Clearance issues for lowered cars?

[Bart23Sept]

Hi all,

2014 GT convertible, thinking about installing springs to lower the car 1" in front, 1.5" in the rear.

Are there issues with curb/driveway or speed bump clearances with cars that have only been lowered a little bit like that?

Do the spring seats allow the stock springs to be cut or is there an adapter that would hold a cut spring correctly in the suspension?

Thanks and happy new year!
Bart

 

[fourdegrees11]

#1 dont cut springs, that's some ricer BS.

A 1" F, 1.5" R drop will not cause issues with clearance, but it will be a firmer ride than factory. These cars have a huge gap from the factory, that amount of lowering just puts it where it probably should have been. You will probably want the Ford "jounce bump" kit for the rear (bump stops). You will also need an adjustable panhard bar to center the rear axle after lowering. LCA relocation brackets are also a good idea to regain the factory geometry. I think 1" on the front is the lowest you can go without causing the front strut mounts to pop, but you could look into gt500 mounts, they just require switching to 05-09 struts.

 

[o2sys]

I’m lowered on coilovers about 2” front and back with cdc classic chin spoiler and clear most driveways and parking lots.

Even the steep ones I just go at an angle and it’s fine.

Wish it was 1” lower actually.


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[01yellerCobra]

Cutting springs isn't ricer BS if it's done right. Don't go crazy and the car will still ride and handle fine. If you want an extreme drop then look into coilovers or bags.

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[Bart23Sept]

Hi guys, thanks for the replies. I figured cutting the springs would be more fun than buying new ones and just popping them in.

@fourdegrees11 thanks for pointing out the other issues. i'll have to look into each one before doing any of the work.

Thanks

 

[bujeezus]

On H&R Super Sports here (almost a 2" drop) and the only issue I've had is the parking dividers/sidewalks hitting the front spoiler. No undercarriage scraping.

 

[fourdegrees11]

Cutting springs isn't ricer BS if it's done right.

Lol, how could it possibly be done right? You're shortening the travel without increasing the spring rate. That is 100% a ricer thing to do vs just paying $200 for some lowering springs

 

[01yellerCobra]

Lol, how could it possibly be done right? You're shortening the travel without increasing the spring rate. That is 100% a ricer thing to do vs just paying $200 for some lowering springs

Shortening the spring does actually increase the spring rate. I can't tell you the exact formula, but having fewer coils does increase the rate. Ever notice how progressive rate springs jave more coils in the softer part and fewer in the former part? As I said, don't go crazy with it. The most I've done is a half coil to get the height exactly where I want.

But I'm sure you're a better mechanic than I am. So do what you want.

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[futat2]

I wouldn't cut the factory springs but if you decide to for some reason do not heat them up first or at all for that matter.... lowering springs are cheap enough.

 

[fourdegrees11]

1

Shortening the spring does actually increase the spring rate. I can't tell you the exact formula, but having fewer coils does increase the rate. Ever notice how progressive rate springs jave more coils in the softer part and fewer in the former part? As I said, don't go crazy with it. The most I've done is a half coil to get the height exactly where I want.

But I'm sure you're a better mechanic than I am. So do what you want.

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What does being a mechanic have to do with anything? It's not even worth trying to argue

 

[Sky Render]

EDIT: Vince is an idiot.

 

[01yellerCobra]

Yeah. I'm the idiot. Coil spacing, thickness, and number of coils have something to do with the stiffness of the spring.

But I'm the numbers. I'll stick what the engineers have told me.

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[fourdegrees11]

No, it doesn't, and you are an idiot.

Shortening the spring means the spring bottoms out quicker since there is less travel, and the rate goes infinite, since metal isn't compressible. So if that's what you mean by increasing the rate, you're still an idiot.



Seriously? It's not the number of coils, you numbnuts, it's the DISTANCE BETWEEN THEM along with other factors, like the width of the spring wire and metallurgy of the material. Cutting springs doesn't change any of those, other than giving you less suspension travel. You can't just compare two springs' stiffness by what they look like.

Good grief.

So, OP, don't cut your springs, unless you're a flat-brimmed ricer douchebag who drives Subarus or Volkswagens. There are plenty of decent lowering springs available for this platform and lots of options to buy used in the classifieds section, and zero legitimate reason to cut springs.

That was awesome. I was starting to wonder if I was the only person around here who thought that was a trashy ricer thing to do.

 

[redfirepearlgt]

BMR 1.5" drop on my car. have no problem clearing curb leaving my driveway on an angle. It's not a shear drop off but it doesn't miss it by much. Put the GT springs in the back and the GT500 springs on the front which only dropped the car 1.0625" as I recall. Rear dropped a good 1.5000". No issues with speed bumps, no rubbing on 305/30/20 rear tires.

Call BMR and talk to them. They are great to assist.

 

[Bart23Sept]

i don't see how cutting springs is a ricer thing, tell that to all of the hot rodders that ever cut springs for a short drop.

just wanted to ask about clearance, wasn't really looking for the other responses. thanks for the replies about clearance after the drop. the car looks so much better with just that little bit of drop.

 

[Bart23Sept]

for what it's worth, the number of coils is in the equation for Spring Constant which is usually represented by the letter k. if the number of coils is reduced, the spring constant goes up which means the spring is more stiff. so if you cut the spring it gets stiffer, not by a lot, maybe not even by enough for you to notice when you're driving, but they do get a little stiffer.

forgot the link when i replied;
https://www.acxesspring.com/find-spring-constant-k-units-calculator.html

 

[fourdegrees11]

Old school hot rodders didnt have many options, there wasnt a huge aftermarket for modifying cars. It's ricer because it isnt an engineered solution, you are literally just winging it at the expense of your ride quality and longevity of your shocks/struts in order to achieve a certain look. Then you consider the cost of lowering springs, and who besides some broke kid dying to look cool would consider that a legitimate solution?

 

[oldVOR]

No, it doesn't, and you are an idiot.

Shortening the spring means the spring bottoms out quicker since there is less travel, and the rate goes infinite, since metal isn't compressible. So if that's what you mean by increasing the rate, you're still an idiot.



Seriously? It's not the number of coils, you numbnuts, it's the DISTANCE BETWEEN THEM along with other factors, like the width of the spring wire and metallurgy of the material. Cutting springs doesn't change any of those, other than giving you less suspension travel. You can't just compare two springs' stiffness by what they look like.

Good grief.

So, OP, don't cut your springs, unless you're a flat-brimmed ricer douchebag who drives Subarus or Volkswagens. There are plenty of decent lowering springs available for this platform and lots of options to buy used in the classifieds section, and zero legitimate reason to cut springs.

Vince, you are wrong, so very wrong.

The calculation to find the rate of a coil spring is:

11,250,000 times the wire diameter to the 4th power divided by 8 times the active number of turns times the mean diameter cubed.

Active turns are the number of turns of the spring that do not touch anything. Any part of the coil which makes contact with anything becomes inactive, that is, it no longer functions as part of the spring.

The mean diameter is the inside coil diameter plus one wire thickness, or the outside coil diameter less one wire thickness.

Let’s take a coil spring made from .610 wire and has an inside diameter of 3.875″ and has a free height of 16.145″ (not installed) and is deflected down to 10.5″ (load height) when loaded to 1,519 Lbs. (load rate) This spring has a spring rate of 269 Lbs.

This spring has 9.33 total coils but 1.33 coils touch the spring seat so they are inactive leaving 8 active turns.

The mean diameter is 3.875 + .610 (The inside is the important diameter because it is the inside of the spring which is used to locate the spring on the corresponding suspension parts. The outside diameter is not considered because it will change with a change of wire diameter)

Do the math-

11,250,000 x (.610 x .610 x .610 x .610) / 8 x 8 active turns x (4.485 x 4.485 x 4.485) = 269 Lbs.

Double check the math: 16.145 – 10.5 = 5.645 deflection. 1,519/5.645 = 269 lbs

Now if we cut say 1/2 turn off this spring the active turns become 7.5.

So 11,250,000 x (.610 x .610 x .610 x .610) / 8 x 7.5 x (4.485 x 4.485 x 4.485) = 287 lbs

Vince, are you sure you want to stand by the statement that the rate doesn't increase with cutting coils or portions thereof off?

 

[Bart23Sept]

Old school hot rodders didnt have many options, there wasnt a huge aftermarket for modifying cars. It's ricer because it isnt an engineered solution, you are literally just winging it at the expense of your ride quality and longevity of your shocks/struts in order to achieve a certain look. Then you consider the cost of lowering springs, and who besides some broke kid dying to look cool would consider that a legitimate solution?

all of these engineered solutions that claim to have basically the same ride but lower height are just a shorter version of a stock spring. and who is swapping out all four shocks when they do a 1" drop?

not broke. spent four years earning a BSME so figured it would be fun to play a little.

 

[Bart23Sept]

Vince, ............. or portions thereof off?

ha ha i thought about running the numbers. nice work.