17's or 18's for track use

[Black BNR32]

Both of those are too large for a REAL slick



I'd say 18s for clearance for some proper brakes. I'm guessing the weight penalty will be negligible for your application.

[Dragon Humper]

Why is that? I was under the impression that smaller/stiffer sidewall resulted in less tire roll/flexing in corners

That only works on an F1 class, smooth as glass track. 90% of the other tracks around the world are rough as hell. More sidewall will make the car less jittery going over some rough stuff mid corner. Tire construction and suspension setup play a role too. More sidewall will protect your wheels a little more as well when you hit something (I guarantee you will). If you drove your car back to back on 17s then 18s and then went back to 17s you will wonder why in the hell anyone would want big hoops with a short sidewall.


Jon.

[Skym]

I found out from trial and error that it's the design of sidewalls that makes the difference. When switched to BFG tyres they made a big difference to reduction in bodyroll (flat / straight looking sidewalls, similar to F1 tyres, instead of curved that you see on most tyres) vs the rounder Falken sidewalls, but ride comfort was harsher with BFG tyres.

[Fred-R]

the question that no one seems to ask is ;

do you really need slicks?

i mean, how much track experience do you have, have you already maxed-out the car's potential?
you could simply run a set of sticky max performance tires (star spec ; ecsta xs ; ad08 ; re01r ; azenis ; nt05 ; rs3) all the time

i'm going to take myself as an example here,
i've always run max perf tires on the car, my daily tires, saves me the hassles of buying another set and changing them at the track
performance? well i've pretty much learned the very limit of my car in the past 2 years, maxing out its potential, and guess what, i rank in the top "street" drivers while beating half the "race tire" field at local time attack events
wear? well i've done 2 summers or about 18,000km with about 14 track days, and my Dunlop StarSpec are still good for at least another 3,000km

so again i ask (because i don't know) how much track do you do, at which level are you, and do you really need slicks?

now, if by "track" you meant "auto-cross" or "auto-slalom", then forget about what i've said and run massive slicks because thats what you need for those types of competition

you're right Franki, with that said, I won't use slicks for a while...

[MarusGTR]

...any reason why I haven't seen anyone talk about the sidewall load rating yet? I went with RS-3s because their rating for the 255/17 was way above the rest (even if there's no direct correlation between brands, it was close to 100 compared to the others at low 90s and offered a better thread pattern)

[sb119]

the question that no one seems to ask is ;

do you really need slicks?

Good point! I've read through all the tire threads on here since first posting and I definitely don't need slicks for lapping days. I get a deal on Toyo so probably going to run R1R's or R888

[Skym]

the question that no one seems to ask is ;

do you really need slicks?

i mean, how much track experience do you have, have you already maxed-out the car's potential?
you could simply run a set of sticky max performance tires (star spec ; ecsta xs ; ad08 ; re01r ; azenis ; nt05 ; rs3) all the time

i'm going to take myself as an example here,
i've always run max perf tires on the car, my daily tires, saves me the hassles of buying another set and changing them at the track
performance? well i've pretty much learned the very limit of my car in the past 2 years, maxing out its potential, and guess what, i rank in the top "street" drivers while beating half the "race tire" field at local time attack events
wear? well i've done 2 summers or about 18,000km with about 14 track days, and my Dunlop StarSpec are still good for at least another 3,000km

so again i ask (because i don't know) how much track do you do, at which level are you, and do you really need slicks?

now, if by "track" you meant "auto-cross" or "auto-slalom", then forget about what i've said and run massive slicks because thats what you need for those types of competition

But that's your car, with suspension setup to match tyres. It will vary amongst cars based on the suspension setup their cars are running, as some will break traction early when cornering with light loads, some with higher loads, etc when running the same tyres. If suspension is set correctly and there's no loose parts on car that affect's alignment, alignment is set correctly, the grip limit's will be alot higher (take higher loads, speed to break traction).

Also alot of people don't realise you need to strengthen chassis with rollcage to run the higher spring rates to suit the semi slicks or slicks. If don't run a rollcage, could stuff the chassis (it twist's under load) and alignment is probably going to be affected which affect's grip.

If you don't believe me about the twisting, jack up car on front jack point and then try and open, close door. Fit a rollcage and do the same and note with rollcage that chassis twist's alot less (it still twist's, but takes higher loads on racetrack to make it twist).

Twisting usually happens alot around the bottom of firewall to front strut area (why Nismo reinforced that area with carbon fibre on R34 Z-tune that doesn't have a rollcage but higher spring rates). Behind rear seats is another area (why Do luck room bar or I think Ultra Racing sell a similar brace can reduce chassis twisting by alot, especially when doing the jack up at front jack point trick to check twisting of chassis).

I have strengthend this area on my car and chassis rigidity was increased, chassis twist's alot less.

That's why Ultra Racing braces (or similar braces from HKS, Do Luck, etc in Japan), etc are worth it (to increase chassis rigidity) if don't run a rollcage -

http://www.ultraracing.my/catalog/index.php?id_category=324&controller=category

[bobbo]

^^ yup ^^

[MarusGTR]

^^ yup ^^

You nearly flying out of my unhinged door can attest to chassis flex on the track :P

[Marke]

Frank's advice is sound. A good extreme performance street tire will do fine for track days. Don't go for the r888, because they will wear out super fast. They are an R-Compound. I would go with 17x10 wrapped in 295/30/17's for track use.

Lower profile side wall = stiffer more responsive tire and maintains better contact patch during cornering. Trade off is poor ride comfort, but ride comfort is for pussies who put performance 2nd.

[bobbo]

^^^you don't need nearly that much tire for so many reasons^^^

[Dragon Humper]

Tire AND wheel, talk about rotational inertia turning your front wheels into giant gyroscopes. I wouldn't run more than a 17x9 with a 255/40 to both keep the weight down and give some decent sidewall to bounce the car off of the rumble strips. You can tune sidewall stiffness with tire brand and construction. Look at what most of the hard core GT and Super GT (V8 Super Cars for you Skym) cars are running, you won't find gigantic, ubber short side wall tires, they are too fragile.



Jon.

[bobbo]

^^^ Thanks for the back up. I was too lazy to type any reasons out.
I used to run 255/35/18s. We put a GoPro on the fender and when I saw how close my rim was to hitting I went to 17s.

[Terrh]

275/35/18 Continental Slicks are CHEAP and abundant used. I'm wanting to go to them from my 275/40/17's that I run now.

What size to run really depends on how fast you want to go. R33's can probably fit 305's all around, R32's and R34's can for sure with some massaging.

[Redone]

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