mx5cartalk.com

Am thinking about going to full slicks
most likley 15s, I'm doing hill climbs and track days
NA6 with plenty of suspension mods but standard engine so not much power
Already have semi's but want more grip
Anybody have any recomendations ?
What brand, width and where to buy (Sydney area )
Olboy

For hillclimbs the slicks may not be the best as they need quite some time to generate heat and therefore grip. For trackdays the slicks may be ok but do keep in mind at somewhere like Wakefield you are looking at 2 odd laps to get some heat in them and not really up to temp for probably 3 or 4 depending on the day. A MX5 is so light that the majority of temp will be generated by the brakes rather than the lateral load and a std NA does not have very big brakes.

Perhaps come to a MX5 club track day and have a chat to a few people about what they have done.

What sort of diff do you run??

Do your class rules allow slicks?

If they do, you probably also need engine mods to be competitive. How much time do you need to make up?

I totally agree with 'mx5racing' - I ran slicks on my rally car in the uk when I did track days and you have to work them pretty hard to get heat into them. It will depend on the compound you are using, but from cold it can get pretty scary pushing them to generate heat, but with relatively little grip.
Si.

If you can afford it, the hot ticket is a set of soft compound tyres for hill-climbs. With no warm-up at all, the soft compounds give a big advantage. Special soft compound grooved tyres would be the best option, as they could also be used in the rain. Toyo sells small numbers of soft compound tyres, usually on advance order.
Special soft compound tyres for hill-climbs are usually too soft for dry track days, and overheat, although they make perfect tyres for wet conditions.
Most slicks and semi-slicks run an "all-purpose" tread compound that works well over a wide variety of conditions and does not over-heat easily, but needs time to warm-up, especially on lighter vehicles like an MX5.

What times are you doing at Eastern Creek and Wakefield Park? A modified road registered NA6 can do 1:56s and 1:13s, respectively, on R spec semi-slicks (Tony Williams at NSW Supersprints). If you're slower than that then perhaps you should be asking "how can I drive circuits faster" rather than "what slicks should I buy because I want more grip". Slicks will bump you to a higher class if you're competing in supersprints, so you'll probably be even less competitive since those cars are usually unregistered race cars with far more done to them than what you have. If you're not trying to compete, then you'd have to ask yourself why you'd pay all that extra cash on slicks just to have a bit of fun on the track.

I am with Steve, - as far as hillclimbs are concerned. Don't even think about using them for a track day or race, unless the track is seriously wet.

Re-reading your post, you are presumably not running in a standard class with 'plenty of suspension mods', so you will need to complement grip with power mods to be competitive. Guran, that is a Type 1 car?

greenMachine wrote:Guran, that is a Type 1 car?

Tony's NA6 is a Type 2 car, so limited mods and road registered. Tony has done LSD, coilovers, swaybars, some underbody bracing, intake, ECU, adjustable cam sprockets, etc in addition to the stuff I'm allowed to do (see below). I think he's still got stock brakes.

Mine is a Type 1 car, which is standard road registered. The only mods I'm permitted are rollbar, seat, harness, R-spec semis, brake pad material (not size), clutch linings, etc.

So Tony is doing 1:13s and 1:56s while I'm doing 1:15s and 2:00s, at Wakefield and EC respectively.

My car is realy a type 2 I guess but because its unregistered it bumps me up a couple of clases.
I haven't run it at Eastern Creek yet but have done a 15.15 at wakefield a while back
I thought if there was 1&1/2 to 2 seconds between semi's and full slicks then it would be worth it

olboy

Slicks are worth about a second versus semislicks but you'd only see that if you're using your semislicks to their full potential. You've still got two seconds to improve on before you'll reach that point. 1:15.15 is possible in a Type 1 (stock) NA6 on semis. I reckon you're better off investing in more track time. For the moment anyway. Have fun!

olboy wrote: I haven't run it at Eastern Creek yet but have done a 15.15 at wakefield a while back
olboy

Guran wrote: I reckon you're better off investing in more track time. For the moment anyway. Have fun!

Whole heartedly agree with Guran, especially the ‘have fun bit’. Without doubt the best way to improve times is to improve your driving by doing more laps.

Until you "hit the wall" with your times, where there is no improvement after a number of meetings, there is absolutely no reason to consider fitting slicks.

1:15’s around Wakefield’s not too shabby in a NA 1.6 but as was pointed out, the quick boys in road registered cars are doing it 2 seconds quicker running R-spec tyres, so that’s the time to aim for first.

Then if you fit slicks you’re up against the likes of Peter Browning with his stripped out windscreen less highly modified NA and need to get down to the 1:09s!!!

Oh and I forgot to mention. Get that watering can out because that money tree down the backyard will need to start growing.

I have Kumho soft compound tarmac rally tyres I use for wets...reckon they would be good for hillclimbs, they were on special when I bought them.

Boyracer wrote:I have Kumho soft compound tarmac rally tyres I use for wets...reckon they would be good for hillclimbs, they were on special when I bought them.

lou! what are u doing on mx5cartalk? enjoy your holiday will ya!!

Fanta (NA 1600 race car) is now sold, but my best time on semi-slicks (Kumho V70A) at Wakfield was 1.10.0 with the best on fresh medium compound slicks at a track day was 1.09.25. I was only using Konis yellows with kings springs (not height adjustable) so could probably have got a better setting for slicks with a better suspension.

I used Dunlop cross ply slicks on 8"rims which worked well for sprints on a good day - came up to temp quickly, but I don't know if they are still available. Radial slicks took too long to get to temperature at track days.

At the Canberra hillclimb I could not get temperature into the front slicks, so used semis on the front and slicks on the rear (a good burnout warmed them up). Specialist hillclimb tyres (most seem to run Avon) would have been quicker but I could not justify the cost.

You also need good horsepower to get the best from slicks (Fanta had 93 RWK from the 1600) as you can get too much grip which can actually slow lap times (ala go-carts).

I went from slicks back to semi-slicks partly due to cost, but mainly due to versatility as you rarely get a perfect day at Wakefield so slicks were rarely at their best, and useful life seems to be better on semis as full slicks have limited heat cycles. It would be a different story if I had been running full races.