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View Full Version : weight and balance, spring rates



lifespeed
10-23-2012, 09:52 PM
Are any of these numbers commonly known?

stock front spring rate
free height
installed height

Weight on front vs rear wheels and/or weight distribution

This info would help if considering spring replacement or modification, especially as a reference to what we are driving right now.

lifespeed
11-07-2012, 03:02 PM
Just looked up some old car review data circa 2004. Supposedly the weight is 4200 lbs, 54.9/45.1 distribution.

Krytin
11-07-2012, 03:28 PM
'03 the chasis got a major upgrade. R&P steering and aluminum front crossmember under the motor. With the aluminum block in the MM the distrubution was a lot closer to 50/50 - around 52% on the front. if you drop the rear height down to level front/rear the #'s "feel" even better! Ask me how I know! (no, I haven't had it on scales yet for axle weight but if I ever get access again I will!)

lifespeed
11-19-2012, 03:46 PM
From our friend Chris at ADTR:

Here's the rundown on the Eaton springs

For the front springs on the 03+ Crown Vic (civilian) free height is 17 11/16" 1" drop is 17" free height and 1.5" drop is 16 5/8"
For the front springs on the 03+ Crown Vic (Police) free height is 15 7/8" 1" drop is 14 7/8" free height and 1.5" drop is 13 1/2"

03+ front stock spring rate: 253
03+ front 1" lowering spring rate: 260
03+ front 1.5" lowering spring rate: 265

03+ front stock PI spring rate: 330
03+ front 1" lowering PI spring rate: 342
03+ front 1.5" lowering PI spring rate: 355

From a post by Drock96marquis (http://www.mercurymarauder.net/forums/showthread.php?t=28375&page=2):

The color coding of the piston (the plastic piece that rests atop the axle's spring perch, NOT the bag itself) indentifies the air-springs rate.

THe black piston-ed air-springs are for HPPs, also used on Marauders and Town Car touring sedans and 99+ Limos/Livery. Cream piston for base RAS equipped non-HPP (or similar) models, towing package included.

The colors and rates go:
-1997 Base RAS: Cream piston and cream cap = 75 lbs/inch
all years HPP air-springs: black piston and cream cap = 102 lbs/inch
1998+ Base RAS: cream piston and black cap = 89 lbs/inch

*Some years of GMQ HPP/LSEs got cream pistons, 01+ LX SPorts also get cream pistons with 17mm rear bar.

Keep in mind air-springs are variable rate, those ratings are with static load.

For comparison, the steel rear coils are: 130 lbs/in civilian, 160 lbs/in CVPI.



I'll very likely end up with a front coilover setup that uses "standard" race car springs. Good for adjustability and easy access to various spring rates and heights.

lifespeed
11-19-2012, 03:48 PM
'03 the chasis got a major upgrade. R&P steering and aluminum front crossmember under the motor. With the aluminum block in the MM the distrubution was a lot closer to 50/50 - around 52% on the front. if you drop the rear height down to level front/rear the #'s "feel" even better! Ask me how I know! (no, I haven't had it on scales yet for axle weight but if I ever get access again I will!)

If those weight balance numbers were for a Crown Vic, then yes, I would expect the aluminum block Marauder to be a significant improvement. I would like to trunk-mount the battery, too. Should get darn close to 50/50!