79Daytona

Hello everybody. Say i was wondering about two years ago i replaced the coil springs on my 92 Z28 5.7 TPI because the person who had the car before me installed lowing spring on the car which made the car ride low and stiff and with the roads around here thats not going to work for me. So I install some aftermarket coil springs i ordered from ebay . Now it did rase the car up to what i though was the stock ride height but the car still rides stiff and the tail end seem a little high to me and i have been hearing online that the after market springs do this. So I was wondering should i try to fine some stock used coil springs to help the car ride better.

Vader

Does the car have the WS6 suspension package? That may be helpful to know when sourcing replacement springs.

79Daytona

Well i don't know the car dose have rear disc brake and a rear sway bar . I don't know if that means anything is there a way to fine out if it has the WS6 suspension.

Drew

iTrader: (58)

Its a Z28, WS6 doesnt apply. It'll be F41 or FE2, but either way the springs won't be much different from each other.

All the aftermarket springs are generic replacements. Original springs will be aged. There's no good answer. Most people seem to cut and experiment with aftermarket springs until they get what they want or just stop trying.

79Daytona

Hey Drew. Thanks for the info.

79Daytona

I think there the same springs i can;t fine anything on a WS 6 spring that would make them any different from what's on a Z28. I looked up the rear springs i bought and they seem to have 8 to 9 coils on the springs and then i looked up some used rear coil spring for a third gen camaro and they seem to only have 7 coils on the spring. I'm starting to think that's why the car is a little higher and stiffer in the back .

79Daytona

Well guys i just ordered some used rear coil spring for the Z 28 it may not be a good idea but the price was right and i thought it's worth a try to get a better rider. I'll let you guys know how it comes out.

Vader

As part of the WS6 package, springs will be applied based on all options and resultant overall vehicle mass. The 6xx and 8xx RPO codes will define what height and rate springs are appropriate.

79Daytona

Hey Vader and thanks for the info. So what can someone do if all there is out there is these crap aftermarket springs . Do you know of anybody that makes the correct coil spring for either the WS6 or base Camaro Z28. Like i said i ordered some used coil spring which I'm not crazy about but what else can you do.

erik69&85

iTrader: (1)

As Vader says above, there is no one correct spring, it was based on the base car plus all of the options.... T-tops, add 30 lbs, a/c, add 150 lbs, power locks, add 5 lbs...etc, etc.

I have the weight and spring tables for first gen cars, but have not seen them for third gen cars...

I think this is why some cars dont sit right after new springs... Wrong total weight...

I get my new stock springs from Eaton Spring... They have the original GM specs for most cars...

79Daytona

Hey erik69 85 thanks for the info. Well the ride height isn't that bad it looks about stock maybe about inch to inch and half higher in the back than i think it should be. Which I'm thinking is why the rides is a little stiff in the back. But like I said I'm hoping the used rear spring i order will help they look different from the ones i install they only have about 7 coils in the spring and the ones i install have 8 to 9 coils in the springs. Well i guess I'll find out one way or the other.

Vader

8+ turns results in more wire length (a.k.a., a longer torsional element) compared to a 7 turn coil. That means that the spring can have a different spring rate and still maintain the correct compressed (working) height. The different spring rate will result in a different ride quality, usually a bit softer.

79Daytona

Hey Vader. Again thanks for the info. Thats what I'm shooting for a little softer ride because right now the back end of the car feels every bump in the road .

DynoDave43

iTrader: (11)

I would guess there was a difference. Suspension tuning was one of the few areas left to Chevy and Pontiac to differentiate vehicles sharing the same platform. From what I have read, Pontiac tended to follow the Herb Adams line of thinking that you could use a softer coil with a bigger anti-sway bar to achieve the same end as the stiffer spring with smaller bar, except that it would be easier to live with on the street. When you go back and read reviews of the early 3rd gens, you'll often find that the reviewer will say the Pontiac rides better, but the Camaro is faster on the track (with track speed usually being the ultimate yard stick of "success".

As VADER said, turns matter. So does wire diameter.

79Daytona

Hey DynoDave. Thanks for the info. I'm really leaning there's more to coil spring than what i though.

DynoDave43

iTrader: (11)

It is an interesting area, and it's discouraging how much peoples results vary from car to car, and kit to kit.

I have an old clipping from a VSE catalog/article by Herb for 2nd gen. F-bodies where he specifically does NOT recommend higher rate aftermarket coil springs for the front. The most he recommend is cutting a half coil from the top. Now, this is dated info., and a completely different front suspension from what we run, but it illustrates his line of thinking.

He's had an interesting career with Pontiac/GM, and he will be speaking at the Trans Am Nationals later this month...a presentation I'm very much looking forward to hearing.

79Daytona

Yeah it would be cool to hear him at the Trans Am national. To hear all the history behide the F body i wish i could go to it.

Drew

iTrader: (58)

Chevy or Pontiac doesn't matter much. They both used the same springs. For a given suspension level, for example FE2 which would be an IrocZ or a WS6 Firebird, the range of springs will usually be limited to two different springs, sometimes three. In some cases you'll find a thirdgen with a different spring on the left and right of the same car.

FE1 jumping to FE2 (F41 in the middle) you'll see pretty much no shared springs. From F41 to FE2 you'll usually see some overlap. Point being, if you've got a Z28 or Trans Am or even an RS with F41 there's not a huge difference in springs from a WS6 or an Irocz or Z28 with 245/50ZR16s.

79Daytona

Thanks for the info Drew.

QwkTrip

iTrader: (22)

There were many different front springs used in our cars (at least 13 according to Moog website). The spring will produce 11" compressed height when the correct spring is matched to the car. Only exception is the most aggressive suspension packages that produce 10.75" compressed height.

All the Moog springs group into 4 different groups of spring rates of approximately 300, 345, 420, 700+ lb/in. Each of those groups has multiple springs with minor variations of spring rate and free length to accommodate the weight of different vehicles so that each lands at the desired 11" or 10.75" compressed height.

So really it all comes down to something pretty simple: Choose the group of spring rate based on how you want your car to handle, and then choose the p/n within that group to get the ride height you want for the sprung weight of your vehicle.

Note: To get sprung weight, you'll have to measure the weight on the front axle of your car and subtract the unsprung weight.

QwkTrip

iTrader: (22)

Regarding rear springs, Moog basically has two choices:

1. Boring (low spring rate)
2. Spirited (higher spring rate)

All the cars have a rear axle weight so similar that there doesn't seem to be a need to account for weight differences. It's two choices based on performance level. If the ride height ends up too tall then tough cookies.... you'll have to cut springs to fix it.

Take a tip from the performance crowd: Install weight jacks in the rear and you'll never have to make another thread asking how to fix your ride height.

QwkTrip

iTrader: (22)

Also, when people complain their car has a rough ride it's usually because they either have insufficient shocks for the spring rate, or the car is so low that it's hitting the rubber bump stops (especially when talking about the rear axle).

1. Get the car off the bump stops
2. Put your money into really good shocks. It's all about the shocks!!!!

Now I'm not promising a Cadillac ride with 750 lb/in springs, but I am saying some of the harshness can be calmed down with proper shocks. And the car will have better traction in all circumstances.

A set of Koni Yellow struts work very well on the front of our cars. The rear axle is a lot more difficult to control and that's where you'll want to spend $$$ on shocks. Double adjustable shocks will give you more range of tuning to get things working right. But the most important thing is a shock with a valving curve that's right for your car (whether adjustable or not). Get a shock for street performance / cornering purposes, NOT a drag racing oriented shock.

79Daytona

Hey QwkTrip and thanks for all the info . My used rear coil spring came in today and after reading your post I'm going to look into some rear shocks as well. Like i said the car when i bought it had lowing spring on it and no telling what shape the shocks are in. So again thanks for all the info.

91banditt2

iTrader: (1)

AustinThirdGen.Org has some useful info on factory spring rates

79Daytona

Cool!! Thanks for the video.