an improvement. Different diffs do however have very different affects.

Plate type are very effective but can be aggressive but are however consistent so you can learn to drive very quick with these. Sadly the MA gearbox does not have enough room for as larger plate diff as many higher power guys would like. So the clutches do eventually wear and require replacing.

AP Racing Suretrac type are in my opinion brilliant. Could not really explain how they work but my old one put up with many years of stick and so incredibly easy to drive. I had on several had occasions experienced racing drivers get in my car and comment how nice the diff was and how well the car turned in and gripped out the corners. They work by magic. No honestly they do. These only have a relatively low torque rating though so one for the normally aspirated guys perhaps.

Could you tell a little more about you experience with plate type - if setup properly understeering tendency much not be significant?

I have 3 options: quife, plate (don't remember the manufacturer but it's from UK, local rally team offers them here) - it's a tad more expensive but i suppose MUCH more efficient and an open diff to save money :cool:

[axsaxoman]

I see you own an elise --now theres a car that if not set-up EXACTLY will bite when on the limit .
they are particular about damper and spring settings + corner weights
and having a rear engine does not suffer as much from lack of lsd in std tune .
put 300bhp + in it and you will want an lsd , if no other reason than you can power drift it out of the corners,having an lsd will mean you can get back on the power quicker and know what its going to do

[Mr_X]

I do class handling and traction as two different things.

Im not being a massive troll, honest.

I have had experience of them with sc k20a with 300whp, axsaxoman, I agree with what you are saying about power on earlier.

I've spend a fair few thousand sorting mine out, I prefer the handling without the lsd.

I still dont think its the be all and end all it is often made out to be.

I haven't raced high powered saxos though.

[AXracing]

Could you tell a little more about you experience with plate type - if setup properly understeering tendency much not be significant?

I have 3 options: quife, plate (don't remember the manufacturer but it's from UK, local rally team offers them here) - it's a tad more expensive but i suppose MUCH more efficient and an open diff to save money :cool:

What is the spec of your car and what sort of racing are you doing? Its a little hard for me to say as for the most part I have use Suretrac or ATB in these cars (well Citroen AX but same car really) and it was always tarmac. I did know quite a few people who used to use plate type and they never looked to have a problem. I did try a few of there cars over the years but its always hard to compare as its not your car. My and a few of my friends all had our cars set up extremely pointy. So under steer was no so much a issue if you drive the cars accordingly. Basically the car inherently wants to spin off the track. Then you rely on your power to balance the car and drag it round the bend. If you do get power under steer you can always use the brakes to bring the car back in line again. All this is very old though so I may be somewhat outdated to what is the done thing now. I have not raced FWD in a very long time :wacko:

[axsaxoman]

the final arbitraitor of what is good + bad must surely be lap time ,and that will be quicker with an lsd
a 300bhp elise would murder a saxo , even the best there is ,on a lap time and an leise with a lsd will murder one without it
high power fwd is for men --no esp .no electronic gadgets traction control or just an animal waiting to be tamed and all cornering is like driving on ice even in the dry

[Mr_X]

the final arbitraitor of what is good + bad must surely be lap time ,and that will be quicker with an lsd
a 300bhp elise would murder a saxo , even the best there is ,on a lap time and an leise with a lsd will murder one without it
high power fwd is for men --no esp .no electronic gadgets traction control or just an animal waiting to be tamed and all cornering is like driving on ice even in the dry

quicker lap time isnt equal to improved handling.

[AXracing]

quicker lap time isnt equal to improved handling.

How so? All else being equal the best handling car will always be quickest.

[Mr_X]

How so? All else being equal the best handling car will always be quickest.

;) i didnt say that



For example, i'd say an impreza handles like a big saloon but has plenty of grip

[Ross]

All I can tell you is over 300hp on fwd, traction is impossible with an open diff. Wheel spin in 4th gear at 80mph was frequent in mine until I went gripper diff. I simply couldn't drive mine with any passion without the diff.

[Mr_X]

All I can tell you is over 300hp on fwd, traction is impossible with an open diff. Wheel spin in 4th gear at 80mph was frequent in mine until I went gripper diff. I simply couldn't drive mine with any passion without the diff.

LOL that's crazy

[e8_pqck]

I found the few i have driven would fight me and the car world dart about side to side on the track/road a bit. It was like torque steering but changed its intensity and direction every few seconds. However effect was quite mild so still controllable and only in really slippy conditions I even found it a real problem. I guess on a road car it could become a bit annoying though.



ax racing i agree on the road about this... again its only since going from 150-250bhp...

+1 I have found the Quaife can snake you down the straight sometimes as it keeps transferring power from side to side, can be a little unnerving.

However, on turn in i found there was a lot less understeer and the car didn't drift out at all instead it turned in tight and when i put the power down it pulled me round and i was able to steer back out the corner earlier and straighten up. It really is a shock when you first experience it having been used to an open diff up to that point. Nowadays you dont notice it as much, but that first corner with a quaife will stick in my mind forever.

[welshpug]

that's where a plate diff works better than an ATB (Quaife+AP)

[Regis_92N]

Nop,

the only drawbacks of an ATB is its need to have the two wheels in contact whith the ground, if its not the ATB just doesn't work.

that's why clutch style diffs are used in rallyes (lot of wheel jump)

But on a smooth surface like circuit one, ATB are very very competitive and their smoothness of operation can be an advantage over clutch type diffs.

[Ross]

My first experience if a plate diff was awesome tbh! As you turned in, it feels "normal" to a point, then sort of locks on target - if the car starts to understeer give it more power not less and it kinda drags you round. Just really allows you to be a hooligan!

[dannygti]

Both types of diffs have their own place and plus's and minus's.

What people need to decide is what diff is more appropriate for their needs..
Too many times people choose race spec parts for a road car, all that does is make the car worse for it's desired use.

[Barry123]

Not an LSD but I've got an ATB in a pretty much standard engine Saxo. I drive like a granny but it's just great for corners, you can carry a load more speed so I don't have to brake as much and accelerate back up to cruise speed.

[e8_pqck]

All about LSD's.

http://www.pistonheads.com/gassing/topic.asp?h=0&f=23&t=1118620&nmt=

[sexy_gt]

^^ nice bit of info.

[Yates]

Not an LSD but I've got an ATB in a pretty much standard engine Saxo. I drive like a granny but it's just great for corners, you can carry a load more speed so I don't have to brake as much and accelerate back up to cruise speed.

grannys drive faster than you

[Jay_]

Sorry if I missed it, but whats an ATB?

[Yates]

Sorry if I missed it, but whats an ATB?

anti torque biasing differential

atb diff

what alot have when they said they have a quaiffe diff

[dannygti]

anti torque biasing differential

Active or automatic torque biasing depending on the company ;)

[sexy_gt]

http://en.m.wikipedia.org/wiki/Quaife

[Barry123]

grannys drive faster than you

f off I drive 'relaxed' that's all.

[AlexFocusST]

My experience with the quaife diff ,
Understeer only when accelarating too early in the corner ,
much more controlable on oversteering as long as you dont lift off the throttle

20k Km later was still working properly, hopefully it will still work in about 2 months when car is back on the tracks!