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Burnouts.
We love doing them, but do we know how to do them properly?
In a recent issue of National Dragster, David Reher
had a great column entitled "Are Burnouts Abusing Your
Engine?" I thought his article was so important that
I referenced it here earlier this year as a must-read.
On a
separate occasion, I had a conversation at The PRI
Show with Milodon about a new
oil pump they came out with because racers were breaking
regular oil pumps on the burnout due to excessive shake.
I’ve
long suspected that racers way over-do it on the burnout,
but seeing David Reher’s article in National Dragster
and my conversation at PRI gave me an idea for a more inclusive
article about how excessive and/or improper burnout technique
can be killing parts.
When
I started racing the Dodge in 1995 it was a small-tire car
with a leaf-spring suspension, and it needed a long burnout.
That became a habit which remained even after upgrading
to a ladder-bar suspension and much bigger tires, changes
that would make it work better without needing such long,
overkill burnouts. But like they say, old habits die hard,
but I was about to change mine.
The first part of my burnout epiphany came one night in
2003 at Island Dragway, when my line-locks failed on my
burnout during 1st Round. The tires barely spun; the Dodge
lurched forward with hardly any smoke. I thought I was dead;
as I approached the starting line I kept thinking that I
was going to spin, that I’ll never run the number,
and to be ready to keep my foot in it at the stripe. Instead,
the Dodge dead-hooked and went quicker and faster.
Carl
Robinson, Motorsports Manager/Race Wheel Product Manager
for Mickey Thompson Performance Tires & Wheels
states, “In general, and in specific to the M/T
products, a minimal burnout is required to maximize performance.
To be more specific, the elapsed time of the burnout while
being minimal must be appropriate to the conditions. The
hotter the track temp, the shorter the burnout. Excessive
burnout will cause a melting of the tread compound at the
shoulders, increase the potential for "slip" and
decrease tire life.”
So
racers, you probably don’t need to kill your tires
on the burnout. Try keeping it short and sweet. This will
result in longer tire life, and potentially lower staging
temps as well. Those of you who know me know that I easily
get 350 passes out of a set of Mickey Thompson 31 x 10.5Ws,
because I'm not killing them on the burnout.
The
second part of my "burnout awakening" came a few
years ago when I was racing the Dodge regularly in Super
Pro, where most of my opponents were dragsters.
I
realized that dragsters don’t use line-locks for their
burnouts; they roll through the water and just stab the
throttle in high gear to get the rears spinning. The car
doesn’t sit there stationary; it moves forward immediately
and the driver is out of the throttle pretty quickly.
When
I realized this, I questioned my own burnout technique and
decided to try it the dragster way. No line-lock, no shifting
the transmission during the burnout, just rolling through
the water, stopping the car, then stabbing the gas in high
gear to get the tires spinning and feathering off the throttle
to keep the RPMs down. It worked great and I’ve been
doing it this way ever since.
This
is pretty much the way transmission and converter companies
suggest doing burnouts. According to JC Beattie
Jr. of ATI
Performance Products, “Start out
your burnout in the highest gear that you are able to spin
the tires easily and not create too much extra heat in your
converter. With our Challenger that is 2nd to 3rd gear.
Why make an extra shift if it’s not needed? Driving
out of the burnout is important for all of your driveline.
The chirp is bad but sometimes hard to avoid especially
on well prepped tracks. Driving out will help with that."
This
same general idea is stated in the instruction sheet that
ATI supplies with their converters:
1) Spin tires slowly in water to get them wet while
avoiding soaking the wheel wells.
2)
Pull to the front edge of the water using Low to High
for Powerglide, Low to 2nd to High for Turbo 400, Ford
C-4 and C-6, and 2nd to High only for Torqueflite and
Turbo 350. For high performance vehicles, do high gear
burn-outs only to save 1 to 2 shifts per burnout.
3)
When the tires are hot enough, release the line lock
and power the car out of the water 5 to 10 feet and
lift. Avoid hook-up that will scuff the tires.
4)
Stage immediately! Dry burn outs reduce traction and consistency.
If you don’t believe this, pay attention to your first
dry leave behind the line. It will hook solid every time.
Small amounts of water left on the tires will dry completely
from the tire heat long before the green comes on.
I
realize that not all race cars are the same and some do
need a longer burnout than others, but what if you want
to try this style of burnout? How do you incorporate these
changes into your routine? Take the advice of Mickey Thompson’s
Carl Robinson: “Take a common
sense approach. Every race vehicle is unique. Experiment
when it doesn't count – "test and tune"
nights were designed for it. Once you learn what the vehicle
requires, operate on the minimal side. The ultimate goal
is to correlate both the "operating range" of
the tire and the "tire inflation range" with
the ambient conditions.”
Sources:
ATI Performance Products,
www.atiracing.com.
Mickey Thompson Performance Tires & Wheels,
www.mickeythompsontires.com
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