today at goodguys I talked to a fellow who was running a stand selling suspension components. I asked how much it would be to replace my springs since it was dropped up front and the springs seemed to have gone soft over years of use. He said that springs do not lose their load rate over time, the merely sag, and that sounded strange. I'm looking for better cornering, and he said that the best way to go about that would not be with stiffer springs but a thicher sway bar and better shocks. is this true about the springs and do ya'll agree that this would be the best way to get better handling from my car?

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Beastly 67 in Resto.
350 with some goodies.

Jeez man, I dunno. All the components sorta work in unison to make for great handling. I would tend to think that replacing shocks and swaybar would help alright, but unless you did the whole shebang and put some springs in there too, the new parts would only wear out prematurely. It's your call, but since you are in there, why not do it all at the same time anyway? BTW, springs do lose their stiffness after a while due to stress and metal fatigue. Just look at a governor spring on a small engine. You have to adjust it every so often to compensate for it getting weaker. Eventually, you will even need to replace it or shorten it as it goes beyond adjustment.

I imagine you'll get all sorts of answers on this one but I agree with the dude you talked to. A major purpose of a spring when cornering is to keep the tires planted on the road. With a factory spring, the spring allows this to happen by allowing each individual wheel move in relation to the chassis. As long as you don't bottom the a-arms out. Several cars, like the corvette with the F-41 suspension and the WS-6 Trans Am are equipped with high spring rate coils. People have put in a softer spring rate for a better ride with no affects to the handling.

69er

[This message has been edited by 69er (edited 03-26-2001).]

It depends on what you want the car to do.
First Gen Camaros and even Second Gen are sprung very soft.
The spring is 327 lbs per inch but it is roughly in the middle of the lower A frame so the wheel has leverage over it.
So at the wheel you get about 116 lbs per inch spring rate.

If you want a cushy ride, you go soft like this. Also, the stock camaro didn't have very sticky or large tires and traction was not high for acceleration or braking.
The 70 series "wide oval" tire was just beginning to be offered on new cars in 1967.
by 1969 the 60 series was offered on the Mach I Mustang only.
These tires were capable of maybe .7 traction coefficient. So, with a good setup you could corner at .7 G's. The 1967 tires would be lower traction coefficient.

So under full acceleration and braking the tires limit the amount of front to rear weight transfer that can be generated. And the amount of front end lift or dive is created by those forces, and resisted or limited by the springs.

In a nutshell, more grip= more spring rate needed, or else more front lift/dive will be generated.

So, when you add more traction, brakes, and power, you will cause more suspension travel when driving at the limit. With stock springs, you will be closer to bottoming out the suspension under braking, and under acceleration, topping out the suspension.
You will experience more travel and spend more time at the limits of travel.
To keep the car within the design limits, you would need stiffer springs.

If you want to improve the handling, you need to control the motion of the chassis closer to normal ride height and stay away from the extremes.
If the car is lowered you are biasing the suspension toward bottoming out or scraping the headers more easily. You are reducing available travel and the only way to prevent bottoming out on the bump stops is to use a stiffer spring.

For handling, I see front spring rates of 600 to 700 in the street suspension kits.
For crusing around with less sticky tires, and about 300 to 350 hp, a rate of 500 to 550 is very nice.
The stock Z/28 spring is 380 lbs and the minimum rate to consider. Moog does not list this spring in their catalog for the Camaro but I have crossed it over to a #6308.
this would be nice in a restored Camaro with mild mods. Or if you have a bit more power but just cruze and are not interested in carving corners all the time.
Springs don't loose rate, they loose height, they bend with age.
David

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Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

thanks guys.
dave (or anyone else)- my main consideration would be the bottoming out of my wheels (they rub in the fender) when hitting bumps while driving, and then cornering, but both of these probles require stiffer springs. When I'm done my car will be sneaking up on 400 horses (hopefully by the end of summer). If I wanted a spring rate of around 550lbs, where could I get these springs and how much would the cost me?

I would call Federal Mogul (1-800-560-1400) and ask them who to talk to about spring rates. Then ask them what spring will give you a 550# rate at a stock height. You want stock height because you have lowered spindles.

69er

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69 Camaro 454
71 Nova 454

If your not living on the edge then your taking up too much space

Stainless steel brakes sells a 550.
David

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Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

I've heard a few theorys on suspension and one is (like BMW's) a stiff chassis and softer springs. If the chassis has very minimal flex than you don't need super stiff springs. But if you have s soft chassis than you have to compensate by putting in super stiff springs. Of course a for a racing setup you want both, but for agressive street driving that seems like a good idea because the ride isn't as harsh. Just some thoughts

Check your wheel size because if your wheel sticks out more then stock by very much, you will hit the fender lip!! pdq67

PS, a stock steel '67 wheel is 14" x 6" w/ 3.75" back space.

67firebird,
I disagree, from a tuning standpoint, if you have a soft chassis, the stiffer you go in spring rate, the less tuneable it will be.
The chassis flex acts like an uncontrolled extra "spring" in the system. This "spring" will get flexed more with a stiff spring rate.
Also, higher traction and horsepower add to the load seen by the chassis and flex shows up more under those conditions.
It is better to stay a little soft on spring rates with a flexable chassis.
When I put the Guldstrand front springs on my 67 for autocross, I could feel the gas pedal moving when I hit bumps! That was due to the subframe moving relative to the body.
With softer springs, this didn't show up.

With a stiff chassis, you can get away with stiffer springs and bars, and small changes to them will make a noticable difference.
David

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Check my web page for First Gen Camaro suspension info:
David's Motorsports page (http://ourworld.compuserve.com/homepages/David_Pozzi/)
First Gen Suspension Page (http://ourworld.compuserve.com/homepages/David_Pozzi/first_gen_suspension.htm)
67 RS 327
69 Camaro Vintage Racer
65 Lola T-70 Can Am Vintage Racer

the tires rub insides the fenders. does anyone know the pricing on the front springs? I want stiffer springs so hopefully with KYB gas-adjust shocks and fatty sway bar the rubbing will stop.