Wear on slicks

[derek]

I was running with pirelli slicks yesterday that had only done couple of track days. Started to get some vibration and the front left and the outer edge have raised ridges evenly spread around the wheels across approx 2-3 inches of the width of the tyre from the outside. Swapped front around and the ridges developed again on front left. I was running about 28psi and -3.5 degrees camber. Anyone seen this before.

[DazBlackCSL]

Slicks make you feel every single inch of the road Derek .. Pick up any shit and you'll feel it .. Over brake and flat spot em and you'll feel it.

Wouldn't worry about vibration, difficult to really see in the pics, tyres look a little lumpy and that you've picked up a fair bit of rubber on the shoulders

[derek]

It's the two edges in the middle of pics that are the outer edges of the wheels. the ridges are quite big and are equidistant around the edges. It's like mini speed humps all around the outer edge of tyres never seen this before.

[shimmy]

if i were to guess, and it is a guess, id say you need way more neg camber

[Chappers]

I have to say I'm amazed you can use slicks on a standard road car, I'd have thought it's break all sorts of things. Madness.

[derek]

if i were to guess, and it is a guess, id say you need way more neg camber
Anyone running more than -3.5 car was going well before the vibration started

[rstoughy]

What sort of times were you setting with the slicks Derek?
I spent all Tues PM there testing in the rain.

[shimmy]

Anyone running more than -3.5 car was going well before the vibration started

-3.5 is very low for slicks, more like cup camber

[derek]

Best was 60.7 done 60.2 on same tyres last month car is about 5mph slower on main straight than Csl it's just under a sec slower than best Csl time

[derek]

-3.5 is very low for slicks, more like cup camber

I was using the Simpson setup you gave me several years ago any recommendations for camber on slicks

[shimmy]

I was using the Simpson setup you gave me several years ago any recommendations for camber on slicks

that was Cups....slicks is well different. Also that was Cup settings for a cmpromise as its a rioad and track car unlike yours which is i guess track only.,

youd need to get pyro testig and advice and to ask soemone more knowledgable than me, but i think youll be around -5 deg


may not be the problem though :beer:

[derek]

that was Cups....slicks is well different. Also that was Cup settings for a cmpromise as its a rioad and track car unlike yours which is i guess track only.,

youd need to get pyro testig and advice and to ask soemone more knowledgable than me, but i think youll be around -5 deg


may not be the problem though :beer:

thanks for your help:thumbs:

[billyboysm3]

I run -5 to -6 front camber on slicks.

Makes a massive difference on turn in.

I left it like it yesterday on a wet track and It wasn't to bad either.

[derek]

I run -5 to -6 front camber on slicks.

Makes a massive difference on turn in.

I left it like it yesterday on a wet track and It wasn't to bad either.

Thanks Billly I'll try more camber. Just need more slicks now

[billyboysm3]

-3.2 ish is perfect for cups and even wear.

I really need someone with a pyro thing.

Still not done a dry UK track day, managed 4 sessions yesterday, 3 wet, one damp. Car had great grip on Goodyear Eagle F1's.

Billy

[trackm3]

Way to little camber -5, Slicks have a much flatter surface area, also was your temp hot or cold ?? and another thing is they look to narrow for your rims which wont help with temps ?

[shimmy]

-3.2 ish is perfect for cups and even wear.

I really need someone with a pyro thing.

Still not done a dry UK track day, managed 4 sessions yesterday, 3 wet, one damp. Car had great grip on Goodyear Eagle F1's.

Billy

matt at tracktoys has all the gear and idea, if you come to a test day with us in the new year you can share his ££ cost

[billyboysm3]

matt at tracktoys has all the gear and idea, if you come to a test day with us in the new year you can share his ££ cost

Donny?

[shimmy]

Donny?

yep, think we will use Donny as our test venue FEb/Mar, we need to test geo and tyres on enew weight and power

[derek]

Way to little camber -5, Slicks have a much flatter surface area, also was your temp hot or cold ?? and another thing is they look to narrow for your rims which wont help with temps ?

using 235 on 9 inch rims which is the minimum width, pressure was 28 hot. What camber would you recommend front and back.

[trackm3]

30-32 hot, -5 on the front -3 rear ?

[derek]

30-32 hot, -5 on the front -3 rear ?

Thanks :thumbs:

[shimmy]

Way to little camber -5, Slicks have a much flatter surface area, also was your temp hot or cold ?? and another thing is they look to narrow for your rims which wont help with temps ?

although quite a lot of Kuhmo guys run narrow 225 on 9 inch rims

[trackm3]

although quite a lot of Kuhmo guys run narrow 225 on 9 inch rims

Not a good practice, better with an 8'' rim, r compounds and slicks rely on wall movement to get to operating temps, if the tyre is mounted stretched it won't move enough !

[cantfind1]

That sort of wear comes from toe adjustment not camber......your left front toe is out....

[derek]

That sort of wear comes from toe adjustment not camber......your left front toe is out....
thanks will get it check, I asked it to be set with 0 toe out/in

[rstoughy]

You doing 7th Dec Derek?

[derek]

You doing 7th Dec Derek?

If your going up i will try and get car ready and have one last outing this year

[rstoughy]

Cool, I'm planning on making it Derek. :smokin:

[derek]

Got car booked in this week for the alignment just ordered pads from martin, so hopefully be there

[derek]

You doing 7th Dec Derek?

Car is all ready but its forecast snow on Sunday.

[rstoughy]

Car is all ready but its forecast snow on Sunday.

Perfect :hahaha:

[billyboysm3]

Hoping for dry track at Snetterton tomorrow. Say suns out but 3*

[shimmy]

Hoping for dry track at Snetterton tomorrow. Say suns out but 3*

You is gonna be slipping all oventhe shop :)

Keep safe Billy and Adem

[billyboysm3]

How did you two get on?

[rstoughy]

How did you two get on?

Id class it as "interesting" that's for sure. By lunchtime you could have built a car with the amount of debris lying around the track. :hahaha:

I will get a vid of a lap or two put together so you can see :whistle:

[derek]

How did you two get on?

I gave it a miss as only had slicks and snow was forecast, couldn't see it being a dry trackday

[billyboysm3]

How were the uniroyals?

[CraigMillwardCroft]

I gave it a miss as only had slicks and snow was forecast, couldn't see it being a dry trackday

You could have used the wife's car :whistle:

[rstoughy]

Tyres were perfect Billy. I stuck them at 32psi cold as they were never going to get hot with sleet falling and 1deg. Was so much more in them but track was just too chaotic.