[Msquared]

Originally Posted by kropscamaro16

they used my old oem springs to testfit and i sent him my old afe springs are orange aka orange line

So "OEM" is a non-1LE SS spring? And on the YYZ charts that looks like it's about 500 rear and 178 in front.

ETA: does that mean the white line is SS 1LE?

BTW, I don't understand the white reference line on YYZ's rear spring chart. The front makes sense since it's roughly 950lb per corner, and it's nearly a 1:1 motion ratio and they apparently assumed full fuel and one or two occupants. But the rear makes no sense. Each rear wheel probably gets 800lbs load as tested, and with a motion ratio of .56:1 the reference line should be around the 250lb mark, not 1100lb as shown. What am I missing there?

[kropscamaro16]

you know you can talk to john powell he is the one that made the yyz and charts he has all of this date himself

[Mountain]

Originally Posted by Msquared

You wrote "...the ZL1 coil diameter is actually a touch less than the SS coil diameter." That means the ZL1 spring is stiffer since all the other parameters that affect spring rate are identical.

On the SS 1LE spring, I guess when you wrote "...the diameter tapers from starting at the same diameter as the ZL1/SS rear spring to a larger one," you were referring to the wire diameter (d)? I assumed otherwise, because it's really rare and expensive to make a spring that way and I can't really see a good reason to do that. But okay, if that's the case, and considering that stiffness is a function of d^4 and that there is also one less coil, that almost guarantees that the SS 1LE spring is stiffer than the regular SS spring. Obviously measurements could still say otherwise, but I wouldn't bet on it.

BTW, even a progressive wire diameter doesn't really guarantee a progressive spring rate. It's only progressive if the softer portions of the spring actually collapse into coil bind through the car's suspension travel. I doubt that happens in this case, but again, without measuring it's impossible to know for sure. Again I noted that F1FTY measured them and found them to be linear.

I would be very interested in your findings if you are able to actually measure the various OE springs.

When I wrote:
"coil diameter" = the actual coil or "wire"
"diameter" = the diameter (ID or OD) of the spring


After seeing the springs up-close and taking some measurements, the SS 1LE rear spring seems like it should be at least as stiff as the SS and possibly slightly stiffer.

It's possible GM decided on the SS 1LE rear spring as such (a construction) in order to keep the rear ride frequency similar to the SS, but lower the car some.

This actually kinda highlights the move to the hydro-bushing in the SS 1LE front lateral link over the pure rubber bushing in the SS (going to a higher ride frequency/wheel rate up front and adding more NVH from +40lb spring).

Originally Posted by kropscamaro16

they used my old oem springs to testfit and i sent him my old afe springs are orange aka orange line

I figured that.
My assumption:
Red - Eibach
White - BMR "Perfromance"
Orange - Afe
Purple - Hurst?
Yellow - Multimatic/ZL1 1LE

[Joey Soul]

Originally Posted by ddipaola

Greetings. I've been searching for a more street-friendly set of coilovers for my ZL1 1LE. Save the roast fest for later. Michigan roads are brutal! And they're no longer covered under warranty so I would rather save them for the track considering I haven't found a supplier willing to rebuild the Multimatic DSSVs in the case they blow out. I've ran across aftermarket suppliers offering downright silly spring rates across the board, so I decided to do my own research and determine the best spring rate to request for my desired goal.

I will keep everyone in touch this spring/summer with the results in terms of ride frequency & comfort. Comfort may not be your goal, but it will prove that I've got the right calcs/ratios for Frt/Rr spring rates & ride frequency.

nice, I did these equations and measurements a few years ago but I was never sure if I was 100% accurate or missing something. Also always wanted to know the zl1 1le rates. big help thanks.
as for the rates. I ran 6k 14k swifts this season and the lack of front compression range was concerning. 338lb spring and ~970lb on the nose made for a 2.8 inch drop on a coilover with barely 4 inches of travel. I will be bumping up to 8k 20k for next year

[Badmojo]

Does anyone have the ZL1 (not the ZL1 1LE) front & rear spring rates? I searched and couldn't find them.

[Marozl1LE]

Also can anyone tell me how can i lowered my 2019 zl 1le with lowered springs ??

Is that possible ?
which springs i need it i want just around 3cm lowered nothing more my car seems like a monster truck with OEM suspension
my front suspension is on the max lowered position already

Thanks for the support guys

[GunMetalGrey]

Originally Posted by Badmojo

Does anyone have the ZL1 (not the ZL1 1LE) front & rear spring rates? I searched and couldn't find them.

I am pretty sure the front is 175 pounds/inch

I am currently trying to find the right springs to match the DSC controller I have for the MRC, I currently have YYZ progressive rate Springs that go from 200 to 400 lbs/inch in the front, but I don’t know if they’re a good match for the DSC controller or not. I believe you had or still have the DSC controller, correct? If so, any thoughts or opinions?

I have to say that without the DSC controller, and despite having the YYZ springs and upgraded sway bar is set at 50% stiffer with SC3R’s I saw a picture of my car going around a particular hard track corner, and I was very disappointed and embarrassed, it had so much body roll It looked like in 1970s Cadillac trying to take a corner…