That sounds pretty strange, but then I never did understand Porsches.
You get more top end with a narrower contact patch, but it shouldn't
add up to four seconds worth unless that track has no corners. If the
tire is wearing in the center, and the temperature in the center is
higher than the edges, then the pressure is too high. I can't think
of anything good that comes from that.
Generally radial racing tires work best with the lowest pressure that
will keep the sidewalls from rolling. Some people hate the feeling
they get from that kind of setting, but iin my experience it's
fastest. I'm going to have to get a set of these puppies pronto and
find a test and tune day to play with them. I'll be astonished if I
wind up with anything over 30 pounds, but you just never know.
I've found that extreme camber (five degrees) worked very well on my
Radical at some tracks that had long straights and very high speed
corners. I could get a higher top end and handle the high speed
corners without lifting. But the low speed corners got touchy.
Different tracks, different cars, different tires.
On Jun 21, 2006, at 11:13 AM, joe dirt wrote:
> I had this all written out in one big report, but my email couldn't
> handle it and I lost it. What just sent through the list was written
> off memory.
>
> I don't have the information in front of me at the moment. I do
> remember changes, but I'm not going to state them until I have the
> exact data as to not confuse things. When it comes my way again (I'll
> hopefully have it for you tomorrow) I'll type it all up in a very
> detailed and easy to read fashion.
>
> This doesn't apply to our cars but I'll tell you what the
> Porsche
> guys have found and are running.
>
> After Sat's Qualifying race, one of the Porsche 356 drivers came
> over,
> one to compliment on all the nice saves from that sway bar incident,
> and another to talk about the Hoosier Speedsters. This fellow started
> the weekend at around 32lbs hot air pressure. With the recommendation
> of Vic Skirmants, he bumped air pressures up until they were reading
> 37lbs hot. He dropped 4 seconds a lap with just this change. I talked
> to Vic later on and he confirmed this is what they are running. Car
> weights are approx 1650lbs and negative camber is -2 degrees. The
> tread
> also showed to be "rolling" a little more than that of the Dick's
> Triumph. This is ODD. The lighter the car the lower you run the air
> pressures, not so apparently with the Porsche's. Vic was running mid
> 2'19's to low 2'20's throughout the weekend. Looking at their tires,
> they too were showing more wear in the center section than the outers,
> but I expected to see more considering the tire pressures they are
> running. BUT remember, these are a different type of car, with a
> different type of a suspension.
>
> As I said, I'll write up a nice report when I get the
> information. We
> have a quick Spec Miata racer / set-up guy among our ranks; he was
> there and has ALL the data at the moment, and he, I, Dick , and a few
> others are hard at work getting these things exactly where they should
> be before the next event. The Zippo GP should be interesting..
>
> -Bob
>
> BillDentin@aol.com wrote: In a message dated 06/21/2006 11:04:09 AM
> Central Daylight Time, oldskooling@yahoo.com writes:
>
>
> . Tires were reading about 31lbs hot, and the pyrometer was showing
> them to be hotter in the middle than the outsides.
>
>
> Bob:
>
> It is not clear to me what tire pressures you folks 'started with',
> and what changes you made during the week end.
>
> Bill Dentinger
>
>
>
> ---------------------------------
>
>
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