Boyd Butler Is "Dr. Gas"
Sterling Marlin won the 1995 Daytona 500 Winston Cup race
with a car that turned heads with its engine sound, a smooth,
high-pitched whine compared with the burbling rumble characteristic
of most production-based V-8 engines. Later that year Dema Elgin,
a friend and well-known camshaft developer who has a shop in
Redwood City near where we lived then, filled me in on some NASCAR
engine tidbits and told me I should call a guy in Sandy, Utah
and talk to him about exhaust systems. That led to an interesting
conversation with Boyd Butler also known as Dr. Gas and I wrote
about him and his products in the September, 1995 issue of TV
Although Boyd and I have had phone conversations over the
years I met him for the first time at the Performance Racing
Industries show in Indianapolis a few weeks ago. Boyd has built
a successful business with some innovative ideas.
Here are some photos I took at PRI and following is a slightly
edited version of that article I wrote in September '95.
Boyd Butler shakes hands with a customer in the Dr. Gas booth
at the Performance Racing Industries trade show in Indianapolis.
The guy in between them is Winston Cup driver Joe Nemechek.
Boyd talks to a customer who has a Dr. Gas exhaust system
on a street car. Those tall, shiny things are exhaust pipes,
called Boom Tubes, for Winston cup cars. They exit under the
left side of the cars in front of the rear tire.
This is an Equal Length Single Side Exit System for Winston
cup cars. Headers from the engine fit into the ends sitting on
the table and a Boom Tube fits on the upper end. Notice the transition
from round to oval cross section. That's Jeff Gordon's signature
on that lower left branch.
A display of an assortment of crossover pipes.
Dr. Gas makes a line of race mufflers called Spin Tech mufflers.
Boyd has patented this concept.
Contact Dr. Gas at PO Box 499, Sandy, UT 84091, 801-563-1110,
Boyd Butler Is "Dr. Gas"
In the summer of 1995 Dema Elgin told me he had heard of a
guy who was working on exhaust systems and was responsible for
the strange-sounding exhaust on the NASCAR Winston Cup car driven
by Sterling Marlin and owned by Morgan-McClure racing. The Kodak-sponsored
number 4 Chevrolet car was getting a lot of attention because
the exhaust sounded different, and it was going fast. They won
the Daytona 500 and Dr. Jerry Punch interviewed Tony Glover,
Marlin's crew chief. The Doc asked Glover if the sound was due
to some special 180 degree headers? Glover, tongue firmly in
cheek, answered, "Actually they're more like 140 degrees."
Glover went on to credit hard work by their engine builder, Runt
Pitman. Runt must have found something, because Marlin won two
of the four restrictor-plate races this year.
Dema gave me a phone number and I called Boyd Butler, owner
of Dr. Gas, a company that develops and sells exhaust systems.
Boyd, like myself is an engineer with an aerospace background.
He told me he started trying to contact NASCAR teams in the early
90s but had problems getting their attention. "They just
wouldn't return phone calls," he said. "Most of the
time I couldn't get past the receptionist. Richard Childress
Racing has a voice mail system that I got lost in every time
I called. I never did get through to a human."
Boyd put some ads in Circle Track magazine and Mark
Giles, exhaust system fabricator for Morgan-McClure Racing, called
with some questions. Boyd followed up with him and, in January
of '95, finally made a couple of sets of pipes for them to dyno
test. They saw a 3 hp improvement, and Boyd got a call on a Saturday
afternoon about a week before qualifying for the Daytona 500.
"Basically they said bring all the tubing you can carry
and get here as soon as you can," Boyd said. "Their
shop is in rural Virginia, so I had to fly into Johnson City,
Tenn. and drive to their place. I spent a frantic few days putting
some systems together. I had always worked with round tubing,
but they have to use oval tubing because they run their cars
so close to the ground. I had to learn how to work with the oval
stuff, and I learned in a hurry.
As I was driving off they were loading the cars into the transport.
I made a system for the Cup car and one for a car they ran in
the Busch Clash. The final configuration gave them an extra 4.5
hp, a one percent improvement. They usually have to find several
small performance gains to make an engine that much better.
"That next Saturday night I was watching Daytona 500
qualifying on ESPN, and there was Benny Parsons and the other
announcers talking about the weird-sounding number-4 car. I guess
it worked. Sterling won his qualifying race and won the 500.
"After that I got calls from all the teams, but Larry
McClure said he wanted an exclusive deal for that season. That
turned out to be a blessing. I got paid some money, and it gave
me time to develop the concept without a lot of pressure. Learning
to work with oval tubing is a big deal. I also had time to design
and build tooling that helps a lot. Ground clearance is very
critical on Cup cars. They spend a lot of time and money getting
everything, including the driver, as low in the car as it will
go. The lower the center of gravity, the less weight transfer
they get. That's very important.
"Next year  I'll be able to work for other teams.
The new IROC cars will be Pontiac Firebirds, and they'll have
our exhaust system. They want our system just because it sounds
good. We also make mufflers and exhaust systems for high performance
street cars. Our goal is to make product that squeezes maximum
performance out of the exhaust system."
How Does It Work?
I asked Boyd to explain what his exhaust system does to increase
power. "It uses energy--pressure and temperature--in the
exhaust gases to help those gases get out the exhaust pipe a
little better. The engine sees a slightly lower pressure in the
pipe and that helps get more air through the engine and makes
"A normal V-8 engine like we all drive and like the one
that powers all the Winston Cup cars, has a 90-degree crankshaft.
There are four connecting rod journals on a V-8 crank, and they're
all 90 degrees from each other. This makes a balanced engine,
which is important for a passenger car. The Indy car V-8s have
180 degree or "flat" cranks which make a stronger,
more reliable engine at high rpms. A 90-degree V-8 engine is
the same as two four-cylinder engines hooked to the same crankshaft.
On each bank there are two cylinders that fire within 90 degrees
of each other. These two exhaust pulses are very close together
as they travel through the exhaust pipe. This is the reason some
V-8s with dual exhaust pipes have a popping noise you can hear.
That's the two pulses arriving at the end of the pipe about the
same time. These two pulses can interfere and cost some power.
"You see a cross-over pipe on most V-8s with dual exhaust.
This is a pipe that connects the exhaust pipes from the two banks
of cylinders. A cross-over pipe smoothes gas flow and lowers
sound levels. We've learned how to use it to make some extra
"We use a four-into-one header on each bank and do some
special stuff to the cross-over pipe so that the high-pressure
pulse caused by those two cylinders firing close together is
vented through the cross over into the other exhaust pipe when
the pressure over there is low. There are some reflected pressure
waves that have to be timed right, but the result is a slightly
lower pressure in the exhaust system downstream of the cross
over. That lower pressure encourages more flow through the engine
which makes more power. The modified pressure waves in the exhaust
is what makes the unique sound, a higher-frequency sound. That
pop sound has been smoothed out. That sound is what says the
system is working.
"I've seen dyno tests that show our system broadens the
torque curve. With a restrictor-plate motor, the torque falls
off really quick when the engine starts to starve for air. Our
exhaust systems let them breathe just a little better and at
a little higher rpm. I figure we increase the overall volumetric
efficiency of the engine by about a half a percent."
I asked Boyd how he got that "Dr. Gas" name for
his company. "I had some technical-sounding names that I
thought were neat, and I asked a friend of mine what he thought
about them. He said he'd tell me the next day, but he couldn't
remember any of those names when I called him back. 'Dr. Gas'
was kind of a joke, but people remember it so that's what we