The Great Suspension Debate

[topher5150]

I've been seeing all this talk about shocks and struts, and how struts blow, but what I want to know what makes which worse or better than the other?

 

[lincolnboy]

Shock are for the rear and strut are for the front. Do you mean air bags vs springs.

 

[topher5150]

We have shocks in the front and back. The shock in the front is similar to coil over

 

[slowmkviii]

So why do you have strut in you op

 

[thaywood]

I've been seeing all this talk about shocks and struts, and how struts blow, but what I want to know what makes which worse or better than the other?

Well, since I'm the one who pretty much initiated the "strut vs. shock" debate, allow me to explain:

The McPherson strut was invented by Earl McPherson in the 1940's. Its first application was on a French Ford model (I don't remember the name or date). Since then, the McPherson strut has been mostly associated with cheap cars because the strut-type suspension was designed to be simpler and less expensive to produce than the more common upper and lower control arm type.

This is an example of a typical strut-type suspension system.


You'll notice that the strut bolts directly to the spindle and that there is no upper control arm. In a strut-type suspension, the strut performs three tasks:

First, it acts as a damper. Second, it acts as an upper suspension locating link, tying the spindle to the chassis through the strut tower under the hood. Third, it acts as a steering kingpin. Because it is bolted directly to the spindle, it has to turn with the steering. The spindle turns on the strut's axis. This also requires a bearing cap on top of the strut to prevent the spring from scraping against the strut tower.

This is an example of a proper upper and lower control arm type suspension as on our Mark VIII's.



Notice the differences? In an UCA/LCA type suspension, there is an upper control arm and the shock mounts directly to the lower control arm, not the spindle. In a UCA/LCA suspension, the shock performs only one task, damping. That's it. The upper control arm provides the upper location for the suspension, and the spindle itself performs as a steering kingpin.

UCA/LCA suspensions and strut-type suspensions are vastly different designs. Most performance cars use UCA/LCA's because they have historically provided better ride and handling characteristics as compared to strut-type designs. Strut suspensions are usually used on FWD cars because it provides room for the shock to mount to the spindle above the half-shaft. Strut suspensions are also cheaper and far less complex than UCA/LCA suspensions. Hence their extensive use on small, compact, cheap cars.

I hope this helps. It should be quite obvious to anyone that our cars use the upper and lower control arm type suspension system and not the McPherson strut type. The simple fact of the matter is that our cars do not have a strut-type suspension. They have upper and lower control arm suspensions. Therefore, our cars have "air spring & shock assemblies". That's what Ford Motor Company calls them. And since they designed the car, I think they probably know what they're talking about.

I know it won't stop the debate, however.

 

[Moes8]

another important advantage to uca/lca suspension is better camber control throught suspension travel, resulting in better handling.

you would never see a macpherson strut type suspension in a performance/handling car.

its fine for family cars and drag racing,but not for cornering in a sporty manner.

 

[thaywood]

another important advantage to uca/lca suspension is better camber control throught suspension travel, resulting in better handling.

True.

you would never see a macpherson strut type suspension in a performance/handling car.

True again.

its fine for family cars and drag racing,but not for cornering in a sporty manner.

Very true. The only exception to that rule that I know of is BMW. They make some of the best handling cars in the world, but they all use struts up front. They have somehow perfected the plebeian McPherson strut.

However, I still prefer a proper upper and lower control arm suspension. That's one of the many reasons I bought my Mark VIII.

 

[Chucklz95LSC]

Makes perfect sense to me

Thanks for the insight.

 

[Moes8]

Very true. The only exception to that rule that I know of is BMW. They make some of the best handling cars in the world, but they all use struts up front. They have somehow perfected the plebeian McPherson strut.

i guess kinda like how ford seems to have perfected the solid rear axle with the 2011 stang.