Cerbera tyres and alignment

[davidd]

Afternoon,

I have some 18" sp12s going on the car on wednesday. I currently run the car on 24psi, but am off to le mans on thursday, do we think that it is worth upping the pressure to 26 for the duration?

Also my fronts have worn on the inners, Offord have corrected the tracking ( it was a long way off), will I need to get the tracking sorted when I get the new wheels on (it currently has 18" spiders).

Final question... (for now )

What settings should I give the tyre place (performance tyres in cambridge if anyone is interested)

Cheers

D

PS Toyos!

[-Jamie-]

Best to get the geo done after the new tyres! and 28psi all around

[Byker28i]

I'd have thought Matt at SP would be the best person to tell you?

[GT4 Baz]

I just had my geometry done at SP and Matt did a cracking job on mine. Don't forget its not just toe that adjustable on these cars, its camber, castor etc.

Mine was a mile out, -1.75 degrees camber on the one side, +0.75 on the other! Its transformed handling wise now (bear in mind that I did a track day on the old settings!), well worth going somewhere that know's what they are doing TBH.

[davidd]

GT4 Baz said:

I just had my geometry done at SP and Matt did a cracking job on mine. Don't forget its not just toe that adjustable on these cars, its camber, castor etc.

Mine was a mile out, -1.75 degrees camber on the one side, +0.75 on the other! Its transformed handling wise now (bear in mind that I did a track day on the old settings!), well worth going somewhere that know's what they are doing TBH.

I appreciate that, the issue is that I just will not have time to get it anywhere other than my local tyre place before I head off.

I know the settings are more or less correct on the spiders.

The tyre place I'll take it are the best localy for laser alignment and there are always a lot of decent cars in an out so I have no doubt they will have attended to cerberas in the past.. I just don't know the correct settings.

I guess that as the wheels are the same sixe I'll be ok to leave it until after I get back..

Cheers

D

[Ireland]

Fitting new wheels won't change your steering geometry.

The set up you have now will remain the same.

All you are doing is taking off one set of wheels and replacing them with another.

The geometry at the hubs will remain unchanged.

[Tanguero]

To get the correct pressures, take the car for a short run and measure the temperature of the tyres at the shoulders and in the centre of the tread with an IR thermometer.

If the centre is warmer than the sides you are over inflated. If the shoulders are warmer then you are underinflated. When the temperature is even across the tyre your pressures are correct. Its the only way to accurately tell the correct pressure for your setup.

[gruffalo]

The set up on these cars depends on what you use it for.

If it is a motorway muncher then standard settings is right.

If you spend all your time on the twisty bits then you want to dial in more camber, standard upper wish bones allow 3 deg camber, you can buy modified ones that allow 6 deg for track use but 3 deg on a car that lives on twisty normal roads should help even tyre wear and give huge feel/turn in on the front.

As I understand most of the racing Cerbs use 6 Deg on the front. Andy at APM is a good source of info on this subject.

[amazon]

davidd said:

Afternoon,

I have some 18" sp12s going on the car on wednesday. I currently run the car on 24psi, but am off to le mans on thursday, do we think that it is worth upping the pressure to 26 for the duration?

Ooooh, how exciting! Look forward to seeing them on your Cerbera .

Not sure it's much of a guide - but I tend to have mine at around 24 (seem a little low compared with some others??) all round and they feel good. I think for a blast down to Le Mans, they are going to stay nice and hot anyway

If you're passing when you collect the car..........