[HorsepoweR]

Do you have to put new Spring Isolators on when you change your Springs?

[ReverendDexter]

Originally Posted by HorsepoweR Do you have to put new Spring Isolators on when you change your Springs?

Don't have to, but I'd suggest it. One of those "while you're in there" things. Poly isolators are cheap, but as typical for poly, will increase NVH over rubbers. I don't suggest removing the isolators, though many people do to get a little bit more drop.

[HorsepoweR]

Originally Posted by ReverendDexter Don't have to, but I'd suggest it. One of those "while you're in there" things. Poly isolators are cheap, but as typical for poly, will increase NVH over rubbers. I don't suggest removing the isolators, though many people do to get a little bit more drop.

Thanx.. I suppose I will change them too then.

[ModMustang97GT]

Thanks for the response Rev. The isolators help with sound and also rubbing of the springs on the perch. Long term this could lead to rubbing and rust on the perch and the spring. Also, it does offer a small buffer or merge zone between the relatively motionless chassis and the expanding and contracting of the spring. With stiff springs, it will show up in the form of less vibration and harshness from the road surface and increased wear resistance by the components.

Alot of people don't use them, in an attempt to get a slightly larger drop. However, considering the cost and the availability of lowering spings. I would say, do it right, do the better thing. Choose the right spring and change the isolators.

[ModMustang97GT]

Ive wanted to make one of these for a while. This is a diagram of the way that a proper spring and shock combination will rebound from a bump. 1.5 wave lengths is the ideal. The quality of the shocks and springs will change the length and height of the wave, but the number of wave lengths will remain the same so long as they match. Over dampered will result in .5 wavelengths which is very uncomfortable, and under damping will result in more than 1.5 wave lengths.

[HBK_2007]

is 1.5 for mustangs sucifically or all cars in general? cuz im curious how this relates to something that rides way nice like a benz or something

[ModMustang97GT]

It is the same for everything. Nize cars like benzes have really soft suspension. so the wave length is pretty long. Making you feel significantly less of it. On the flip side, some cars like the new lexus's have suspension that actually sense bumps and forces the wheel to drop into it really quick and then pop back up. The end result is that the body of the car does not move at all. That is the ultimate goal of the suspension.

A perfect suspension would keep the car flat at all times and would feel like you were hovering over the ground. This would be achieved by having 0 wave length. Which is nearly achievable. But if the car body does bounce from a bump, 1.5 wave lengths is the correct amount for the car to recover to normal position. Does that make sense?

[HBK_2007]

kinda

[ModMustang97GT]

Well esentially. The goal of the suspension is for the car to stay totally flat while always keeping maximum traction. There are 2 options. No suspension, so the wheels are always touching but you fell and experience every bump. Or, you add suspension and essentially make a compromise.

The goal of the best suspensions is to move the wheel as quickly into those bumps and back out of them as possible, so the contact is always constant between the tires and the road surface. The problem is, you have to use some sort of constant force to give enough play in the suspension for the wheels to follow the ground at all times. The best simple machine to use for this is a spring. The problem with a spring is, it doesn't absorb all the engergy, it just stores it, and releases it.

The goal of your shock is to absorb that energy in a way that is not too quick. and not too slow. If it takes to long your car would bounce endlessly from each bump. And too much would mean the spring doesn't do anything and you are driving a brick with no suspension.

The goal is the happy medium. Idealy, it is 1.5 wave lengths. Enough to take the bump and recover. You don't want less because the car is not truly being allowed to recover in a natural way. And to little and you bounce more than necessary.

Air bags are a new age idea that actually works really well. They give the force of the spring but also absorb more of the engery. So they work really well, however, they still need some sort of damper to help keep them optimal.

Really nice cars liek mercedes have soft suspensions that absorb more of the bumps and have more suspension travel. So when the wheel bounces down and comes back up, the soft spring doesn't exert as much force on the body, making the ride smoother. however, the car will not turn as flat and will not conture to the road as well. Race cars are the oposite. They have very stiff springs that contour really well and exert alot of force on the body of the car. This makes the ride harsh, but the handling really good.

[BEASTstang]

So much good info !!!!!!!!

[HBK_2007]

that makes more sense

[motomack]

my rear passenger tire only scrapes the fender when hitting bumps. I know the car has tokico shocks when I bought it. Is it a bad shock or what???

[ReverendDexter]

Originally Posted by motomack my rear passenger tire only scrapes the fender when hitting bumps. I know the car has tokico shocks when I bought it. Is it a bad shock or what???

Shocks don't support the car, so the shock itself is irrelvant to your issue. (though, for what it's worth, tokicos are fine)

Is the car lowered? If so, how much? Performance or drag springs?
What size tires? What size/offset are your wheels?
Has the fender been rolled?

[ModMustang97GT]

Also, it is important to know whether you have some type of spacers or Pan Hard bar. A PHB can cause that issue very easily.

Also, are you sure that it is rubbing on the passenger side, not the driver side. And where in the fender well, inner side, outter side, rim?

[slowey]

so much info...da brain...she hurts lol
thanks

[NIghtShade]

So after reading this thread Im still debating on rear coilovers.... If I went with a soft rate wouldnt they still out perform my hard ass H+R Supersports??

I also added subframe connectors to my car and the damn thing only know when direction now... A STRAIGHT LINE! I love how the rear is planted but how can I correct this a little? I plan on adding LCA's and besides the bilsteins I have the ebiach prokit. Perhaps only doing a front coilover conversion will my problem?

[ModMustang97GT]

The super sport springs in the back are not that stiff really. They are stiffer than most springs but by no means insane. Rear coil overs will definitely out perform them.

As for your issue with the straight line. I'm kind of confused what you mean. Do you mean the car doesn't turn very well?

The SFC's should basically tie the car together really well. What you might be finding is that you now notice the under stear that is built into the cars.

The understear is created by the front being stiffer than the rear. The rear is looser so it has better traction, the problem is, the front is stiffer so the inside tire gets pulled off the ground in hard turns. The solution is to stiffen the rear. There are a couple of ways to do this. The simplest way is to get a new rear sway bar. The other way is to get rear coil overs. You are supposed to keep stock sway bars with coil overs so you want to choose one or the other. The problem then is balance. You don't want rear coil overs and no front ones. So deciding what you want now and going for it will save you money if you do decide to change your mind down the road.

Coil overs will out preform every option out there with exception of SLA suspension which is a different type of Coil Over, so there is really no losing. The only down fall would be the cost.

The cheaper route is the sway bars. A couple hours of work and $200 will make all the difference.

[ReverendDexter]

Alignment may also be causing an understeer issue. Factory alignments usually call for some amount of toe-in in the front as that makes the car more stable and gives it more return-to-center. Set your toe to straight up, and that should help.

[NIghtShade]

Yes what I mean is after adding the SFC's the thing won't turn for crap. Plenty of understeer. Before the rear was so far out on a curve that I barely had to turn the wheel, now its completely the opposite. I have the ebiach sway bars on there now. Alignment didnt do much at all.

I have a set of used termi A arms on hand but thats probably going to make the front worse without correcting the rear...

So you recomend:

I just get a thicker rear sway bar and some LCA's? I was going to get some LCA's next.


Id only go for coilovers for "comfort" because the roads BLOW over here, and the H+R's make you feel it already so I dont want to have a stiffer spring.

So if I went without the coilover setup...How would that setup compare to say a 250 rate coilover system? I dont think Id want a stiffer setup than that here for a DD.

Thanks

[ReverendDexter]

Coilovers give the spring more leverage over the control arm (relative to the stock Mustang setup, this isn't something to generalize to other cars). This means that you can run a softer spring rate and get the same wheel rate. Softer spring means less harsh of a ride.