tyreleader cups performance on track :(

[khooni]

thanks for that. At least someone is paying attention. Indeed, I've booked an evening at Brands next week to see if running at 30psi magically solves the issue.

I don't do setup. I let the pros do it. I just try to improve my own so-so driving and to have a bit of fun at the same time. You guys know, there's just so few places to push the car on our roads and feel the sublime balance that they are capable of.

[Chappers]

I think you've answered your own question, it's fuck all to do with the tyres and all to do with set up

Unless, as he seemed to be repeatedly saying, the only thing that's changed are the tyres (and the track temps) in which case it's everything to do with the tyres (and how he's using them). Whilst a vehicle set up will probably improve things, from an engineering point of view if it hasn't changed it's not the issue.

We're not trying to diagnose vehicle performance here, we're trying to work out why there's a massive difference in tyre performance between apparently identical sets. My guess is track temps and slightly high pressure.

A video would be good so have a look at your steering inputs, just for interest's sake.

[s.mac]

I think you've answered your own question, it's fuck all to do with the tyres and all to do with set up

[khooni]

didn't do anything on setup. Don't know how to.

I just wanted to ask if you guys thought it was strange to have performance degrade so much from session to session from a new set of tyres all things being equal.

Guess I must the first person to get a bad set of 2012 cups. maybe it is indeed a fluke set. hopefully. as 2015 sets are pricier by ~£150

[s.mac]

I did a set of front cups in 1/2 a day, it was due to incorrect camber for the track. Knocked them well out and got through the afternoon.
IMHO it's not down to the tyres but the set up, which is a combination of the lot.
You need to alter everything on the day but if you are normally a tenth out lap to lap you know all this

[khooni]

51 to 53s on a standard CSL is pretty good going. My best time was 55 sec so far.

[khooni]

pretty sure it is NOT only due to high pressures.

I have explained time and again that my previous 2 sets of 2012 tyres didn't behave this way. The 3rd set did.

I may be running high pressures but I have been consistently running high pressures for the last 8 trackdays. and only the last one did this crop up.
And I can ususally lap to within a couple of tenths on average so 10 sec is a lot of ground to cover.

[octainejunkee]

Pretty sure your problem is down to high pressures.
(always adjust once hot after a few laps) 26-28psi hot,is good for cups.
You should put a few mild road miles and a couple of heat cycles on the tyres to bed them in before tracking them also.
Not sure they'll behave properly regardless of what you do to them if youve cooked them now.
Keep them for road use only if they dont behave well at Brandshatch.
You should be in the 51-53 second a lap on the indy circuit with coilovers and a bbk.

[khooni]

I am not a good driver by any means but I did manage a 2.20 flat last wednesday.

let me know how you get on. I don't see many CSLs out there anymore. only the extreme modified e46/e36..

when are you thinking I might join you. It's a pretty cool circuit.

[billyboysm3]

What sort of lap times can your beast get round Snetterton, hoping to go end of month.

[khooni]

it took me 75miles to drive to Silverstone on the new set so it is effectively heat cycled. But for arguments sake, I'll try an evening at Brands before i change over to the new set and run it at 30psi HOT to see if it feels better.

[mattCSLnut]

Me, shimmy and Duncan paid track group to do ours or alternatively go for a very long drive heating up the tyre gradually. Spa would be good or drive to track night before.

This saves them from going hard, I managed to wear mine down to canvas with little loss of grip.

I'd say 7-8 track days if all dry, plus a couple of wet ones.

Run to the Ring on a fresh set day before the On track hooniganism usually does the trick :supz:

[khooni]

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)

what i meant was that at the limit it has a tendency to understeer and that it is very difficult to provoke the tail to move under trailing brakes. The converse side of it is that I can brake very late and very hard and come off the brakes quite easily to provoke the turn without being afraid of it snapping on me.

I think standard CSLs are more neutral than my cars you can have fun more easily under braking. But, they all react the same way to throttle.
I asked Anthony the same question and he said we all set them up to race this way. hmmm.

[khooni]

Sigh.

This phenomenon is on new 2012 cups. Previous 7 track days were on 2 different sets of 2012 cups. Yes I am on my 3rd set this year. And I just ordered a proper new set.

I am not sure we are all on the same page here. All I am pointing out is the inconsistent performance which may be due to a freak set

[billyboysm3]

Just for the record, how is this best done?

Me, shimmy and Duncan paid track group to do ours or alternatively go for a very long drive heating up the tyre gradually. Spa would be good or drive to track night before.

This saves them from going hard, I managed to wear mine down to canvas with little loss of grip.

I'd say 7-8 track days if all dry, plus a couple of wet ones.