If that’s the case (makes sense), wouldn’t a more or less square contact patch provide the best balance between cornering and braking? The friction circle tells us that there is only so much grip available to be split between cornering and braking.
Wider tyres dont help with aquaplaning.
1 Like
205 width tyres look better under the wheel arches of a S1 or S2 E-Type. 185s look inept.
Michael, thanks for you contact comments. I am not a racer, but why, then do dragsters have wide tires. I know tires are very complicated, but I do not know in what ways.
Tom
Not true: they help immensely with hydroplaning…
What tire engineers found to be the most effective in helping lessen that issue, was the gatorback tread design, coupled with very wide circumferential grooves.
Not if you mount them on 6" wheels. I did a comparison back in '13 between two 185HR15 Vreds, one mounted to an original 5" wheel and the other to a new 6" wheel. These are the pics I posted
The tire mounted to the 6" wheel is 5/8" wider.
In addition to the wider, more aggressive aesthetic there were a few advantages of the newer wheel/tire combination than the older.
- no inner tube
- the six inch wheel/tire weighs less than the five inch, by 15 oz (read, unsprung weight reduction)
- tread footprint unchanged, meaning lighter steering, especially at low speeds
- splaying out the sidewalls stiffened them, so handling at higher speeds was improved.
My two cents … go with the original spec tires on wider rims. You won’t be sorry.
1 Like
You can learn nothing about street tires from racing practice. A dragster runs a huge, treadless rear tire, made of soft rubber and inflated to maybe 8psi. When the throttle drops, so much torque is applied that the sidewall collapses and causes the tread to bunch up, creating a huge wedge of sticky rubber as a lauch pad. Once the wheel starts spinning, the rubber is flung out by centripetal force, effectively creating a taller, narrower tire which has the mechanical effect of a higher gear and lowers rolling resistance. The life expectancy of a drag tire is maybe half a dozen quarter mile runs. I personally wouldn’t want my street car to work this way.
2 Likes
Guys… (and ladies)
In a narrow tire, a certain amount of air (psi) is needed to keep the tire “round” or to keep a flat spot from causing drag, and to allow it to wear even across the tread (right to left)…
On a wider tire, as I recall, it is recommended to use a few psi less. That is why a wider tire holds the corners better. If the same psi is used in the wider tire, it causes the middle to “bulge” which in turn wears the tread more in the middle of the tire, as opposed to the edges.
LLoyd.
Wherever space and time interact, there is information, and wherever information can be ordered into knowledge, and knowledge can be applied, there is intelligence.
Pavel Mirsky, mid 21st Century Russian General
On my Datsun racer (stock tires were 155-80/12) I ran 185-65/13 Yokos: felt awful at low speed, but handled awesome at 22/18 psi. (F/R)
Another factor not yet mentioned is lower aspect ratios enable the tire to build up less internal heat, and to decrease slip angle, which results in tighter, more precise steering response.
Oh yeah
Neither of those clearly show the growth in diameter but it does happen
https://www.caranddriver.com/features/a26089565/drag-racing-tires-explainer/
2 Likes