Top Questions About Performance Underdrive Pulleys
"Do underdrive pulleys really deliver more horse power?" Every experience we have with underdriving
engine accessories shows that yes underdrive pulleys do deliver more horse power
by freeing up power lost to parasitic drag. The amount you will realize depends
on your car and the accessories you are driving, a car with alternator, water
pump, power steering, A/C and a smog pump will see a larger HP gain then a car
with alternator and water pump only. Dollar for dollar underdrive pulleys are
one of the best value for HP gain on the market.
"But won't underdrive pulleys cause a charging problem?" Again that depends on your car and how and when
you drive. Automotive manufacturers build a certain amount of extra capacity
into their cars for situation of high demand like driving on a cold rainy night
with the lights on plus whippers and defrosters going. An older car with a less
then optimum charging system and a small weak battery may have charging problems
with underdrive pulleys and some cars with monster audio installations require
higher that normal electrical demands. A well maintained auto should have no
problem at all. Sometimes raising the idle by 100 RPM is all it takes to bring
the charging rate back up to normal.
If electrical charging is an issue with your particular
application March Performance has a smaller alternator pulley available to
increase alternator output but to still allow a HP gain from underdriving the
other accessories.
"Won't underdrive pulleys cause a engine cooling problem?" Again that depends on your car and how and
when you drive. Putting underdrive pulleys on cars with already minimal cooling
capacity could conceivably push the car into overheating but our experience is
that 99.9% of the cars out there has enough reserve cooling capacity to use our
pulleys. Some user find that the simple installation of a cooler thermostat is
all it takes to bring the temperature back into normal range.
Underdive Pulleys can in some cases cure cooling problems.
With racing applications cavitation can be a problem at high rpms. When a pump
cavitates, it actually spins too fast to push coolant, Coolant must also stay in
the radiator long enough to lose heat before returning to the motor so you can
actually move coolant too fast. Both these issues can be solved by using
underdrive pulleys.
But If low speed cruising is your thing then March
Performance And SLP Performance line of High Water Flow Ratios pulleys may be just what you need to
prevent overheating in those situations.
"Underdrive pulleys sound good but won't an electric water pump set-up give me even more HP?" Yes it is
conceivable an electric water pump can give you more HP than a underdrive
pulleys set BUT there are some issues you should consider before you make that
commitment. Your HP gain with an electric pump may not be as much as you think,
in a recent test Hot Rod Magazine ran our performance ratios pulleys on a small
block Chevy (alternator, water pump only) and to their surprise our pulleys only
made 1 HP less then a electric water pump set-up.
You should also consider that electric kits flow even less water then a
underdrive pulley kit and that could cause cooling problems.
Most electric WP are made for racing applications and not
designed to be run for long periods of time, and if that electric motor gives
out you are stuck with no water flow at all unlike a standard water pump which
may start to leak and make noise but can allow you to limp home.
The electric pump does draw power from your charging system
and so you can't underdrive your alternator, you must have adequate electrical
power just to drive the water pump.
"How hard are they to install?" Unlike engine modifications like cams, cylinder heads and
intake and exhaust, underdrive pulleys can be the simplest power freeing
modification you can do to your car. Some special tools are required such as an
impact wrench to zip off the alternator pulley and a crankshaft dampener puller
if your installation requires removal of the crank pulley/dampner assembly but
all and all most kits are a simple "Bolted-on"
operation. Our Mustang 5.0 pulleys can be installed without even draining the
cooling system. Even if you are not the do it
yourself type any automotive shop should be able to install your pulleys at a
reasonable price.
Ford Mustang, Cobra, Mach 1, Chevy, Corvette, Camaro, Pontiac, Firebird, Trans Am, and GTO
AUTOMOTIVE FORUM
