Accelerated tyre wear after fitting new suspension

[stef1808]

Hi, on my 911 the cup2s would last about 4-5 track days
After fitting Nitrons and monoball bearings, only after 2 track days the outer tyres are shredded and chunks missing.
This makes me think I possibley hit something or could it be because of the new stiffness?
I also think the corner balance was off as right turns never felt stable compared to left
Would a new firmer setup (same geo) affect tyres that much?

[mwstewart]

Did you have a geo check after fitting the bearings?

Bear in mind that less compliant suspension and joints puts more initial load into the tyre.

[itsnotarace]

You need a full alignment done after any changes like that

[Pupbelly]

itsnotarace said:

You need a full alignment done after any changes like that

THIS^^^

Common sense says any suspension changes warrant a full alignment set up if you are a serious driver.

[Dave.]

stef1808 said:

....outer tyres are shredded and chunks missing.

Are you aggressive over curbs?

[mat205125]

If geometry is the same, the additional stiffness could put more force into the shoulder of the tyre, as body roll that were previously present has been removed

Maybe you can increase the camber a degree or two

[mikey k]

stef1808 said:

Hi, on my 911 the cup2s would last about 4-5 track days
After fitting Nitrons and monoball bearings, only after 2 track days the outer tyres are shredded and chunks missing.
This makes me think I possibley hit something or could it be because of the new stiffness?
I also think the corner balance was off as right turns never felt stable compared to left
Would a new firmer setup (same geo) affect tyres that much?

It looks like you did the geo after the changes?
The fact the handing isn't symmetrical suggests its out
First thing I'd do is get it checked by some one that know 911's well

[Penelope Stopit]

Yes, does look like geo was done

If geo wasn't done get it done

Have nearly scrubbed off the inside of 2 new tyres having rebuilt the car without having a geo done

[GreenV8S]

When you say 'outer tyres' do you mean the tyres on one side, or the outer shoulder of all tyres? The location of the wear gives a good indication of the cause.

If handling seems asymmetrical and the geometry is correct, double check the damper settings and make sure you are always adjusting from the closed / full hard position. You wouldn't be the first person to get the direction of adjustment wrong on one side of the car while working upside down out of sight and so on.

[spikeyhead]

Probably worth a trip here

http://www.centregravity.co.uk/

Which might not be cheap, but if you're taking chunks out of tyres...

[mikey k]

spikeyhead said:

Probably worth a trip here

http://www.centregravity.co.uk/

Which might not be cheap, but if you're taking chunks out of tyres...

Know Chris for years he is a true artist and professional
Also a 911 nut as well

[stef1808]

Thanks for the replies. Yeah I did a geo but not not corner balancing

[Munter]

To me suspension seems like flying a helicopter. You can't change any single thing, without having to change a bunch of others at the same time to compensate, or you'll get some kind of negative effect.

Say if camber increases (more negative) when the spring compresses. If you use stiffer springs, you'll have less camber when the car runs through the same corner at the same speed, than you would with softer springs. Which might wear the edge of the tyres. Of course caster also comes into play, because the more you turn the wheel the more (negative) camber you'll get, and you might be able to adjust caster too.

But is any of that how your suspension geometry works on your car? I don't know. I just know it's a minefield of unexpected results for the "uninitiated".

Experts fly helicopters, and setup car suspension.

[GreenV8S]

stef1808 said:

Thanks for the replies. Yeah I did a geo but not not corner balancing

Corner weighting isn't necessary and won't make any difference unless you have adjusted the spring heights differently side-to-side, or something is bent. In that case it's better to fix the problem than hide it by playing with the spring seats.