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Subject:Re: Tire question: Sorry, but ...
From:Don Hanson
Date:Sun, 29 Aug 2010 22:52:00 -0700

Hey well just for the fun of it...I am going to use my tire temperature
probe from the racetrack.  Left over in my tool box from my racing days
where I use that to tune suspension, etc.
  I learned a LOT about tires when I raced, but not much about street
tires.  I did learn about heat generated by tire pressures.
 One wide-spread practice in racetires is to inflate them with nitrogen to
minimize heat-generated pressure increase.  As a tire comes up to racing
temp with atmosphere inflated inside, they can gain up to 7psi but with
nitrogen, they will only gain a few lbs....So when you filled the tires with
nitrogen, you could start a race with almost the correct pressures, rather
than running a lap or so underinflated while the temperature caused the
pressure to increase.
  When you are running about 20psi in a 12.5" wide slick racing tire...7lbs
is huge.  You couldn't really start at 13psi and depend on the tire staying
on with the forces generated by high cornering G-forces and big HP.

  I started these Hakkas out at 44r and 39f..then after my test drive, I
upped the fronts to 43 and the rear to 46...I will take some tread temp
readings...see what temps I get...I bet cold, compared to a race tire

Don Hanson

On Sun, Aug 29, 2010 at 10:00 PM, Loren Busch <starwagen@gmail.com> wrote:

> On Sun, Aug 29, 2010 at 9:03 PM, Scott Daniel - Turbovans <
> scottdaniel@turbovans.com> wrote:
>
> >
> >
> > interestingly, on the same vehicle...
> > for the 185 R 14 C 6 PR they say 39 front, 48 rear.
> >
>
> Not totally true Scott.  Some years back, just for kicks, I did a survey
> (on
> vehicles I could walk up to at a WetWesties gathering and also asked people
> online for info and several in a local bone yard) and VW increased the
> recommended pressure over the years.  From about '88 on, on a Westy, for
> the
> 185R14 they say 43 front, 53 rear.  What prompted my mini survey was a
> discussion just like this.
> And my (very subjective) testing of various inflations on my rig, first
> with
> Michelin Agilis and now with Hakka CS I've found the 43-45 front 53-55 rear
> gives me the best feel/handling.  But this is a truly YMMV situation.
>