Conference terri::cars_uk

    First, let me say how lucky you and your family are ! It must say
    something for modern cars that are able to write in a notes file
    today.
    
    On 3 occasions I have been in a car as a passenger when we got
    into the high speed snaking you talk about. I can only say it is
    *very* frightening.
          
          
    Whilst not wishing to cast any doubt on your wife's driving ability
    it is my opinion that my 3 experiences were caused by an inexperienced
    driver getting into open oscillation as they correct, OVER
    compensating, OVER COMPENSATING etc etc. Perhaps the more experienced
    driver will let the car go a little, and then ease it back without
    the need to overcorrect. But then it is very easy to be clever as
    an armchair driver.
          
          
    Perhaps other people, much more expert than me, can add some science
    ?     
          
    DejW

	Front Wheel Drive tends to be more stable in crosswinds, in
	my experience.

	-John

    When I have the misfortune to have to drive a Sierra, I keep my speed
    below 70mph; the Sierra seems positively dangerous to me at greater
    speeds in even the lightest cross-wind. 
    
    The Cavalier (saloon and hatch) is much stabler, though by no means 
    perfect, but generally OK.
   
    I have only driven a Montego estate, but that too was better than the
    Sierra.
    
    Andy

    My first thought is three cheers for seat belts. Without the
    combination of modern car design and modern seat belts, you would
    certainly not have walked away from that.
    
    My secon thought is to do with aerodynamic design. Sierra was the
    first of the jellymould school of aerodynamic design, and early
    sierras, in particular, could be seen on windy days on motorways
    jinking about all over the place. They later put a tiny spoiler
    on the D-post, by the ventilator, which improved things, but they
    still hop about. In contrast, my old Cortina was very stable at
    speed on the motorway, seeming almost impervious to sidewinds, so
    bearing in mind that a Sierra is (basically) a rounded Cortina this
    seems to indicate that it is not rear wheel drive that is to blame.
    
    Add to this that estate cars, by definition, have more "side" than
    hatches or saloons, and you might expect the situation to be
    exacerbated.
    
    To my perception, there seems to be a cost to straight line
    aerodynamics, in the form of making it more difficult to design
    in stability. They seem better at it now they have had a few years
    practise; so I guess my advise, FWIW, is to pick either an old,
    non-aero car, or a newer one where they have got the problem licked.
    In any event, all the aerodynamics only really pay back at illegal
    speeds, so there is not much to be lost from that perspective anyway.
    
    Steve

    I empathise completely with .2! I tread VERY warily whenever I have the
    misfortune to hire any Ford but particularly Sierras. I find they feel
    like they are on "tip-toe" at high speeds (ie 70-80mph) and do not feel
    as if I am in full control of the car. Several folk I know have put
    them into the scenery, too. I guess the more sporty versions (XR2, XR3,
    RS2000, etc) are stiffer and therefore not so susceptible to the
    problem but the "shopping" variety are a definate risk.
    
    Thank goodness you all walked away ok - what an experience! Don't let
    them repair it if you can!!
    
    Colin

Tim, 

Do you know if the tyre pressures on your car were correct?  This could
make a significant difference to stability, especially when running heavily
laden. 

Does Ford give two sets of figures for the Sierra Estate, laden/unladen? If
so, these should always be observed - or always set to the "fully laden"
values, which shouldn't give any disadvantage when running solo (apart from
a possibly slightly harsher ride). 

As a general point (but other noters please give their views on this
critical area) - straight line stability should be improved by increasing
the rear:front pressure ratio.  For example, consider running at 25/30 F/R
instead of specified 25/27 (hypothetical figures, not Sierra). 

Under no circumstance reduce pressure at either end to below the maker's
figure, nor inflate any tyre higher than the max. value which should be
embossed on the sidewall. 

While on this, suggest invest in a decent tyre pressure gauge; surveys have
shown most garage ones to be hopelessly inaccurate. 

Finally - were all 4 tyres the same type, and in good condition? 

Well survived, and commiserations that it happened, 

Richard 

ps One of the magazines a few years ago fitted a rear boot spoiler to a
Sierra saloon and found that it cured the instability problem. I've never 
seen an equivalent for an estate.

I had that happen on a W reg Renault 5, which was I think due to bad shock
absorbers. It was very frightening.

It put me off Renault 5's until I had a drive of a newer one.

Mark.

    Richard,
    
    thanks for the note. Good point re. tyres
    
    Tyres were at the specified pressures the evening before we set
    off. 26 front, 26 rear (as we were not running heavy laden) as per the book.
    Laden values are 26 front 40 rear.
    
    However, we did have brand new tyres fitted to the front the day
    before (DUNLOP SP's), and I checked them that evening..all
    seemed OK.       
    
    Rear tyres were Pneumant (East German) brand ( got OK rating from
    Which? magazine), and with plenty of tread. (6 months old)
          
    Any thoughts ?                                                          
    

    Glad to hear everyone was OK,
    
    I too remember about the first Sierra saloons being unstable in
    Cross-winds, They corrected most of it (apparantly) by adding a little
    spoiler to the rear most window on the side, it looks like a 1 inch
    high "lip" which follows the  window rubber at the sloping side of the
    rear window.
    As for sierra estates, I have no idea wether they fitted a similar
    device, as I seem to recall the rear doors are different from the
    saloon.
    Seems like a recognised problem by Ford?
    
    Carl.

Shock absorbers are more likely to cause this problem than tyres.

Dave.

Re all:
  I was a passenger in a similar accident about 5 years ago, it seems that the
  road had a reputation for wind and ice thus forcing the Sierra saloon onto a
  gravel verge after a juggernaut had passed in the opposite direction. The
  car took up the traction (!!!) and the driver just kept turning the wheel
  against the inevitable skid - but nothing happened. At the time the driver
  hadn't faced any such incident before and so totally overreacted with
  regards to the necessary manoeuvre. The car eventually took the bait and
  jackknifed (as far as cars can) and we ended upside-down in a ditch at the
  side of the carriageway which we had been travelling along. I for one found
  it quite eerie watching a ditch approach at a rightangle illuminated by
  the headlamps!!! We both walked away so let's hear it for Ford engineering,
  and that's despite every panel being dented.

  I now own a Sierra, and I agree with the fact that it can be unstable at high
  speed in wind - cross or otherwise. Given this I have spent the time getting 
  to know its foibles, and believe it or not simply changing the tyres made all
  the difference to it's grip. I did this after a series of tests along the
  country lanes where I lived with an experienced passenger to teach the
  necessary skills, and I found that one of the faults is the fact that the
  back-end gets a little bit light when at speed. I've also discovered that
  it's compounded by the dreadful nose dip that can be found on independent
  suspension cars. Take a look the next time you pass a lorry - the front
  nearest the lorry will slightly dip then raise as you pass through the
  'bow wave' off the truck.

  The moral - get to know the car without just diving in and expecting it
  to respond like your Group A Sierra Cosworth!!! It'll bite - and hard.
  Taken reasonably carefully it will be a forgiving car to drive and for
  my Sierra at least to pull it out of the worst of skids leave the brakes
  alone - *ease* off the gas, and *ease* in the clutch briefly and *ease*
  on the brakes - all in half a second :-) Even the most serious Sierra
  wallow will cease as the car 'snaps' erect ready for any evasive action.
  Best of all don't get it in that situation unless you intend to - clear of
  me if possible...

  Andy

    Sounds to me the best bet is get rid of the thing and buy a car that
    stays on the road without all the nasty things going on that writers in
    this note have noted.....
    
    Colin

Derek,
There's not much weight at the front of a 23 to make it dip!
Scott

    Hi there,
    		Glad to hear that you got out of this one all OK. 
    	I have driven Vauxhall cars for most of my company car days.
    When I have driven a Sierra (hatch or estate), when my cars in for
    a service, I have found them very difficult cars to drive at high
    speed. They do have their advantages as cars go but the main
    disadvantage is their high speed stability (or lack of it). I found
    it most frightening the way the car would snake very easily at either,
    a sharp movement of the steering wheel,(eg to get out the way of
    a juggernaut pulling into my lane) or a bit of side wind. The best
    thing is to either, know the limitations of the car and stick below
    high speeds or get another car. (this doesn't include the sporty
    Seirras which I'm sure do handle well.)  
                  
    	Any way best of luck and happy event free motoring.
    
    
    	Chris.

RE: .4
Steve,

>>    My first thought is three cheers for seat belts. Without the
>>    combination of modern car design and modern seat belts, you would
>>    certainly not have walked away from that.
  
Try telling this to Frank Williams - he is confined to a wheelchair after
rolling his rental Sierra in the South of France. Mind you, when he left the
bend he did have a sizeable drop of 8-10 feet before he landed in a field.

I also know of someone who crashed a Sierra into a tree, and the dashboard
trapped his ankles. A passing motorist managed to free him.

Steve, who doesn't trust Sierra's.

    I Remember reading somewhere that Ford has also modified the bodyshell
    on later sierras ( in addition to adding the rear quarterlight thingy)
    If you take a 1990 hatchback and compare it with say a 1985 model there
    are subtle differences in the back end.
    
    I dont know about the estate though.
    
    I drive a 1989 Sierra and have never experieced any problems with
    winds, not even during February!  and it will run true at illegal
    speeds without my touching the wheel.  Mind you it is a GLS with the
    sports suspension and all the associated spoilers etc...
    
    I find it more stable in winds than my old 1983 cavalier.
    
    The point about over-correcting a deviation might be valid, because I
    remeber driving a hired escort 1.4L at night on a fast road. I was
    stupidly doing about 60 mph on dipped headlights, breaking the rule
    that says you should travel at a speed where you could stop in the
    distance you can see to be clear.
     There was a bale of hay in the middle of my lane, I swerved to avoid
    it and immediately went into a snaking oscillation, It was only through
    gritting my teeth and giving it progressively less and less opposite
    lock that I managed to stableise it and avoid the oncoming traffic..
    Phew!
    
    Huw.

    If you end up in this sort of situation, what is the best way of coping
    with it?
    
    Mikef

    re -1,
    
    
    There is always the arm chair advice :
    
    If you go uncontrollable then take your hands off the wheel, feet
    off the pedals, and let tha car know best ( get back to stability
    ).
    
    On the one ocassion I have used this ( slow speed skid on snow) it
    worked. I have not been brave enough to do it again !
    
    DejW

    Re .17
    
    Not sure what your point is. The two incidents you mention do not
    seem to invalidate my point about the combination of seat belts
    and modern car design. Are you saying that Williams would have suffered
    less injury without seat belt and/or Sierra? Are you saying that
    your recently trapped friend would not have been without seat belt
    and/or Sierra? Or what?
    
    Steve

RE: .21

Steve,
	The point that I was making was that in many cases modern car design 
is nothing to shout about. In the case of the Sierra, I think that it is
very flimsy, and too prone to collapsing (in my two examples - lack of 
strengthening in the roof and driver footwells). Modern designs tend to have 
too much weight saving in the interests of reducing building costs and
improving fuel economy. 

	Happily, the trend seems to be away from this. For example, the
new Tipo deliberately went for heavier, chunkier body parts. Reasons cited
were safety, noise reduction, and quality "feel".

	In summary, seatbelts are much better than they were (though there is 
room for improvement), Car designs, whilst better for front-on collisions,
are in many cases worse than older designs in situations where you roll the
car or get hit side on. This is because of economising on materials.

Cheers

Steve

>>	What is not being done in applying race to road


1)	Seat belts
2)	Rollover Protection
3)	Fire extinguishers ( plumbed in )
4)	Seat which hold you in a crash.
5)	Side impact protection.
6)	Flame proof materials
>>

these are only used in races because regulations demand their use,

i'm sure their not just included by manufacturers out of the goodness of their 
hearts

btw. re:seatbelts : the new BMW 850i & the nes merc SL have seats & belts
designed to prevent 'submarining' (which could also be prevented by using a 
6-pointer)


...art

    Re.22 (I think)
    
    Steve,
    
    I don't disagree on specifics; I don't doubt that many modern cars
    have achilles heels. My original point is that the incident which
    started this discussion off was survived, when in (say) a 1950s
    car half the occupants would have been trapped and squashed, and
    the other half thrown out and squashed by following traffic.
    
    Modern cars, at least since Ralph Nader in the 60s, have been designed
    with accident survivability in mind. That, I guess, is the difference.
    
    Steve

Steve,
	Agreed - modern seat belts and design make a big difference. I guess
I've just got it in for Sierra's!

Steve

Below is a summary of an article on Sierra front wheel wobble in July's
"Car and Car Conversions" magazine, which readers of this topic may find useful.

The problem: severe front wheel wobble in Sierras (and other cars) when braking

Most likely cause: too much lateral movement in shock absorber stems inside the
strut.  This in turn is due to low castor angle, which is reduced even further
when braking.

Remedies (do them one at a time, in this order, until the wobble stops):

To reduce the change of castor angle: fit upgraded front anti-roll bar bushes
and outer track control arm bushes (eg Sierra Cosworth bushes).

To reduce the tendency of the shocks to wobble: new shocks (article recommends
Koni).

Also suggests increasing toe in by 30 seconds each side (1/120 �) [I wonder if
they mean 30 minutes?].  This preloads the suspension, preventing the wobble.
The article warns against adjusting the toe-in too much.

To increase the castor angle, fit a small spacer behind the track control arm
rubbers (between 1/8 and 1/4 inch); check the lock nuts on the end of the anti
roll bar after doing this; preferably drill them and fit a split pin.

The article's author says:
"I know it sounds a bit complicated, but I do know it works."
"That should then be a complete cure for the problem."

I can mail photocopies of the whole article to anyone who wants it...

Scott

    I have had a hire Sierra (GLS - 2 litre, I think) while my BX is in for
    major heart surgery. While there are many small niggles I have with the
    car, I did not find the "tip-toe" effect I had experienced previously,
    although perhaps I was not driving as hard as I had no plane to catch!
    and this beastie has a rear wing thing.
    
    However, one evening last week, after a shower had dampened the road, I
    experienced a god-almighty rear wheel slide as I came onto the
    roundabout from DECpark at Junction 11. I VERY nearly lost it! and
    completed the circuit of the roadabout very carefully indeed as it
    still felt extremely twitchy.
    
    I guess, after 3� years of front wheel drive motoring, I was a little
    complacent but my Citroen just does not have nasty habits like this! It
    really took me by surprise ; like a cornered cat, it turned vicious in
    a split second!
    
    I shall be glad to get my own car back, hopefully tonight. It's much
    nicer to drive and more comfortable and gets you where you want to go 
    much safer!
    
    Colin

    But Colin, *thats* what rear wheel drive is for!
    
    (Bring back 3-litre (Essex engine) Capris, or, 16-valve, BDA Engined
    RWD Escorts!!! :-)))))))
    
    JK

>>16-valve, BDA Engined

what is this engine, i've seen several references to it in various magazines,
but I don't know much else about it,

is it a ford 'Kent' block with a 16 valve cosworth head??

cheers...


...art

RWD => oversteer => rear wheel skid => tail out
FWD => understeer => front wheel skid => complete loss of steering control

I've only ever had one front wheel skid, and it was rather frightening, as
every reflex says slam on the brakes, when that's exactly the thing not to do...

Give me RWD any day...

Scott

    Re: .31 and BDAs
    
    Yes it was a Kent block and was essentially a follow on to the Lotus
    Twin-Cam engine. I've also heard it referred to as Half a F1 V8, which
    everyone in F1 was using at that time.
    
    I'm not sure of the Cosworth connection. I know the engines were built
    for Ford by a motorcycle Co. in Stevenage (Old town), but can't
    remember the name. That was before AVO came along and starting building
    Mexicos and RS2000s.......
    
    JK (How I regret selling that car .........)
    

    	I hope to get my BX back tonight - do you think Bratt's will mind
    the stain on the seat.....
    
    Colin
    
    PS Thanks for all the "advice" folks! I have had my share of RWD cars
    (and raced in Formula Vee AND survived!!!) and enjoy hanging the tail
    out as much as you obviously do :-) ....it was the sudden change from
    docile cruisemobile to savage beast that took me by surprise!

    Old Town Stevenage	

    I drive the Sapphire 2.0i GLS and find that it is a very different
    car from the Sierra 1.6L hatchback...
    
    Maybe it's the bulkhead in the back of the Sapphire or the S pack
    that does it but it doesn't wobble when you push it into tight bends
    but tends to jump round corners like my trusty old Cortina 2.0 GL
    (many years ago).
    
    Perhaps I'm a natural RWD driver but I've lost the front end on
    all the FWD cars I've ever driven, Cavalier, Astra, 205 and Orion,
    but never lost the back end on the Carlton, Sapphire, Sierra or Cortina...
   
    Give me a RWD car any day...
    
    	Milton (sunny Bristol)

    
    I'm surprised... lifting mid-corner transfers more weight to
    the front of the car, hence more grip to the front wheels and
    less to the rear. The result is normally oversteer.
    
    That said, with a mid engined car, its anybody's guess which end
    will do what - the only sure thing is that it'll be quick when it
    happens...
    
    Bill.

    Glad, I read this note.  I was beginning to think it was just my
    driving that was causing my Sapphire to snake.  So, without further 
    questioning, I slowed down until I gained my confidence again and now I 
    choose to stay just below my/car's limits. 

    Onto another aspect of safety, I have two questions,

    	o safety cage -is this effective or is this advertising gimmick
          which mass produced cars employ it

    	o tuned springs/gas struts etc (as employed in Cavalier SRi)
    	  -is this effective in making the car have straight line stability
           or is this just an alternative arrangement

    In partnership with my Sapphire until I get something different.

    - Perwesh 

    Safety cages are effective - but all cars have to have them, not just
    Volvos. Any modern car will pass the
    driven-through-the-window-by-a-dummy test; only Volvo advertise that
    their cars are driven by dummies.
    
    Steve

Anyone interested in the effectiveness of the Citr�en BX safety cage, there's
an interesting example at Hatfields on the A329 near Ascot.  They always put
the worst wrecks right by the road, as though trying to bring the message home
to passing drivers.

Anyway, this BX (at least I think it is (was?) a BX), has a "modified" bonnet
about a foot long, and a totally intact passenger compartment.  Quite
impressive.  Trouble is, the other forces in an impact that strong (broken
bones from seatbelt, internal injuries from the shock of going from "fast" to
"stationary" so rapidly) probably outweigh the benefits of the cage...

Scott

    Wonder if anyone could confirm this, on a recent visit to a Ford
    dealer a salesman mentioned that new Sierra's have been fitted
    with limited slip diffs to help with traction in wet and slippery
    conditions.
                    Thanks in anticipation.
    				Graham.

    	Good! I nearly killed myself in one a year or so back when my fwd
    BX was in for major repair - got the thing broadside on the roundabout
    at the M4 junction doing doing what I always did in the BX... I hate
    the things!!
    
    Colin

>>>    Safety cages are effective - but all cars have to have them, not just
	^^^^^^^^^^^^^^^^^^^^^^^^
>>>    Volvos.

	
	Funny, I thought that were absolutely useless AND detrimental to
performance and economy etc. due to the extra weight - unless you have an
accident.

				Malcolm.

    
    and the lastest research seems to indicate that they aren't to clever
    in accidents.  
    
    Firstly, there is a problem in getting the door open if the bars have
    gone forward or backwards, and secondly there appears (if i remember
    rightly) to be a potential problem of the bars doing more damage to the
    people in the car than if they hadn't been there.
    
    I think it was in the Sunday Times (that bastion of modern journalism)
    a week or two ago.

    .48�    there appears (if i remember
    .48�    rightly) to be a potential problem of the bars doing more 
            damage to the
    .48�    people in the car than if they hadn't been there.
    
    Without the bars, it seems that the whole door deforms in a side-on
    crash, and so the effect of the damage is spread over the whole of
    your body. With the side-impact bars the effect is all concentrated in
    one place.... - and a human body is better able to cope with smaller
    shock/stress/damage over a larger area, than a large impact in a small
    area.
    
    What is NOT discussed, though, is whether these bars can prevent ALL
    damage to the human at certain speeds... so I suspect that in crashes
    at < 15mph the bars are a great idea, while over 40 mph they are not...
    
    So the next design will be like those little wings on the back of a
    Corado that extends when the car goes fast.... and these bars will move
    out of the way in the split second when a car hits the outer skin of
    the  door, and before the bar gets bent and damaged..... :-)
    
    Cheers, Chris

    Giant Airbags.
    
    Attached to the four sides of a car these devices can prevent injury
    and damage to an extent previously not thought possible. Sensors will
    detect an oncoming vehicle and assess the approach speed, then trigger
    inflation to a size calculated from the direction of approach, speed
    and distance. Ford will fit bags the same size as those present in
    steering wheels, though may deploy several along the side. Other       
    manufacturers plan on something approaching the size of a small house.
    These will inflate and deflate in the blink of an eye.
    
    An added cost option will be to have helium as the inert gas and fire
    all four bags together, thus lifting the vehicle smoothly out of the
    way of oncoming traffic. Further work needs to be done on landing
    techniques and CAA approval.
    
    Andrew

    
>>>    An added cost option will be to have helium as the inert gas and fire
>>>    all four bags together, thus lifting the vehicle smoothly out of the
>>>    way of oncoming traffic. Further work needs to be done on landing
>>>    techniques and CAA approval.
    
>>>    Andrew


	Love it Andrew!

				Malcolm.