quote Originally posted by Rickady88GT: Sorry if I misled anyone on this.

Hey Rick, don't feel bad. I suspect a lot of people believed what you initially thought... that's why I wanted this discussion!

Over the years I had seen it mentioned numerous times that people had flipped over the top plate for the struts and I wondered why. As as been pointed out in this thread, it doesn't make any difference in how the rear of a Fiero sits. However...

When shorter rear springs are installed, flipping the top plate over helps to put a pre-load on the springs which keeps them in place. When I cut the rear springs in my '84, it was a nuisance every time I jacked the back of the car up as the rear springs would come off their perches in the struts. When I flipped over the top plates, this reconfigured the strut assemblies and the rear springs were now held in place. However...

What I was unprepared for was the fact that the decklid would no longer close. With the "knob" of the top plate sticking up, the end of the strut now hit the decklid. I'm sure someone has mentioned this previously over the years, but I don't recall ever reading it here (prior to this thread). Interestingly enough, Pontiac put a partial "hole" exactly where this contact is made, and by drilling out another layer of material (with a hole saw), the hole is then deep enough to allow the decklid to fully close. The drilled out hole is pictured below. You can easily tell when you've drilled out the necessary layer. Just don't drill any further!



Here are three shots of the top of my 84's struts. You can see how the "knob" sticks through.







Compare that last shot with the end of the strut on my '88 Formula that hasn't had the top plate flipped over. If you have a good eye you'll notice that if the top plate was flipped over, the "knob" would hit the flat edge of the grill. A little trimming of this area would be required.



One factor which no one has touched upon is whether or not the action of the strut itself is affected by flipping over the top plate. At any given compressed height, the strut would be extended differently by at least an inch depending on which way the top plate had been installed. As I understand it, some struts (maybe all?) contain valves which have a variable rate depending on how far the struts are compressed. Monroe calls this "position sensitive damping". Is anyone brave enough to post an opinion on that?

[This message has been edited by Patrick (edited 11-23-2013).]

quote Originally posted by Will: If the strut is sitting at a certain point at stock ride height, and the car is lowered, the strut will then sit at a lower point in its travel. Flipping the plate would bring the strut back up to a higher point in its travel. If you lowered the car by the amount the static position of the strut shaft changes when the plate is flipped, then the strut would be at its design "zero" position with the car lowered around it.

I agree 100% with what you've posted Will, but you didn't actually state how this possibly affects the performance and/or "feel" of the strut.

I think Ogre's on the right track below...

quote Originally posted by theogre: ...can affect strut's "road feel." Example Some shock/strut designs use/used slots cut into cylinder walls to make a "sweet spot" in the middle of travel. That slotted section gets a softer ride and Lower cars could mess up that.

So stated another way... If the suspension is lowered with cut and/or shorter springs, the strut might have a stiffer feel to it due to where the now more compressed strut sits at rest.

In conclusion, it would appear then that struts with variable rate damping can retain their smooth riding "sweet spot" on a lowered car if the strut top mounting plate is flipped over and the strut is extended a bit. I imagine the same should occur with front shocks if a spacer is used between the bottom shock mount and the lower control arm. (That would also help prevent the front shocks from bottoming out as discussed HERE.)

[This message has been edited by Patrick (edited 05-21-2014).]