Jim Hall Interview
Page 2 of interview
Page 3 of interview
The Brian Redman International Challenge, Jim Hall Grand Marshal
In June I learned that Jim Hall's Chaparrals would be featured
at the vintage races at Road America, near Elkhart Lake, Wisc.,
July 20 to 22. The event title was The Brian Redman International
Challenge. Jim Hall was the Grand Marshall. The black and white
photos on this page are from the event program.
I called Cheryl Barnes, communications director at Road America
to see if I could get some time with Jim Hall. The book I'm working
on will try to explain some technical aspects of tires, vehicle
dynamics, and shock absorbers. Jim Hall was one of the first
technically educated people involved in designing modern racecars
and I wanted to talk to him about his experiences.
The event at Road America, was titled Can Am Thunder. I decided
to drive to the track from my home in Springfield, IL. on Thursday,
stay somewhere that night and drive back home Friday afternoon.
After a few phone calls I found a room north of Milwaukee less
than a half hour from the track.
The drive up on Thursday proved uneventful taking about six
hours. A friendly young lady quickly issued my credentials, and
I found my parking pass into the into the paddock area right
in the middle of all the racecars and haulers. Let me tell you
that doesn't happen at CART or NASCAR events.
As soon as I drove through through the front gate I heard
the unmistakable sound of big-bore race engines so I stopped
at the first grandstand I saw. The treat layed out before me
was the sight of a bunch of old Can-Am cars roaring down the
hill from the right, tip-toeing into Turn 14, and then blasting
up the straight pounding the ground with their exhaust. Ten minutes
later I got back in the car and drove to the media center. The
rest of the afternoon I walked around the paddock looking at
the cars, an impressive gaggle of historic racecars from mundane
Triumphs to the almost unique Scarabs to Formula 1 cars less
than 10 years old.
Maybe the most beautiful Formula 1 car of recent years is
this Ferrari from 1991 owned by Tom Murphy of Wilmette, IL.
These next two photos are a 1988 Nissan GTP car. Note the
size of the tunnels and diffusers. This car developed so much
downforce that Goodyear had to make special tires to take the
load. The low rear wing creates low pressure behind the car that
propagates into the diffusers augmenting underwing downforce.
On Friday just after noon I sat in the media center over my
notes. Then Jim Hall appeared in tow behind Cheryl and he sat
down followed by Brian Redman. Brian's appearance was a surprise
to me. He's a subscriber to the newsletter and I've talked to
him at various races finding him to be a charming and delightful
guy. I had only prepared questions for Jim Hall so I would have
to figure out how to get Brian into the conversation.
We sat in three chairs in one corner of the media center and
I explained the topics I wanted to cover. Jim started talking
and I turned on the tape recorder. Almost immediately the other
eight or ten people in the room began edging closer so they could
listen in on the conversation without actually looking like eavesdroppers.
It didn't work because Jim soon included them in his words and
gestures and we were just a bunch of racers listening to a pair
of our heroes telling stories.
As I transcribed the tape it was easy to recognize and differentiate
the two voices. Brian's deep, rich British tones contrasted with
Jim's tangy Texas drawl now softened by time and world travels.
PH: Early on you bought racecars made by other people. How
did you get started designing racecars?
JH: I drove cars and tried to make them better. I'd make an
educated guess as to what to do. And I used the feedback from
the driver, which in my case for a long time was myself, which
I think was pretty critical for my education. The feedback is
kind of instantaneous and pretty reliable when you do it that
way. I think that helped me a good deal. I got to do some work
with what was probably some of the original instrumentation on
racecars. Chevy R&D put together an instrumentation package
because they wanted to know the numbers, not just the subjective
driver feedback. So I got to see quite a bit of real data and
that helped a lot. It's not anything like they have in data acquisition
today but it was very useful even though primitive."
PH: "That was going to be one of my first questions,
did it matter being a driver. So you were an engineer and you
had some ideas and you were a drivers so you got instant feedback
whether those ideas were good or not."
JH: "Yeah, I think that was really important to my career
as both a designer and a driver. Sometimes I thought it helped
me as a driver and sometimes I thought it hindered me a little
because I was always thinking about ways that I'd like to make
the cars better rather than just worrying about getting it around
the corner. I think it might have hindered me a little bit in
some ways but all in all, just looking at the guys I drove against
and how I competed and so forth I was not unhappy because I felt
like it was a good balance."
PH: "You bought a Porsche Spyder early on. So that was
one kind of car you looked at."
JH: "Yeah, I didn't have any experience with Porsches
up till the time I got to racing nationally in SCCA races. When
I went to local races I always had a better car than the local
guys so it wasn't good for them and it wasn't good for me."
PH: "You had some good battles with Delmo Johnson [Jaguar
D type with a Chevy V-8 engine] at Green Valley Raceway."
JH: "Yeah, but that was a big car vs. a small car and
that was good. I enjoyed those races. That was the real reason
I got the Porsche and it was a great experience for me because
it was a different handling car and it was a car that had a lot
of racing history and I got to experience that.
"How I got that car is interesting. Buddy Berlin from
Albuquerque was the VW dealer there and I knew him because I
grew up in Albuquerque. He called me one day out of the blue
and said, 'I've got an RS61 on the dock in Houston and I don't
really want to take delivery. I don't have the money. Do you
"I asked him how much it would cost and he told me and
I said I'd take it. I went and got it and drove it one time at
Green Valley and, to tell you the truth, I didn't like it at
all. It really pushed badly and it wasn't fun to drive.
"The next week I got a call from Roger Penske. I didn't
know him at that point. He told me he needed an RS61 because
Bob Holbert had one and was beating Roger with it. He suggested
trading his Porsche RSK for my RS61 but we'd keep our own engines
and gearboxes. He said make him a price. We figured out a deal
and he sent one of his guys down with the car and we swapped
engines and transmissions and he went off with the car.
"The K was a helluva car. It would take a set real nice
and you could drive it around a corner with the throttle and
it seemed like it had a lot of cornering power.
"We used to wonder, before we began to think of the science
of it, why the little cars like the Porsches would beat the big
cars. We'd go to the short tracks and they'd be all over us.
They'd come off the corners a little quicker, they'd squirt for
a little while, and they'd go deeper into the corners on braking.
I'd wonder why I was having so much trouble staying ahead of
this guy in this little 1600 cc car. What it was was he had about
the same size tires as I did but the car was a lot lighter. He
got a lot more cornering power than I did. That wasn't so obvious
to everybody in those days, how important the tires are."
PH: "We know now how important tires are. For both of
you, Jim and Brian, has there been some time when tire development
jumped ahead and you went seconds faster? [At last I had figured
out how to get Brian in the conversation.]"
BR: "I was driving a Lola T70 Can-Am car in England in
1966. We were running on Dunlop Green Spots, I think."
JH: "Only about five and a half inches of tread on those,
BR: "Bruce McLaren was the official tester for Firestone
tires. They brought three of their cars to Oulten Park in North
England which was only an hour from where our car were garaged.
The McLarens all blew up and the Firestone people asked us if
we could bring our car to fill in the next day. We did. Firestone
had a wider tire that was almost a slick and we went four seconds
faster than our previous best."
JH: "That tire had almost no tread, only some little
sipes cut in it."
BR: Even then the wider, slick tires didn't get going for
several more years."
JH: "During that time I was with Firestone. Bruce and
I were the guys that ran Firestone tires. I did the testing in
the States and he did it in England. When we first built the
so-called automatic car it was a single speed torque converter,
with no transmission. All you did was put it gear and go. It
had a two-to-one torque multiplication out of the torque converter
so it was like having a high second gear. On the Dunlop Green
Spots, the best tire we could get, we could spin the tires from
about 10 feet out of the gate up to 80 mph or something. So we
thought why do we need anymore transmission than this. It was
fine not having any gears.
"Then I got with Firestone and they brought us development
tires. The first tires we got were wider than the Dunlops. They
had an inch or so more tread on the ground. We were runnin' 7-inch
rims in the back I think or maybe 6-inch in the front and 8-inch
in the rear. Or 5s and 7s. I don't recall exactly. They were
15-inch diameter wheels. We put the Firestones on and tried them
in our skidpad testing.
"We had started runnin' skidpad tests, just going round
and round on the skidpad. We did a lot of tire testing and that's
the way they checked the friction coefficient to see what kind
of cornering power you're actually getting. We got good at it
and we found out we could balance the car this way. You could
put the car on the scales and balance the weights but you go
out there on the skidpad and it won't turn the same both directions
because somethin' is amiss in the car.
"It was a little bit more technical than we could figure
out. Either the chassis was tweaked a little bit or the caster
was off on one side or somethin' and you'd find out running around
on the skidpad that, in one direction, it would go up to 0.98
Gs and only 0.92 the other way.
"That skidpad was really handy. We'd crank a little weight
in the car to balance it. You could look at the camber by looking
at the temperature across the tire. We found a little time on
the skidpad made a big difference, made a nicer car. We started
setting up all our cars that way. We'd get them all ready to
go to a race and we'd go a few rounds in both directions and
make sure it was balanced. That was good for slow speeds, about
40 mph, and then we'd go out and run through a hig-speed turn,
150 mph, and we'd see how it was balanced. That was the way we
set the aerodynamic balance.
"So Firestone told us their tire was built to run on
a 7-inch wide rim. I had built some modular wheels and we could
vary the width by what mid-section parts we used. We'd run the
tires they gave us on a 7-inch rim and maybe an 8 and a 9 too.
The wider rims made the sidewalls stiffer and istead of running
a 0.95 average G you'd run a 0.99. So of course we put them on
"Well, we'd go to the next race and the Firestone guys
would look at them and say, 'We didn't design those tires to
run on a 9-inch rim. We better build a new tire.' They'd add
an inch to the tread. They'd do them quick too. They can build
prototype tires in a hurry. In a couple of weeks they'd have
another tire. And we'd run it on a 9-inch rim and a 10 and maybe
an 11. And we'd find it was better on a wider rim so it would
happen all over again.
"In a matter of less than a year we went from those narrow
little Dunlop Green Spots to a tire that was almost double the
width. And our single-speed torque converter just couldn't handle
all that grip. We immediately went to a two-speed transmission
so we could get more torque multiplication off the slow-speed
"So that's what happened with me on tires. In the middle
60s, probably 64/65, Firestone took us from less than 6 inches
of tread with up to 12 inches."
PH: "Just because you kept skidpad testing them on wider
BR: "Speed is the criteria, at the end of the day. Speed
on the skidpad is speed around the racetrack."
JH: "Cornering speed is the key to everything. You can
have more horsepower, you can accelerate fast but you got to
stop it at the other end. But, if you leave the corner just that
much faster, you carry that speed all around the racetrack. The
whole thing is cornering speed, basically."
Interview continued. Links to the other pages are on this