Power Steering – Slowing the Pump – Underdrive Pulley

By: Bob Goodson
June 28, 2021

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After being a part of Corner Carvers forums for the better part of 20 years there’s a lot of reading I’ve done. Many conversations revolve around the Fox Mustangs weaknesses which there are a lot of when it comes to road racing.  One of those weaknesses is power steering.

The stock steering on a Fox Mustang is very numb in my opinion. The feedback is pretty horrible but the simple effort to steer is an A+ for any grandma driving her Fox Mustang.

As you can see from the pic above, we’re adding an underdrive pulley to the pump. That combined with the underdrive pulley we plan to run on the crank should slow the pump down enough for it to give us some assist and not push the fluid through so fast that it overheats.

That’s one of the traits on track of a Fox Mustang. The stock power steering pump with the stock 5.0 Mustang pulley will puke out fluid when it reaches high temps from being spun too fast at high rpm.  Even the stock 5.0 Foxbody Mustangs have a basic power steering cooler on it. It’s nothing fancy because it is basically a U shaped pipe with barb fittings on the end but it is there in front of the radiator to cool the fluid.

The pulley is sourced from a 1999-2004 V6 Mustang. The pulleys were once plentiful in junkyards but most of the yards around me have crushed all those cars.  Most of them save the V8 pieces.  V6’s get recycled. 

The good thing about this pulley is that it is composite from Ford. So this Dorman replacement is made from a similar material. It’s a very light piece as well. It weighs less than the stock steel pulley.  Not by much, but hey, every ounce counts in racing. 

The pulley is offered as a Dorman replacement at many auto parts outlets. It’s only 25-35 bux if you want one.

Hopefully this one won’t come apart at high rpm.  We’ll find out.

Pulley Cost – $26.17

Total So Far – $6322.09

1 Comment

  1. Dan Garn

    Good research Bob, back in my March Performance pulley days I developed a kit for the NMRA Factory Stock racers with a huge P/S pulley because that class required functioning power steering.


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