Torque Steer

[boldy205 75]

Hi, i have a Gripper LSD in my gti6 205. I have a problem where it slightly pulls to one side under acceleration and deceleration, from memory it pulls to the right on acceleration. I know the obvious such as beam mounts (which are very new and solid), wishbone bushes (which are uprated and reasonably new) subframe bolts tight, ovaled hubs maybe? If so whats the symptoms of oval hubs?

 

I have thought maybe it could be the unequal length of drive shafts, as the N/S is shorter, therefore torque getting to the N/S wheel marginally sooner? or am i talking rubbish and its just a problem of a quick FWD car?

 

Any ideas welcome!!

 

Thanks and happy new year

 

Matt

[Rob Thomson 6]

wishbone bushes (which are uprated and reasonably new)

I think some torque steer with a powerful FWD car is always going to be inevitable but I wouldn't be at all surprised if your bushes are the problem. Standard OE Peugeot are the best by a mile. I got through three or four sets of Polyurethane bushes in less than 10,000 before I twigged that actually they're no use in this application. What are yours?

 

Incidentally, Peugeot's intermediate driveshaft bearing on the back of the engine block is designed to help eliminate the problems associated with unequal length driveshafts.

[welshpug 1,661]

What do you call "uprated" wishbone bushes? more often than not they are softer than o.e.

 

the symptoms of ovalled hubs or knackered balljoints are exactly this, also worn top mount bushes can cause some movement.

 

could also be track rod BJ's.

 

the effective length of Peugeot driveshafts are pretty much equal, that's the function of the intermediate driveshaft bearing, I don't know of a large engined pug that suffers from "Torque steer"

[Tom Fenton 1,542]

Sounds like play in something as it will do it on acc and decell, however when you get to having a powerful FWD car with an LSD you have to expect it to move about a bit following dips in the road etc under hard acceleration as the tyres struggle for traction.

[Tesstuff 222]

I have considerably more torque than you in my FWD 205 and since my phase 2 suspension revisions i have no torque steer at all, and that is without an LSD.

 

So it isn't the power and torque you have that is the issue, so look at each component as suggested.

[Baz 421]

I have considerably more torque than you in my FWD 205 and since my phase 2 suspension revisions i have no torque steer at all, and that is without an LSD.

 

The LSD will be the main reason for torque steer, so even though you have more torque, it'll never be the same without a diff trying to make the front wheels turn at the same speed so when they try to spin under power they both spin, causing the car to veer across thr road following tiny steering inputs, undulations and camber changes in the road, hence 'torque-steer'.

 

Presuming you mean your V6, you also have a lazier power delivery and alot more weight over the front wheels aiding traction anyway.

[Tesstuff 222]

I agree Baz, the extra weight should help matters, but before we made the recent changes which included changing the driveshafts i had terrible torque steer, which thankfully is sorted.

[harryskid 193]

My car handles better with a lsd than with out and yes is has torque steer. You have to hang on to it at fast pull aways and as its a rally car i usually take off at about 5 thou. I would not expect it to have no torque steer as if it didn't the diff would not be doing is job.

[kyepan 291]

sorry guys i have to disagree.. somewhat, not totally but a bit.. lets forget the word torque steer for a second..

 

is what your talking about the snatchy left right feeling as you accelerate hard over uneven surfaces

or

is what your talking about the way the steering feels like it weights up as you turn in and then apply / lift the throttle.

 

 

 

the snatchyness will be made worse by neutral toe or toe out, because it's not trying to self center.

the general weight of any given snatchy effect and or force coming back through the steering will be made worse by larger brake discs

same is true of by heavier wheels.

 

this is because of gyroscopic torque.

 

spin a top and it stands up, the heavier the top the harder it is to knock over. same is true of a wheel and turning it.

heavier wheels and discs will be less willing to change direction.

 

also wheel offset will also factor in, if the scrub radius (distance from king pin inclination angle hitting the ground to actual wheel center point) is greater than zero it will increase any gyroscopic torque effect.

 

so yes, a diff shoving power to one or either wheel will create a snatchy feel, but, the effects of this in my experience (adding 3kgs of disc weight, then removing 5gks of wheel weight) can be massivly reduced. go to standard pug toe in if you are still suffering from directional instability when getting hard on it over uneven surfaces.

 

Hope this helps.

 

J

[Anthony 1,003]

As has been said, I would be a little dubious about the wishbone bushes if it's doing the tale-tale pulling one way under power and the other way under engine braking - "uprated" poly bushes are frequently inferior to standard OE bushes and can fail in no time at all. The only ones I've personally found that are any good and last are the Polysport range that Rally Design sell.

 

Check the wishbone-subframe bolts are tight too, as they can come loose and cause similar problems to a knackered wishbone bush, particularly if you've reused the nylocs too many times or failed to torque them up correctly.

 

An ovalled hub or loose clamp bolt tends to give a distinct snatch/lurch mid-corner and can make the car feel generally nervous, although they don't usually give problems of swerving around on and off power.

 

Also, check the tyres - I had an odd problem with a Quaife-equiped car pulling to the side under power, and after checking all the usual suspects and scratching my head, it turned out to be the front tyres being worn oddly. The fault hadn't shown up on the open-diff'd car they were fitted to previously, which is why it hadn't occured to me initially that they could be at fault.

 

Otherwise, check the tracking, as if it's taken a knock and showing toe-out it can make the car pull around noticeably under power with a diff fitted.

[edbar 6]

What toe settings would you recommend with a diff fitted then? I've just re-shelled into a 205 and fitted a quaife and under power mine has quite a bit of torque steer, had the 309 set at parralell so would be the same on the 205.

[boldy205 75]

Thanks for the replies, loads of em!

I have the track set at 0, year ago or more i must admit, but this was before the LSD was fitted, and i never noticed the problem im having now when the open diff was in.

 

I have superflex purple bushes for what its worth. People say OE Pug bushes are 'best', best for track work? As the car is a trackday car. Again, never had the problem before the LSD was fitted, but maybe the LSD has highlighted slight wear?

 

Top mounts have never been changed in at least 7 years!! Maybe its a time to change!

 

Many thanks,

 

Matt

[kyepan 291]

Top mounts have never been changed in at least 7 years!! Maybe its a time to change!

very knackered top mounts will lead to the whole steering / placing experience to be a little bit wooly, and just make everything else worse.

[boldy205 75]

Thanks for the replies, loads of em!

I have the track set at 0, year ago or more i must admit, but this was before the LSD was fitted, and i never noticed the problem im having now when the open diff was in.

 

I have superflex purple bushes for what its worth. People say OE Pug bushes are 'best', best for track work? As the car is a trackday car. Again, never had the problem before the LSD was fitted, but maybe the LSD has highlighted slight wear?

 

Top mounts have never been changed in at least 7 years!! Maybe its a time to change!

 

Many thanks,

 

Matt

[whizzer71 0]

Had real big probs like this, turned out to be Yokohama Paradas complete sh*te !

 

[MerlinGTI 3]

I know very little about fancy diff's not having one, but don't under estimate tyres.

 

I remember changing a whole accident damaged corner on a new shape monedo, including new wheel and new tyre identical to the rest (michelen premicy)

Geo'ed up lovely, drove nice, but under hard acceleration it would violently aim you at the kerb.

6 hours of fault finding later I swapped the new tyre for a part worn from another Mondey and the problem was gone!

 

After all saying all that though, I'd be looking at your wishbones!

[edbar 6]

Drove mine in the dry today, no real torque steer problems( must just be in the wet ) lots of lovely grip even with absolute s*ite budget ditch finder tyres!

[Henry Yorke 269 3 Cars]

Does the Gripper diff have settings in it? Having driven Tom and Allanallens cars with the same diffs, the way they handled coming out of a corner was totally different with one providing plenty of grip in the direction you pointed it and the other felt like I was wrestling a lion!

[boldy205 75]

Indeed the gripper diff has various settings, mine is set at 30/60, which i was told was less vicious than the 45/45 also on offer.

 

Tom and Allenallen both have Gripper diffs do they? Do they have PAS?

 

Mine feels rather lairy, though not totaly sure whats 'normal'

 

Thanks

 

Matt

[Henry Yorke 269 3 Cars]

Not sure quite what they have but I know they both run the same diffs but on different settings. it may even be a Kaz but I am sure Tom / Al will correct me (and if you want a quick answer, it will be in Toms thread!)

[Tom Fenton 1,542]

Tran-x diffs, I love mine, far far better than the Quaife ATB in my other car to be honest. Just don't take it on the MOT brake rollers.

[boldy205 75]

I presume if similar ramp angles are used, thena Gripper/tranx/any plate type diff would act very similar?