

| 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. >
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