Looking for lowering springs

[Gnestovia]

Hey guys! Merry Christmas and Happy Holidays to you all!
So I have decided on getting lowering springs for my Mirage and I've been looking around to see what I may like. Main thing is, how much it will lower my car, for a better look and all. I've been wanting to drop the whole car around 2 - 2.5 inches. So far in researching, I've read on one of the forums that the AST lowering springs actually drops the car at 1.75 inches. If you know about any springs that can lower the car more than 1.75 inches let me know, it's appreciated! Thanks!

[Eggman]

Found this thread:

Eibach Pro-Kit lowering springs

Not sure if it’ll get you where you want to be but figured it’s a start.

[Loren]

I'm just gonna leave this here:
http://www.rentoncoilspring.com/whyti.html

[Gnestovia]

Thank you for the help

[PityOnU]

Please be sure to keep an eye on the strength of the spring in addition to the height reduction. Heed my warning: the majority of the springs available for the Mirage are way too stiff. You don't want to go through all the effort of swapping everything out and then end up with a car that drives like peepee-poopoo-garbage on normal roads. Seriously.

For reference, you can look at the spring strength of the Fiesta ST (considered as having great handling/road feel while not being too stiff to be painful, and being similar to the Mirage in terms of suspension) in Ford's supplemental manual. You will see the front rate is ~2.7K and the rear ~2.3K. This is after Ford softened things up from earlier generations after owner's complained of things being uncomfortable.

Also keep in mind that the strength of the struts/shocks is co-designed with the height/strength of the springs. If you change the springs without taking the struts/shocks into consideration, you can end up greatly reducing the lifespan of those struts/shocks and also have a car that rides like crunchy doodoo.

[Loren]

Springs have to be stiffer if you're lowering the car. If you don't make the springs stiffer, you risk bottoming out the suspension. There's math involved, but basically:

Imagine you've got 6" of suspension travel. Full stroke of the shock = 6". With the car at rest, you'd want about half, maybe a little less than half of that be compressed. So, say your remaining travel is 4". You load the car up with a bunch of weight an hit a big bump, you've got 4" of upward suspension travel. Between that, your shocks and your progressive bump stops, you shouldn't "crash" into the end of your suspension travel when you hit that bump.

Now, you think lowered cars are cool, but you're conservative about it, so you want to lower the car by 1". Now you've got 1" less suspension travel. You're going to get into the bump stop much earlier (unless you trim the bump stops, or fit shorter ones) when you hit a big bump (or maybe even a little bump). And with less travel, if the spring rates are the same, you're going to hit the end of travel much sooner and much harder.

So, let's say that the static weight on the corner of the car that you're thinking about is 600 pounds (pretty close to the front corner of a Mirage). If you want your suspension to be loaded, but not completely maxed out when you're cornering at .9G, you need a spring rate that will compress LESS than the available suspension travel at .9G. 600 pounds x .9 = 540. And if we've measured our stock suspension travel in the compression direction at 4"... and we're taking away 1"... that's 3" of travel. You need a spring rate of at least 540/3 or 180 pounds per inch. Which translates to 3.2 kg/mm.

So, "too stiff" is relative. You can go softer and get a smoother ride... as long as you're not planning on loading up the car with stuff or people... and you never hit any bumps. If you're too soft and hit that bump, you're going to crash into the bump stops harshly. You'd be trading one kind of harshness for another... therein lies the "black art" of suspension tuning (and car design in general). Making those compromises and finding that happy medium. Comfort is a factor. But, not breaking parts due to bottoming out the suspension is also a factor.

Rough math seems to indicate that somewhere around 3-3.5kg would be a good rate for the front of a mildly lowered Mirage. The lower you go, the stiffer you need to go... the same math will get you there.

Godspeed chose rates of 4kg front and 3kg rear. Which is pretty good for lowering something like the 1.5-2.5" that the kit is intended for. A bit stiff? Yeah, a little. I prefer to call it "firm". It's the price you pay for lowering a car.

[PityOnU]

...

Godspeed chose rates of 4kg front and 3kg rear. Which is pretty good for lowering something like the 1.5-2.5" that the kit is intended for. A bit stiff? Yeah, a little. I prefer to call it "firm". It's the price you pay for lowering a car.

I've seen a lot of your post scattered around various forums, and they're always full of useful information - this one is no exception.

I know you have multiple cars, and take some of them to the track regularly (if not maybe exclusively?). In this case, someone like you take an experienced look at things and make the call one way or the other w.r.t. the tradeoffs.

I would like to reiterate my warning if OP isn't as experienced, though. I have owned low, stiff sports cars before and, while very engaging to drive on the twisties, the realities of day-to-day practicalities were... stressful. Memorizing the location and height of every single pothole and curb along my 12 mile commute became tiring, and lapses in concentration were rewarded with bottoming out struts and rattling vertebrae. Getting in and out had me groaning and grunting like an old man. Curbs at the entrance to parking lots were my sworn enemy. And this was on a late-model Monte Carlo SS - just about the least "sporty" sports car you can get.

If you are not the type of person who can (in your head) map spring rates to a certain "butt feel", then you are running the risk of putting a decent chunk of money and effort into the car and ending up with it being completely unpleasant for you to drive. While I agree that the Mirage would look better with probably ~1.5 inches shaved off ride height, you need to keep in mind what you will be sacrificing to get to that point. If this is your one and only daily driver, why not just keep it comfortable for that purpose? If this is your fun weekend car then... why is it a Mirage? lol

[Loren]

I with you, everything is a compromise. I guess my point was that if you can't handle the ride being a little firmer... the answer isn't to lower the car with soft springs. The answer is to NOT lower the car. Spring rates are (or should be) directly related to the amount of suspension travel available.

Gross generalization that probably isn't accurate... but, also probably isn't TOO far off: If you're reducing the available suspension travel by 25%, you should expect to increase the spring rates by 25%.