As noted previously, the 1995 Camaro that
served as the basis for “Project Road Rocket” received
a change in rear end gearing and that, in combination with the
repair of an exhaust system leak really brought the car to life.From
a best quarter-mile performance of 12.87 at 109.27 miles per hour
the Camaro blasted to a 12.24 at 113.55 miles per hour. That’s
as quick and as fast as some supercharger-equipped Camaros. As
with any vehicle that’s being groomed for improved performance,
the key to hitting impressive numbers is the overall combination.
In the case of LT1-equipped Camaros, Corvettes and Firebirds,
free-breathing intake and exhaust systems combined with aggressive
rear end gearing are essential. So is a good pair of rear tires.
Once the 4.10 rear end gear had been installed, it became almost
impossible to launch the car without a blaze of tire smoke.It
took a change to 10″ wide Mickey Thompson slicks to get all
the power to the ground.While a 4.10 gear may seem excessive in
a street-driven vehicle, the advent of overdrive transmissions
brings viability to overkill. The manual gearbox that’s installed
in Z/28 Camaros has six forward speeds with both fifth and sixth
being overdrive ratios. Sixth has a .50:1 ratio, so a 4.10 rear
end has an effective overall ratio of 2.05:1 in sixth. That compares
to 1.71:1 for the original 3.42:1 rear end. Consequently, the
overall effect is a surprisingly slight elevation of engine rpm
at normal speeds. In fact, in sixth gear at 80 miles per hour,
there’s only about 300 rpm difference between the 3.42 and 4.10
gears. The car still travels over 22 miles per gallon of gas on
the highway.
Pro Stock program
If you’ve been wondering about the recent
proliferation of Pro Stock teams running competitively at National
Hot Rod Association (NHRA) national events, think “Rent An
Engine”. A couple of engine builders have plans under which
a racer rents a competitive Pro Stock engine for approximately
$5,000 per race; that totals $95,000 per year for the whole 19-race
series. Breakage and miscellaneous expenses are extra.That might
seem like a heavy hit, but when you consider the amount of money
a typical independent team spends on research and development
to stay competitive, it’s actually a bargain. One side effect
of the rental programs is that occasionally one of the renters
is asked to take a dive so the engine builder’s house car winds
up in the winner’s circle. Of course, such goings on are routinely
denied, but in my opinion, a look at the competition record indicates
several “group efforts”.
Where are the Dodge boys?
Any mention of NHRA Pro Stock naturally brings
up the subject of the Wayne County Team MoPar Dodge teams. After
several years of front running performances, including three Pro
Stock championships for Darrell Alderman (1990, 1991, 1994) both
Alderman and teammate Scott Geoffrion vanished from the Pro Stock
scene in May, 1995 when vandals allegedly broke into the Wayne
County Speed Shop and destroyed six racing engines. Since that
time, there has been one excuse after another as to why the Dodges
haven’t returned to competition.Supposedly, after moving to a
new type of cylinder block, the engine builders haven’t been able
to come up with a competitive combination. Rather than being non-competitive,
they’ve decided to abstain from racing.The rumor mill has
it that the Dodge teams were caught running nitrous oxide and
given a one-year suspension. Rather than embarrassing the teams’
primary sponsor (Chrysler Corporation) both cars were simply withdrawn
from competition voluntarily. At first, that theory seemed preposterous,
but as time goes by, and the “Dodge Boys” continue to
sit on the side lines, you have to wonder. Alderman won three
of the first four races in 1995, Geoffrion won the fourth. With
a string of victories like that, the Dodge teams obviously had
a winning combination. With all that’s at stake, the obvious move
would be to return to the original engine combination, start winning
races again and put an end to the speculation. Why hasn’t this
been done?Could it be that nitrous oxide was in fact being used?The
whole situation is bizarre. More than a few people have put forth
the opinion that the break-in is a complete sham. According to
some observers, the vandalized engines shown in photographs in
various publications don’t seem to look like competitive Pro Stock
engines. Other people have stated that much of the damage appears
to be from the inside out, which means it couldn’t have been caused
by someone with a hammer.An interesting aside is that some race-savvy
observers think that the cars were equipped with nitrous oxide,
but that the drivers were completely unaware of it. The theory
is that the systems were triggered remotely, or with a timer.
Of course, all these theories are nothing more than speculation,
but the longer it takes the Dodge teams to get back on the track,
the more credence they seem to have. Stay tuned to the year’s
remaining NHRA national events to see what develops.
Computers rule
Computers have had a dramatic effect on racing
and high performance and their influence continues to grow. And
while there is a resentment against the semi-conductor invaders
in some quarters, there’s no doubt that the information they provide
is invaluable. One of the latest developments is a system called
the DataMite from Performance Trends, Inc. of Dearborn Heights,
MI (810)-473-9230. DataMite uses sensors on front and rear wheels
to determine the amount of slippage in the tires and/or driveline.
It can also plot tire growth and with proper input data, it will
also compute horsepower, torque, G-force, vehicle speed and number
of feet traveled.All information gathered is contained in a small
“black box” and can be downloaded to a computer for
subsequent analysis. Since the DataMite also computes horsepower,
it can evaluate the effect of modifications. As a tuning aid,
this system is invaluable. The DataMite is particularly attractive
because it can be used on drag race cars, street machines, oval
track and road race cars. (Racers in all quarters are often unaware
of the extent to which slippage compromises the performance of
vehicles.) Of course, the one requirement is all four wheels must
remain on the ground if the system is to supply valid data.
Eye spy
Another recently introduced piece of equipment
that has tremendous potential is the Powervision Inspecta-Vu System
recently introduced by Powerhouse Products of Memphis, TN (800)-872-7223.
The system includes a five-foot long, 1/8″ diameter fiber
optic scope that is used to look deep inside an engine, transmission,
rear end or anything else you can imagine. The scope, which contains
its own light source, attaches to a small box that houses a miniature
video camera. By connecting the camera to a video monitor, you
can probe places normally visible only after disassembly and view
it all on a television screen. As an example, if you want a close-up
look at a cylinder wall, valve, valve seat or piston dome, all
you have to do is remove a spark plug and insert the 1/8″
diameter scope. Then by simply manipulating the scope, you can
view any part of the cylinder above the piston on a video monitor.
It’s also possible to record the inspection on video tape for
future comparisons or to send off to interested parties that aren’t
close by.The Powervision system was developed to allow racers
to inspect engine and driveline components without having to disassemble
them, but obviously, it can also be used by repair shops and parts
stores to diagnose suspected problems.
Getting a grip
One of the reasons that late model cars are
recording such fantastic quarter-mile performances is tire technology.
For years, most research and development efforts have been focused
on the large slicks used by professional racers. But tire companies
have recently begun refining the smaller slicks used by Sportsman
type cars. Much of the impetus for this development has arisen
from the increasing popularity of associations like the NMCA (National
Muscle Car Association) which have a number of classes designed
for street-legal cars. The rules for many of these classes place
limits on tire size, so it’s essential to develop maximum bite
from a given width.One company that’s been particularly active
in this area is Mickey Thompson Performance Tires (800)-222-9092.
According to sales manager Jerry Francis, a number of changes
have been made to not only improve bite, but also to increase
longevity. A case in point is the slick that has become the tire
of choice in NMCA’s Super Street class, which requires a maximum
sidewall width designation of 10.5″. In 1995, most of the
cars ran a 29.5″ x 10.5″ tire and after 15 passes, it
was time for a new set. This year, a redesigned version which
still has the 10.5″ width designation, but actually measures
11.2″ has taken over. (These “wide” tires are designed
to take full advantage of the rules which allow for an actual
tread width of up to 11.5″ to accommodate the increase that
normally occurs as a tire wears.) After 45 runs with the new tire
design, one racer reported that starting line bite was still as
good as when the tire was brand new. The racer replaced the tires
at that point because he felt he was pushing his luck- he had
already gotten three times as many runs as he ever had previously.Francis
also noted that with the burgeoning import drag racing market
in California spreading eastward, demand for front-wheel-drive
slicks is booming. So Mickey Thompson has released a 22″
x 7″ drag slick and a 205/50D15 DOT race tire. Both tires
are designed specifically for FWD applications. And that’s not
all that’s in the works. Within the next year or two, a host of
new drag slick designs will be released.
