SPRING RATES & DROPS: ALL IN ONE THREAD!!

[ronnieb1958]

Yep, I did. Mine was off by a bit less than .25"

was that before you installed the kit or after?

 

[MtnBiker]

Post some pictures when you get them installed. Sounds like a great setup.

Waiting for Koni's. Will do.

 

[Todd15Fastback]

was that before you installed the kit or after?

Before. After the kit, I am all square now.

 

[VertMustang98GT]

Waiting for Koni's. Will do.

As am I. Has yours arrived yet?

 

[MtnBiker]

As am I. Has yours arrived yet?

Pre-ordered on TireRack (they had the individual shocks/struts at the 20% off sale price and free shipping). Should be here end of April to mid-May (the shocks are trailing behind a few weeks).

 

[09jsw]

Pre-ordered on TireRack (they had the individual shocks/struts at the 20% off sale price and free shipping). Should be here end of April to mid-May (the shocks are trailing behind a few weeks).

Now that is one hell of a deal

 

[VertMustang98GT]

Pre-ordered on TireRack (they had the individual shocks/struts at the 20% off sale price and free shipping). Should be here end of April to mid-May (the shocks are trailing behind a few weeks).

Not yet, it's probably going to be mid to late April before I have everything.

 

[jbailer]

Has anyone who has Steeda Progressives added the Steeda S550 Mustang IRS Subframe Alignment Kit #555-4838 at the time of the install?...do you recommend?...a Steeda rep claim they do it on all their installs...

I installed these myself right before taking it to the shop for the spring install and 4 wheel alignment. Mine wasn't off but I've heard a lot of people's were. The nice thing is now I have the peace of mind that it is squared up. I'd be willing to bet, the large majority of places you take your car to for an alignment would never touch that to correct it.

The Steeda Progressive springs were surprisingly an improvement in the ride quality over the stock springs, PLUS I got the car lowered so it looks and handles much better, a win-win-win! I'm very anxious to get the dampers replaced to make it even better. Not anxious enough to put dampers on that aren't going to improve things or add noise issues.

 

[Todd15Fastback]

David confirmed the exact rates for the Ultralite liner springs here.

http://www.mustang6g.com/forums/showpost.php?p=1250433&postcount=33


225 front and 880 rears.

 

[Silver Fox]

I have a non PP 2015 GT. I'm thinking about replacing the rear springs with PP rear springs and adding the Koni shocks. It's a DD and really don't want to lower the car. Does anybody know the part number for the PP rear springs. My super parts guy at the Ford dealer is no help on this one and there are ten different springs available for the rear of a 2015 Mustang. Actually have the part number just need the letter at the end of the part number. Thanks

 

[FFPM46]

It is possible to get the Ultralight linear in front and the Steeda Sport Linear in back. Same spring rates but not as much drop in back. I just ordered a set direct from Steeda.

Did I read Steeda's site wrong? I thought I read they both are 1" drop in the rear.

Maybe David from Steeda can clear this up.

 

[FFPM46]

So that was you on the phone!

Can you advise if the Ultralites Linear and the Sport Linear have the same 1" drop in the rear?

 

[Doctor Fishtail]

Hi there

I thought it might be a good idea to compile all the spring rates of the springs of the market all in one place, I shall keep this original post updated so people don't need to read all the replies.


So far I have compiled these from reading many threads on this great forum.


Front/Rear

GT: 160 / 668
GT PP: 165/728
BMR Performance: 170/740 (1.2" F / 0.5" R)
BMR Handling: 300/980 (1.2" F / 0.50" R)
BMR Drag: 150/800 (1.2" F / 0.5" R)
Steeda Sport Linear: 198/874 (1" F / 0.95" R)
Steeda Ultralite Linear: 198/874 (1.20" F / 1.05" R)
CJPP: 182-217 / 799 (1.5" F / 1" R)
Eibach Pro Kit: 200-314 / 800-914 (1.1" F / 1.0" R)
Eibach Sportline Kit: 217-331 / 879-994 (1.50" / 1.3" R)
Swift Springs Progressive: 270 / 782 (1.1" F / 1" R)



Linear VS Progressive

For those who don't understand the difference, Linear has a set constant spring rate and progressive is as the name suggest, progressive so as you drive the car harder causing more body roll the springs become firmer to try and control body movement more. Linear are the choice for those who want best handling characteristics with great predictability and less noise, plus linear springs work in harmony more so with the dampers. In short a linear spring will typical be a better handling car. The plus of progressive is when your driving on better roads they maintain better levels of comfort and only firm up on poor road surfaces which can actually mean worse ride quality or when you push the car harder, the downside is your dampers are linear and have a set rate so sometimes dampers can struggle with progressive springs and this is why coilover kits have progressive springs. Another downside of progressive springs is they can be noisy due to coils being much closer together causing squeaks. I enjoy corner carving and a predictable car with as little noise/NVH as possible, so I will always go linear springs.

Anyone knows the rates and drops for other springs or if I made a mistake please post and I shall add them to the OP. Be nice to have them all in one place, maybe an admin/moderator could sticky this?

Talked with Swift and their springs are LINEAR not PROGRESSIVE. Might want to change this. Also Front Rate is 279 not 270.

 

[TrackpackGT]

What about GT350R springs?

 

[David@Steeda]

Can you advise if the Ultralites Linear and the Sport Linear have the same 1" drop in the rear?

As long as the springs are clocked, they should be pretty close in the rear.