First track day a success. Now some advice please !

[jl34]

Hi guys. just completed 3 track session's at the Castle Combe action day and had a great time. It was the first time taking to the track since buying the car recently. The session's went very well hitting 140 mph through folly going up to Avon rise, about 15 mph quicker than my old (but quick) VX220 Turbo could manage!

i found out a number of things after yesterday, the suspension is fabulous, the built in compliance coping admirably with the bumps of castle combe. However i did notice the outside inch of the rear tyres had developed a greater wear than the rest of the tyre. Rear end grip was lacking when using nearly 400lb/ft of torque out of corners and im guessing i could improve a lot by getting more tyre onto the track. My tyres are bridgestone potenza RE050a so pretty standard tyres, however i dont want to burn through them if drive as hard as i did yesterday!. So couple of questions :

1, Could i improve the wear rate by using a tyre with a square profile and stiff sidewall such as a Yoko AD08 (superb on my old VX) Am i experiencing the soft wall of the bridgestone rolling over ??. pressures were set as recommended 20/30 psi cold.

2, Can i improve rear Negative camber by lowering the car ?

3, If i have to go down the machined upright route, what's involved and how much would this cost ? Im a little reluctant to go down this route because i know from experience more neg rear camber means more skittish behaviour on a typical bumpy B-road. I also dont want to take the suspension apart and get it setup every time i want to go on track which would be about 4-5 times a year.



Is option 3 the only answer or is it worth trying 1 and 2 first ?? im also not interested in stiffening the shock and spring to reduce roll as the standard combo is bloody perfect in my opinion.

Appreciate your advice folks

jason

[ajf]

Hi Jason

Is this Paul's old one

[Gadgeroonie]

what tyre pressures are you running ?

i guess the solution would be adjustable camber

if you are going to do a lot of track days it may be worth investing in some shocks and adjustable camber

---

i am not sure if an anti roll bar alone would help - in theory the car should roll less and that may help with the camber wear

[TuxMan]

Sounds like you need a bit more rear camber .
Sounds like you had fun !!

[Adrian W]

Here we go again, do you want a track or a road set up, it's very difficult to get both.

Camber will produce more grip in the corners but, the more you put on the less stable it will be on the straights, and wear goes with camber whatever tyre you choose.

[TuxMan]

Slippery slope I will agree but a slight Tweek to the rear camber should be ok .

Tux

[mgbond]

Was I reading it right that you used 20 front and 30 rear cold for track. It's 18 front and 27 rear for normal road work.

So shouldn't you have just dropped pressure. I used RE050's on track before and didn't notice any uneven wear?

[jl34]

Do all you guys who adjustable camber , done it because of outer tyre wear, or simply improve rear end responsiveness?

Is an adjustable camber set up a big job?

[TuxMan]

I guess the biggest step is better Tyres
Then it just seems to snowball

Rear camber not a easy job , machine uprights or adjustable wishbones , both bespoke work and nothing available off the shelf .
In the end you end up chasing performance but as Adrian points out at some stage your road car becomes a track car , suppose it depends how far you want to go .

We are at Silverstone on Monday the 6th if you want to come over for a chat .

Tux

[D_G]

TuxMan said:

In the end you end up chasing performance but as Adrian points out at some stage your road car becomes a track car , suppose it depends how far you want to go .
Tux

This is a good point, there are several owners who have modified their cars so it's great on track but not on the road anymore. It's a fine line between the two, I would't like to drive my track car on the road for any distance.

[F.C.]

I had my upright machined to get a bit more contact patch, (I had similar wear to yours, with Corsa's) your tyre pressure seems a little on the high side also, IIRC I was running 16 at the front cold (M400) can't remember the rear pressure.

[jl34]

Hi there, What was involved with the machining?, did you have shims in there? Did it change the on road handling?

[TuxMan]

Daddysumo did my rear hub machining , he is probably the best guy to contact if you want to strip everything out yourself or Jetstream can do the work for you .

Might be better to go for better tyres and dampers first though , you can get good steps in performance with not much hassle and effect to the way your car drives .

My car is probably one of the most modified for track , still drives ok on the roads just the clutch i hate !! very heavy and juddery .

Tux

[Hollowpockets]

When you think your out of grip, teach yourself to apply more power, it goes against what you naturally want to do but you'll find the car bites in and follows the line you want.

My advice, don't touch anything yet, practice and push the limits, then fit Michelin pilot sport cups.

[jl34]

Thanks for the advice.i think i will experiment with a stiffer side wall tyre and try some different tyre pressures first before ripping my suspension apart. I've done a lot of track days over the last 5 years and i really feel the damping and overall balance is superb. I just want a bit more rear end grip and to prevent the tyres from shredding the outer edges

[TuxMan]

But thats kind of the problem , the grip is causing the soft suspension to allow the car to roll excessively tipping the tyre onto its outside edge , if you go to fit track tyres you will get more grip causing the car to roll more and so on . as i said slippery slope .

[jl34]

Hmmm. See where your coming from. Slippery slope indeed!!

[Gadgeroonie]

would front and rear ARB help the problem ?

[wessexrfc]

And spotted only just squeezing past the racing Citroen!!

http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Silver is the quickest colour incase anyone had any doubts