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Anyone got an underdrive pulley fitted? cheers
Moderators: IMOC Moderators, IMOC Committee Members
Standard Belt Layout(Underdrive)
Our Tuner Series crank pulleys provide HP& Torque gains across the entire RPM range.
Power gains come from the reduction of weight.
An average of 2.7 HP is gained from every pound lost off the crank shaft.
80-85% of our gains are from weight loss.
Additional power gains, between 15-20%, can be seen from underdriving all the accessories.We do not push the percentage of underdrivie to high for two main reasons.
First it is important to keep charging systems, air conditioning, power steering, and water pumps moving fast enough for every day driving.
Second not much horsepower is gained from extreme underdriving.
We always keep our underdrive percentage under 20% which allows us to maintain factory spoecified output for all of the accessories.
Our testing has shown that for most vehicles you can upgrade to a stereo of up to 600 watts
(RMS) without any charging problems.
Layout(Underdrive)
Our pulley sets provide most of the power gains through weight loss(80-85%).
The remaining part of the gains from these pulleys comes from underdriving of all the accessories
(15-20%).
However, we do not push underdriving for two main reasons.First, it is important to keep charging systems, air conditioning, power steering, and water pumps moving fast enough for every day driving.
Second, not much horsepower is gained from extreme underdriving.
In most applications all of our underdriving is done with the crank pulley, not the accessory pulleys.This is done so maximum weight loss can be achieved at the crank where most of the horsepower gains are found.
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Our underdrive pulley sets are available in polished finish only