Project Grey Mustang 5.0: Part 5 – Putting the Power Down with Eaton


On the way home, I got the perfect opportunity to test out my new limited-slip differential, as it started raining about a block from JPC.  Previously, the worn-out Trac-Lok would spin one wheel or the other very easily in wet conditions.  There was almost no wheelspin at all with the new Eaton unit.


Pictured: a great trial-by-fire method of testing your brand new limited-slip differential.

But what everyone really wants to know is how it does while corner carving.  In a word: incredible.  I didn’t realize how busted and worn-out my previous Trac-Lok was until the Eaton unit was installed.  Previously, using the throttle while turning was an exercise in frustration.  The weak and worn-out clutches were doing a terrible job of directing torque to the wheel with the most traction.  The car would alternate between understeer and oversteer when trying to steer with the throttle.   Now, the much higher bias ratio of the Eaton TrueTrac allowed precise control of the torque to the rear wheels.


The TrueTrac was especially helpful in slaloms and fast transitions, where I could stay on the throttle much more without fear of the rear end simply breaking loose or understeering like a Subaru.

This is a Mustang.  It has tons of torque and a solid rear axle to put it down right now, and that means that when racing around corners, you’re always this close to the rear end swinging around on you with too much throttle input.  (That’s what makes a Mustang fun to drive hard.)  The Eaton TrueTrac allowed me to ride that ragged line between using the throttle to help corner faster and exiting a sweeper taillights first.


The new LSD also helped in long sweepers, where the consistent power delivery of the gear-type differential allowed precise throttle input to corner at a much higher speed without spinning out.

The Eaton TrueTrac is simply a great bang for your buck for anyone who enjoys spirited driving of their car and doesn’t want to have to worry about the differential being rebuilt once a year.  It works great on the street, strip, and around corners.  It is one of the more transformative modifications that I have done to this car.  I highly recommend it for anyone who is looking to replace a worn-out clutch-type differential.





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