I guess I'm hoping a Chevy dealer would have the proper equipment/experience to service a product they sell.

 

I do have a Belle store locally. If I have a problem with Chevy, I'll call them.

 

I find the C7 aids to be very intrusive and "no fun allowed." I wouldn't mind this as much if it wouldn't reset everything when you turn off the car... It doesn't even let you leave it in track mode without having to cycle back to it every time at startup. The only time I've had things start to get wild with the aids on was when passing someone at wot in 3rd on a very bumpy road and even that wasn't terrible.
I assume this has to do with the large amount of low end torque and lawyers trying to keep 70 year old men from killing themselves on accident.

 

when I first got my z06 I think I checked with a half dozen tire places before finally just going to the chevy dealer to swap rubber
nobody else either had the equipment for 20 inch wheels as wide as these or complete confidence it wouldn't damage them, which was a deal breaker anyhow

the problem is not only the 20 inch diameter but the 335 width as well

 

Firestone said they can't handle the stiff sidewalls on low profile run flats.

 

https://www.corvetteforum.com/forums...rack-mode.html

Some of you may want to read up on how traction control and the PTM modes work. There's brake application, throttle reduction and application, etc. The C7 is torque based so keep that in mind as well.

 

Zumzum, I think I can remove some of the suspense for you, as you and I have had similar C7 experiences to yours with traction control. I've had my 2017 C7 vert 7M for 3 weeks now, bought with 9500 miles on the odo. and original nearly 8-yr. old OEM Michelin Pilot Super Sports (RF) with half the tread remaining, i.e.--5/32nds. The squirrelly, twitchy results I've experienced include traction control kicking in (dash light blinking) at WOT in 1st and in high'ish RPM shifts to 2nd. The ones in first just stayed there for more than a second until I backed off the throttle because nothing was grabbing and I could feel the back end shifting sideways a bit. I systematically then dialed down my hard accelerations gradually, and had to back down quite a bit to eliminate the 1st gear traction control and the 1st and 2nd gear twitchiness in general--more than I thought I should have to back it down.

Well, Saturday I gave up. I had planned to wait another 6 weeks for my Aerolarri wheels to get here, but I went ahead and bought a set of Michelin Pilot Sport All-Season 4's (also RF). The difference is substantial. I have done everything I did before except for WOT from a standstill (which the traction control abruptly curtailed in my previous attempts.) So far I've had ZERO traction control intrusions. All hard acceleration runs have been like those in the old tires, in temps from 65-75 F. Last night from a 5 mph rolling start turning onto a 4-lane road I floored it and shifted to 2nd maybe 1000 rpm short of redline with no traction control and no perceptible twitch or loss of traction. Tires were warmed up, but it was only 65F outside temp. Conclusion? I think the old Pilot SS's had gotten harder for sure. And maybe the the newer AS 4's are an advancement anyway. I don't know what tire you are settling on, but I highly recommend the Pilot AS 4's. My C7 was in the first bay at Discount Tire where I could watch everything and they had 3 guys on it being very careful jacking it up and down. Seemed like it took longer than normal to balance things, but they appeared to be taking great care from where I stood.

 

You should search his other posts. Lots of other comments that will give this one a run for its money.

 

Well, after a two week saga my new tires are on. To repeat, they're Michelin Pilot Super Sport ZP's.

I haven't had a chance to test any traction limits yet and I'm not sure if I can make an accurate comparison under similar conditions. It's getting rainy and colder here in Central Illinois.
I do notice somewhat of an improvement in ride quality over the 10 y/o original tires.

 

I really noticed a difference when I got my new ones

 

As you allude to, it's going to be difficult to compare if it's gotten colder out. The traction reduction in colder temperatures is significant with straight summer tires.

 

Our C7 Owner Manual recommends using winter or A/S tries if driving frequently in temps below 40' on the summer Super Sport tires (50' for Cup 2), and not even moving the car if the tires are below 20'.

 

Yep. In my area it won't be long. There will be brine and/or salt on the roads. Hello battery tender and dust cover. Good-bye driving fun.

 

^^^^^
We're about 200 miles north of you and experience the same thing. The A/S tires we put on in Fall give us several weeks of good driving at each end of the season, and allow us to make a January dash to Florida or Arizona if we wish. Since I'm like you and will only drive in the salt if I can flush it off right away, normal winter driving is something I don't do in a Corvette.

Our C5 had real winter runflats and I drove it through 5 Chicago winters, including work. It still looked good at 5 year/60k miles but I always felt like I was abusing the car in winter.

 

My DD and winter car is a Caddy XTS with AWD. It even has the magnetic ride control. It's no C7, but can still be an enjoyable experience.

 

I had the C7 Z51 rear kickout once with the wife in the car she started b^tchin' and I said relax it's under control she just had an orgasm.

 

OK. Here are the totally unscientific results of my traction experiment. The new tires are same as the original. Michelin Pilot Super Sport ZP's.
I've already mentioned the ride quality has somewhat improved. I lucked into a day where the temp was almost the same as my original experience, the mid 60's.
I was on the same stretch of road at about the same time of day. When I hit it hard after the 1-2 shift the car still struggled to find traction, but the rear didn't jump sideways like previously.

My totally unscientific conclusion. The Z51, M7 with 3:42 ratio: Traction is definitely hard to come by, but to probably no one's surprise, new tires are considerably better than 10 y/o tires.

 

Interesting, maybe not totally unexpected results, ZumZum. Your test vs mine yielded different results under similar temps/road conditions both with new tires. I've continued to push mine here and there in 1st-3rd shifting (I won't say where that gets me, but you know) and I've yet to set off the traction control light in the dash since the tire change. I wonder if others who have longer experience as C7 owners can opine on the differences, but I suspect mine being a grand sport with the wider tires--285/30 and 335/25 GS vs. 245/35 and 285/30 Z51, so more rubber on the road for traction--is the key difference that might explain me having better traction in my GS under hard acceleration than ZumZum--???

 

Well with one exception

 

I would think that 335's on the rear would definitely make a difference. You basically have tires set up to handle Z06 power without actually having 650 hp/tq.