theduck
|
| posted on 13/4/12 at 03:00 PM |
|
|
Question about slicks
I'll building a Robin Hood S7 to use on track days, and as it will be towed to and from events I was going to use slicks as this should
theoretically give the best performance on track.
I have never driven an S7 and it will have been a long time since I drove a 7esque car at all, and because the car will not be road registered, I wont
really be able to do any testing/proving before taking it to its track debut. I have also never driven a car on slicks, in fact I havent driven a car
on anything better than sticky road tires, which I have done a reasonable amount of on track.
If I went out straight on slicks, will they potentially mask other setup issues? or will any setup issues be made more obvious because of having
slicks on instead of decent street rubber? Really what I am asking is, should I just buy slicks as that is what I intend to use, or due to my lack
of experience with them and the car, would I better on street rubber first and then change to slicks at a later date?
This question was far harder to word on here then it was n my head...
|
|
|
|
|
CNHSS1
|
| posted on 13/4/12 at 03:16 PM |
|
|
lots of Qs there, will have a go at answering.
firstly are they crossplies or radials? lots of both in 13"
if crossplies, you want 0-.5deg static camber and very litle toe, as near to zero as poss generally.
if radials, they love camber and you can go silly, 3-4deg isnt uncommon.
You will need to set camber as part of the setup, generally use an infra red temp gun and check inner shoulder, centre and outer shoulder temps. All 3
should be indexed, ie close in range. If centres way high, too much pressure when warm, if inner shoulder high, then too much camber etc etc
as for the way they drive, thats a big question. generally a well set up car on sticky road tyres such as List 1Bs, R888s, A048Rs etc etc , will end
up being a little soft in springing and damping when fitted with slicks (huge generalisation before the 'warriors' bite ;-) so if it has
'road' tyre springs/damper settings, may be way off
also compound makes a big difference. if 5years old and a hard compound, they will take a number of laps to get up to temp. Generally you
under-pressure the tyres when cold so that they come up to pressure when at operating temp. Wehn cold and under pressured, they are pretty
'orrible to be honest. When warm they come alive and are wonderful (setup dependant blah blah)
if you are picking up cheap slicks and just caning them on track, they are a good budget option, but with some time, effort and thought they will
transform lap times, even 2nd hand ones
HTH
CNH
[Edited on 13/4/12 by CNHSS1]
"Racing is life, everything else, before or after, is just waiting"---Steve McQueen
|
|
|
coyoteboy
|
| posted on 13/4/12 at 03:17 PM |
|
|
Good question that I won't answer but I will say slicks will be mind-bogglingly better gripping than normal road tyres. Mindbogglingly. Even on
a poor setup prototype car.
|
|
|
blakep82
|
| posted on 13/4/12 at 03:19 PM |
|
|
what are you expecting to achive on a track day? its not a race, you won't win anything for fastest lap times or winning, so put them on, take
it easy to start and see how you go! 
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
|
|
|
mark chandler
|
| posted on 13/4/12 at 03:53 PM |
|
|
I just popped some on my car, they are great (only in the dry)
Grip better, breakaway on the limit better cost longevity also great.
They will put more load into everything, as for the sience of setting up... I just twiddled with camber so they are at the same tempreture on both
edges, then added/removed air so the centre was the same heat as the sides.
First couple of laps nice and gentle to get some heat into them, followed by flat out 
Mine gain around 4 PSI, so start off at around 12PSI on my light BEC.
|
|
|
adithorp
|
| posted on 13/4/12 at 03:55 PM |
|
|
Is this going to be your only wheels? If so are you just not going to run in the wet or even damp ? That could leave you set by watching at quite a
few track days or are you just very brave and going to go for it anyway?
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
|
|
|
theduck
|
| posted on 13/4/12 at 03:55 PM |
|
|
CNHSS1 thank you, that answers my questions perfectly.
Blakep82 I've done enough track days to know that, just want to maximise my car for what's being built for.
|
|
|
theduck
|
| posted on 13/4/12 at 04:16 PM |
|
|
quote:
Originally posted by adithorp
Is this going to be your only wheels? If so are you just not going to run in the wet or even damp ? That could leave you set by watching at quite a
few track days or are you just very brave and going to go for it anyway?
Will have something for wet conditions but not decided what yet.
|
|
|
CNHSS1
|
| posted on 13/4/12 at 04:30 PM |
|
|
if the cars optimsed for slicks in the dry, then swapping tyres for wets wont make the best of the 'wets'. really need to soften the car
up to get some body roll, usually drop off the anti roll bar drop links (if you cars fitted with AR bars), and if its slashing down all day, raise the
ride height a bit.
if its just damp or even wet but with no standing water, slicks work the best in my experience anyway. You have to be a little more gentle with the
loud pedal and brakes, but you will lap fastest on decent slicks (not 10yr old rock hard jobbies...) in the damp/mildly wet.
if its wet enough for wets, i leave my car on the trailer, no decent times will be done that day. Different on a track day of course, so soften setup
and away you go.
another tip with wets is to not under inflate them in the wet to try and induce more grip, it doesnt work. The water keeps the carcass too cool, so
you dont get the static to operating pressure increase anyway, so the carcass stays a funny shape, primarily running on the tyre shoulders. Often a
couple of psi MORE than your normal slick operating (not cold pressures) allows the carcass to become more rounded and opens the tread blocks up a
little too, which helps to dissipate the water.
pic of mine in the pi55ing rain at Castle Combe... on slicks
[Edited on 13/4/12 by CNHSS1]
"Racing is life, everything else, before or after, is just waiting"---Steve McQueen
|
|
|
kjouk
|
| posted on 13/4/12 at 06:52 PM |
|
|
quote:
Originally posted by CNHSS1
generally a well set up car on sticky road tyres such as List 1Bs, R888s, A048Rs etc etc , will end up being a little soft in springing and damping
when fitted with slicks (huge generalisation before the 'warriors' bite ;-) so if it has 'road' tyre springs/damper settings,
may be way off
[Edited on 13/4/12 by CNHSS1]
This advise is well worth taking seriously, running road tyre setting was OK but significantly increasing front spring rates really helped make better
use of slicks. I traded the higher springs against weaker ARB settings to keep balance.
|
|
|
theduck
|
| posted on 13/4/12 at 08:29 PM |
|
|
Car has 180lb springs up front and Sierra arb, not sure on rear. I know that is deemed too stiff by those running these on road and they tendrindrop
to 120lb springs and change to tie bars.
|
|
|
MikeRJ
|
| posted on 14/4/12 at 05:53 AM |
|
|
Be very wary of oil surge when running slicks, a car that was previously ok on road tyres can become an unreliable nightmare on competition tyres.
I have to wonder why you'd bother with competition tyres for a track day anyway, they are expensive and don't last long.
|
|
|
