Tire recommendations

[gbmidyear66]

Good to know 4-Cam.

I've decideed to go with the Nitto as well. Was originally thinking of the Veredstein, but Nitto seems to receive consistently good feedback.

Did you go with 315 or 335 on the rear?

[4-cam]

I just went with the 315. I did not see a 335 available in the 555 on the Nitto website so I did not even ask.

[-=Jeff=-]

apparently D3 are available again

http://forums.*************.com/c4-z...ble-again.html

[xlr8nflorida]

Nitto 555R's only come in 315.

They are narrower but they grip great.

They are drag radials, I hear they are better then most in rain but I'm sure they are scary.

I don't drive my Z in the rain so its not an issue for me.

On my Vettes that see rain, I have GSD-3s.

[A1990]

Originally Posted by -=Jeff=-

apparently D3 are available again

http://forums.*************.com/c4-z...ble-again.html

Really?

[A1990]

I wonder when they are going to stop making these? Seems like GY could charge about whatever they want for them. As soon as they become available they are bought up.

Heck I run 18's but I bought 4.

[batchman]

Having run several of the mentioned tires at one time or another I'll chime in with a couple data points. Sorry if it's turned into a book!

Bear in mind I'm an autocrosser. I spend as much time as possible in slip angle. It's what weekends are for!

I had several sets of Sumi HTRZ-2's on my 99 Cobra, liked them a lot wet or dry. Very sensitive to air pressure - run recommended pressures and they're docile, cushy even. Not crisp turn in but quiet for 3/4 of their life and very good in the wet (these were 245s, the 275s seem similar but the 315s are different). Aired up and not-too-much heat they worked very nicely. For those that don't know the company (I didn't), at the time they owned Dunlop and cross licensed manufacturing with Goodyear (meaning most US Sumis were made by GY and most Euro/JP GYs were made by Sumi).

On the same Cobra I went through many sets of Kumho Ecsta MXs, which are the predecessor to the XS. This tire loved heat and all the abuse you can throw at them but would go square sitting overnight, and were very greasy for the first 500 miles until you wore off the mold release agents. Conclusion seems to hold true for the XS as well, again much air and almost as much heat as a race tire. OK in the wet down to about 1/2 tread, got noisy then too.

Ran a couple sets of Nitto 555R2 in drag radial and non-drag radial. Nice enough street tire with softer compound, worked reasonably cold to mild heat. In reality they're neither fish (street tire) nor fowl (race tire).. I kept them around for early spring/late fall events when you knew you weren't going to get enough heat in the slicks and/or you saw enough wet to be "beyond a sheen". Not sure about the non-R compound, guess I'd expect it to be slower and more forgiving than the XS. Note these turn square after sitting a few days too. 5 minutes (or more air) fixes that.

The GS-D3s were OEM on the 03/04 Cobras, many of the guys I ran with liked them well enough (and they got high marks for wet) but they pretty much all migrated to faster & cheaper tires after a set or two.

FWIW the new hotness in street tire autocrossing amounts to Toyo R1R and Dunlop Star Spec, I've not looked to see which are available in 275 & 315.

On our Z I really only run Hoosiers so can't say so much about c4 street manners, the rim protectors I use are just to get back/forth between shops/inspection and distant events . But I found with all the tires I've used "in anger" they all prefer different pressures, temperatures, and alignment tweaks to get the best out of them. For street with weather and novice event work I'd save the $ get the Sumis and remember a little cheapie compressor for track stuff. Next choice for the same duty would probably be the 555s, the later Nitto NTs don't have enough sipe for weather IMHO.

PS none of the above performance tires are worth a tinker's damn below about 50 degrees. Also it does not take much mileage with abuse or alignment issues to wear a tire into behaving badly - I had to get religion about rotation and flipping on the wheels. I'll guess that could have been a part of 4-cam's Sumi problems. And I should note that it's taken me 10 years of multiple sets a year and much experimentation to learn what the dynamics are telling me a tire needs in terms of alignment/pressure etc and even then it's successive approximation.

I should also throw in that the OEM alignment specs for C4 are hideous and the performance difference to be found in just that is profound. Of course I should add that if anyone tried to transport either of our c4s (88 z51, 91ZR-1) on a worn-in road with our event setups they would pronounce them undrivable in 1/2 mile or less - keeps you alert!

Thinking back to the 70s, all these tires are freaking amazing. YMMV!

Cheers,
- Jeff

[Aurora40]

Originally Posted by batchman

FWIW the new hotness in street tire autocrossing amounts to Toyo R1R and Dunlop Star Spec, I've not looked to see which are available in 275 & 315.

Neither are available in ZR-1 sizes. The Star Spec is only available in fairly narrow sizes, I think about 265 max.

The Toyo R888 is available in stock sizes, as is the Kumho Ecsta XS. It's hard to imagine either of those being very good in the rain, just from looking at them. But who knows.

[bldavis11]

Originally Posted by GTOger

The wife and I are planning a road trip (Dallas -> Las Vegas -> Dallas) in the spring. We're prepping the ZR-1 for the trip. One area I'd like to think about are the tires and wonder about recommendations from the group here. Here are my considerations:

• The GSC's on the car are older. They don't show any signs of rot, but I've been down the old tire blowout road before, and I'm not anxious to do it again. I'll be most comfortable with new shoes.
• Our Z will spend most of its time on the road. Maybe once or twice a year to a track event. So priority is overall comfort over max performance. These GSC's seem awfully noisy and if there's something quieter out there, it's worth a look.
• Money is an object.

I understand the Goodyear Eagle F1's are pretty popular, and Kumho seems to make a good ZR-1 tire.

Tire Rack is selling something called the Sumitomo HTR Z for $490/set (as in, all 4 tires). Being that's less than what I paid for new meats on my pickup truck, I'm both interested and skeptical, but it's almost worth it just as a test.

Thoughts and input welcome.

I've had the michelens and sumitomos on the car. Sumis are on there now. For what I do, weekend / date night driving in mostly good weather (though I'm not afraid to ride in the rain), they are great. I'm not engaged in "spirited" driving when doing so, but I'll punch the gas and ride the grin when I want. The tires are just fine. They need to warm up, but after driving the 1.5 miles from the back of the neighborhood to get to the main road, they're ready for highway driving. For $500, you can't beat them.

When I had mine road force balanced, they came out just fine.

I would totally buy again. For the money and what I do, the tires are going to dry rot before the tread goes bear.

[JThomas]

I currently have the Khumo tire on my '92 Z. I have found it to be good in the rain and better in the dry. As far as noise goes, well it's not as noisy as the Goodyears on my Z06!