Page 1 of 3

NC Miata tires

Posted: Sat Apr 12, 2014 11:13 pm
by NaregM677
Time to replace my tires. I'm thinking 225/45R17. I'm looking for something pretty aggressive, with good turn-in. I drive aggressively on the roads and go to track events once every three months. I need something with at least 220 tread life and under $700 for the set. I don't care much about wet performance (sunny southern California) and I want great grip and performance. Any suggestions? I just used up my Pirelli P Zeros. Thanks folks.

Re: NC Miata tires

Posted: Sun Apr 13, 2014 7:28 am
by Brian
What wheel size?

The reason I ask is that putting a 9 inch wide tire (225/45R17) on the stock 7 inch rim will not get you the 'good turn-in' you seek.

Re: NC Miata tires

Posted: Sun Apr 13, 2014 4:04 pm
by NaregM677
For my stock 2013 Club, which I'm fairly certain is 17x7. I found this article from Road & Track and wanted your opinion as well:
http://www.roadandtrack.com/go/news/new ... ck=main_sr

So while the wider tire will give better grip in the corners and stability on fast straights, thinner tires give better turn-in? Does the width also impact steering feel? I love the communication that the Miata provides.

Re: NC Miata tires

Posted: Sun Apr 13, 2014 9:11 pm
by Brian
The stock class autocross guys must stay with stock width rims under the rules, but they can stuff as much tire as they want. The result of stuffing wider and wider tires without giving support to the tires with wider rims (again, because that's the rules in 'stock/street' class), is that we can get more ultimate grip but steering feel does take a nose dive. Watch some of the youtube videos of the oversize tires sloshing around on rims when the ratio of rim to tire is poor and see what you get. Autocrossers make up for the slop as best they can by jacking the PSI much higher, but there is only so much you can do when the tire sidewalls are so far from straight.

I like steering feel, so I go the other direction.....tending to use 10 inch rims for the same amount of tire other guys use a 9 inch rim. So, for example, on track days I have a 255/40 tire on 17x10 despite fact most MX5 guys would put that tire on 9 inch wide wheels,...and I would use 11 inch wide if I could find it! The result of 10 inch with that 255m is that my tire lasts longer and turn-in response is amazing. Look around at the NA/NB track guys and notice more and more put a 205mm tire on 8 inch wheels, and 225mm tires on 9 inch wide wheels....the reason is because it is faster, and MUCH more confidence inspiring to drive at the limit when the tire sidewall is stabilized. Since that tire is NOT sloshing all over the rim you can actually feel what it is doing!

Every choice is a tradeoff. The upside of giving the tire proper support is quick and precise steering and longer tire life and more grip from a given size. The dowinside for stabilizing the tire sidewall includes stiffer ride, more risk of curb rash, etc.

Re: NC Miata tires

Posted: Sun Apr 13, 2014 10:13 pm
by NaregM677
I started off looking for tires but now it looks like I'm looking for tires AND wheels :mrgreen: Well, I guess wheels will be for next time, when my wallet allows. For now, guess I'm sticking with tires that aren't as wide. So any suggestions for 205/45R17? Something fun, grippy and responsive. My time on the track isn't to get the best track time possible but to have fun and improve my skills. Now that you mention it, I'm willing to sacrifice some grip of wider tires to the responsiveness of thinner tires. Should I stick with OEM or do you have a better suggestion?

Re: NC Miata tires

Posted: Sun Apr 13, 2014 11:40 pm
by JamesK383
I wholly support testing yourself before upgrading the car to get to know yourself better. I waited until after my first HPDE and know I'm a better driver for it.

But if you want to play with your tires, I suggest:
1) a performance oriented alignment. This will drastically affect the responsiveness in the way you are seeking.
2) 215 mm tires are cheaper than our stock 205. Understand though wider isnt always better on our stock 7" rims. Wider can stick better but will slosh side to side in wider tires taking away the turn in responsiveness you said you want. That is unless you get wider rims to match the tire.

Re: NC Miata tires

Posted: Mon Apr 14, 2014 11:02 pm
by NaregM677
Thanks for the info, James. Actually, I've done a few HPDE already. I didn't want my car advancing before me which is why I've hardly touched my car in regards to modification. In fact, I've got another HPDE at Willow Springs in May, and I need new tires before I go.

I'm open to suggestions.

Re: NC Miata tires

Posted: Tue Apr 15, 2014 9:13 am
by Brian
Not much fun if you add tires on soggy stock springs and sways. If you add much more stick with the stock suspension it results in even more severe flop over onto the bumpstops, and more squat and dive. But assuming you have added some better sways and springs perhaps sticky stock size replacement on the stock wheels until you are ready for wider rims.

Re: NC Miata tires

Posted: Tue Apr 15, 2014 12:39 pm
by NaregM677
Brian wrote:Not much fun you can add with tires if still on soggy stock springs and sways.
The Club edition comes with the Suspension Package, which includes Bilstien shocks. I'm looking to eventually get the Ohlins Road and Track coilovers and PT sway bars.

Your statement about squat and dive actually makes a lot of sense, thanks. In the meantime, got any suggestions for which stock size tire I should get?

Re: NC Miata tires

Posted: Tue Apr 15, 2014 1:36 pm
by Brian
The Bilstein shocks are softer than standard shocks and all the other bits still soggy soft. To give you some idea of what I mean, the stock springs on the 1990 Miata were about 50% stiffer FROM THE FACTORY....and that was a much lighter car.

But the point I am making is that I have had a few customers add really nice tires and wheels to otherwise stock NC and get results worse than stock because the extra grip just revealed how soft the other bits were and they were tossed onto the bumpstops rather violently in turns, etc. So, got to consider the system as a whole. If you want wider tires, then best to go equally wider rims. Thus, for example, on my wife's 2012 we did just half inch wider 17x7.5 wheels...with 215/45/17 tires (which is 10mm wider than stock tire). And we added Progress springs and some Progress Sway bars. You don't need all of that but I would at least upgrade the springs if doing rubber upgrade.. You would be amazed how springs and/or sway upgrade will get you much more performance from whatever tires are already on the car....because the contact patch of the tire will suddenly be much more flat on the ground.