Norm Peterson

The quad shocks are a crutch for soft rear control arm bushings, themselves a handling compromise in the name of ride quality. As soon as you swap something firmer back there for bushings that doesn't bind everything all to hell and back, the quad shocks don't have any reason to be there.


Norm

UPRSharad

I always upgrade my control arms and remove the quad shocks entirely. It's a worthwhile upgrade. (but it will change your autocross classification)

Daniel Bente

The rear control arms and the setup (for top and bottom) are the reason for the quad shocks. The rear control arms will bind unless you shave the sides of them for a little clearance. Stiffer bushings in a flawed setup will only partially remedy a handling issue like wheel hop. I have 3 Mustangs and none of them have bind issues. They all hold the road great and have no wheel hop.

My sons Mustang had wheel hop (which caused an accident) after he had removed those "quads... he had Energy Suspension Poly bushings already installed (That also weren't shaved on the sides). He now has the quads back on and the shaved bushings. No more hop and a solid handling ride.

Believe it or not, Engineers do know what they are doing. Compromises for profits sake tend to hinder what want to do at times, but correcting the actual flaws and even improving something good does not always entail remaking the wheel.

Norm Peterson

Shaving the faces of poly bushings is not the only modification you can make to them to reduce "bind". In fact, simply shaving the flat faces may not even be the most effective tweak available. Good that you're doing that much, though.

There are other causes of wheel hop besides rear control arm bushings that are too soft, cracked, or otherwise just plain shot. Sometimes you can firm up all 5 or 6 or 8 of them (depending on your chassis) and still have some hop. It can even be a case of "conditions + driver error".


When your priorities are clearly different than those of a car's original intent, your modifications can involve anything from minor tweaks (alignment) to wholesale revision (swapping in a torque arm). How well it turns out is a reflection on how well somebody did their homework and how well the mod is matched to your use(s).

Sometimes that means that the "somebody" who is re-engineering stuff is you.


Norm