MrLatte

I've got a 2007 GT with the stock suspension and I'm looking into adding/replacing the following parts:

Eibach Pro-Kit (~1.5" drop)
D-Spec Dampers
Adjustable Panhard Bar
GT500 HD Strut Mounts possibly with caster plates (or Steeda HD strut mount)

I know I'll need to have an alignment done, and there's my question. Do the guys at the alignment shop (i.e. Les Schwab) need to know it's been lowered or do they just use the factory alignment specifications they look up in a book/computer?

Are the caster bolts/plates only needed then if they can't get the caster adjusted to the proper setting? Would they know how to adjust the caster plates or the adjustable camber on the Steeda HD strut mounts?

Thanks! Looking forward to a lowered Mustang soon!

P.S. In the above setup are there any "one use" bolts that I would have to buy and replace?

parchisi

First off, I know most people around here would recommend the Steeda Sport springs over the Eibach pro kit, but that's up to you.

I've never had a problem getting my lowered mustangs aligned at your typical tire/alignment shops, and I usually get compliments on the caster/camber plates. That said, it couldn't hurt to ask around to find a reputable alignment shop that can do a good job. Usually they'll just align your car to stock specs, but you can ask them to use different specs if you want. As far as "one use", Ford says to get new strut bolts, but I and many other people have reused them without a problem.

MrLatte

Thanks for the response. I'm not set on the Eibach Pro-Kits as I've been looking at the Steeda Ultra-Lites and others trying to figure out not only the drop all the different springs give but now I've discovered they all have widely varying spring rates as well!

If I understand correctly the Eibach's are progressive springs and many others aren't? Do the progressive springs offer a "better" ride until you start cornering?

Norm Peterson

It depends.

Springs that are advertised as being progressive can be truly progressive, where typically the coil spacing gradually closes up toward one end and the spring rate gradually increases as it is compressed. Or they can be "bi-linear" where you have only two distinctly different coil spacings and you either have a softer rate or a firmer rate with nothing in between. It is possible for a bilinear spring to nearly always operate at the stiff rate, except when the wheels are drooping down from the chassis. Or you could be in and out of the stiff range almost constantly.

Either way, ride quality the way most people notice it will be tied more closely to the shocks and struts, and on their condition. Somewhat stiffer than stock spring rates - up to perhaps 50% stiffer than OE if you're reasonably tolerant - will feel "firmer" or "more stiff-legged" without being particularly harsher. Shocks/struts that give an acceptable ride before you hit sharp bumps can feel either "stiff" or downright harsh when you do. Dead or dying shocks/struts will let your car get into the bump stops more frequently, and have other adverse ride and handling consequences.


Norm

Norm Peterson

Quote:

Originally Posted by MrLatte

Eibach Pro-Kit (~1.5" drop)

The average shop will use the alignment rack's console database, and there is no caster or camber adjustment on these cars that does not involve modification of some sort. Just toe.

The good thing is chances are you won't need caster adjustment. It's camber adjustment that 1.5" lowering will probably have you needing, as that will change by about 0.75° more negative (give or take a little).

Quote:

Are the caster bolts/plates only needed then if they can't get the caster adjusted to the proper setting? Would they know how to adjust the caster plates or the adjustable camber on the Steeda HD strut mounts?

The factory specs for caster and camber permit up to something like 0.75° deviation either way from the preferred settings and from each other side to side. Stock, without camber adjustment, a shop might just call it good enough as long as you were within that. A good shop might call you to discuss being close to any of the limits.

With camber adjustment, you'd probably want to make sure that the shop was aware that it was adjustable (and speak directly to the tech if at all possible). I have no idea if they'd charge more since I do all of my own alignments.


Norm

timothyrw

i don't know about the bolts but i wouldn't reuse the mounts. mine failed...

then i went w/the steeda hd mounts. and like norm suggested i took it to a shop that was recommended and told the tech what i wanted camber-wise.

at the very least i would get the gt500 replacements.

chrumck

How do you measure camber and caster? What tools do you use?

SteedaGus

With a 1.5" drop you will probably end up with 1.4 to 1.6 degrees negative camber. Anything below 1.5 your tire wear will be acceptable IF you rotate your tires every 5,000 miles. If you forget to rotate or if you cannot because of a staggered wheel and tire setup you will have excessive tire wear.

If you go with Steeda springs you will have less of a drop, and end up in the 1.2 to 1.4 range for camber. This is better but you may still run into wear issues if you can't rotate the tires.

If you are in a situation where tire wear cannot be controlled by rotating the tires then our HD strut mounts for camber adjustment would be recommended.

You are doing it the smart way and doing spring/shocks at the same time cause it saves a great deal of time on labor vs doing them separately. Might as well knock out the strut mounts too in one shot and get camber adjustment out of it.

ffk_pennywise

My 2 cents: Make damn sure you get the alignment done right. Ford specs allow for a wide range of settings but that doesn't necessarily make it right. After I lowered I had a local reputable chain shop do my alignment. While it was technically in spec it wasnt right. After less than a year my tires are so chewed up its not funny. Plenty of tread on the outside and bald on the inside. The car shakes like your driving on railroad tracks. I called Sam Strano and he told me what it should have been aligned at and then I made the shop do it again.

Norm Peterson

For camber, this (though at different times I've also used some really simple common measuring equipment, or a gauge I built that uses a dial indicator)




Parallel strings on jackstands for toe.


Norm