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Julie Cook | 3 Mar 1997 04:10
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Road Atlanta

Well, the Road Atlanta National is over and our first race with the
Rotax engine is in the book. Things went
pretty good, although we're going to have to spend some time figuring
out what clutch and carb setups are going to work best for us with the
Rotax, but then that's to be expected. We've got to get Rusty well also. 
Saturday was beautiful with 80 degree temps and clear skies. The first
session out both cars studdered and cut out. We immediately pinpointed
that one to a fuel problem. On Rusty's car, we put a pulse fuel pump and
on Jack's we bypassed the surge tank. Both solutions fixed the problem.
We plan to take the surge tanks out, this
will give us more room in the back of a really crowded engine
compartment! The second session was the only qualifying session. Both
cars ran well, but Howell Jones was flying! I clocked him at a 1:31.6
his crew guy clocked him at 1:31.4, T&S posted his time at 1:28.11.
We're sure that was wrong (they also made a couple of mistakes with the
Vee's) but regardless this was still a track record time. Scott Woodruff
qualified second with a low 1:32 and Wesley Wilfong qualified 3rd with a
mid 1:32. Rusty qualified 4th with a 1:33.3. Tom Edwards, Fred Edwards,
Greg Reihle, Jack Walbran and another KBS with a kawi rounded out the
field.

Rusty had low EGT's and his RPM's never got above 7600 and the car had a
serious push. Add to that he was sick with the flu or something and was
running a fever of over 100, his arm's still not strong, and a serious
lack of sleep this past week so he just wasn't in top form. We worked on
Jack's car on Saturday night and yes, we partied a little bit and ended
up getting in not late, but I was too tired to post anything.

We got a good night's sleep, and the rain that was forecasted hadn't
arrived, but we had forgotten to get gas so we didn't have enough gas
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Nick Massey | 4 Mar 1997 00:14
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Tire Pressures

With all the experienced F500 racers out there, just thought I'd ask 
your advice on tire pressures.  What tire pressures do you use on your 
cars, particularly the KBS Mk-7?  What is your starting temperature 
(cold) and what temperature are you trying to achieve on the track?  
Does increasing tire pressure tend to increase or decrease the ability 
of the car to stick at that end?  What if it's a cool (or cold) day - 
do you increase pressures to try and be sure the tire gets up to the 
desired pressure, or do you decrease pressure to try and get the tire 
to squirm more and generate more temperature that way.  Same question 
for both Goodyears and Hoosiers.  Thanks for your advice.

Nick Massey
Oklahoma City
KBS Mk-7/AMW/Hoosier
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dg | 4 Mar 1997 17:13
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Tire Pressures

Gee Nick,
After we cover tire pressures, we can jump into insurance, politics, and
religion !:)

Nick, you are asking a question that will garner you a wide spectrum of
answers.  Unfortunately, some of the participants will not respond,
believing that they have the hot secret tire setup equation.  Although
some really do, others just believe they do.  Let results be your
guide.  We (SANCO SPECIALTIES) use factors such as ambient temp., track
temp., track surface, rubber compound, qualifying or race, weather, and
whether or not there is morning condensate on the track to help
determine a starting point for tire temps.  If we have an opportunity to
obtain temp. readings, this also becomes a guide.  We read temps. across
the entire tread surface.  Reading tire temps. is a science unto
itself.  We, too, are learning.  Those who claim they have all the
answers should be regarded with skepticism or worshipped as a deity.

As the day wears on and track temp. rises (even though ambient may not
rise so much), tire pressures will fall.  The goal is to have the proper
tire pressure when the tire is at optimum temp.  The challenge is to try
to start with a static pressure that will see the tire "grow" into the
proper pressure (without growing to much).

I have seen pressures as low as 8#'s but I have never used a pressure
below 9.5.  I have used pressures as high as 14 but believe now that I
should remain at or below 13.

Someone else may be able to offer more definitive answers.  I can only
offer a start.
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Don Staggs | 4 Mar 1997 19:18

Tire sizes and compounds:

since we been on the tire subject, I would like to know about the tires 
you use on the f-500's.  size, compounds and brand. Also the price and  
 suppliers. thank you.
                              Don Staggs
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Don Staggs | 4 Mar 1997 19:07

chapparel parts for sale

If anyone would like chapparel parts please E.mail                      
   "staggs@..." 
          complete engines,  pistons, new crankshaft, heads, jugs,
starter kits, too much to list.
                                       Don Staggs
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Julie Cook | 4 Mar 1997 18:53
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Tire Pressures

dg responded to your post:

>>Nick, you are asking a question that will garner you a wide spectrum of answers.  Unfortunately, some of
the participants will not respond,
believing that they have the hot secret tire setup equation.  Although
some really do, others just believe they do.<<

I doubt that there is a single person who runs up front in National
races that won't tell you exactly what tire pressures they are using.
I'm not sure most of us even use the complex guidelines that have
suggested. We've always run 12/13 or 13/14 with Hoosiers and 14/15 or
15/16 with Goodyears, regardless of any outside factors. We check tire
temps only to make sure the the temps are even across the tred  which
tells us if we have the set up right, if the tire temps aren't even we
don't adjust the tire pressure, we adjust camber/toe/weight, etc.

Nick, for your information, if you have any questions you'd like
answered, about set-up of chassis, clutches, engine, ask. I'm willing to
bet you'll get an honest answer from any of the top running teams that
will put you into the ballpark, they won't give you their final setups,
but they'll get you close enough that if you put some research into it
you can get there.
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Dillon Pyron | 4 Mar 1997 23:22
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Re: Tire Pressures

Speaking of tires, what are people using for wets?  My friendly Yoko dealer
says that A008's are available in a 10" rim, but he's never seen any and
doesn't know if they are actually made anymore.

--

-- 
dillon pyron
dillon.pyron@...

PADI OWSI-54909    USPSA TY-26031
And next time, use a bigger needle
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Eric Christensen | 4 Mar 1997 19:51

RE: Tire Pressures

Tire pressures are largely a metter of current conditions. What we're trying to achive is a given HOT
pressure. For the Hoosiers this is about 18psi as a general rule. I'm not sure with the new R160 Goodyear
what the pressure they were designed for is. The Goodyear engineers should be able to tell you what the hot
pressure should be. 

Now, how do you get to that hot pressure? By adjusting you cold pressure. This is where the black magic comes
in. The only real way to determine this is through testing. Different cars, different tracks and
different weather conditions affect your cold pressures. For example, on a really hot, sunny day you may
run a slightly higher cold pressure than you would on a cold cloudy day since the tire starts warmer and will
gain less pressure as it comes up to temp. Also, softer compounds tend to build more heat (and pressure).

Using nitrogen instead of air minimizes the problem since it doesn't "grow" much with heat gain. But it's a
pain to carry a nitrogen bottle around, and even more of a pain to try to flush all the air out of a tire and
replace it all with nitrogen after the tire busters hav mounted them in the rim. I personally don't bother
anymore. Air works just fine. 

A good pyrometer is absolutly nessecary to optimize you tire pressures. Longacre's memory pyrometer,
though a bit pricy, is the best that I've found as far as accuracy, convenience and repeatability. DO NOT
USE the new non-contact IR pyrometers. They measure the surface temp which won't give you a good
repeatable accureate reading. Use a needle type probe pyrometer that can read 1/8 - 1/4" below the
surface. There are also computer programs, like TirePro, that are very helpful for analyzing and
compiling a database of tire temps.

Ok, that's the long answer. Now the short answer: I use 12 rear, 13 front as a baseline with the Hoosiers. 

p.s. anyone tried using these new pressure pop-off valves that are on the market? They seem to be very
popular with the roundy-round folks. I like the idea if setting the valves for the hot pressure I want, set
the pressures high to start and let the valves bleed them down as the tires heat up. I'm concerned about 2
things. Are they realiable? I've never liksed the results of having a tire go flat on me. And I'm not sure
what would happen in an extended yellow flag situation where the tires cool down. I'm not sure I'd like to do
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KBSENGR | 5 Mar 1997 01:40
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Re: Tire Pressures

Hi

We run about the same pressures 13/14 but will adjust to 14/13 to change a
push/loose condition.  Might run 12/14 if the spacer likes the set-up. you
are right about hot pressure being the key and the track, track conditions,
weather, spacer, everything affects it.

As far as the pressure relief valves,  they work great IF there are no
yellows, if the sun dos'nt go behind a cloud.  Quit using them, too many
yellows!!!

Mike

def Mike's dictionary: Spacer-----that replaceable part that keeps the rear
roll bar from hitting the front roll bar,  also can make the most differance
in lap times.
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Don Staggs | 5 Mar 1997 03:47

pressure valves,

It is my experience that they work very well as long as the race 
is green flag all the way. When the tires get heated up and the 
preasures are working just fine, great. When there is a caution and you 
get slowed down, the tire can lose temperature changing your weights 
around and set-up. A tire can lose up to 50 degrees per sec. when hot.( 
if stopped) When your weights are off, the tires that need to work 
harder may take a few corners to get heated up. I don't like the feeling 
of coming to the corner after the restart and not having any control 
because the car lost pressure from cooling off.The tires will have less 
air in them than if you would have run them the old way.
       This is my opinion, I race on ovals and you may want to try them 
yourself. 
 P.S. I think that the lower tire pressures affect the valve. They also 
tend to leak.
                                         Don Staggs
                                         M.I.R.A.M  (mini-indy)
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Gmane