joeygill

iTrader: (4)

For those of us who track our Z/G's on street tires, I just wanted to get your take on how your tires are holding up at the track.

I have been running Kumho MX (255/40/17) for ~14 track days, and they have started chunking recently, and its slowly getting worse. I noticed the front chunking got worse after I stiffened up my front sways.

So let's share/compare our thoughts on our tires. I'll start, feel free to add more items to the list:-

Tire Brand:- Kumho Ecsta MX
Size:- 255/40/17
Favorite psi:- 47 hot
Mods:- 350EVO sways, Ferodo DS2500 pads
Wear rate:- ~14 track days and ~2000 miles of street driving. They have ~30% life in them (aside from the chunking).
Review:- These tires seem to hold up at the track well, they hold their own and don't get overheated easily on 25min track sessions. Grip levels are high for a tire at this price, but probably a little less grippy than Azenis or AD07's. Tires are loud when driving on street. Braking on these are great, I've pulled 1.6G's on the brembo brakes. Instructors that ride with me always comment on how sticky they are for street tires. Overall, I think these are great starter HPDE tires, but there are better out there.

Stack

I realize this MAY not be what you're looking for in a response...

The MX is an excellent DE tire... but it would be even better if you adjusted you air pressures. 47psi hot is WAY too high. You should be striving for around 40 psi max pressure hot. That's generally the magic number for most HP street tires. 47psi, combined with a stiff front sway bar is probably causing your car to push enough so that you're over-heating the tires, causing them to chunk. Also, 14 track days is a lot to ask of a set of tires on a 350Z. You may have reached their limit.

ForcedZ

iTrader: (2)

Tire Brand:- Falkin Rt-615
Size:- 245/45/17 all around/stock 05 rims for track use/19" for street.
Favorite psi:- 30 hot
Mods:- stoptech 13" front/EBC yellowstuuf pads/Eibach sportlines/Eng mods
Wear rate:- 5 track days, get gressy when real hot out 90+, wear good for street tire, predictable-good feel tire, stiff side walls+
Review:- These tires are good to drive to the track with and then track them. I would still get r-compounds if I didn't have to change tiresonce at the track-maybe later own the line. Good feel but will slide too much when the weather gets hot.

plumpzz

iTrader: (10)

I dont have much to comment, but for those looking for an all-season tire with great handling, the bridgestone potenza re960 AS pole positions are great. I had kuhmo ASX before and these have a smaller width (both were 275/45) and yet are stickier. They did chunk a little on autoX, but they only have 150 miles on them lol.

SinCity350Z

iTrader: (19)

Tire Brand:- Bridgestone Potenza RE050A Pole Position
Size:- 285/30/18 Front 295/30/18 Rear
Favorite psi:- ~34 hot
Mods:- Check www.DoubleDown350Z.com way too much to list.
Wear rate:- 4 time attacks and you can't even tell they have been beat on.
Review:- Best street tire I have ever driven. Grip is unbelieveable for a street tire. Won my class on them at California Speedway .

12AutoX

iTrader: (7)

I am a big fan of the RT-615's too, especially as cheap as they are. The Bridgestone RE050's are getting a lot of positive feedback though. Suprisingly, the BFG KDW's handle track abuse pretty good for a rain tire. They get a little slippery when they heat up, and you can't push them as hard as the dry weather tires, but they beat the snot out of the OEM tires.

laze1

iTrader: (17)

I can't find Falken RT-615 in the right sizes for stock 18" wheels..what sizes would you suggest? no 245-45-18 available

RBlover69

iTrader: (2)

agreed, i seen nothing but amazing review on these tires, i currently have the re50s on the GT wheels setup on the GT 06/07 Zs with the 19s (rays) in the rears and 18s in the front. Since they come with re50s 255 in the front and 265 in the back im thinking of getting re50 pole positions in a 275 size for the rear. For extra grip for my future track days.


btw are any of these events on the speed channel. Loving the website. man road racing is the sht

SinCity350Z

iTrader: (19)

Thanks! Select episodes of Redline TV have covered some of the time attacks and ESPN2's Import Racers did a show about it too. You can watch the Import Racer's show on my website in the gallery section. I don't have any link to the Redline TV stuff though.

joeygill

iTrader: (4)

Thanks Stack. Some of the instructors I talk to say the same thing regarding tire psi's. However, oddly enough, when I run 42 hot the tires grip fall off drastically after about 15mins of lapping. The grip seems more consistent when I run them high, i.e. ~47 hot. This baffles me as well, but ~47 somehow 'feels' better. Also, using the old shoe polish trick, the tires seem to be rolling over just right at this high pressure.

I have not tried as low as 40 hot, but I will the next event.

joeygill

iTrader: (4)

Check this list out ... they don't have the exact stock sizes, but close enough.

http://www.vulcantire.com/azenis_rt615_t.htm

l30thelion

iTrader: (3)

#1
Tire Brand: BRIDGESTONE POTENZA RE-01R
Size: 245/45/17 All Around
Favorite psi:- ~37 front, ~35 rear HOT (should be lower actually, need to keep testing)
Mods: AutoX Setup -> Hotchkis Front Sway Bar and Koni Yellows
Wear rate: They are holding up as well as the Kumho Ecsta MXs but have much better grip.
Review: Very grippy, very stiff sidewall. My favorite of all street tires. They are also
decent in the rain so thats a plus. I'd say they are worth ~0.5 seconds on a 55sec AutoX course vs the Kumho MXs.


#2
Tire Brand: GOODYEAR EAGLE F1 GS-D3
Size: 245/45/17 FRONT, 255/45/17 REAR
Favorite psi:- ~43 front, ~40 rear HOT
Mods: AutoX Setup: Hotchkis Front Sway Bar and Koni Yellows
Wear rate: Incredible wear rate considering how sticky they are
Review: Very, very good tires. Right there between the Kumho Ecsta MXs and the Bridgestone RE-01R.
These tires are awesome in the rain also.


#3
Tire Brand: KUMHO ECSTA MX
Size: 245/45/17 All Around
Favorite psi:- ~44 Front, ~47 Rear Hot (for AutoX)
Mods: AutoX Setup: Hotchkis Front Sway Bar and Koni Yellows
Wear rate: Can't say exactly, but I felt they wore very quickly
Review: Great tire, they break away really slowly giving you time to catch/correct, confidence inspiring.

T_K

iTrader: (5)

If you have the 8.5in wheel, you can probably get away with a 255/40/18. Tire calculator on 1010tire says 255 minimum rim size is 8.5in. Would be about 2.5% difference in overall circumference.

TK

97supratt

iTrader: (61)

Anyone have any experience with toyo t1r's at the track?

RBlover69

iTrader: (2)

my question is, is anyone getting together a damn track event.(south east lol) i havent been to one since pocono (up north),....this is really giving the credit card itch ...man. seriously. lol.

tmak26b

Was at Pocono in May, VIR in September. Glen, Lime Rock and Shenandoah in October. The Z is giving it one last ride before i get a new car

SinCity350Z

iTrader: (19)

Also, I thought I would throw in that the Bridgestone RE01R is actually a little better than the RE050A Pole Position. Its the same compound as the RE050A, but it has a better tread pattern that gives the tire more rubber on the ground than the RE050A. The only reason I don't run those on the Z is because they don't come in any optimal sizes for my setup. I do run them on my Evo though with 265/35/18 all around.

Z1NONLY

iTrader: (2)

Tire Brand: Kumho ecsta MX

Size: 255/40-17 front 275/40-17 rear

Favorite psi: 45 front and 43-44 rear (hot)

Mods: AutoX Setup/: RS-R Ti2000 springs, Hotchkis sways (R=softest F=one hole in from softest. +80%stiffer rear, +48% stiffer front) Quaife differential.

Wear rate: Good. In addition to a few thousand road-trip miles and less than a thousand DD miles, (I don't use dedicated "track" tires) Rears get about 50 runs on autocross tracks. Fronts get twice that when remounted halfway through a season.

Review: Good grip. Nice smooth loss of traction once pushed over the limit, and they love the heat. My last visit to the Tail of the Dragon, I drove hard enough to heat the tires up to about 45psi. (from a cold 37 psi) The tires just gripped better and better and better.....

Stack

These are your friends:

www.motorsportreg.com

www.trackschedule.com

Kolia

iTrader: (2)

Hey Joey,

I’m taking a slight tangent here, I think it might help though. I’m guessing you’ve had Autocross experience before you did driver events? The shoeshine trick isn’t much used on a full race track. If your tires are rolling on their side wall, you basically have an alignment problem. Upping the tire pressure to compensate will do all sorts of nasty things the tire. Including blistering, premature wear and reduced grip level.

Follow Stacy’s advice. A street tire that works for 15 minutes is actually doing very good at the track! Part of the game is to listen to your tire and not work them overt their limit. Take it a bit slower to allow them to last a full session if necessary. Tires will always overheat if you’re over driving them, even R compounds.

Back on topic, I’ve heard really good comment on the track endurance of the Hankook Ventus Z212. You might want to check them out next.