Dave, I think you're taking your anathema waaaay too far I'm not exactly for cutting coils (as I said in my original reply), but it's not going to do anything really destructive. It's going to change the ride height and spring rate, you just don't really have that much control over the spring rate like you would with a new set of springs. This is why I recommend new springs instead.

109 is right, though. None of the original engineering applies to modifying the car's ride height and handling ability. Ford used different springs for different cars, engines, and suspension packages. They tailored the springs to achieve a specific ride height and quality (usually really mushy, in the case of Mustangs). Obviously their tailoring isn't what we want, otherwise we wouldn't be altering or replacing otherwise perfectly good springs.

As I said before, I'm going to cut a bit off my coils when I go in and do the Shelby drop. If money was no object, I'd just buy a set of 540lb 1" drop springs. But my budget is rather tight, and since I'm going to have the front end apart anyway to do the Shelby drop, I might as well fix the ride height while I'm in there. I doubt I can cut enough off the springs to make them too stiff for my personal taste without bottoming the car out. I probably only need to cut 1/4 of a coil or so. Worst case, I end up with a really harsh ride that I just have to deal with until I can buy a set of new springs. Best case, I get my lowered ride height and a stiffer ride for better handling.

 

As I understand, there is usually a battle between "production engineers" (who focus primarily on both costs and ease of production - precisely why indept. rear suspensions were left off production Mustangs) and the original "design engineers" of the various components. Therefore, it is not unreasonable to guess that the "final product" was a compromise between the 2 differing approaches. In this spirit I ask, is it not likely that the production engineers had the final say but there existed debate as to what the proper spring choice would be for the Shelbys with the drop?

Furthermore, the Shelby drop has been around for a long time. Some, regardless of whether they had informed reasons or not, have shortened the coils and others have not. The question no one is asking, much less answering, is how do the rides compare when controlling only for that variable (the variable being coil shortening)???

I suggest that those of you with similar cars with Shelby drops actually physically get together and compare the rides. Keep track of the different tire and wheels, suspension types, etc... try to be somewhat scientific about the results.

If this debate warrants the spirited disagreement that is transpiring, then perhaps more effort towards an objective "outcomes-based" study is needed.

 

 

thanx for all the spirited info!! i have decided to buy the new 1" shorter springs and do the leaf spring relocation. this is a pic of my car to show why the lowering is needed for a nicer look.

http://img241.imageshack.us/img241/1...back005ut9.jpg

 

You see, it's comments like this that concern me...

You've picked out what you want hear to support your argument.

From Mike (the Eaton Spring guy)....

Quote:

how to cut the RIGHT way.

DO NOT USE HEAT. Did you hear me......NO HEAT
Cut the coil with a hacksaw or a rubber cutoff wheel.

Also from Mike....

Quote:

While we have all sorts of springs which will vary ride height, spring rates and ride quality on the shelf, cutting coils maybe, in some cases, the only way to achieve the desired stance one is looking for.

Fortunately for us classic Mustang owners, we have a broad choice of ready made aftermarket springs to choose from to "achieve the desired stance one is looking for"... and it is not our only alternative. Mike is stating to buy the right spring, unless you have no other choice. You've read it as a green light to start cutting.

Lastly,

From the example coil spring used in the link... the '67 Mustang GT.... using the same formulas and math, for every full coil that is removed, 0.70" of spring deflection is lost. If total spring deflection is 5.645", this equates to 12.5% of "lost" deflection.

How can a front suspension benefit from reduced suspension articulation? In a hard corner, keeping all four wheels firmly planted on the pavement is key to coming out of the corner as intended. Reduced suspension articulation will limityour speedon hard cornering.

Haven't you ever seen a kid in a Honda driving in front of you with his springs cut? Not only is the ride harsher, but his tires are sometimes literally "hopping" off of the road during a sharp corner.

You and I can discuss this until we're blue in the face. At this point I suggest we both just agree to disagree.

Dave

 

Fine, cut it with a hacksaw, but If you cut the coil with a wheel, the heat affected zone is in the unused portion of the spring. When he says don't use heat, he means the part that you conveniently left off which says "NOT A TORCH!!!!". Bottom line is that you can cut coils. Information straight from a spring manufacturer says you can.

Suspension travel is reduced with any kind of shorter spring whether cut or store bought anyway unless you shorten the suspension stop. If you cut a coil, then you have also shortened the height at which the coils will bind. This means that the chances of coil bind when installed are even lower if you have not modified the suspension stop.

What I've picked out is that cutting the springs is not taboo as you claim. You have picked out what you want to hear as evidenced by your convenient ommission above. Fine, Whatever. I can see that you will never let it go. I'm done.

 

66 fastbach,

After looking at the picture of your car, it appears to me that it may already be sitting lower than stock. Personally, I like the way your car is sitting in that picture and I wouldn't change it, but that's just me. It could be that the coils already in there are worn out, or someone has already put in coils that are shorter (cut or manufactured that way). You may find out that the new springs don't do anything to lower your front end ride height. Somewhere I saw a table that gave measurments from the center of the wheel to the fender lip for different coil spring configuration on various classic Mustangs. This would be a check as to whether you car is already sitting lower than stock. If I can find it I will post a link, but it has been a while.

 

Cut or no cut, I would give consideration to doing the drop first, and driving it that way before lowering it another inch.
I know you have 16' rims, what size are the tires and what is the diameter? Are your fender lips rolled?

Simply put, your tires might rub. It's got something to do with "two objects occupying the same space."

 

Again, I'm with 109jb. Cutting springs with an angle grinder is not going to create enough heat to alter the metal's grain structure for any more than 1/4" from the cut point, which isn't going to affect the spring's characteristics at all. The point Mike was trying to make was "do NOT use a cutting torch," as I'm sure many people have tried to do.

Rice rockets withcut springs can't keep tires planted because a) those ricers are stupid and like to cut the coils as much as possible to get the car as low as possible, making the springs waaaaay too stiff in the process; and b) cheap shocks that can't keep the tires planted on the ground. They also generally have much less suspension articulation to begin with, so reducing that by several inches is going to have drastic consequences. If you dropped your car to the ground and used 620lb springs, I guarantee you wouldn't be able to keep the tires on the ground on a rough road.

 

I am going through the same process, I bought 1" lowering springs, and it did not lower the car enough, so now I am going to relocate the UCA's and then I will cut a small bit off my coils. I agree, A grinder or chop saw will not affect the spring that much. I would not be afraid to cut the coil.