nathansmith50

I pulled apart my front suspension a couple weeks ago only to discover that both of my front springs were broken. i cut them even and threw them back in just to make the car mobile again. it sits low and looks good but i don't like the ride. I'm looking to replace all 4 springs and i'm noticing that a lot of the springs say the fitment is for coupes only or convertibles only. but the ford racing ones just say they fit the years(minus cobras)

what gives? are they the same or not. My suspicion is yes but having 2 kids and being the sole breadwinner means i don't have the luxury of being wrong.

Derf00

From the factory Ford will sometimes use different spring rates for vert vs coupe.

http://web.archive.org/web/201210141...ings_calcs.htm

That's because the vert is usually a couple extra hundred pounds heavier from chassis stiffening. Aftermarket spring rates are usually as stiff or stiffer than the more stiff factory version so it doesn't make any difference. Yes, FRPP is considered aftermarket.

Sonic Mustang

Well, there goes logic.

A heavier car will require stiffer springs to obtain the same levels of performance as a lighter car. That's why convertibles have different spring rates. IT DOES MAKE A DIFFERENCE.

The OP should take a look at H&R springs. They are very high quality and available in different rates and ride heights. I'm running Super Sports on my Mach 1 which may be a little too low for a real daily driver, but H&R makes springs that leave the vehicle at original ride height and others that drop it about 3/4".

0331

Also to tack on. I am not sure if the OP was asking about the "minus cobras" but the cobras have IRS and it would not fit.

school boy

Most of the information above is correct. The verts are heavier and MOST spring companies have a set for verts and a set for coupes. The reason for doing this is to balance the suspension. Could you use vert springs in a coupe and vise versa? Yes but I don't know how the handling would compare. So check the link below and if you click on the part, a new page will open and you can look at pics and judge the ride height you want
http://www.americanmuscle.com/99-04-...g-springs.html

nathansmith50

The minus cobras...was just a quote basically. not all cobras have IRS. So far as I know that's only a feature of the 03-04. And to make a note my GT is a 96 so when i'm looking at the springs i'm looking at the 94-98 section of american muscle.

I hadn't thought about the weight difference being a factor but it makes sense. thanks.

I think the guy who puts in the additional stiffening on the verts might have been on break or asleep when my car came by on the line. I think of it like a yoga instructor. It's sexy and EXTREMELY flexible.

school boy

Yea, the 99-04 cobras have the irs. I say this as in factory form. Some irs guys swap in a straight axle while other guys (96-98 cobra, 03-04 mach, 96-04 gt's and v6's) swap in the irs. I've even seen a few fox bodies swap in a irs.

Sonic Mustang

Mach 1s came stock with convertible sub frame connectors. I threw mine away and replaced them with MM full length weld-on connectors. Welded subframe connectors should be your first suspension modification.

Derf00

If you read the original post and my reply, the logic is there, you just failed to comprehend it.

IF Ford OEM offers different spring rates (stiffness(es) for Vert and Coupe...yet aftermarket doesn't differentiate...it is because the aftermarket rates are already stiffer than what the OEM offers for either version so they do not differentiate (or feel the need to differentiate). So to be more clear/concise, aftermarket doesn't necessarily feel it matters.

I never stated that the performance would be equal for the same rate on different models did I?