understeer

[diceman]

I've just replaced the front corsas as the outside edges were quite heavily worn. I had expected the mild understeer which i'd noticed recently to have gone. However i seem to have a more pushy front end than before!

This is even after getting some heat into the tyres and without overdriving the car.

So my questions are.. Is the front geometry adjustible? i.e if a problem is found when checking the geometry is there much scope for correction? has anyone had any similar problems? And, do i need to allow more than 60 or so miles to bed in the new tyres (am i expecting too much too soon)?

Cheers in advance

[m12_nathan]

Geo other than toe is fixed, worth checking that though.

[plipton]

I assume the pressures are right (18psi IIRC on the fronts - any lower could cause heat, understeer and edge wear)

If you have LSD and rag it a lot, that won't be helping either

[diceman]

Thanks guys,

Will get the toe checked asap. I'm running the fronts at 20 psi, which i thought was the m400 handbook pressure.. I'll check it up later

Steve

[Ash M400]

20 psi is correct.

If I remember corectly, 100 miles to run the tyres in.

[plipton]

Ash M400 said:

20 psi is correct. If I remember corectly, 100 miles to run the tyres in.

Yep 20 for M400 - 18 for M12

[V6GTO]

Is it possible to soften up the anti roll bar? That should help if it's "pushy"

Martin.

[joust]

Sure you aren't still on the release compound of the tyres? It takes around 100-200 miles to get rid of it.

Also, if it's wet, M400s with new fronts part worn rears do get understeery - just seems to be a trait of them. Give it a few hundred miles to 'even out' and it's back to it's normal.

Also, check the pressures with a reliable meter - tyre fitting places are notoriously bad at setting the correct pressures.

J

[Mr Noble]

Also check the pressures when the tyres are hot. Checking they are 20psi at the garage before a trackday is one thing, but give it 5 laps and re-check and you'll be running about 25psi!

G

[diceman]

Just checked the prssures again, turns out they were at 22 psi. Dropping a couple of pounds in each together with a few more miles and she's back to her pointy self. Amazed at the difference such small changes can make!

Thanks for the quick replies and ideas, I'm off to the ring next week and was a bit concerned that it would feel like i was in a scooby there

[joust]

1 or 2psi makes a big difference to the M400.

J