Weekly
Column
Click & Clack Talk Cars
By Tom and Ray
MagliozziDear Tom
and Ray:
My roommate and I have been
arguing about tire traction. I said that a racing
slick (or just a bald tire) has more traction in
a dry environment, and is able to stop a vehicle
faster on a dry road. He said that a tire with
tread has more traction and is able to stop a
vehicle faster. We are on the verge of war;
Ive taken his dipstick hostage, and
hes got my hubcaps. Please help end this
war and bring peace (and my hubcaps) back to this
house. - Matt.
RAY: He needs to return your
hubcaps with a humble apology, Matt. Youre
right.
TOM: On a dry road, a racing
slick will give you more traction. Why? Because
theres more rubber surface area actually in
contact with the road. Thats why drag
racers, who need as much traction as they can
get, as quickly as possible, use
"slicks," or tires with no treads.
RAY: But remember, as soon as a
half ounce of rain comes out of the sky,
youll be in the ditch with your slicks. The
problem with slicks is that when theres
water on the road, the tire rolls up on top of
it, and the water has nowhere to go. And when the
tires on top of the water, NONE of its
rubber is touching the ground! Thats called
hydroplaning, and it severely limits your ability
to turn or stop.
TOM: The purpose of the grooves
in treaded tires is to provide pathways for the
water to escape. That way, while the rest of the
rubber is maintaining full contact with the road,
the grooves are channeling the water out back,
behind the tire. And onto the windshield of the
poor schnook driving behind you.
RACING
By Greg Zyla
Sponsored by Curry Automotive
The Secret of
Front-Wheel-Drive Dragsters
Q: Greg, Im a big fan of
Import Drag Racing, and I am wondering how
front-wheel-drive cars can run so fast? Ive
seen cars go 7.5 seconds at more than 190 mph in
the quarter mile with front-wheel drive. How can
they do this with all that torque steer? -- B.H.,
Spokane, Wash.
A: I wondered the same thing
until I found out how they do it. First,
lets explain what torque steer is.
Torque steer is common in
powerful front-drive cars. When the throttle is
opened full, the car usually pulls either left or
right depending on the engine and transaxle
setup. This results from unequal shaft lengths
leading to the front wheels because the engine
sits sideways in the car.
On a Pro FWD drag-racing Sport
Compact Car, the engine is actually turned
90-degrees and sits in the car longitudinally
(the long way) and is connected to the front
axles by what is called a V-Drive, which was
developed initially for boat drag racers. This
way, a regular aftermarket transmission can be
used, like a racing Powerglide. The power is
transferred to the front wheels by equal length
shafts via the V-Drive. The V-Drive eliminates
the use of the transaxle, which uses unequal
length shafts to move the power to the front
wheels.
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