Anyone have the spring rates for Eibach Pro Kit &
Ford Racing Springs M-5300-K ?

Ford factory spring rates are:
Hardtop - 165lb front 142lb rear.
Convertible - 144lb front, 122lb rear.

Steeda Spring Rates:

Steeda Sport Springs - Spring rate is 200lb front, 175lb rear.

Steeda Ultralite Sport Springs - 195lb front, 175lb rear.

Steeda Street/Comp Springs - 225lb front, 185lb rear.

 

Thank God the fronts are a coil over shock otherwise we'd be rolling around like pigs in mud with that spring rate.

 

<div class='quotetop'>QUOTE(GTRacerX @ December 3, 2005, 1:40 PM) Quoted post</div><div class='quotemain'>
Anyone have the spring rates for Eibach Pro Kit &
Ford Racing Springs M-5300-K ?

Ford factory spring rates are:
Hardtop - 165lb front 142lb rear.
Convertible - 144lb front, 122lb rear.

Steeda Spring Rates:

Steeda Sport Springs - Spring rate is 200lb front, 175lb rear.

Steeda Ultralite Sport Springs - 195lb front, 175lb rear.

Steeda Street/Comp Springs - 225lb front, 185lb rear.
[/b][/quote]
I called Eibach tech support the other day and obtained the following:

Eibach Pro Kit:

Front: 171-230lb Progressive
Rear: 110-200lb Progressive

I also asked Jason at BMR about their new 1.5"/1.75" kit:

BMR SP009:

Front: 120-165lb Progressive
Rear: 130lb

 

<div class='quotetop'>QUOTE(GTRacerX @ December 3, 2005, 3:40 PM) Quoted post</div><div class='quotemain'>
Steeda Spring Rates:

Steeda Sport Springs - Spring rate is 200lb front, 175lb rear.

Steeda Ultralite Sport Springs - 195lb front, 175lb rear.

[/b][/quote]
Difference of only 5 pounds up front and none in the rear?
If the Ultralites' are marketed for having 'the best ride quality', then the BMR's must feel like jelly and the Eibach's are like ultra-stiff! Both of which I know are untrue.

These spring rate numbers make no sense to me. [img]style_emoticons/<#EMO_DIR#>/headscratch.gif[/img]

 

I agree the spring rates are a little confusing, especially when trying to compare fixed with progressive. My understanding on the Ultralites is that they're lighter in weight and thus the ride is better as it reduces unsprung weight.

06TUNGVERTGT installed BMR's SP010 1.5"/2" progressive springs and he said:
<div class='quotetop'>QUOTE</div><div class='quotemain'>It is much firmer, but not harsh, I may still do the Tokico struts soon, I would try it first and see what you think, before investing in the struts[/b][/quote]See thread: showtopic=43641

I am inquring as to the spring rates for SP010...[edit] They're the same.

 

<div class='quotetop'>QUOTE(GTRacerX @ December 3, 2005, 3:40 PM) Quoted post</div><div class='quotemain'>
Anyone have the spring rates for Eibach Pro Kit &
Ford Racing Springs M-5300-K ?

Ford factory spring rates are:
Hardtop - 165lb front 142lb rear.
Convertible - 144lb front, 122lb rear.

Steeda Spring Rates:

Steeda Sport Springs - Spring rate is 200lb front, 175lb rear.

Steeda Ultralite Sport Springs - 195lb front, 175lb rear.

Steeda Street/Comp Springs - 225lb front, 185lb rear.
[/b][/quote]

GTracerX

Where did you get your stock spring rates

Taken from a spec manual for the 2005 Mustang

Front
Spring rate N/mm (lb./in.)
GT Coupe: 23.9 N/mm (136.5 lb/in). All others: 20.0 N/mm (114.2 lb/in).

Rear
Spring rate N/mm (lb./in.)
Convertible: 21.5 N/mm (122.8 lb/in). Coupe: 24.9 N/mm (142.2 lb/in)

 

<div class='quotetop'>QUOTE(Redfire 05Gt @ February 6, 2006, 12:18 PM) Quoted post</div><div class='quotemain'>
I am inquring as to the spring rates for SP010...
[/b][/quote]
SP010 has the same rates as SP009:

Front 120-165 Progressive
Rear 130 Fixed

 

Make sure you are not confusing spring rates with wheel rates

 

<div class='quotetop'>QUOTE(softbatch @ February 6, 2006, 12:42 PM) Quoted post</div><div class='quotemain'>
GTracerX

Where did you get your stock spring rates

Taken from a spec manual for the 2005 Mustang

Front
Spring rate N/mm (lb./in.)
GT Coupe: 23.9 N/mm (136.5 lb/in). All others: 20.0 N/mm (114.2 lb/in).

Rear
Spring rate N/mm (lb./in.)
Convertible: 21.5 N/mm (122.8 lb/in). Coupe: 24.9 N/mm (142.2 lb/in)
[/b][/quote]

Link to Spec Manual (pdf file)

 

From http://www.2005stang.com/gallery/albums/us...stang_specs.pdf (Thanks Don)

SPRING rates:
Front
GT 136.5
Others 114.2

Rear
Coupe 142.2
Convertible 122.8

The WHEEL rates are:
Front
GT 170.7
Others 148.5

Rear
Coupe 170.7
Convertible 145.6

A GT Coupe has a Front AND Rear Wheel Rate of 170.7...