tyreleader cups performance on track :(

[Rick H]

8 tracks days - same set of Cups? Is this realistic? I was expecting 2 maybe squeeze 3 at most?? what's normal for somewhere like Oulton?

[s.mac]

Agree with all, pressures too high. Also suspension set up, this can be different on the same track on different days. Needs tweaking to suit on the day.

If you are that keen you should check the tyre temp across all tyres and 30 to 32 psi max HOT, I would be closer to the 30

Lap time could drop because you are over driving chasing times. You might not think it but been there done it. Lacking confidence on grip could also hinder times.

[estoril]

Don't forget to "Heat cycle" your next new set of CUPs before any track action :beer:

Just for the record, how is this best done?

[mattCSLnut]

Hi Matt,
I accept that the pressures could be a bit high. What it doesn't account for is consistency of the track and why it degrades evenly through out the day.

It should be a 1-time.. oh that's bad and remain the same. But it doesn't, it just constantly goes down. NB I have tried these 35 psi HOT temps for 8 trackdays now and have never felt the tyres going off the way they are doing now. Gradually rubbing off performance the entire day such that at the end, it was basically understeering everywhere.

I'm going to try again and see if i can get new cups on soon and report back.

Unfortunately there is no "could be" about it You've run these Cups now (over inflated) for 8 track days, overheating & over working them (due to the wrong pressures) so you've probably altered their compound in the process. Now they are at the very end of their life it's natural for them to behave the way you've described. They are telling you it's " GAME OVER "
Don't forget to "Heat cycle" your next new set of CUPs before any track action :beer:

[alexk]

You are starting with wrong tyre pressures and I believe this is making everything else irrelevant.

One more point.
What do you mean with your car is setup to understeer ?
Again I am puzzled because I have a setup in my car, it doesn't understeer nor oversteer and I go fast with it.

Edit: obviously it can drift when I want it to drift but not on it's own (like KITT)

[khooni]

Hi Matt,

I accept that the pressures could be a bit high. What it doesn't account for is consistency of the track and why it degrades evenly through out the day.

It should be a 1-time.. oh that's bad and remain the same. But it doesn't, it just constantly goes down. NB I have tried these 35 psi HOT temps for 8 trackdays now and have never felt the tyres going off the way they are doing now. Gradually rubbing off performance the entire day such that at the end, it was basically understeering everywhere.

I'm going to try again and see if i can get new cups on soon and report back.

[mattCSLnut]

Tyre pressure too high

Your tyre pressure was too high @ 35 psi (hot or cold) and Cups are very sensitive to both pressures & temperatures. Sounds like you were overheating them from the start.
On track the correct tyre pressure for Michelin Cups is 26 psi (cold) and should hover around low 30's psi hot unless there's something amiss.
The 2012 DOT is perfectly acceptable as the rubber life span of these tyres is around 5-6 years (if they were heat cycled correctly from the start) although they don't phisicaly tend to last that long if you track your car frequently :supz:

[khooni]

I didn't realise that but point is it is consistent to all my other track days. That's what I find puzzling

[alexk]

The pressure is very high in my opinion.
5 laps is nothing.

I tend to do 15-30 laps in a row and I have no such issues even with old cups.
In Monza I do 30 minute sessions.

[khooni]

one other thing. The tyre pressure light kept coming on despite re-setting and manually checking of pressures using a gauge. What is this for? I never knew what it did nor how it read low tyre pressures.

[khooni]

9 to 10 secs is a lifetime Billy....... with consistent temps and low numbers of cars on track, I can usually lap to within 3/10s.

Anywho, I'll try again with newer tyres.

[billyboysm3]

Grant went to Silverstone a few weeks ago and that had poor grip, Id say tyre pressures to hot and track had poor rubber laid down on it.

[khooni]

5 laps.

22deg ambient temperature.

It just wasn't turning in and when I put the power down it just wanted to understeer. My car is setup to understeer so I can brake as late as possible and trail. It's gives me great confidence in that the tail won't snap on me and just gives me the extra turn in required when trailing the brakes. Yesterday it was just a pig, and when i gave up setting times and wanted to hoon, I discovered that because my front end doesn't grip, I have difficulty booting the tail out. The symptoms are that the tyres are fooked.

I'm buying a new set now. ............. but i'd appreciate if anyone thinks it could be something else..

oh, 1 more thing. that bonnet is really irritating me... I'm gonna tape it shut with masking tape.... is it ok to use masking tape on the paintwork?

[billyboysm3]

And how many laps per session,

[billyboysm3]

tyre pessure is 35psi all round.
suspension is kw clubsport (gen 1) non adjustable
track geometry setup by simpson motorsport

none of the above had changed. I just went on a track day at Snetterton 2 weeks ago and the grip was fantastic.

Yes.. 5 trackdays on a set of cups.

Yes the previous set had a huge amount of grip as well. Maybe this is a 1-off... but.. wtf.

I run 30 psi hot, how hot was it yesterday.