Vitesse Mk2 Front Camber Adjustment

[Freyasgrandad]

Advice Please.

Having converted to CV rear shafts and telescopic shocks and renewed all  bushes and trunnions my Vitesse has much improved rear grip. So much so that understeer is an issue when I push even a little.

Given that the rear now drives with about 1 degree of negative I think it is probably best to try and get the front camber to at least 0. I know this is achieved with shims on the lower wishbone location points but are there assorted sizes available or is it just a question of adding more standard shims? Either way does anyone know the formula to calculate the required shim(s)?

Steve

[dave.vitesse]

Steve, No assorted sizes they should be all the same. It is just a matter of adding for more neg camber or removing for more pos camber. There should be an equal amount of shims on each lower wishbone mount point.

There is no tec info re the amount. Two to four on each mount point was the range used by the factory.

Dave

[Clive]

And don't forget to reset the toe after! Probably worth checking the rear too. Easy to do with a tape measure and straight bits of wood (or steel bar/bed iron etc)

 

If you want to really play, you could try removing the front ARB as that will reduce understeer. It is a case of experimenting to see what suits you, but remember that chunk of iron up front (AKA a 6-pot) is difficult to overcome.

[Nick Jones]

As above but I disagree about the equal number at the front and rear. Caster angle is altered by varying the relative numbers of shims front to rear which shifts the outer end forwards or back. Caster is important for steering weight, feel and self catering action.

My own Vitesse is set approximately as follows

350 lb springs 10.5" free length giving approx 1.5" lowering

Konis set about 2 clicks from fully soft

std ARB

Camber 1deg negative

Caster 3deg (iirc, need to find notes!)

Toe parallel (this with poly bushes-may need 1-2mm toe in with rubber ones )

Rear is roto with CVs, std (but well sagged) spring and standard mk1 dampers on chassis extensions. Camber more like 2 deg negative due to lowing ride height.

This adds up to a fairly neutral handling road car. It still has a slight understeer tendency which is further reduced by 25 - 50 Kg in the boot.

It is fair to say this won't give max tyre life on the front -tends to wear the inner edges, though not at a great rate, but the parallel toe really helps turn-in.

Also have a Herald rack for the faster gearing - doesn't affect the basic handling though.

Nick

[Pete Lewis]

and without unladen geometry figures for vitesse its 150 lbs on each seat to get the ride height  setting  ..........before you adjust anything  !! or its a waste of time 

[Mjit]

Re: The number of shims - you're both correct.

• Adding/removing the number of shims equally from both lower wishbone mountings will generally* change the camber.
• Adding/removing shims from the individual lower wishbone mountings will generally* change the caster.

* Of couse make a single-shim change to adjust the caster will also change the camber so means some dual-shim changing to reset the camber...which will change the caster.

Buy a wedge of shims and find a quality wheel alignment centre who actually know what their doing (95% don't in my experience) and had over car+shims.

[dave.vitesse]

Nick is quite right re the caster angle. Though the factory normally fitted equal all round.

Follow Pete's Ride High first.

dave

[dave.vitesse]

Factory info attached.

Dave

[Pete Lewis]

my days with castor needs the wheels turned 20 deg in set the angle spirit level on the stub axle  then  turn wheels 20deg  out and measure the angular change  you must firmly apply the brakes for castor or the wheel will rotate and give you some daft results 

Pete

[Nick Jones]

4 hours ago, Pete Lewis said:

and without unladen geometry figures for vitesse its 150 lbs on each seat to get the ride height  setting  ..........before you adjust anything  !! or its a waste of time 

All the figures I gave were unladen. Don't know why the factory were stupid enough to quote laden figures. Very awkward to comply with and thus pretty much guaranteed to be ignored. Unladen figures would be so much more useful.

All worthless if the car is lowered too, though I suppose a lowered car might match the laden position.......

Forget to say before but have my rear toe set to 2mm toe in. If you like a "lively" rear try parallel or even a couple of mm toe out. Suggest the latter for track use only!

Nick

[Pete Lewis]

most makers of the era used static ride heights to determine geometry setting as it derives the 'mean' ride attitude of the suspension whilst driving, and sets all the unequal lengths of wishbones and track rods etc in a known  state,  purley because  unladen is not what happens on the road 

anything modified away from triumfs plan can use whatever they feel works , its not in a 'as designed' condition  so no rules here 

just some thoughts Pete

 

[Freyasgrandad]

Thanks for all your input everyone I appreciate the information.

Having looked at the suspension today I think I am going to go for Canley's adjustable wishbones simply because they will be much easier for me to install and adjust with my present reduced mobility and dexterity.

Quite what I am going to use as ballast I don't yet know but there is a reason why geometry should be set laden.

Steve

[Pete Lewis]

Rent a crowd  or bags of coal/ sand  would work 

Pete

[dave.vitesse]

The laden weight is the correct dynamic measurement or reference point to start from. "How does the car sit on the road" was the old term. 

On the standard factory set-up there is normally no need to adjust the castor or camber angles unless things have changed in some way. However, fitting new standard front springs after allowing to settle in may still need a very small change to the camber (but not the castor) due to productions tolerance spreads. See factory instructions.

As Pete rightly points out modifications can change the original factory design references. So in some cases it can become trial and error to set up. Therefore you must have access to the relevant test gear plus some knowledge of car suspensions. Which you may have.

If you do carry out any modifications you may need to check the castor angle as well as the camber. Because of the reasons given by Nick.

Dave

[Freyasgrandad]

In theory at least, fitting an adjustable top wishbone of the Canley design should not alter Castor angle.

As I want to reduce castor anyway I shall obviously measure it.

After much thought I am going to do this job single seater style removing the springs and shocks and using ride height blocks whilst doing the geometry.

 

[trigolf]

Regarding Pete's comment about making adjustments with the car laden - I was watching Wheeler dealers the other day and Edd China was setting up a Lotus Elise geometry for a fast road /track car. He used weight lifting weights to simulate laden car.

Gav

[Freyasgrandad]

A. I'm not that strong.

B. Setting geometry without springs and shocks is the best way as you can adjust bump-steer as well.

Steve

[Nick Jones]

Agree. Has been an ambition of mine to measure how the various settings change over the range of suspension travel. Then we'd know how much the laden/unladen thing matters and what the correct unladen figures would be.

Nick

[Pete Lewis]

oddly the GT6 Manual does give geometry with an unladen specification   much of which would correlate to other models 

 

Pete

[dave.vitesse]

Pete, Following your post I did some digging and yes there is some in the factory workshop manual. For Mk1 Vitesse and GT6 page 4.103 table 1. For Mk2 Vitesse and GT6 page 4.119 table 1.

Not sure if its enough but it is a start point

Sorry chaps my error.

Well done Pete.

Dave