Coilovers - how to determine spring rate needed?

[BetterDays]

I am hearing everything across the board on this topic.
Street/strip car, adjustable struts, tubular suspension.

Heard everything from 130# rates to 400+# rates...

Any advice, assistance, links, is much appreciated.

Kevin

[Gravel]

Mr. Black just did this, ask him how he figured it out...



http://www.badassmustangs.com/forums/index.php?topic=2680.0

[Mr. Black]

When you run coilovers on a street/strip car they usually don't do either very well at all.  You need to think long and hard how much you are gonna use the car for the 1/4mile.

[BetterDays]

Why do you say that?
It seems that a lot of people run coilovers for S/S duty.... 

Is Dragracing bad for coilovers (or should I say, coilovers bad for racing)?
Street driving - coilovers bad for that?

That car will be built to go fast straight..  no corners..  Hell, I don't even have a place to mount a front sway bar!

[Mr. Black]

What I am saying is you can't have both.  Most street and corner carvers are gonna go 300+ and a good drag race combo seems to be under 150 and a much longer spring. 

That being said you can't put in a 200 pound spring and do both well.  That's what I meant.

If I were you and going drag/striaght line I would go with a 150 or less in a 12 or 14" spring.  Even remotely too stiff up front and you will kill your 60' times and this for some reason seems to be even more noticable with coilovers.  They do not store the same kind of energy as a standard spring configuration.

There is hours of reading on this subject in the drag racing forums at you know where.

Hope this helps. 

I have two sets of springs, one set of drag springs and one set of street corner springs.  They can be changed in minutes.

[BetterDays]

What all is needed to change the springs?

Could this be done at the track?     

[Mr. Black]

You really need an air impact to get the strut nut off at the CC plate and your spannner wrenches sometimes and that is it.

[BetterDays]

So, a change at home then drive to the track kind of deal...

[Mr. Black]

Yeah that is best. 

It really depends on how you drive the car though.  Some people like to drive on the street with no bar, skinnies, and 150 springs with 90/10s.  Around here though that is a good way to die lol. Personally I don't enjoy to drive a car like that unless it is at the track where it belongs.

[BetterDays]

I plan on running 5" wide fronts and no sway bar (I cut the mounts off when smoothing the engine bay)...

What are the downfalls of the light spring on the street...

On the street, it will be a speed limit queen...  No top end runs, street racing, etc...

[Mr. Black]

Not a lot of downfalls other then feel. It hurts braking as well.  So long as you respect the car for what it is then I think you will be fine running your strip combo all the time.  You will just have to build it and make changes as you go along if you don't like the feel.