Skip to product information
1 of 4

My Store

T7DESIGN K20 K24 Alternator Underdrive Pulleys 10%

T7DESIGN K20 K24 Alternator Underdrive Pulleys 10%

Regular price $119.00 AUD
Regular price Sale price $119.00 AUD
Sale Sold out

Honda K20/K24 Underdrive Alternator Pulley 10% - Black

The T7Design Alternator Underdrive Pulley increases performance by reducing the force needed to overcome the inertia of the alternator during acceleration and gear changes, this will result in a snappier throttle response and more horsepower reaching the wheels.

Alternators, in general, have a broad generating power band with the Honda K20 alternator producing a reasonable output from just 1,500 rpm, with max output being produced from 4,000 to 18,000 RPM, with this latter figure technically being the maximum warrantied rev limit. In some applications, where the engine is spending most of its time in the upper half of its rev range, you simply do not need to drive the alternator at such a high speed. However, the only issue you would potentially face is a lower output at idle, in which case you may need to increase the idle speed to ensure the alternator is producing more current than is being consumed by the vehicles electrical systems. An underdrive pulley should also be considered if you have raised your rev-limit of your engine, for example if it is now 10% higher we would recommend fitting a 10% underdrive alternator pulley and so on.


  • Underdrives the alternator pulley to free up additional Horsepower.
  • Hard anodised black for superior finish, corrosion resistance and wear resistance.
  • Precision machined to very tight tolerances.
  • Almost half the weight of the OEM steel pulley.

Specification Metric Imperial
Weight - 10% Underdrive 0.145 kg 0.319 lbs
Weight - 20% Underdrive 0.175 kg 0.385 lbs
Weight - 30% Underdrive 0.177 kg 0.390 lbs
Weight - 40% Underdrive 0.203 kg 0.477 lbs
Weight - Stock Steel Pulley 0.275 kg 0.605 lbs
Construction Billet 6061-T6 Aluminium
Finish Hard Anodised Black
Manufacturer T7Design
Part Number 73F-3C7-D49


View full details