I raced the SSS for the first time this year down at Levels raceway at Timaru over the weekend and while the car was great to the point of actually winning the last race it has absolutely destroyed a right front tyre( brand new Dunlop Direzza )
Now Levels is known to be very hard on right fronts due to its many high load left hand corners but this is ridiculous.Parts of the middle of the tyre look as if it is starting to delaminate and the outer half is absolutely hammered.
I run 3.5degrees negative camber and over 4 positive caster and 2mm toe out. The cold pressures were set at Dunlops recommended 23 lbs.
The car is not overly stiff with front springs at around 185lb and rears to match but it is beautifully balanced and handles really well with absolutely no vices whatsoever and minimal body roll.
All the front end is solid bushed with rod ends and moves freely with no binding whatsoever.
The only thing that I can see that is making me suspicious is the sway bar looks as if its been hitting the front outer chassis rail thus perhaps rendering the right front solid under extreme cornering?The bar is in the factory position with uprated bushes.
Has anyone come across this before?
Any input here would be hugely appreciated.
Cheers
Dave

I spaced my sway bar down 10mm at the chassis mounts because it was hitting the chassis. It wouldn't help tyre wear, because if it binds it will cause understeer and scrub the tyre accross the road.
Sounds like more camber and castor are needed. 3.5deg camber and 4deg castor is pretty mild for a track car.
Did you take any temps off the tyres after a seesion? even a cheap little infrared temp gun will give a useful indication if you take temps straight away on that RF.

I can understand the frustration, killing a tyre in a single event would be an expensive habit. Maybe you need a harder compound for that track. The Dunlop DZ03 comes in a few compounds. Or if it's a sprint event rather than a race, don't do so many hot laps in a row - alternate hot laps and cool down laps. That will make life alot easier on the RF tyre.

I googled the track - looks like a ripper, but can see why it's hard on the RF!

This is a useful link for reading competition tyre wear:

http://insideracingtechnology.com/tirebkexerpt3.htm

Hi Harry,
Thanks so much for the feedback.
When you put the 10mm spacers in between the sway bar mounts and the chassis did you shorten the little pedestals that connect to the bottom arms of just leave them standard?
Thanks too for the article- a good read.
I certainly agree re the alignment specs. Interestingly enough the wheel alignment specialist was hesitant to give it even 3.5 negative. Next time it will be 4.5 and I'll show him the tyre.
Haven't taken any tyre temperature readings. Just checked the pressure and the r/f had gone up 5lbs to 28, the left up 3 to 26lb which I would have thought was about right but Dunlop are now saying that they think it could be a couple of lbs too light.
Cheers
Dave

my sway bar end links were Stanza ones. Not sure if they're longer or shorter or the same, sorry mate.

26-28psi sounds fine to me. That's what I use on Advans on my old 1200 with the heavier L series up front. But if the tyre's overheating or tearing up the center of the tread, the last thing you'd want to do is add pressure. Dunlop's advice sounds strange to me.

No worries Harry.
Just had another look at it tonight and the top of the sway bar has really been hitting especially on the right hand side so I'll drop it probably 15mm and get some pedestals made up.
Just a thought- I realise that my spring rates are not the stiffest( but as I have said the car feels great and I really am loath to change anything)this wouldn't be one of the possible causes would it or is it more a case of the swaybar hitting and locking the suspension up because the softer suspension settings are letting it move through its full arc rather than having heavy springs restricting its movement to the point where the swaybar hitting issue didn't really exist?
Be interesting to know what rate springs Simon is using in his IPRA coupe.
What are your thoughts re new geometry settings?

Put some springs in it I reckon. 185lb seems very 'road car' to me and will do you no favours on a track. Benny or Harry will be able to give you a guide on rates - my B310 specs will be no help!
Cheers.

for reference i run 3deg neg camber and about 5deg castor on mine with no tyre wear issues. i run double your spring rate though
with a chubby sr20

Your Sr gives me a chubby

All that sounds right Dave. Most track 1200s would have front spring rates around 250-300lb. Mine were cut gemini springs, but they would have been about 300lb. But it does depend on other factors like swaybar and roll center height. You don't want it too soft or you lose all your static camber with bodyroll and pitch more weight onto that corner.

I had something like 6deg castor and 4.5 camber. In other words as much as I could get! But I still had stock spring diameter and stock strut tops limiting camber.