A110 front wheel camber adjustment

Just had the wheel geometry adjusted on my A110 1400 FASA (following recent track day at Goodwood which showed that all was not quite right).

All necessary adjustments made by very patient mechanic apart from the camber on one front wheel which is out by 0.75 of a degree. We couldn't determine how to make adjustments to the front wheel camber settings.

Any guidance would be much appreciated. Thank you.

Punterian

[johnb]

I have a 1289cc FASA A110 which, I imagine, has the same front suspension as your car, being taken from the Renault 8. If yours is different then ignore the following.

On my car, the only front suspension adjustment is for castor. If you look at the attached extract from the parts book, the lower wishbone is attached to the chassis by the arrangement shown in the middle of the page. The long stud at the inner end of the lower wishbone goes through the sleeve (06 07 467 500) and the two fixing pieces (06 07 464 600 & 06 07 464 7..). To adjust the castor the eccentric bush (06 07 431 600) is turned ( fixing bolts slackened) which moves that end fixing piece relative to the chassis. The eccentric bush has the hole through its centre offset from centreline thus providing the fixing piece movement. Turning the eccentric bush effectively moves the lower suspension arm outer ball joint forwards or backwards. So, as the top wishbone is fixed the castor angle can be changed within small limits.

Regarding camber, my understanding is that this can't be adjusted. Thinking about it, I also think it is affected by how much weight is in the front boot, including fuel in the tank. Out of interest, today I measured the change in camber from the car resting on the ground and then jacking the front wheels off the ground and remeasuring. The camber changed by 2 degrees where the top of the front wheels moved in towards the centre of the car. This seems to make sense as the distance between the upper wishbone chassis bolt and ball joint is shorter than the same reference points on the lower wishbone. So as the car is jacked at the front and the wheel drops, the upper wishbone will rotate the hub towards it at the top increasing the camber.

As a matter of interest what values do you have for castor, camber and toe in / toe out and where are these values published, A110 MDR? I only have values for the Renault 8. If Alpine quote a camber value this might be qualified by some comment like - full fuel tank, 2 passengers seated, etc.

JohnB
Thank you very much for your time/response. We sorted the castor angles in the way you describe – these were a long way out which explains the car’s rather twitchy behaviour. What you say about the suspension’s geometry is absolutely correct, so am left to assume that the difference in camber on the one side is a result of the car’s original build. It’s less of an issue than the castor values being wrong, and also being different from one side to the other.
These are the values I have for the various geometry settings, taken from a translation of a Spanish service handbook by my car’s previous owner.

FRONT (half-laden with 140kg ballast or front cross member lowered by 42mm)
• Camber – 1.5 degrees negative
• Castor – 8.5 degrees
• Toe out – 2mm
REAR
• Camber – 1.5 to 2.0 degrees negative
• Toe in/out – 0

Hope this is helpful.
Regards Punterian

[johnb]

Thanks for those values. Gives me something to check against.

I'm a bit surprised about the 1.5 to 2.0 rear negative camber. I'm sure mine is more than that. As you'll know the rear camber is fairly obvious without taking measurements. I'll measure mine for interest.

Any idea what the Spanish book means by the comment ' front cross member lowered by 42 mm'. Could this be 42 mm lowering from no weight in the car to 140kg load? Do they also define 'half laden'?

Apologies for the questions.

The half-laden situation described is with the 140kg loading and sure enough with this weight in the car the front cross member is exactly 42mm lower to the ground (with the suspension arms resting on their rubber stops).

Regarding the camber on the rear wheels. If I'm right this can only be adjusted by adding/removing spacers at the top of the suspension unit.

The measurement I'm not completely convinced by is the toe-out on the front axle. I thought rear wheel drive vehicles always had toe-in.

Any thoughts on this would be welcome.

[johnb]

The half-laden situation described is with the 140kg loading and sure enough with this weight in the car the front cross member is exactly 42mm lower to the ground (with the suspension arms resting on their rubber stops).

Does this mean you had this much weight in the front boot or two people stood in it?

Regarding the camber on the rear wheels. If I'm right this can only be adjusted by adding/removing spacers at the top of the suspension unit.

You're probably right about the rear suspension camber adjustment by spacers. Presumably by spacers at the top of the springs. I'll look at the parts book tomorrow.

The measurement I'm not completely convinced by is the toe-out on the front axle. I thought rear wheel drive vehicles always had toe-in.

Regarding front toe-in/out. I was given a value, 20 odd years ago, by one of the founder members of C.A.R. A very knowledgeable guy (about A110s and R8s), he advised parallel to 2 mm toe-in. I have a copy of the 1977 printing of Odhams Motor Manual which is a practical book written in the pre-electronics era. Regarding this subject it states 'Often front wheels are set with a fractional "toe-in" so that any flexibility in the steering linkage does not let them toe-out or splay apart excessively during braking, but front wheel driven cars are sometimes set with "toe-out" of their front wheels'.

Not conclusive but seems to agree with your thinking.

Ballast:
I achieved the weight loading with bags of sand placed in the front boot (x3) and in the driver and passenger footwells (x2 each side) - transported to the garage in another car!

Rear camber:
Have found a note that mentions 'adding or removing 10mm aluminium spacer cups above the rear springs'.

Toe-in / toe-out:
I think what you were told is right - up to 2mm toe-in at the front. I think there may be some confusion here around whether toe-in and toe-out are negative or positive values. My understanding is that toe-in is positive, and toe-out negative.

[johnb]

Rear camber:
Have found a note that mentions 'adding or removing 10mm aluminium spacer cups above the rear springs'.

This photo was taken 20 plus years ago when I was restoring the A110 and shows the aluminium spacer cups you mention. Looking at my notes from the time, the black 'cups' to the left of the aluminium ones are shaped to fit the top of the spring. They have a rubber 'cup' glued on top and then the aluminium spacer sits on top of that and the assembly then goes up into the cross member. So, I guess, removing the aluminium spacer would increase camber if you wanted to do that.

From memory, this was fairly simple because jacking the rear of the car and disconnecting one side of the retaining straps allowed all the spring tension to be released as the wheels lowered. So there was no need to use a spring compressor.

Having done a lot of playing with modified R8s and 4CVs, I would be inclined to not load the car up with the sandbags, but sit the driver in the seat and set up the suspension as its likely to be driven, with a half tank of fuel etc. It is also worth having a look at the bumpsteer that can be excessive on these vehicles and can be sorted mostly by spacing the steering rack back from the mounts. On an R8 that had 25mm bumpsteer through its travel, this was reduced to 6mm by spacing the rack back 8mm. When the car is sitting on the alignment machine, push the nose down and push it up from underneath, how much does the toe change whilst doing this? 2mm or less is good for production car. On a Formula Ford it is more like 0.15mm.

I would set up straight ahead on the toe, anywhere between 8-11 degrees of caster is OK as long as they are both very similar. Does it have more camber on the LHS? If so this will suit when the car is road driven in the UK to counter the crown in the road. The camber can be changed by slotting the chassis mounting points for the lower arm.

[stephendell]

You can fit an adjustable camber kit to the front:

http://www.mecaparts.com/Chassis/page.p ... 8&page=22a