Buying street tires for my ZR1, recommendations?
 

I am going to be buying new wheels for track use, and putting my existing SC-ZPs on them. I want quieter tires for road trips, but don't want to give up much grip since the car is a beast. SS-ZPs are the obvious OEM choice...but I started wondering about getting non-ZP SSs for a better ride and theoretically better NVH. Front size is the same, rears would increase diameter slightly: 335/25 vs 335/30 (26.6" vs.27.9").

Thoughts...?

Also: I have no plans to lower my ZR1's front, even for track use, because of local driveways. Perhaps the slight increase in rake from raising the rear could be aerodynamically beneficial to the same end.


p.s. If going with the non-ZP tires they would be MO1 front and NO(Porche) rears. Not sure that matters, since the structural differences are proprietary and slight.

I would wait and drive the car some. You may be surprised. I have the Cup 2s on mine and I was really concerned about them. I am liking them so far.

I have a set of forge line wheels coming with the standard michelins like on the Z06 for the ZR1.

It will be interesting to compare them,
D.

Michelin Pilot Sports A/S 3+ ZP

https://www.tirerack.com/tires/tires...rmance+Package

Why the AS tires? I live in southern CA, rarely rains. And with a high performance car that I'm actually going to drive hard I would think the AS tread blocks would squirm a lot.

The SCs boom a lot on concrete freeway sections, but are quiet on other roads. So I'm hoping the SSs will be quieter particular on concrete.

At this point I'm leaning more toward the non-ZP SS option.

My cup tires are in the factory wheels in boxes, use them for road race events, did this on my last two Z06/Z07's and now my ZR1, replaced the cup tires with non run flats pilot super sports on Forgeline wheels. Great in all conditions, better ride and no noise

I just swapped out my Cup 2's in favor of SS's for the same reason, to achieve a quieter ride and also to reduce the amount of road debris being flung up into the wheel wells and onto the car. We live in Wisconsin and the roads up here are terrible... lot's of loose asphalt patch, especially in the spring time. Those Cup 2's are some sticky tires when getting some temp to them and are like magnets picking up debris.

Goal accomplished.... could not be happier and would highly recommend to anyone having the same use case. The Cup 2's are going on a set of Brixton Forged PF3 CARBON+ for the track.

Side note: when at Spring Mountain in April, the first day was on SS and the second day Cup 2's. Wow what a difference, the Cup 2's are amazing but the SS's were no slouches either. One thing I did notice leaving the back straight away into turn 8, lot's of rubber pellets off the Cup 2's. The first time I experienced it felt like the rear end was coming out of the car. The instructor indicated it's rubber pellets from the Cup 2's being pelted up into the wheel wells/underbody.

I’m in Nor Cal and we get our share of weather. The cup 2s are no bueño on damp roads.

I have had zero issues driving hard on the A/S 3+ tires.

Also the A/S 3+ tires do not kick up nearly the road debris the other factory tires do.

I would not recommend going up 1.3" in the rear and not changing the fronts. You would likely introduce braking issues (Ice Mode) from a difference in front to rear tire diameter. I just a had a friend try mixing different tire sizes on his ZR1 at LS Fest and he had all kinds of braking issues.

The Brixton Forged PF3 Carbon+ only come in 9" or 12" wide by 20" sizes or a 12.5" x 21" size. Not sure your Cup tires will fit any configuration.

-Guys, what size non-LP SSs did you get? Cause this might be a concern...

Brixton is awaiting the release of 19" carbon barrels in roughly 6-months. My understanding Dymag supplies carbon barrels to many of the carbon wheel providers and 19" is low on their list. Have to patiently wait unless something better comes out in the mean time.

Not really what we are talking about here. This is a thread about tires, not wheels.

Guys...can I get some more feedback pertaining to possible side effects of my proposal to run non-ZP SSs?

tires
 

Yes, I had it happen as well. It puts the AH into fits and gives service rear axle and service active handling codes like crazy and it won't let you go into any of the PTM modes or turn AH off. It will only let you turn traction control off. That's OK if you are only drag racing and not using launch control, but all the other nannies are compromised while the codes are there. It really gave me a hard time last year at Barber. It ruined the entire weekend.

-So then what you are saying is that is it simply not possible to run non-ZP SSs on the ZR1? Or a Z06 for that matter? Unless I dropped 10mm to 325/30R20s. Although that is a different diameter from stock too. What is the threshold before electronic interference?

tires
 

No, that's not what I'm saying. What I'm saying is if you change one then you have to change the other to keep the ratios close enough not to throw codes. I'm sorry I don't remember any exact numbers, but when I needed them I was able to find them here using the search engine and some time on this forum.

The 325's are less than 1% from the 335 in overall height, and are wider according to Michelin because of softer sidewalls, you start getting in trouble when you change more than 3%

OP

Here's the starting thread in one of the earlier times this was discussed.... Also I would encourage you to contact one of the forum wheel and tire dealers, they cover this stuff all the time. Yes, this is Z06 here, but so far my 19 ZR1 has been the same, wheel and tire size wise, as my 16 Z06.
Hi,

It's that time - I am no longer satisfied with a high performance street tire and want to get a second set of wheels and tires for track use for my 2016 C7 Z06. In my ideal world, I'll swap the wheels the night before, drive the hour or so to the track on the DOT-approved track tires, have fun on my sticky track tires, then swap back to street tires at home. Have truck and could get a trailer to tow the car, but that seems like more work. I track ~1-3 times a month from about April to October in HPDEs and am working toward time trial certification (slowly).

I am having trouble figuring out what size wheels to purchase for this folly. I have realized that the stock OEM tire size isn't available in many of my first choice tire options, so I'd like to get track wheels that give me some options. For right now, I'd want to try something like the Nitto NT01, Bridgestone Potenza RE-71R, Toyo R888R, or similar.

It looks like many people have a set up of 18 x 11 on front and 18 x 12 or 13 on the rear for their track wheels, but I don't know what tires they are using. I understand tire width and wheel size and know I can go a little bit wider or narrower on the tire width (i.e. if I have 285 on the front now, I can probably fit a 275 or 295), and obviously an 18" wheel has to have an 18" tire, but I don't know how much +/- tolerance is possible for aspect ratio - for instance, if it's a 285/30/19 now, how do I know if an aspect of 35 or 40 would work? For example, Nitto NT01 comes in the sizes below - the size 18 x 11 wheel seems like I'd need to run 305/35/18 on the front- how do I know if that fits inside the wheel well!?

275/35ZR18 95W3710106.325.5510.919.0-(9.5)-11.01521@5128.19

275/40ZR18 99W3711306.326.6510.949.0-(9.5)-11.01709@5130.03

305/35ZR18 101W3711806.326.4212.3210.0-(11.0)-12.01819@5132.18

315/30ZR18 98W3710006.325.3512.6010.5-(11.0)-11.51653@5130.46

Conversely, the Bridgestoe Potenza has at least one tire that is:
285/30R18, which seems a lot closer to my ideal size, but appears to be more of an autocross tire.

And then, the golden option - the Toyo R888Rs come in a beautiful 295/30ZR18, which I'm almost positive would fit an 18X11 wheel on my C7 Z06. But it seems like very few people run these! Why not?

SO. If you are so inclined to help, I'm requesting:
- Any recommendations on track wheel size and why.
- An explanation of what aspect sizes would fit, or whether I just need to know outside diameter specs and then measure against the wheel well.
- Examples of what your road racing sticky DOT approved tires and wheels are and how you like them

Thanks!
Kaitlin

-Hmm, hadn't considered the actual width might be similar with different section widths from the same manufacturer and tread design. Good input, thanks.

Hey I saw your PM and thought I'd just reply here. My experience with the Z51 was that the non-ZP Super Sports do not handle nearly as well as the MPSS ZPs and that was with the correct sizes. The compound, tread, and construction are different and to me the car just did not feel right. I would not mess with big changes to the overall diameter for the reasons others have noted and frankly the C7 wheel wells do not handle taller tires without getting torn up if you are really hammering the car.

If you're never going to drive in less than 50 deg or in rain then the MPSS ZP seem like the best choice to me. When hot it will handle better than any of the other options you are considering. I briefly ran the Pilot Sport A/S 3+ run flats on my ZR1 and still have them. When it was cool out they were far better than the MPSS and I expect them to be much better in the wet (I'm keeping them to try as wet track tires on my GS track car). I think at the levels you can safely push a car on the street they're probably not giving up much to the MPSS but I did not get a chance to really push them yet.