FOT,
For those of us that can run 60 series tires, the passing of the venerated
Yokohama 195-60-15 008Rs' tires was a sad turn of events. Like many FOT, I
turned to the Hoosier Vintage TD 5.50-15 Bias Ply tire. I did this even
though my race organization, CVAR, had decided to waiver all CP and DP cars
that ran 15" wheels, TR's, MGA's, Healeys and Porsches, allowing us to run
50 Series tires. CVAR runs 1972 SCCA rules so it is not too out of period in
terms of correctness. It took a while, but I got used to the Hoosiers and
brought my lap times back down to where I was starting to approach the lap
times I had recorded with the 008Rs Yokes. The biggest problem I see with
the Hoosiers is how fast they wore out. Admittedly I should have flipped
them inside out to get more life, but 4 race weekends was substantially less
than what I was accustomed to. My last time out I finished the weekend
running on donated 1995 build-date Yokes (thanks Brad Kahler) due to one of
the Hoosiers showing it's cords. I posted my fastest times of the weekend on
those tires, partly due to the relative gear ratio changes, but also because
I raced them like the Hoosiers, drifting through turns. I needed tires and I
noticed that Dunlop, through Roger Kraus Tires was offering a 205-60-15 race
compound radial tire.
A quick note to this list provided no feedback as to these tires. I took a
chance and bought a set based on Roger Kraus' promise that they would
outlast the Hoosiers and were almost as fast as the Yokes. Now, I've been
told by others that after getting used to the Hoosiers, they were as fast on
them as they were on radials, but I never have been able to duplicate that
feat. I think that might be related to the fact these same guys were
comparing the Vintage TD's to the 70 series Radials they were used to
running. Wider is better! In Kraus' sales pitch he talks about a test they
ran in which a racer was 4 seconds faster on the Dunlops than he was with
his Hoosiers. I can't say that happened for me. I was as fast as I am on the
Hoosiers, but there is more work to be done to see if they can be faster. I
did discover that the tires worked better for me at lower pressures than I
was expecting. I started out at 32/31 and had trouble getting the front end
to turn in the 180 degree carousel at TWS . Dropping the pressures to 29/28
helped. The weather was inconsistent varying from a hot sunny race on
Saturday to pretty cool with intermittent rain on Sunday.
Unfortunately I suffered through a few parts failures this past weekend and
only completed 2 out of 4 races. That kept me from learning more about the
tires. While starting the car to take it off the trailer, my High Tech
Starter turned into a Budget Arc Welder. I think the cap screws that allow
rotating to fit different cars must have loosened. I avoided using it all
weekend once I saw that light show. Not a big problem, unless you have other
problems, and I did! Apparently, I managed to eliminate that gap on the No.
3 spark plug while installing it at home. While tracing that miss, I traded
out my cap and wires for a back-up cap, one of those Intermotor brand caps.
These are the ones with the aluminum posts that are ground thin on some
posts and not at all on others. Be careful, they come in Lucas packaging
too! I only put it in as a spare because the NOS Borg Warner cap I was
carrying as a spare had one of those little screws frozen tight. You never
know for sure when you buy stuff on eBay. I've used the repro caps in the
past, and they worked OK, but the posts get torn up and that scared me into
paying $20.00 a cap for NOS. Anyhow, it wasn't the cap and the miss remained
until I looked closer at the spark plugs. Regapping fixed that issue. Went
out for my session, and was doing great, but the miss returned after about 8
laps. I attempted to finish the race, but it got worse over time and
surprised me by suddenly dying completely on the far back straight at TWS. I
tried to bump start it a few times while coasting to a stop, but it was
dead. No pit crew to push me either. I was pretty worried at that point, but
after the long tow in we traced it back to the distributor and a faulty
rotor, no doubt caused by the crappy cap. Of course, there was nothing wrong
with the first cap I had removed, but this one was evil! A buddy had worked
the screw loose on the good spare so it went in with a new rotor. A short
distributor cap ceremonial smashing ceremony failed to completely destroy
the offending cap so it was simply thrown in the trash. The afternoon race
Saturday was quite exciting, and I did well, except that I over-heated the
outside front tire in the carousel and it wouldn't turn. The best way I can
describe how it acted was little hops interspaced with grip. Playing with
the throttle wouldn't bring the rear around. Pressure had climbed too high
but the tire temps were pretty even at 156 degrees across the tire. The
other 3 tires were not at all similar, with the centers close to 140 and the
sides some 7 or 8 degrees less. On Sunday I dropped pressures and the
results improved, but due to moist conditions and overcast skies that result
in inconclusive. More track time will tell. Oh yeah, I had another stupid
problem that resulted in a very weak mixture Sunday morning. One of the SS
safety wires that I rigged to hold in the jets broke and I lost jet on the
track. It's a wonder I didn't start a fire, but I guess it sucked most of
the fuel and a lot more air. It felt a lot like the rotor problem! Needless
to say, I found a better way to wire the jets in place.
The real good news was that the Southwick axle I built worked. It's my first
diff rebuild to actually see action. Adding 4.1:1 gears changed the car
dramatically. I can now use 4th overdrive on the front straight, I mean I
have to use 4th overdrive. Race starts require 2nd overdrive and I can out
pull some 911's on the start. I still have trouble with their top end, but I
make a lot of it up in braking and handling. I'm still about 2 seconds a lap
behind the core group of 911's, and I hope that I can get up there when I
figure out the Dunlops. Cheerio!
Bob Kramer
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