So we've all been reading so much about how this very narrow 285 tire is a perfect fit for the new C7 and it's finely tuned set up. My question is simply this.

If and when they build a hi-perf. model what type of footprint will it carry? With all the discussions of how the base C7 will perform amazingly well with a 285 what would they put on a ZR1 variant. I can't see a big bomber without at least a 325 or more.

And if this very simple topic can't be discussed amicably then just don't respond, there is no motive or agenda here!

 

Look at it this way, if they can get the same grip out of a skinnier tire, they are doing something right.

You would think a wider tire would mean more grip, and for the C7 Z06/ZR1 they will most definitely go wider. But it could be argued that for a given weight there is a limit to tire width to achieve max grip. As the tire gets wider, the footprint also gets wider, but it gets shorter. Because the force pushing the tire down to the road hasn't changed, but the amount of tire distributing the force has.

You could also speculate that the new e-diff may control tire spin better, where a wider tire was previously used to control tire spin.

I'm just throwing out some theories for sake of the discussion.

Narrower tires also give better steering and chassis feel. Now I am one who always tries to fit the widest wheel/tire possible, but this is usually on cars that weigh as much as a Corvette, but have narrower tires.

 

I disagree with the premise of your question. I do not consider this to be a very narrow tire:



THIS is a narrow rear tire:



You are wondering if the higher performance model will have wider tires, particularly in the rear? Legit question I don't have the answer to.

 

I agree with Joe. 285 is pretty much normal these days for high performance cars. With improvements to tires and suspensions, I suspect the days of huge rear tires are dwindling.

 

I'm just basing my question on the history of how tire patch has grown over the years! Now GM is suggesting that method is not necessarily correct? So point being will a ZR1 variant print be a 285-295? And Viper as a for instance is putting down a 355 and we all know how they did at LS.

 

Dan I would tend to agree. Having that meat on the back gives a mean look to the car and the ZR1 is supposed to be the baddest vette ever so what better way to distinguish this from the rest of the pack. I would also think a wide body would be necessary to carry those wheels to also distinguish it from the base car. Lets face it nobody wants to buy the best if it looks like the rest. At least I wouldn't anyway.

 

Veyron and supercars may be quite meaty, but there are advantages to smaller footprints for street cars. Porsche and Ferrari manage to limp along at 285 with the occasional 305. I would say my Carrera with stock 295s has the same grip and pretty much the same performance as my GS and the tires are way smaller.

 

I have a question for you Dan...

If a tire can deliver the same grip at 285, but better aero and better efficiency than a 305...which would you rather have? Are you motivated plainly by look, or by function?


I spoke with Michelin engineers in Detroit about your EXACT question and the answer was:

They said, "yeah..the 'z06' or whatever they end up calling it, has a tire larger than 300mm but I can't remember exactly". He asked another guy, but he was an engineer working on a different project...they couldn't remember either.

I suspect that you'll see a percentage in reduction of size consistent with the GS to C7Z51. I think we'll see "Z06" on 305's....

The fact is the EXACT engineer that is with the race team at every race developing those Michelins, is the guy who developed the tire for Z51 C7. It works...bottom line...why worry about the size

So many people are infatuated with these numbers when there is a WAY bigger picture here. Don't worry about the numbers, worry about the result.

 

Ron I'm with you, nothing like the look of a steam roller tire under the car!

 

Well I guess my response would be have they been wrong for all these years then? Who has the fastest times ever at LS? And those two American behemoths weren't wearing 285's or even 305's. More simply put do you think the SRT or ZR1 would run 1:33's on 285's and if they could well then why aren't they wearing them? This is the basis of my thread, not to conflict about it but to try and figure what is better.

 

Wow, looks like a Viper lift kit.

 

That's some serious g's being pulled Ox!

 

Dan, be honest now, doesn't that look more like a 1/4 mile drag machine than a sports car?

 

I will be honest with you! Growing up in the 70's I've always likened the muscle cars to be drag racers and the Vettes and Cobras to be more of a circuit car. Now we know the Vipers did not come around until '92 but I've never thought of them as a 1/4 mile car. And if you ever get the chance to drive an ACR on a road course do it, the grip and raw power is intoxicating. So I honestly say no, I see a sports car that is diving deep into the corner with very little body roll.

 

The way I view it is that the C6 Z51 had 285 Supercars tires(better grip than the 285 GS-2 tires on the base coupe) but the Z06 had to go with 325 Supercar tires to give the 505 HP half a chance to get the power to the pavement.

If the new Michelin compound and tread design(used on the Z51, but not the same as used on the base C7) and is supposed to better the old 285 Supercar tire's grip(maybe equal the 325 Supercar's grip), then the 575HP(????) C7 Z06 will still need a wider tire to get that additional 120 HP to the pavement. The C6 Z51 was good for 1.0g skidpad
and that's the number that's been thrown around for the C7 Z51. The 325 Supercar's are good for around 1.05g on the GS and the Michelins used on the Z06/Z07 are good for around 1.13g. I seriously doubt that the Michelin 285's will allow the C7 Z51 to do a 1.13g skidpad.

 

Still looks like a lift kit.
It needs a seriously stiffer anti sway bar.

 

Why is the right rear so high? No roll but front to rear pitch? That is not a good thing. The rear tire width would look about right here:

 

Good technical stuff Joe! Thanks for explanation.

My car had the smaller finnican pins and undercut buffalo bearings so it was a little sloppy in the corners.

 

It's all a matter of balance. Theoretically, the amount of friction generated by the tire is dependent only on the material properties of the tire (coefficient of friction) and the weight of the vehicle (normal force). In reality, the tire is also limited by road imperfections and heat generation. As tire design and chemistry improve, they deal better with generating friction over wider temperature ranges and better at dealing with road imperfections. Couple that with better suspension and you don't need huge tires. If you took 20 year old tires in new condition and compared grip to current tires, you would find that a much smaller tire could be used with current tech. The Z model will likely have bigger tires to better distribute the heat generated, but my guess would be a 305 at the most unless we are pushing 650 or more horses. Just a shot in the dark of course.

 

It's really quite amazing how you twist things into a totally skewed perspective.

The C7 Z51 isn't targeting a Viper.

Engineering is building to suit a specific requirement based upon your goals, needs, costs, etc. Would the C7 Z51 have MORE GRIP on a compound it's tire will use, but at 305mm...SURE...is it necessary to achieve the goal set forth for the car....NO.

You can put the big wide tire on there...then you face the cost of the tire, the cost of the wider rim, the all weather performance factor, road noise, etc.

For market the C7 lives in, the 285 is adequate and provides better fuel efficiency and better aero characteristics. It's the best tire for the prescribed job.

SRT's Viper is what I call a "stupid simple" car. The Corvette has always been more advanced and more refined than the Viper, and always will be unless they start selling more cars. The Viper takes the bigger is better approach, and for guys like you...that floats your boat. I have 345's on my C5Z...sure, I like a big *** tire...but the facts are the facts....they cost more to employ, they are less fuel/aerodynamically efficient, and the car already exceeds 95% of typical owners driving capabilities...including yours.

Your little LS record statement...that comparison doesn't even make sense. The original test had the ZR1 beating the Viper with a smaller tire. Viper took the stupid simple approach and somehow came out with a new model in a week and slapped some aero parts on and ta da....now they win.

Corvette can do it better than SRT...on less motor, on less tire, for less money....just look at ALMS for God's sake. We run a 5.5 liter, they run an 8.0 liter...and they have a BIGGER diameter air intake restrictor just to be competitive...lol. The fact they have 8.0 liters versus our 5.5 isn't enough for them to make the same performance. Corvette has a FAR more developed car, FAR bigger budget to develop the car and MUCH more racing success than Viper/SRT. The end...