I'm looking to put a lowering kit on my stang, 94 5.0 302. I'm fairly new to the game What's the difference between progressive rate and specific rate? Which would you recommend and why? Thanks!

Springs have ratings based on compression factors. This compression factor is measured in lbs (ft/lbs). A spring w/ a rating of 400lbs takes 400lbs of weight to begin compressing the spring. On the otherhand a spring with a rate of 300lbs begins to compress at only 300lbs. Therefore the second spring gives you a softer ride.

Specific or linear rate springs have one spring compression factor throughout, whereas progressive rate springs are designed to compress at lower weights then progressively stiffen as more force/weight is applied. For example the progressive spring may have a rate of 250lbs and 450lbs. This spring will ride softer initially until compressed to the point where the stiffer coils take control.

Linear rate springs are more predictable under extreme handling conditions, but they may stiffen your lowered ride a bit. Progressive rate springs handle about as well, but they do not compromise the comfort of a smooth ride on a lowered stang.

Either set will be an improvement. I have progressives on my stang.

My advice is going with specific rate on the SN95 Mustangs, i had both Eibach PRO and now Spec. rate MRP springs 700front/170rears, and boy is there a difference.
The Eibachs were unpredictable, mostly on the rear end.

With the linears even though stiffer the handling is 100% better.
Ride quality only suffers a bit, but with a good set of Struts&shocks to match it can be made smooth on uneven roads. This last thing is very important, if you get linears and match them to stock shocks be ready for a bouncing nightmare. Get Konis, Bilsteins, Tokicos or KYB adjustables.

We can talk all day about progressive vs linear rate springs and which is better. In my opinion I would not worry so much about just the springs but look at the bigger picture. You should not plan to upgrade any part of the suspension without asking a few questions first.

Take a look at what you want to derive from you hard earned money and work towards a complete package.

For instance if I plan on drag racing at the track each weekend then my suspension setup would be different than if I planned on crunching cones every weekend. If I just want to cruise the street in a slammed car and not race then I might go another way.

Since this is the Road Racer's Corner forum then I'm assuming you are road racing with it. In that case I would for sure look into a complete system design from either Kenny Brown or Maxium motorsports, griggs racing, etc..

Plan, Plan, Plan, then proceed.



Dale

[2000MustangGT]

if you dont know what your going to do with your suspension set up get a lowering kit then the umm...i cant remember the shock name but its something d-spec u can set it up for anything u like. i think its tokico d-spec.