off topic / traction control

[Walter Sherwin]

Right on!........

Not to pick on anybody in particular, but, a good example was when Chevy/GMC
truck decided to first install   B.F. Goodrich 275/60/R15 HR4 tires on a
15"x7" rim assembly, in 1990,  as part of their C1500 ZQ8 truck performance
suspension package.  The intention was good, but, what were they smoking at
the time?  At highway speeds, from behind, you could see daylight between
the shoulders and the pavement.  I've got a set of these where the center's
are worn to the limit while the shoulders still have the "nubbins" pretty
much intact.  Dozens of other ZQ8 contacts have had the same experiences.
How much handling do you think a person has with 2-3" contact patch width at
the rear at speed?  Even B.F.G. themselves do not advocate this combo in the
aftermarket world.

Real world performance all comes down to what exact tire you have, on what
exact rim, under specific conditions,  and under specific inflation
pressures.  Test, Test, Test, and then reTest, just to make sure.


Walt.




> depends on the car, the tire, and the rim size. In most of the cars I've
driven 40 psi wont let the outside edges of the tire contact the road. For
example at 36 psi 215/70/15 tires on a 92 tracker 2 door only the center
inch was touching the road ( measured using the puddle method) and the car
was scary. On a 87 Subaru 4dr 4x4 sedan 36 psi gave about the same contact
patch.
>
>  The best tire pressure is a trade off between wear, and traction, and
ride. The tire maker sets a pressure that makes the tire last longer on the
test stand, to automakers give the pressure for best economy with handling
factored in as small
> part.
>
>  The only solid rule I've found is that you have to test.
>
> Previously, you (John Edward Miller) wrote:
> { > Normally, you lower tire pressure for traction
> {
> { </LURK
> {
> { Not cornering traction, not on street tires.  Best grip ~40-46psi in
most
> { cases.
> {
> { John.
> {
> { <LURK>
>
{ --------------------------------------------------------------------------
--


----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org