hueyhy

Just got my 05 V6 Mustang and wanted to change the factory suspensions. they are too soft, don't like it.
found a set of cheap used koni STR.T struts on ebay and bought. now need some springs. who can give some suggestions?
BTW: can the koni STRT struts work with lowering springs? is it strong enough?

If I'll go for some springs that lowers the car, what else will I need? camber kits? spacers? or nothing?
don't know much about suspension system but I know it's very complicated and to lower the car you cannot just lower it without compensate the lowering. surely I don't wanna screw it up.

So, can you guys give me your thoughts on springs? also, it's very nice if anyone can give a list of other things I need to buy? (if i'm gonna use some lowering springs).

Thanks a lot.

Jazzer The Cat

The Koni will be fine with lowering springs, but what spring-rate are these struts to be matched? (you need to ask the seller or find out the actual part number)

I recommend a set of CC plates and would be necessary, if you were to go CO's (which I can recommend). They will improve your cars handling and ride, with an improved wheel rate. You may consider a bump-steer kit, but not required with a moddest drop. They are not actually "required" anyway, but a good idea, with a 1.5" or more drop.

What are the ULTIMATE goals for your car?

Jazzer

PS. Hopefully Norm will chime in, as I always differ to his VASTLY improved knowledge, over that of myself, when it comes to shocks/struts/springs. He can be offer some insight, I might miss.

hueyhy

It's my daily driver, but I would like to go autocross. I used to drive a civic si, and i had a lot of fun in autocross with that. I know mustangs are not idea for autocross (heavy, big), but I am just a casual autocrosser purely for fun.
For the lowering part, I'm not that into lowering the car too much. Just a modest lowering would be very good. the reason I want to mod the suspension is because I feel the stock one is too soft. I don't like the shaking when braking or turning. So, a more stiff ride is my first goal. lowering is just like a by-product.

I was just worried if the lowering would ruin the alignment thing, so I wanna know if there's anything needed. If a camber bolt can solve the problem (and if they can hold the camber set), I'll use them, instead of expensive camber plates. I don't think I want to adjust the camber very often. just for daily driving but maybe a little negative camber to help autocrossing.

hope I explained it clear.
and is there something else that need to be considered when lowering the car (just modest lowering)? will rent a lift bay to do the job, so want to get everything before I start the job, and finish it in one shot.

BTW: what are "CC plates" and what is "wheel rate"?

hueyhy

just checked, the koni str.t parts for mustang should be

8750 1030 8250 1008

but cannot find the spring rate specs

Jazzer The Cat

CC plates = caster/camber

Wheel rate = Wheel Rate: The force it takes for your tire to move up and down. This means how quickly your tire will move into the bumps on the road. You calculate it by the spring rate multiplied by the leverage. In the case of your stock front suspension. Your spring is roughly 1/3 - 1/4 of the way from the pivot point to the wheel. This means you have a 1/3 to 1/4 mechanical advantage on your wheel. For example: With 800 lbs/in springs, the wheel rate is closer to 200-250 lbs/in. and my force on the bottom of my car is closer to 2/3 - 3/4 advantage. Meaning I feel 3/4 of the bump, and have 1/4 the wheel reaction time it could. This is the main reason coil-overs (CO's) are so much lower in spring rate. A 300 lbs spring will get 90% of its force on the tire and the same amount on the car. This means you will feel roughly half the force on the car and gain 50% more force on the wheel. This leads to better handling and more comfortable ride. There is no real downside to going CO's up front other than cost.[taken from The Official Suspension Guide]

I do NOT recommend the use of camber bolts They are far weaker than the bolts required to properly support your struts. CC plates cost more, create more NVH, but do a VASTLY better job at addressing camber. They also allow adjustments in caster and a nice thing for improved cornering.

Check out the "more info" link on the following struts/shocks on ***THIS*** page, for info on spring rates per specific models.

Take a look through The Official Suspension Guide for some additional things you should consider, when lowering your ride and looking for improved cornering.

Jazzer

hueyhy

how about the modification of the geometry?
Like said in this post
http://www.miracerros.com/mustang/sway_links.htm
but that's for older version mustang, which uses a modified mcpherson suspension.
not sure what's the situation for 05+ mustangs. Can I also use the short end link? not sure what size to purchase.
the length of "A" in the stock endlinks are 3-9/16'' in the old mustangs, is it the same in the 05+ models?
http://www.energysuspensionparts.com...kSizeChart.jpg

hueyhy

the pack including sway bar like this:
http://www.latemodelrestoration.com/...ro-System-Plus

do I still need the camber plate or this kit can correct the suspension?

If the answer is no, I'd go with the pack because buying a set of struts/shocks+springs+CC plate, and sway bar end links that to correct the geometry, it would cost more.

and the integrity of parts from one brand would be better too.

Thanks.

Jazzer The Cat

One never "needs" CC plates, but are a good thing, even if you don't lower the car. The ad does not say how much drop the kit will provide, but you would not be able to achieve an OEM alignment, assuming you want one!

Can you install this kit WITHOUT CC plates..... yes
Should you install this kit without CC plates.... no, IMO

Jazzer

hueyhy

Thanks for the reply.
eibach pro kit should drop about 1.3'' and 1.4'' (F/R)

It would be OK if I get some negative camber. (would be better for my occasional autocrossing). just don't be too crazy.
budget is tight and i don't really need that adjustable camber.
how bad it could be if I lower it without the CC plate?

if I can only choose one, what do you think is better?:
1. springs+shocks+CC plate
2.springs+shocks+new swaybar, bushings, etc.

or, 3: springs+shocks.

Thanks

Jazzer The Cat

A sway bar is a tuning device and meant to address understeer/oversteer issues. If you are happy with your current "balance" in this reguard, do not replace them.

My recommendation would be shocks/struts and CC plates for sure! Biggest bang for the buck right there and do not forget about the ever-so-important first "C" in CC plates.... caster! This is a very nice tool for improved cornering and actually HELPS to reduce tire wear, rather than increase it, as camber does. Can make your car a bit more "darty", but improves contact patch and is worth the trade off for me. If you run wider than OEM tires/wheels, caster is a good thing to increase

Jazzer