Horsepower Is In The Tune by ProQuest


Today, almost anyone can begin with a good basic combination, but many racers struggle to find the tune-up that will extract maximum power from the engine and maximum traction from the chassis to produce the right numbers on the time slip. Couple that with data gathered at the track and/or on a chassis dyno or engine dynamometer, and you have all of the tools needed to find (and maintain) maximum power from any drag race engine.

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									 Racing Technology with Evan J. Smith

Horsepower Is In The Tune
O     ver the years, racers have found different ways
      to tune their engines while searching for the
ever-elusive “perfect run.” Those who have mastered
                                                             few hundred bucks, and many are advertised in
                                                             National DRAGSTER.
                                                                 And with the bevy of affordable air/fuel ratio
the difficult art of tuning have gained great                equipment on the market from companies like
prominence in our sport, along with championships            Innovate, Dynojet, Altronics, Computech, and others,
and race wins. Tuning, in simple terms, refers to the knowing your air/fuel ratio is not that hard. Couple
act of dialing in the variables that affect                  that with data gathered at the track and/or on a
performance, and this can mean changes to the                chassis dyno or engine dynamometer, and you have
engine, clutch/converter, transmission and rear-end          all of the tools needed to find (and maintain)
gearing, and/or suspension.                                  maximum power from any drag race engine.                        Jeff Bardekoff has a strong-running Max Wedge
    Today, almost anyone                                                                    You have to wonder how           Plymouth. The question was, with tuning, could we make
can begin with a good                                                                    anyone can spend thousands          it quicker?
basic combination, but                                                                   of dollars on a set of
many racers struggle to                                                                  headers, collectors, or other       then hooked up the data-logging oxygen sensor into
find the tune-up that will                                                               performance parts and not           the collector and went to work. We systematically
extract maximum power                                                                    know what effect it had on          made our baseline runs, which showed us the engine
from the engine and                                                                      the tune-up. How can you            was very lean. I was amazed at this considering how
maximum traction from                                                                    determine if a new part did         well the car had been running. Normal operating
the chassis to produce                                                                   or did not work if you don’t        range for most naturally aspirated race engines is
the right numbers on the                                                                 know why it caused a change 12.8-13.3:1. Nine times out of 10, you’ll find the
time slip.                                                                               in power/e.t./speed? How            sweet spot somewhere in that range, but if an engine
    With regard to engine                                                                many people make a change           is out of that range, chances are power is not being
tuning, many things affect                                                               and claim the new parts             maximized.
performance. Ultimately,       Before making any changes, we made three baseline worked or didn’t work but                       By the end of the day, we threw the biggest jets
we want the engine to          runs. It can be difficult running a car with a loose have no idea why?                        Bardekoff had at the 426 Max Wedge and found 10
ingest as much air as          converter on a chassis dyno because when the throttle        For example: Did those           horsepower at the peak and even more below the
possible (for this, we rely    is kicked open, the rpm can spike, which leads to new headers lean the engine                 curve. Torque production jumped 13 foot-pounds,
on weather conditions),        erroneous numbers. Thankfully, we had the help of Jim out, therefore causing a gain           and, remember, this is at the wheels!
then we make the               D’Amore and JDM Engineering in Freehold, N.J., to help in power? Did they make it                 Because the dyno monitors weather conditions,
necessary jet or fuel map      us make smooth, consistent pulls.                         go dead rich, killing power         it’s able to correct as the day goes on. Additionally,
changes to mix in the                                                                    and e.t.? Perhaps if you got        we were careful to monitor other variables, such as
correct ratio of fuel, and we set the ignition timing to     the engine back in the proper air/fuel                                                          the temperatures of
produce an efficient burn, which hopefully results in        range those new headers that cost                                                               the intake manifold
maximum cylinder pressure. When this is achieved, the you .04 might have actually showed a                                                                   and coolant. While we
engine makes plenty of force on the pistons and a lot    
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