Needed: Specific 1LE lowering Springs!
 

Disclaimer...I am not an engineer, only an enthusiast (and claimed "driver") so my thoughts below are only derived using deductive reasoning from racing and real world experience. Take them for what you will.

My 1LE is a weekend, open track day and drag raced car. I will use it when I instruct and want it to perform and behave on the track......It is not currently a dedicated race car (or daily driver) so I have been looking at lowering springs to lower the center of gravity (cg) and reduce the gap between fender and tire. Coil overs will come later....but not yet!

What I have found is that the springs on the market now were all developed for the 2010+ SS (non 1LE) YES, we do have SS springs but GM went through the trouble to sort out the car and provide a neutral balance instead of a platform that under steers with the 1LE. I want to keep it that way.

I did talk to a couple of springs companies this week and I do appreciate their honesty and most had the same response that "most customers are more concerned with ride height / looks"

If the numbers I found online are correct the SS comes with:

165FR and 370RR (lbs/in) spring combo.

Most aftermarket companies are increasing the front to:

210-220 lbs/in or about a 30% increase. (BMR 220, Pfadt 210, Eibach 143-222,)

The rear spring rates vary from 395-485 or 21% to 34.5% increase (Pfadt 210, BMR 460, Eibach 143-222).

The closest I can find to a (close to) equal increase is with the Eibach (34.5% FR / 31% rear increase) but I wanted to stay away from a progressive rate springs (Eibach, Pfadt, SLP) and use a linear spring. Now Progressive rate are much nicer for the street, but that is not my focus.

BMR and Pedders offer linear rate springs. Pedders does not publish springs rates so they can not be considered unless I can find/see those.

I spoke with Kyle at BMR and they offer a 220/460 combo for the V8 and a 200/430 combo for the V6. The V6 is lighter, but I asked if I could order a V6 front spring 200 lbs/in and a V8 rear 460 lbs/in and I can. That would increase the front rate 21% and the rear 24%. It sounds great in theory, but my concern then turns to ride height as I fear the front V6 Springs will sit lower than the rear V8 Springs. the only way to find out would be to try it....So what now? I'm not sure....

Please feel free to correct, interject or discuss...

-Matt

Well i am work right now but i put a set of ZL1 rear spring on the back of my 1LE . The ZL1 rear spring will drop the back of the a 1/2 inch and even out the ride high on the car. I took some cell phone pick today at work and will post springs NP and pic when i get home to night.

Interesting...

The front ZL1 springs are linear spring but the rear ZL1 springs are progressive. (I believe 260-400ish lbs/in) This is fine on the ZL1 as it has ride height sensor and magnetic ride can adjust/control the shocks (make them stiffer as needed)

This may work fine on the street, but I have got to believe mixing a linear front and progressive rear has got to be unpredictable at the limits (on a track).

-Matt

Finally nice to see someone actually buying springs for the right reasons and not just throwing off the shelf springs onto a car to lower it and never considering how the performance will be affected! I will be watching this thread Matt!

This is one of the big reasons why I have not really pursued any springs for my car yet. I'd rather go with a suspension that I know has been engineering to work as a system.

Get some good 3 way coilovers, have the car properly corner balanced and aligned and then take it to the track and run a 2-3 laps with each setting, adjust to where you like your car and then have fun. I had some KW V3 Coils on my old Genesis Coupe 3.8 and also have owned some track specific cars (92 VW GTi VR6 Swap with about 10K in suspension work). This is the method ive used for years now and it works great... but be prepared with extra tires.

:readthethread: lol...just playin. sounds like good advice, but he's focusing on springs here.

i'm in here for information, i could stand to learn some things about suspension :)

Dropspeed you mite surprise at how well this works with the stock rear shock . The springs are 55 dollars each new so if you put them on your self have the rear aline the way you like for about 200 dollars you can put a set on and give them a try .

Can you tell us more about the results (driving dynamics) you have with them compare to stock?

I am interested as well. Although I will not see a track for a few years, I don't want to throw off the balance and capability built into this car for the sake of appearance. If I upgrade hard parts, it will be for the right reasons.

In my opinion you gain lower cg on a heavy car and lots more camber in front and rear ( we both bottomed out at 0.8-0.9 negative on rear including another local guy). Both of these will help a lot. Spring rate wise you are going stiffer because you lost coils and have less travel, so assume you take stock spring and cut 1-1.5" off. This will tell the stiffness of ur stock spring lowered so go pick the option closest to it.

Dont shy away from progressive springs for dual purpose cars like ours. You will roll less from lower cg and the springs are all stiffer. A little prog spring cleans up your ride without busting your kidneys.

Ok home from work .

How dose the car drive with the ZL1 springs on the Back ? Well first off I see the spring in three ways soft , med. and hard be it the right or wrong way to look at the spring .

When just putting down the road you are on the soft part of the spring rate. The car ride better with the ZL1 spring .

The hard part of the spring is when you hit a big ass bump with speed like 80+ going down the road this move you into the hard part of the spring rate the stock shock on
the 1LE dose a half way good job with the ZL1 spring . I think the stock shock could use a bit more rebound damping for this part of the spring.

I know were there this really bad bump that I test my spring and shock on with my last car all at speeds 80 + and a full tank of gas . I look or should say feel, if the back of car kills its bounce stop
and my lower back from the shock of the fast spring compression and bonce upward if it makes through this with out hurting my back and maintains good control over the car than I am happy. The 1LE pass.

The middle part of the spring rate is about the same as the stock spring.
it feels the same as you go through this part of spring as the stock spring.

I know it a bit of a shoot from the hip set-up but over all I like how its working out for me .

Here the ZL1 rear spring NP #20942619 I got them from here http://www.gmpartsdirect.com/results.cfm here a pic of the car http://www.camaro5.com/forums/attach...1&d=1371858762

Sorry for posting the pic twice was trying to learn how to do that part .

Damnit, where was this post two days ago when I ordered a set of springs!!!!

There is nothing right about it with the exception of the cost and stance. You are correct in that with a progressive rate spring the rate increases as the spring is compressed.

You have a linear rate spring in the front of the car that has the same spring rate at all times as your car is pitched into a corner. Your rear spring is going from a soft rate to a hard/higher spring rate as the car leans into the corner. Your are effectively stiffening the rear end of the car only as you corner.

This makes the car unpredictable and possibly dangerous as it may be prone to unexpected oversteer. If you do not drive the car hard this may not ever be an issue, but even an unexpected lane avoidance maneuver in cold weather or rain could spell distaster.

It is your car so you can do as you want. But there is a reason GM did not use these on the 1LE, which they could have easily as they are cheap. I would take them off or swap to an aftermarket set of progressive rate springs if you like the ride.