firebirdfan

I've recently picked up a 99 FRC that I'll be using as a new Autocross and street car. At this point, the car is 100% bone stock. I need new tires, and I'd like to keep the factory sizes for the time being so that I don't mess with any of the geometry or weights before I can get the thing aligned and corner weighted as a baseline (I have my own scales). I also like to keep my speedometer accurate.

I only want to go as low as 200TW, as this thing is driven on the street quite often. Tires like the NT01 are out of the question as they'd be completely bald by the middle of summer. I'd like these tires to last about a year.

I will autocross this car about 2-3 times a month with the local club and some pro-touring guys. I will drive it to and from every event (I'm not rich, I don't have a truck and trailer to haul with). I don't plan on doing track days, but they aren't out of the question.

At this point, I'm considering the RE-11 and the MPSS. The MPSS is the talk-of-the-town tire right now. Everyone seems to love it, but I don't know how it stacks up against a more "aggressive' tire like the RE-11. I also can't find many reviews of the RE-11 that are autocross specific.

I'm not concerned about rain. If the craptacular NT05s that I had on my old 1994 Mustang don't hydroplane in heavy rain, then either of these tires are going to do just fine.

The cost of the two sets are within $20 of each other ($900 vs $920).

Has anyone tried both tires? The only review I found was a Tire Rack video about a pro-touring car that compared a bunch of tires, and the MPSS was about a second or so quicker than the RE-11.

http://www.tirerack.com/tires/tires....e&autoModClar=

http://www.tirerack.com/tires/tires....e&autoModClar=

Xian

If you're aiming for a 200TW autocross tire, I wouldn't recommend either of those. There's a pretty decent thread here with a good rundown of the current (and future) tire options:

https://www.corvetteforum.com/forums...questions.html

Or if you don't want to read through all that ^^^, check out the Dunlop Z2 Star Spec, the Bridgestone RE-71R, the Hankook RS3, and the Rival-S once it's released.

firebirdfan

I'm well aware of the plethora of tires available, however, every single tire you just listed doesn't come in pairs for the factory sizes. They might fit either the front or rear size, but the opposite one is going a weird size.

Honestly, most of those have the front tire, but there rear is a hard one to get. Downsizing the rear to a 275-35-18 nets quite a few choices, but then the rear tires are smaller (diameter) than the fronts. Then I have to downsize the front tire in either width or aspect ratio to get them to fit.

And then my speedometer isn't accurate anymore and that is something I'm trying to avoid until I have a handheld tuner or other software to reprogram it (if it's even possible).

dhowdy

Well do you care about being competitive or not? You're looking at ~4% difference in diameter, it's not really a big deal. You should just run 255/40R17 and 275-285/35R18 in one of the three tires he mentioned.

Xian

IMO, you're making a mountain out of a molehill in regards to the sizing differences. If it were me, I'd be looking at a 245/40 or 255/40 front with the 275/35 rear. That nets you a couple really solid options right now with more (possibly) available later this year.

If performance is more important than non-factory sizes, go with the Bridgestone/Dunlop. If factory sizing is more important than performance, go with the RE-11's.

Just my $0.02, YMMV, smarter minds may have other options, etc.

Edit & PS:
You could also do a 275/35 19 at the rear to get roughly the factory diameter.

firebirdfan

The 275/35 and 245/40 both drop approximately an inch off the diameters, but keep the ratio the same. Opens up the RE-71R, Z2SS, and RS3V2. Again, the speedo is now inaccurate, but the TC/AH system should be okay. Looks like I can get a Hypertech for about $200 to fix the speedometer. Cheaper than I thought it'd be. Figured you need LS1edit or some other editing program to fix it.

The 275/35 19 isn't happening. That requires new rims, and if I put rims on, I'm getting 18x10.5" rims and going with a square setup. This is the ultimate goal, but I'm trying to avoid spending $2800 right off the bat with the car. Modding is addictive and I've gone down that path before. I'm trying to keep things simple for now.

dhowdy

Are you running with SCCA? Don't reprogram your speedo if you care about classing. You're talking about a 2-3mph difference at highway speeds, it's just not a big deal.

Stock C5Z wheels will be much cheaper than 2800 for a set and are a good option.

firebirdfan

Don't care about the SCCA at all. The local club uses their rules for classing and regulation, but their not SCCA affiliated. Any SCCA autocross club is 2 hours (or more away) and would cost me 3x as much just to show up and register, not to mention the SCCA membership. The local club gets as many runs in a 3 hour night series as you might get all day at some of these other clubs.

I also run with some pro-touring guys at their events. They're stupidly cheap and you get more runs than you could ask for. The only thing, is that they require treadwear to be no lower than 200 if you're looking to place and/or win prizes.

As for the $2800, that's the price of rims and tires. Just the tires this year is gonna cost about $900. I'll look at upgrading the rims next year (maybe).