In article <DxDpf.6453$k76.6056 (AT) bignews6 (DOT) bellsouth.net>,
"armpit" <udontneedit (AT) myemail (DOT) addy> wrote:


Read the above, pit!!


No... there is only ONE spring rate.
You can change your tire pressure 50 pounds if you want
and the "spring rate" will ALWAYS be the same.

Absolutely. But that is what was first mentioned.
That air pressure has an effect on spring rate, and shock rate,
which it does not.

I was just replying to that inaccuracy.
Not debating whether an air pressure change did or did not affect
the handling of a car.

If you have a shock with 40% bump/60% rebound, I don't care if
you put 100# of air in the tire, it's still a 40/60...
And the spring is still 400#. Period.



Dan
----------------------------------------------
Why is it when a man talks nasty to a woman it's harassment,
and when a woman talks nasty to a man, it's 5.99 a minute?

I think you're talking about the 'stiffness' of the spring or shock.
I'm talking about 'rate' as in the amount of movement or 'work'.

On Mon, 19 Dec 2005 16:19:10 -0600, Chuck_Steak (AT) nospam (DOT) com (Chuck
Steak) wrote:

Alan Jones <alan (AT) alanjones (DOT) us> wrote in
news:dlaeq11gmdvc9et8mo8r2cj3l4the77rc0 (AT) 4ax (DOT) com:

So what you're saying is that the tire acts like a spring, and
transfers the "shock" to the rest of the suspension. And a
more inflated tire acts like a stiffer spring.

Interesting. Yesterday you were denying the tire acts like
a spring.

John

"armpit" <udontneedit (AT) myemail (DOT) addy> wrote in
newsxDpf.6453$k76.6056 (AT) bignews6 (DOT) bellsouth.net:

I said that about 8 posts upthread. Alan took severe exception
to the idea.

"Total spring rate" isn't that helpful a concept, because the
rest of it (the spring rate, the shock, and the sway bar)
interact depending on what the car is doing. It's simpler
to continue viewing the tire seperate from the rest of it.

It also helps to remember that only radials act like springs,
at least in the sense that you can tune with them. Short
track drivers that are familiar with bias ply tires won't
see the same behavior, partly because the bias ply tire
doesn't change it's springyness as much with air pressure,
and mostly because the change in stagger with the bias tire
totally masks the other changes.

John

On Mon, 19 Dec 2005 23:34:01 -0000, John McCoy
<igopogo (AT) ix (DOT) netcom.com> wrote:

No. I'm saying a tire acts like a tire and, as a consequence of
its design, it will absorb a certain amount of shock.

A tire acts like a tire. A tire absorbs shock. A spring acts like
a spring. A spring is 'specifically designed' for the 'exact'
purpose of absorbing shock. A tire is not a spring.

I took exception with recommending a tire pressure change as
a shock or spring adjustment. Bad advice.

On Mon, 19 Dec 2005 23:41:03 -0000, John McCoy
<igopogo (AT) ix (DOT) netcom.com> wrote:

In article <j4eeq15a5omp9j139a6dgs42ils3j0s66p (AT) 4ax (DOT) com>,
Alan Jones <alan (AT) alanjones (DOT) us> wrote:

There is only ONE meaning to the words "spring rate".
It refers to how much weight it takes to compress a spring one inch.
It is the gauge that you use to select a spring.
It is the number you use to purchase a spring.
It is the ONLY meaning in the racing world that applies to
"spring rate". How much weight it takes, to move it one inch...

If you ask ANY crew chief on the planet, what spring rate he
is running on the left front NOBODY is ever going to say,
"it depends on how much air we have in the tire"...
They will instantly tell you for example, "a 450".
No ifs/ands/buts.
It's a number. Not a variable.

If you buy a 400# right front spring, that is the spring rate.
If you buy a 600# right rear spring that is the spring rate...

If you buy a CS5-400, it's a 5 inch 400# spring.
A CS55-500 would be a 5-1/2", 500# spring
A CS25-250 would be a 2-1/2" 250# coil-over spring.
That is the RATE!!

I've bought dozens of racing springs,
I'm not sure I understand why you think
"I'm" the one not getting this....

In that case, I'm in error. I guess saying 'rate' is not technically
accurate. I meant the amount of work the spring/shock must do;
the rate of 'travel'; as in how far and 'often' it must move/react.

On Mon, 19 Dec 2005 19:40:12 -0600, Chuck_Steak (AT) nospam (DOT) com (Chuck
Steak) wrote:

Alan Jones wrote:
"In the age of radial tires, the change you hear the most about is air
pressure in the race car's tires. Basically, this adjustment has the
effect of changing the spring rate on that corner of the car. Each tire
in itself acts like a spring; the lower the pressure, the softer the
spring. If the car is tight, or pushing, the crew will lower the
pressure in the right-front tire. If the car is loose, they will lower
the right rear, just as they did with the spring rubbers."

http://stockcarracing.com/techarticles/32898/

'Acts' 'like' a spring, but 'is not' a spring. Again, my response
to Jerry was not about changes that can only be made during
a pit stop. His question did not require that.

Except when on-the-fly, on race day, I do not believe shock
and spring adjustments should be made with tire pressures.
You can fine-tune the S&S in that way, but your air pressures
are best left to getting the best grip (bite) to tire heat (wear)
balance.

On 19 Dec 2005 19:02:26 -0800, mcook (AT) prodigy (DOT) net wrote: