Fiat Fiorino brazil 1992 front wheel alignment

[eastelectronics]

Fiat Fiorino brazil 1992 front wheel alignment here is my story ...Please be nice with me I am Greek and electronics engineer so my description might not be described correctly .

Own the Fiorino 1100 petrol Brazil 1992 car. A superb car absolutely no issues at 300000klm

Since day one i was aware that this car features no camber adjustments
In lower side of front wheels actually wheels leans towards inside and is supposed that when car is loaded wheels might stand correctly

Now in my latest shock absorver replacement had them fixed which means the lower holes for the screws of the absorver are lo longer round now they are oval so this car now has adjustable camber

After that car can drive very fast at any turn left or right steers exceptionally well in high speed 130-140 klm and compared to the past car was leaning a lot left or ride side depending on the turn
Compared to the past before adjustable camber you may now say that the car move on rails after that its extremely stable at any speed

Here is what happens and my questions

so in the alignment data for camber is 0,58 +or - ( dont remember i will have to check ) and measures correct
wheel alignment is -0,25 and also measures correct .

From experience -0,25 front alignment for a car that doesn't feature adjustable camber makes some sense and its there to make the steering a bit more stiff and (often mechanics add a bit more to that) still though within allowable green area.
In practice they make the front wheels a bit open probably to compensate the non adjustable camber

At first alignment factory settings performed and steering wheel was way too stiff So we actually reduced having the wheels open and from 0,25 we went to 0,15 and things got a lot better

here is my questions
Factory settings of this car as said is 0,58 +or- minus i dont remember i have to check for camber
And -0,25 wheels open as described above

Point is that these values are given in the computer for a car that never had adjustable camber Now this car has adjustable camber
Should i aim now for 0 degrees wheel alignment and presume that having my wheels open doesn't make sense any more and gain a much lighter steering ?

Then again if any one can advise about wheel alignment then what is your opinion about the camber what should i aim for now ?


Kindest regards
Sakis

 

[F123C]

Hi Sakis,

I had a Fiat 127 (from which the Fiorino was derived) in the late 1980's and modified the front shock absorbers to make the camber adjustable. A small elongation (to oval) of the lower mounting holes has a very big effect.
Too much negative camber (wheels leaning inwards at the top, outwards at the bottom) will make the steering heavier and also tend to make the car follow irregularities in the road surface, e.g. ruts, lines, road markings.
If you go with too much negative camber you may also experience problems with constant velocity (CV) joints and bottom ball-joints as they may now be operating outside their designed arcs of movement.
I'd recommend going to no more than -1,00/-1,30' degrees of camber.

Re:- the wheels pointing out at the front - this wheel alignment is referred to as 'toe-out' i.e. a negative figure for the wheel alignment, whereas wheels pointing in would be called 'toe-in' i.e. a positive wheel alignment figure.

The reason that front wheel drive cars (almost) always use negative front wheel alignment i.e. 'toe-out' is because, in use, the wheels pull the car along.
As the engine/gearbox/driveshafts turn the wheels, they move forward to pull the car along but first, the various clearances in the steering linkages and suspension bushes are taken up (distort/move a little), the front wheels thus tend to toe-in, i.e. turn inwards slightly.
So the manufacturers stipulate setting the front wheels to e.g. -0.25 so that in use the wheels are running approximately parallel, which is best for tyre wear, fuel economy and handling/steering.
As you can't measure how the wheels are aligned when in motion, the manufacturer gives you a static adjustment which should result in more or less parallel alignment of the wheels when in motion i.e. the wheels pulling the car along.
In your case, if the rubber bushes on the anti-roll bar where it connects to the track-control arm, (i.e. bottom suspension arm) (these are the main bushes controlling fore-and-aft movement of the track control arm and therefore variation in wheel alignment under load) are in excellent condition, you could try reducing the toe-out setting to approx. 1/2 the manufacturer's figure, just keep an eye on the tyre tread surface for 'feathering' (abnormal wear pattern indicating incorrect wheel alignment).

This above info/explanation should be available in any textbook used by Mechanics during their early training (apprenticeship or equivalent), here you'll also find an explanation of the various technical terms and why things are done as they are done -there's good reasons for everything, suspension has evolved over the years and continues to do so.

One thing to bear in mind, is that on ordinary (not high-performance) cars, manufacturers are usually trying to achieve what is referred to as 'centre-point-steering'.
Iirc, this essentially means that an imaginary line drawn from the upper strut (shock absorber) pivot point down through the centre of the bottom suspension ball-joint would meet the road surface in the centre of the tyre contact patch.
This gives the best overall safe handling, low steering effort, tyre wear, economy etc.
When you make any changes that deviate from this 'centre-point-steering', you lose some of the benefits - in your case, altering the camber setting to negative, increases the steering effort. You might also find that your tyres wear faster.

Hth,

Al.

 

[eastelectronics]

well yes more or less all the above is understood
Just last night i had a talk with my mechanic and he explained a few things to me but the picture is not complete for me

Existing picture from factory settings for alignment is like that \ / 0.25 degrees per wheel
Existing picture of camper is a alike \ / ( though i dont rememeber how much )

after SA was modified camber should look like that I I

But the mechanic says that wheel alingnment should look like that / \ by 0.05 degrees per wheel and when that car starts ( since there some tolerance in the front system )wheels will be aligned automatically to I I when pulling the car

The mechanic also said that if camber looks like that / \ at static conditions this will help the car have a good grip if turning at very high speed

let us not forget that Fiat made this pick up is a light cargo truck so probably adjustments are to perform well ( probably ) when car is loaded

In reality i use this car to drive to work daily that's 50klm of hiway where you drive from 100 to 150klm\h and at some points you have some nice turns to deal with .

Indeed car gets loaded to max load maybe once a year at the most

so target is to drive well in high speed not loaded

EDIT


At some point i forgot to mention that i have also changed the wheels from 13" to 14" to gain some overdrive since load is not my problem

 

[Pugglt Auld Jock]

Hey Al, I really enjoyed reading that. Haven't heard anyone talk of centre point steering in ages! Hence why the really old cars, you know, the ones with beam front axles and cart springs nearly always featured very obvious amounts of positive camber. See old Bentleys, Bugattis, Amilcar, etc.

It's very obvious in this clip:

 

[F123C]

Hey Al, I really enjoyed reading that. Haven't heard anyone talk of centre point steering in ages! Hence why the really old cars, you know, the ones with beam front axles and cart springs nearly always featured very obvious amounts of positive camber. See old Bentleys, Bugattis, Amilcar, etc.

It's very obvious in this clip:

https://www.youtube.com/watch?v=s0JlQeCeExs

I just mentioned 'centre-point-steering' to the OP so that he could look it up and see what manufacturers are trying to achieve for ease of driving, safe-handling etc. I am aware that true centre-point-steering has not been used in many years, as car steering/suspension systems have evolved along with everything else on the car. I well remember when Audi? came out with a steering system coupled with (iirc) diagonally-linked dual circuit brakes that allowed a car to brake in a straight line when the wheels on one side were on ice. Another issue was 'bump steer' which iirc was avoided by careful positioning of the steering rack and length of track rods in relation to the suspension arms/wishbones, also tried was the practice of attaching the steering track rods to the centre of the steering rack (a la Opel/Vauxhall Astra etc.)

Thanks for the video, enjoyed it very much. I always tune in to watch the classic/vintage races held at the Goodwood Festival/Member's Meeting, I'm not so interested in the modern F1, Sportcars/Hypercars.

My late father was a great fan of the ERA (the original one's, not the Mini interlopers!). Thanks to him, I developed a great appreciation for Raymond Mays and what he had achieved. (Dad even bought David Weguelin's quite expensive book on the ERA in 1980). My father, as a child, had seen the Bugatti's, ERA's etc., back in their heyday, race here in Ireland when they appeared at Phoenix Park, The Curragh, Dunboyne etc. Road Races. We even toyed with the idea of building a replica of the ERA, but decided not to on the basis that he was too old to race (he had raced successfully in his earlier years in Midget Car Racing using a home built car that looked like a smaller..... ERA!) and I'm too slow (or so he thought, was always on my best behaviour if I drove him in his car, lest he ban me from driving it ).(although I did frighten the life out of him when I took him out in a Porsche 356B Super 90, I had 'acquired' when I was 17 - oops).

Thanks again,

Al.

 

[F123C]

well yes more or less all the above is understood
Just last night i had a talk with my mechanic and he explained a few things to me but the picture is not complete for me

Existing picture from factory settings for alignment is like that \ / 0.25 degrees per wheel
Existing picture of camper is a alike \ / ( though i dont rememeber how much )

after SA was modified camber should look like that I I

But the mechanic says that wheel alingnment should look like that / \ by 0.05 degrees per wheel and when that car starts ( since there some tolerance in the front system )wheels will be aligned automatically to I I when pulling the car

The mechanic also said that if camber looks like that / \ at static conditions this will help the car have a good grip if turning at very high speed

let us not forget that Fiat made this pick up is a light cargo truck so probably adjustments are to perform well ( probably ) when car is loaded

In reality i use this car to drive to work daily that's 50klm of hiway where you drive from 100 to 150klm\h and at some points you have some nice turns to deal with .

Indeed car gets loaded to max load maybe once a year at the most

so target is to drive well in high speed not loaded

EDIT


At some point i forgot to mention that i have also changed the wheels from 13" to 14" to gain some overdrive since load is not my problem

The modifications I made to my 127 were for me alone driving the car, no passengers and no load being carried. I loaded the driver's seat to match my weight and then carried out adjustments using the guideline figures I gave you in my post.
The Official Fiat workshop manuals gave figures for a car loaded with 4 occupants plus some luggage. I don't recall them giving figures for an unloaded car.

I think your mechanic may be confused about which way the front wheel alignment changes when the wheels try to pull the car forward. What he says is correct for a rear wheel drive car where the car pushes the front wheels along.
If you don't believe me, have someone attempt to pull away with the brakes applied and see which way the front wheel alignment changes. I think you'll find the wheels try to go from \ / to / \, which is why they're set to \ / statically.

A possibly better way to set up front wheel alignment is to use either a Gunson's Trak-Rite gauge or a 'Side Slip' gauge at a vehicle test centre. You're looking for minimal side slip.

Re:- your mechanic's advice to go for some negative camber on the front wheels to help high speed cornering- fine, but don't overdo it! The aim is to have as much of the tyre contact patch (about the size of the palm of your hand) in contact with the road surface. The reason for using negative camber is so that as the tyre sidewall distorts/shifts under the cornering load, the maximum tyre contact patch is maintained. But if go with too much negative camber, you may never get full tyre contact patch anyway - just look at how much neg. camber some rally cars are using.

You might wonder why Fiat went with positive camber in the first place. The main reason is safety both when the Fiorino is being driven unloaded and when it's fully loaded and everywhere in between. With positive camber, if you go into a bend too fast, the vehicle will understeer i.e. tend to go straight on, the normal reaction is to apply more steering lock. This is a safe situation.
If you have better grip/steering on the front and you go into a bend too fast, the back of the car may skid outwards, especially if you react as most normal drivers do, by either lifting off the accelerator or worse still braking hard - this is a dangerous situation and may result in an accident. ( they used to say that most rwd Porsches were crashed in the rear - the driver overdid it in a bend, lifted off and went off the road backwards).

If you go with negative camber on the front wheels, you will probably need to do something at the rear also. I think with a Fiorino, you might find the rear of the vehicle may sit up too high for good handling in bends due to probably a heavier rear spring being fitted to cope with the load capacity. Maybe the spring on a 127 hatchback (if the suspension design is the same) could be fitted to lower the vehicle as well as be more compliant. Camber is adjustable on the rear by fitting shim washers behind the lower suspension arm mountings.

Al.


Yo

 

[eastelectronics]

Ok starts to make some sense

for a few days i am driving now in a toe out situation less than recommended by 0.10 degrees.... data says toe out 0.25 i have now 0.15 per wheel

The car handles i think the same but for sure not better than it was with 0.25 in high speed turning steering is a click lighter easier to handle at low speed than it was before BUT i noticed that fuel consumption is increased .... so that is pointing to something wrong

I think i will go back to 0.25 and blame adjusted camber for the heavier steering I might as well have to live with that

Indeed i was also thinking that alignment has to take place with me inside the car ....I am 106kg of 40 years audio electronics knowledge.... ( feel free to ask any questions so i can return the favor )

For the fun of it ...
the little crap will consume 6.5 to 7.5 lt per 100 klm inside town with a quiet driving and will start to consume up to 10 lt per 100 klm at speeds above 120klm

carburator is in excellent shape cleaned and tuned correctly Ignition is brand new Marelli parts are easy to find here sparks are NGK and cables are also new .

Surprisingly speedometer tops at 180 klm and the car will drive a bit more over that under ideal conditions which should be a straight road , no wind , and an ammount of time to be able to achieve that target ...

Had a few wonders about the speedometer accuracy and checked with the gps saying that speedometer says more or less 7-9 klm /hour more than is supposed to ...

so top speed is about 175 klm / hour

Yaep this is fun but i take as a fact that if something happens you will never be able to stop at this speed so i only drive that in highway in the open and top it at 175 to see if is possible .... 140-150 klm/h is more normal speed

 

[Pugglt Auld Jock]

I just mentioned 'centre-point-steering' to the OP so that he could look it up and see what manufacturers are trying to achieve for ease of driving, safe-handling etc. I am aware that true centre-point-steering has not been used in many years, as car steering/suspension systems have evolved along with everything else on the car. I well remember when Audi? came out with a steering system coupled with (iirc) diagonally-linked dual circuit brakes that allowed a car to brake in a straight line when the wheels on one side were on ice. Another issue was 'bump steer' which iirc was avoided by careful positioning of the steering rack and length of track rods in relation to the suspension arms/wishbones, also tried was the practice of attaching the steering track rods to the centre of the steering rack (a la Opel/Vauxhall Astra etc.)

Imps too!

Seem to remember the original Sunbeam tiger - the one where they shoehorned a ford V8 into the Alpine - had bump steer problems. I remember doing wheel alignment on one and being amazed at the shape of the track rods which were necessary to accommodate the repositioned steering rack.

Talking about steering geometry I learned about the Ackerman steering principal in college and it all seemed very logical and a good idea to my young brain. Then I got involved in racing where I was a trackside race engineer for Firestone. One of my main jobs was to advise the teams on setting up their suspensions to take best advantage of our tyres - great fun in those days involving sticking needles (which had a thermocouple in the end) into the tread rubber of the tyre so you could read the temperature from which you could deduce how the car was working the tyre and so advise on camber, anti roll bar stiffness, etc, etc. Imagine my astonishment to find that many of the really fast sports prototypes etc ran Anti Ackerman steering! For those not in "the know" here's a wee video about it:



I enjoyed your reminiscing about the old race cars. For me it's all become to clinical these days. I like the brutality and danger of the likes of the old group B rally cars. Nothing like the guttural roar of a Metro 6R4 or a Stratos and the sound of a Quatro screaming and backfiring it's way through the forest makes me go weak at the knees:



Even worse is the sight, sound and smell of a nitro burning drag racer like "Wild Willy" Borsch's "Winged Express". Have to put the incontinence pants on for that! I'm especially addicted to the sound of it at idle - if you can call that "idling":



Wild Willy was famous for driving it with only his right hand on the wheel whilst hanging on to the bodywork with his left!