joelster

I raced my first autocross last Sunday (came in 2nd). My Z originally came equipped with Trofeo R's which are a TW60 or something, but I bought the car with Potenza's which are currently a TW140. They let me slide because it was my first time, but told me if I were to win then they'd either bump me to a tougher class or force me to change tires. Next event is July 15th so there's plenty of time to make the switch.

I was told that the Bridgestone Potenza RE71 is a great TW200 tire, but I've only heard from a few people. I'd like to hear some more opinions especially guys that have run several different brands. Either way they're crazy expensive in my size 305/30/19.

Mojave

iTrader: (4)

RE71R and Rival S are the hot tires right now. Bigger is better.

BassAckwards

Chrisingermany

I've been using the Rival S for a little over a year now (315x30R18 on all 4). They are great tires but they wear super fast (like all 200TW will). They are stamped 200TW but realistically are probably more like 150ish. I am due for a new set and that sucks because they run like $1,600 before mounting costs.

joelster

Thank you guys! They are crazy expensive due to the size I have, 305/30/19. I'm probably going to get an extra set of wheels for track use only.

I thought drag racing was expensive lol

EDIT: I just looked and apparently they don't make the Rival S in my cars size yet. Bummer.

landstuhltaylor

iTrader: (6)

This is not true.

landstuhltaylor

iTrader: (6)

It is coming this year, just no date yet.

Chrisingermany

You're right, probably closer to 100TW....

landstuhltaylor

iTrader: (6)

Clearly you don't understand the measurement. Should probably look into that before posting misinformation

Chrisingermany

All I am saying is the manufacturer assigns the treadwear ratings that are not controlled by the government. So if they are advertising to a particular group of people (auto-x) they will meet the needs of the masses (200TW). Treadwear numbers are very subjective.

All arguing aside any 200TW tire will not last very long. Just be prepared OP.

BassAckwards

Chrisingermany

That's what I was trying to get at so thanks for putting it that way. It would be nice if the treadwear ratings had a true measurement stick to go off of between the different manufacturers.

smitty2919

TW rating is also measured based off how many people run them what the 1st place people are using. If a company can dupe the industry putting a 200TW stamp on a tire that is more like a 100TW tire, people will run them until someone complains that the tire is "unfair" at which point they will ban that tire. I believe SCCA banned the factory Viper ACR Kumho tires.

Rival is your best bet in a wide tire since Bridgestone does not come in a 315/18. Expect to spend about $1000+ on new or $300-800 for used.

Oh and get rid of the 19" wheels.

joelster

Why get rid of the 19's besides being an oddball size? I honestly don't know if 18's will fit for sure. Some guys say you have to trim the steering knuckle on an SS to get them to fit in front. I'd imagine I'd have to do the same on my Z, but I don't know if the 18's would clear the brakes either.

EDIT: front rotors are 15.5", and rears are 15.3", figure the calipers overhang 1" or so.

smitty2919

Waiiiiit. What car are we talking about? You have a '94 Z28 and a '15 Z28 in your signature. I assumed we are discussing your 94, but I feel my assumption is wrong.

If discussing a 5th Gen Z28, I don't know what will fit on those. You can get a hold of JDP motorsports (Jordan Priestly) who ran 5th and 6th Gens heavily in Optimal etc events.

LT-4Play

iTrader: (1)

Always take a look at the specs of the tires you are considering, in the case of the 305/30-19 the Hankook RS-4 has a tread width of 11.4" compared to 11.1" on the RE-71R.

Just like treadwear ratings, the actual tread width is at the discretion of the tire manufacture, the actual tread width on all of the available options may be as much as 1" to 1.5"!

The fastest guys usually figure out which one of the cheater tires runs the widest and figure out a way to make it work. We did this in NASA before they came up with their own way to measure actual width.

In some cases a more narrow tire will be faster due to a better compound, but more often than not width trumps compound - as long as the compounds are close (which 200 treadwear tires should be).

joelster

I don't have them mounted yet, but a quick measurement looks to me that they are 11.5" for tread width. My tires right now are RE 050, but 2 of the instructors (pros) at the last event said that the RE 71's are better.


^^^That is the run that put me into 1st place briefly. The Porsche Cayman you see in the background in the beginning ended up beating me on the last run.

joelster

4' 3" of rubber

Slick68

iTrader: (7)

My buddy, Danny runs the 305/30/19 RE71R on his 68 C10. With some simple Ridetech and homemade suspension upgrades, he's upset quite a few people on the autocross courses. He came in 5th place overall at an event last year against some heavy hitters. The Rival is highly publicized, especially at the events I usually attend, and it's a great tire, but most people I've talked to say the RE71R is a serious tire. A buddy from California said there's a guy that shows up in a foxbody with simple suspension mods on a skinny 245 or 255 RE71R and holds it's own against fully prepped cars with wide tires.