Tire Traction?!?!

[yelnatsch517]

Ok, I have not seen this anywhere since I've started my research on cars and wanted to ask the pros here first before I get any more tires or buy rims. Many of you here have over 250rwhp. Its one thing to get that on the dyno and another to get it on the street. What kind of differences in traction can people see between lets say tires that are 215 and ones that are 275? More surface area logically equate to more traction, but how much more are we talking about? If someone has the time and knowledge or know of already a site that has the info, post a chart of some sort comparing tire size and traction. I think this would help a lot of people in many ways.

[yelnatsch517]

Bumpity bump bump...?

[Noventa]

amazing, according to classical physics, surface area has very little to do with traction.

Although in our case, it is untrue of course.

[yelnatsch517]

amazing, according to classical physics, surface area has very little to do with traction.

Although in our case, it is untrue of course.

Really...who told you that ? I could have sworn traction and friction from tires was equavilent to traction. And coefficients of friction from tire ratings are directly related to surface area. Meh, must be my imagination. O Btw, I'm talking about comparing similar tires. Not something like racing slicks to all season tires. That would be just absurd. I think you were thinking about something like this. But in the case of tire traction, it is considered an exception.
Modified by yelnatsch517 at 2:35 PM 11/17/2004

[adrock]

The UTQG (Uniform Tire Quality Gauge) classifies tires into three traction categories- A, B, and C. A is the best, C the worst, but I think any decent tire you're going to consider putting on a sports car has an A rating.

Tread wear is another thing rated by the UTQG, with a base of 100. Lower numbers indicate higher tread wear. These tires don't last as long because they're made of a softer compound. This is good for traction. Again, most tires you'd consider buying for your 240 are going to have a high tread wear and not last as long as regular touring passenger car tires.

So traction rating and tread wear ratings aren't really variables in your quest for traction.

I think the most important thing to consider is the tire's contact patch, or where the rubber meets the road. The aspect ratio of your tire, or the ratio of the tire's height to it's width. A P275/40 ZR17 has a sidewall that's forty percent of the width of the tire. Generally speaking, any tire that has an aspect ratio of less than 50 is considered low profile. Anyway, the contact patch is directly related to the tire's size and shape. Tires with a high aspect ratio have long, narrow contact patches and low aspect ratios create wide, short contact patches. In the latter case, the wide patch combined with the short, slightly flexing sidewall is responsible for superior handling, stability and traction. A taller sidewall on an already wide tire would enhance traction because it's more flexible, but would negatively affect handling and stability. Drag racers take the contact patch thing to the extreme with Mickey Thompson's that are as wide as they are tall, and the sidewall flexes upon itself to create a slingshot effect. As far as a 275 vs a 215, wider does equal more traction, but a wider tire effectively means the same amt. of weight distributed over more area, which in turn means less friction- eventually- so there is a point of no return.

After all that, I think it's safe to say that the key to unlock horsepower is not in your tires as long as you're current setup has a generally high traction rating and tread wear factor. Just stick (no pun intended) with proven, name-brand rubber that promotes performance as a selling point.

Correct me if I'm wrong.

-adam

[yelnatsch517]

Nice write-up. Thanx for the info.