Best handling springs

[2013DIBGT]

Update.
With Dot R tires the Boss 302 springs are not firm enough. Thinking about Steeda Comps for a winter project.
What I want is stiffer but not much lower than stock. I can't find anyone that does a set.

If the post from Whiskey11 hasn't swayed your decision any I have a brand new set of Steeda Sport springs never used sitting right here on the floor next me that I would sell for a loss to anyone interested.

 

[todcp]

I am not interested in "lowering" springs. Why is it that all the stiffer springs are lower? I want springs that are effective on the track but won't beat the car and I up too much on our poor roads in New England. The 1.4 inch drop in the rear that the Steeda Boss 302 springs create is too much for a non coil over setup and leaves too little suspension travel.
Whiskey; you are correct. Just did not want to pour that much money in. Also as a former SCCA racer I know what a pain race dampers can be with rebuilds needed. Not a good idea for a street and track car.
Maybe GC next?

 

[Vorshlag-Fair]

You know, there are a number of us who have been down this path and really the only thing I can think of is why you would also want to go down this path when so many of us have documented prior? The lower the car gets, the more spring rate you will need to keep it off the bump stops. You are welcome to spend your money as you see fit but I think this cycle is destructive.

What I'm getting at is good coilovers do NOT kill ride quality nearly as bad as people make it out to be and are well worth the investment. No one is saying you have to get 1200lbs/in front springs and 600lbs/in rear springs. Just pick a decent amount of spring rate from the get go and avoid this "find the right lowering spring" nonsense. You'll probably even save money in the long run!

Just my thoughts.

If I had a dollar for every customer I've told this exact advice, and another dollar for every time they eventually realized this themselves and wished they would have heeded our advice, came back to us and bought coilovers after going through 1 or more iterations of crap handling suspension, I'd have a successful business designing/making/selling coilover suspension upgrades for these cars....

Oh, wait.

Some folks are deliberate, do their research, listen to the advice from the right people, and make their suspension decisions for the long term. Do it once, do it right.

But many folks, especially in the Mustang community, base their suspension choices on bad "internet forum group think" advice, go for the cheapest solution (Lowering Springs!), and ignore the many well documented consequences of these simple suspension "upgrade" choices (loss of bump travel, inadequate spring rate for the lower height, adverse rear geometry changes, rear axle offset and... terrible ride and piss poor handling).

It pains me to see people turn a nice car into a horrible riding, terrible handling, pogo-stick dump truck, but thousands of Mustang owners do it every year. These debates over "which lowering springs are best!" are the place that many of these bad decisions stem from.

My advice is: Run. Run far away from this thread, and don't look back.

 

[Racer47]

If I had a dollar for every customer I've told this exact advice, and another dollar for every time they eventually realized this themselves and wished they would have heeded our advice, came back to us and bought coilovers after going through 1 or more iterations of crap handling suspension, I'd have a successful business designing/making/selling coilover suspension upgrades for these cars....

What does that complete coil over set up cost?

 

[SlowJim]

I think for someone who really wants to enhance the handling of their car for track work, coilovers are absolutely the answer. If you are dead set on sticking with regular ol springs, I believe they go in this order (from stiffest to softest):

-MM Road & Track
-H&R Race
-Eibach Pro-kit/Ford K/UPR (and maybe a couple others that are essentially identical)
-All the rest

 

[Lucky_13]

~3,000 when you factor in the cost of springs, CC plates, etc.

 

[Racer47]

Thats a big price difference over a set of $700 Koni Sports and a $300 set of springs. Even if it takes buying a couple sets of springs until you find your right combo you'll still a lot of money ahead. Plus you can easily sell your lightly used springs to the next guy looking for the right combo.

Sure you will never get the the coil over benefits of ride height adjustment that is independent of spring rate. But you do have an extra $2k to spend somewhere else.

I just went through this. I had Ultralights and now I went to Steeda Comps 555-8241. I'm very happy with this combo. Here is all the spring data I could find scouring the forums. I'm sure its not 100% accurate but its probably close enough. The first numbers are inches of drop front / rear then spring rate front and rear. Not all springs have all data. The links at the bottom are where I found most of the data.

Stock/Factory GT springs (Tags= Yellow, Orange) - front: 136lb/in / rear: 142lb/in

Steeda Competition (pn 555-8241) 1.0/1.25 - front: 225lb/in / rear: 185lb/in

Steeda Sport (pn 555-8216) 1.0/1.25 - front: 200lb/in / rear: 175lb/in (more progressive rate)

Steeda Sport (pn 555-8215) 200lb front, 175lb rear (more linear rate)

Steeda Ultra-lite (pn 555-8206) 1.25/1.5 front: 195lb/in / rear: 175lb/in

555-8220 New Steeda 05-12 GT Convertible sport springs 200lb front, 190lb rear

555-8245 New Steeda Comp Springs Boss302 and GT 225lb front, 195lb rear

In a different post, he said that the Boss 302 springs on a GT (not a Boss) "drop about 3/4 of an inch in the front and around 1 1/4 in the rear"

Eibach Pro-kit (pn 35101.140) / Ford Racing (K-springs) (pn M-5300-K) 1.5/1.7 - both variable front: 173-248lb/in / rear: 195-236lb/in

Eibach Sportline (pn 4.10135) 1.6/2.0 - UNKNOWN (*tested by Chip- reportedly very high)

H&R Sport (pn 51655) 1.0/.75 - UNKNOWN

H&R Super Sport (pn 51655-77) 1.7/1.9 - both variable (working rates) front: ~250lb/in / rear: ~200lb/in

H&R Race (pn 51655-88) 1.5/1.4 - both variable (working rates) front: ~300lb/in / rear: ~275lb/in

Roush Performance {sold in pairs} (pn 401294 and 401295) 1.0/1.0 - UNKNOWN

Roush Extreme (pn 402331) 1.0/1.25 - UNKNOWN

Tein H-tech (pn SKG12-BUB00) 0.94/1.65 - front: 163lb/in / rear: 163lb/in

Tein S-tech (pn SKG12-AUB00) 1.5/2.24 - front: 174lb/in / rear: 174lb/in

Vogtland (pn 950084) 1.3/1.3 - variable front: 160-240lb/in / variable rear: 120-220lb/in

Saleen/Racecraft (pn 10-1302-B12999) 1.25/1.25 - UNKNOWN

Sprint (pn 2115) 1.6/1.5 - UNKNOWN

BMR Fabrication Inc. - see below

http://mustangforums.com/forum/s197...ng-rates-and-heights-no-guessing-allowed.html

The Steeda Sports I use and recommend are NOT the 555-8216's that you find on most sites. That's a progressive spring made by Eibach, I use a linear rate version made by Hypercoil. http://forums.themustangsource.com/f726/those-brembo-package-485279/index5/

Mustang Shelby GT500 Competition Lowering Springs Steeda (07-09) http://www.brenspeed.com/555-8241.html

 

[BMR Tech]

^ I just want to clarify the BMR Rates in that post above.

The SP009's are 165F Linear, and 120/160R Dual Rate

The following springs will be available hopefully by the end of the year:

SP065: 240F / 200R (Linear)

SP070: 220F / 200R (Linear)

SP072: 260F / 220R (Linear)

 

[Racer47]

Thanks for the correction. What will be the amount of drop with these springs? And will be they sold as pairs, so you could buy only the fronts or rears as needed?

 

[BMR Tech]

You bet!

And yes, this will be what we will offer.

Fronts Pairs:
SP069 - 150lb/in (Drag Specific)
SP011 - 165 (GT)
SP076 - 165 (GT500)
SP071 - 220
SP066 - 240
SP073 - 260

Rear Pairs:
SP012 - 160lb/in
SP067 - 200
SP074 - 220

I wanted to offer them in pairs, so people can play around with different rates.

Most of the drops, will be in the 1.5" range.

 

[Whiskey11]

I am not interested in "lowering" springs. Why is it that all the stiffer springs are lower? I want springs that are effective on the track but won't beat the car and I up too much on our poor roads in New England. The 1.4 inch drop in the rear that the Steeda Boss 302 springs create is too much for a non coil over setup and leaves too little suspension travel.
Whiskey; you are correct. Just did not want to pour that much money in. Also as a former SCCA racer I know what a pain race dampers can be with rebuilds needed. Not a good idea for a street and track car.
Maybe GC next?

My opinion is pretty biased, but my GC kit has been doing extremely well for what I expect it to do. The 440/200 setup I had before rode about as well as stock. My newer setup (550/275) is a lot more firm and has more "head toss" but is not harsh by any stretch of the imagination. The custom valved Koni's still carry the Koni warranty. The springs are Eibach's Race Coilover springs which are better than what any coilover kit in the price range comes with and the camber plates work well. It's not a bad choice in the bang for your buck category but don't expect them to perform like those MCS's do either.

If you do go down the GC route and are curious as a baseline on where to start, the track/school valving with 450/250 springs is probably a good place to start. Rear springs could be dropped to 225 if you were feeling you can get away with that much rear swaybar and high enough roll center. I know at 440/200 I wanted a lot more rear spring rate and even at 550/275 I'm thinking that 550/300 would have probably been more beneficial as my rear RC is still waaaay high. (highest position on the Fays2 Watts link). When I had the 440/200 setup, watts link all the way up and the stock bar it pushed pretty badly still. Added the rear bar and was told that the car doesn't put down power well enough and less swaybar more spring rate would be beneficial. I tweaked the wheel rate ratio when I upped the spring rates and stuck my stock rear bar on the car. Much better.

 

[frank s]

Thanks to Racer 47 for the research and condensation.

Adding what someone put up as stock rates:

2005 front springs
GT Coupe: 23.9 N/mm (136.5 lb/in). All others: 20.0 N/mm (114.2 lb/in).
GT Coupe: 29.9 N/mm (170.7 lb/in). All others: 26.0 N/mm (148.5 lb/in).

2005 rear springs
Convertible: 21.5 N/mm (122.8 lb/in). Coupe: 24.9 N/mm (142.2 lb/in)
Convertible: 25.5 N/mm (145.6 lb/in). Coupe: 29.9 N/mm (170.7 lb/in)

My solution for a previous (2009 GT/CS with KONI yellows) was the FRPP "P" springs about which ModeernBeat (Vorschlag) said: "I much prefer the Ford "P" springs that are about 204f/130r and are more progressive at both ends."

The "P" springs lowered the car less than an inch, slightly more in the rear, and were a nice fit for my needs: mostly street/highway, occasional autocross and track.

Just sayin'

 

[BMR Tech]

"P" Springs are 130R?

That doesn't sound right to me. Is that the initial rate?