Stock spring rates for the Mirage?

Does anyone have any info on what the stock spring rates are?

I have zero information for the fronts.

The rears are claimed to be:
Early 2014: 118 lb / 2.1kg ???
Mid 2014 - 2015: 168lb / 3.0kg
2017: ???

Quote:

---

Originally Posted by cyclopathic

I think the 2014 had 118lbs/in (unconfirmed) and they bumped it to 130 for 2015 (per Little Stan measurements)

---

Quote:

---

Originally Posted by cyclopathic

OEM springs are straight rate you can measure it by looking at preload. Uncompressed springs are 12" and compressed 9", 390/3 = ~130lbs.

---

Alright, found some more info. However, its only about the rear springs off a 2015.

Quote:

---

Originally Posted by Littlestan

Attachment 5768

Attachment 5769

Attachment 5770

Attachment 5771

Alright! I was reminded that we had a mechanical scale stashed away in the basement that is
accurate to within a half pound, and it worked wonderfully for this purpose.

Using a motorcycle tie down and a couple chunks of plywood to stabilize, I was able to compress
the Amazon (AD) rear spring at 1", 2" and 3" compressions. The rear OEM springs I was only able
to compress 1" safely for reasons which will soon be clear. The first pic is at 2" compression,
second pic is at 3" compression, third pic is the stock spring at 1" compression and the final pic is
the test bed.

Here's the test bed details...

First, I measured the spring and the wood chunks for the weight to subtract from the measured
compressed weight. For every stage of compression, I used a level (not pictured) to re-orient the
top piece of wood so that a consistent measure could be taken from the aluminum ruler you can
see standing upright at the back of the scale. It's not perfect, but it's pretty damn close.

Here's the results:

Amazon (AD) rear spring (-5lbs for weight of spring and wood)

1" - 50lbs
2" - 99lbs
3" - 159lbs

Stock OEM spring (-6lbs for weight of spring and wood)

1" - 163lbs

I think it should be pretty clear the rear springs are garbage at this point. I'm just uploading a
short video to Youtube showing me hand compressing both springs that I'll post once it's done. The difference is huge and frankly, I'm not sure how these ever got OK'd to be produced. They should
have stuck with a linear design.

---

While this is interesting, it really is a little puzzling since a lot of the aftermarket springs seem to have softer rear spring rates:

Suspension & brake aftermarket parts index

As per KYB Ph when they've released the KYB rear springs for the hatchback in 2016, the stock rear spring (probably models earlier than 2016) has a rate of 1.9kg/mm, while their new springs are rated at 2.3kg/mm.

2016 springs were significantly squishy than the KYB, which gives me the impression that it's rated far below 2.3kg/mm (0A468041991A, not sure if this was the part #). Furthermore, despite most claims, kyb increased right height by 3/4 of an inch but solved the bottoming issue as expected with stiffer rates.

Recently, I had a chance to peek under the rear of the newer models assembled here in the Philippines, surprised me with a newer series of springs with the serial/part number inscribed 0A468045820AL. These models also had higher rear height than 2016 models from thailand, so I'd assume they've put more stiffer springs on these new models. I'm yet to ride a friend's 2017 model soon to figure out.

Misleading info here:

Quote:

---

Amazon (AD) rear spring (-5lbs for weight of spring and wood)

1" - 50lbs
2" - 99lbs
3" - 159lbs

---

Let's say the free length of the spring is 12" and the installed length is 9". Probably not too far off from reality, but it doesn't matter... just an example.

If you're measuring a progressive spring rate, your effective spring rate at normal ride height is the rate after 3" of compression. Most progressive springs have a set of "tight" coils that will be completely compressed under the static weight of the car.

That's so that when you go flying over a railroad crossing at Mach 2 and the suspension unloads completely, when you come back DOWN, you don't get a sudden jolt. You get a softer spring rate for the first few inches as the suspension recovers.

The calculation for spring rates includes the thickness of the wire and the diameter of the spring. But, a major factor is the NUMBER OF COILS in the spring. More coils = softer rate. So, the typical progressive spring has coils that are closer together and fully compress quickly. Once they are "bound", then they're out of the equation, you have less active coils and more spring rate.

What I'm saying is that the test method above, if you're talking about a progressive spring, is probably flawed. Would be more accurate to measure the spring and crunch the numbers. "What's the spring rate with all coils active?" "What's the spring rate with the progressive coils compressed?"

I like to use a calculator like this one because I'm lazy:
http://www.racingsuspensionproducts....ing%20rate.htm

Physics doesn't lie!