gaius49

I got about 4 thousand miles out my old ZIs before they heat cycled to death. My 195/50/15 R1Rs were good even when bald.

Seefo

iTrader: (5)

^ok, cool. More details would be nice.

soviet

iTrader: (10)

I got a set mounted on 15x8 Gen2 6ul for our lemons car.
Haven't run them yet but the weight, mounted and balanced, is about 32.6lbs. This is pretty light, the Z1 was heavier.

For comparison,


32.2lbs 6UL 15x9 GenII + Worn out RS3 (225/45R15, mounted, balanced)
32.6lbs 6UL 15x8 GenII + New Direzza Z2 (205/50R15, mounted, balanced)
33.8lbs 6UL 15x9 GenII + New NT01 (225/45R15, not mounted, not balanced)
34.8lbs TRMotorsports C1 15x8 + New Direzza Z1 (205/50R15, mounted, balanced)

gaius49

The R1Rs are more progressive, but require larger slip angles to generate the same force. As a result you drive the car fluidly and a little looser. The ZIs were cripser, but less grippy as slip angles increased. Basically the ZIs like a narrow slip angle range and are quite unhappy outside that range, whereas the R1Rs use a broader slip angle range.

I drive the **** out of my tires, normally I get around 8k out of a set. The ZIs were doing ok with regards to tread at 4k, but the compound was dead. They were down on grip and crispness and seriously up on road noise and harshness. They were shot. My R1Rs on the other hand, felt great with mild loss of grip even when the tread was virtually gone.

In short, the ZIs heat cycled to death quite quickly while the R1Rs didn't. Also, the R1R's manners better fit my driving style.

BoostedSmurf

iTrader: (1)

Last year I was running the ZI's and was more than happy with the grip, but I didn't run them too long before selling the wheels with tires still on them and that was on pretty well stock power levels. Now I'm looking to buy another sticky tire to run on the street especially since I will be boosting my NA in the next few weeks. I was considering getting the RS3's this time around but that was before I saw the ZII's were coming out so I'm still a little up in the air about which tire to run.

Leafy

iTrader: (1)

RS3s kind of struggle in the longitudinal grip department, they're easy to spin, easy to lock up, but IMO make more lateral grip than the toyo if you can get the RS3 up to temp. And they're pretty bad in the rain, dangerous in the cold rain. I'm thinking the ZII are going to be the go to tire if you're not terribly concerned about going the absolute fastest on the track (on street tires) but want good street manners.

miatamike203

I got a set of ZII on my NB and love them i have had the RE11s and the RS3. They are like having the RE11s but better in the rain then the RE11.

swimming108

iTrader: (3)

so, what are your impressions so far folks?

I have done 2 autox events and 1 HPDE on these 205/50/15s on 15x8 6uls so far along with about 2k street miles.

~Street impressions~
i am very confident in these tires in all situations except for snow. Wet and dry conditions down to 30 degree air temps never leave me guessing if i will run out of traction unexpectedly. Even in slush they have surprising grip. They seem to be more comfortable than the rs3s and NT-01, but not nearly as comfy as the bridgestone x-ice. They have a little road noise to speak of at lower street speeds.

~Autox~
first autox was quite cold (30-40* day) these tires were some of the fastest and most predictable tires that day.

At the second autox (65-70*) i set my fastest time of the day on my second of my morning runs. after that it seemed that the more heat i got in them the slower they got. i am questioning my tire pressures since i started with 27psi cold. Tires showed a little bluing at the outside edge and a little more wear on the side of the tread than i would have liked.

~HPDE~
This was a very informative event for me since the first day was dry in the mid 70s and the second day was rainy in the high 50s. Started out at 28psi cold for the first session. was shocked at how squirmy they felt after 2 laps. They did not communicate well and were difficult to manage the heat even after backing off for a couple laps. ended the session at 34 psi hot.

Next session i bumped the front up 2psi and the rear 1. This gave me much more confidence in the tires. heat was still petty easy to build up, but it became much more manageable. ended at 36f 35r psi hot

3rd session i added another psi all around. this was still a move in the right direction. I felt that i had a little more overall grip and they felt more predictable. could push the tires for about 3 laps before i had to back down to get some grip back.

Day 2 i left the pressures from day 1 and found all 4 were within .25 psi of 30.5psi cold. It was rainy so i was not able to build up any heat at all. I do not have much to compare to since i have not done any other rainy HPDE events. even at only 8psi from my chinacharger and with the COT wing at -7* AOA compared to the ground level, each corner exit became an exercise in smooth throttle modulation. The grip circle became very unforgiving, but near the end of the 30 min sessions i was able to feel a small amount more traction than i could in the early laps and was able to become a little more confident in them. This car was easily turning the fastest times in my beginner run group.

~Overall~
Great DD tire!!! autox and HPDE i feel put this about midpack with >130 treadwear tires. Just keep your pressures up and manage the heat.

2ndGearRubber

Just mounted up my new 185/60/14 ZIIs, on refinished 14X6 OEM 7 spokes. Went for a drive, and the following are my impressions.


As I observed with the Z1, the tires are fairly sensitive to match-mounting. Each wheel took about 1.25oz total, on a dual plane balance. I did confirm that all the wheels are straight, but as with most "street" tires, they need to be balanced with an attention to detail. They also have a good deal of road noise, about on par with the original model, but at a lower frequency. Comfort, however, was above my expectations. These are not built for your fathers lexus, but they ride fairly well, being what they are.


After a quick drive, I'm very impressed with dry grip. Even with the 185s, I'd put the level of grip as very close to my 205 star specs, on 15x8s. The grip is quite progressive, and once broken away, can be reeled in easily. However, their audible sound (squeal) is very low, so you need to rely more on feedback through the chassis to feel where you're at.


I'll be taking them to an autox event sunday. I built the course, knowing I'd be testing the tires there; so expect more later this week.

2ndGearRubber

Wild event today, rain, sun, even some sleet. Overall average temp of about 50, no dampness stuck around, and all the runs were dry.

The car is a 94 R-Package, with AC. It's running the OE R-Package bilstiens, with an FM front bar.


After fiddling with the pressures a bit, I found 38 front, 36 rear, to be the best spread, as far as grip was concerned. Too much more up front, and the cars' grip became too "on/off" for my liking. Ran out of time to play with the rear () pressures more. The tires had accumulated a hair over 100 street miles, prior to the event.


Anyways, the tires performed spectacularly.

Launch/Braking: As with any stock powered miata, it's tough. Launching above 3500 usually ends with a bit wheel spin, but it's manageable. The tires stick well enough to induce a good amount of wheel hop, and I didn't try above 4000, for this exact reason. The longitudinal grip is very good, and you can really slow the car down in a hurry, despite the small contact patch.

Slalom/transition: Despite the tall sidewall, the ZII really shined in quick response. Very predictable, you can really feel the slip angle through the wheel.

Steady State/Sweepers: As good as the grip is, there is a downside to the ZII. This is a very quiet tire, and unless you're over-driving it, don't expect any feedback you can hear. Most of the feedback you get about slip angle, is through the steering wheel. You can work them at a good slip angle, even when you feel the tires trying to skip out in the front, the car just keeps turning.


Overall: