[andybird]

Hi guys,
I'm looking at firming up my suspension some to improve handling on my 78 Camaro, I've already ordered my koni adjustables and am currently looking at springs, I've found a pair of leaf springs that will fit and are about 30% stiffer than the standard Camaro suspension and my local stockist has a pair of coil springs for a 78 455 Trans Am that are the right size but the spring rate is 414lbs/in compare to the 78 Z28 rating of 329lbs/in
both have installed height of 10.5"

My question is, does that all sound a bit too firm?

I don't mind a firm (read less comfortable) ride as long as it means the car will handle better (and I'll stop grounding going over speed bumps faster than 2 MPH),

any opinions appreciated!

[andybird]

anyone?

[jimfulco]

I wonder if the installed height takes into account the extra weight of a Pontiac engine over a Chevy. You might see if you could find the sway bars from a TA. Be aware that the TA's with the larger front bars used a larger frame bracket than the regular F-bodies. Bigger sway bars decrease body roll without causing a stiff ride. Too stiff springs cause traction problems on uneven road surfaces.

[camaroguy_1967]

It does not matter the rating of the spring to 414lbs/in or 329lbs/in. The shock makes the ride smooth or firm. Take off the shock and drive the car with either spring rating they will both bounce and be mushy. Use a good gas shock or your koni adjustables will improve your ride.

[andybird]

cheers guys, my main problem is that everything is a bit bouncy, even though it has fairly new stock shocks, and the rear does sag a bit so the leafs definately need something,

my main concern was just that it's difficult to get big parts (like leaf springs) in the UK because of the shipping costs, but I'd managed to find a set of TA springs fairly cheap, just wanted to check if they weren't too high a spring rate,

I found an article on nastyz28.com about tuning camaro suspension and they said a spring rate of 500-600 on the front and 200 on the back was a good starting point on performance suspension (some even run 700 on the track), so it doesn't look like 414 and 150 is too firm!

[camaroguy_1967]

Your camaro will ride higher in the front with the Trans am front springs. With the 455 the firebird will sit 10.5" but you camaro with the sbc will not sit as low. there just is not as much weight to push them down. Yes you can put 500lbs/in springs in and get a lower ride or stock ride hieght but the spring is shorter than the 329lbs/in spring unloaded, out of the car.

Shocks will improve the feel of the ride. if you ride is bouncy then you need stiffer shocks.

your rear springs may need replacment if they are sagging. You may be able to use the rear springs from the Trans am

[trees]

Andybird, spring rate is not what you are dealing with: it's spring loading (pounds per inch). When you put the 30% stiffer springs in the rear, your ride will be slightly higher and firmer. If your present springs depress three inches under load, the new springs will depress approximately 2 inches. This change could require a shock change as well. The same applies to the front coils, but it is more like a 25% stiffer spring. If you want the stiffer ride and can live with about an inch taller ride height, then see if you can negotiate a trial deal. Try the new springs and if you like, buy, if not return. Could be a lot of work if you don't like the ride, but if you do, it's going to be worth it!!

Trees

[andybird]

sorry, I've caused a bit of confusion

I have ordered new / firmer shocks and that is where I'm expecting the main improvement,

as a seperate concern, I think my existing springs are tired and worth replacing at the same time as replacing the shocks but I can't get stock Camaro parts cheaply due to lack of availability, but my local supplier has trans am parts in stock which will fit

they're from a 78 Trans Am, which I've double checked and they only did a 400cu.in from 77, so not much difference in weight and the trans am that year did have firmer suspension as it was targeted as being a better handling machine than the Z28 (it was considered equal to or better than the same year corvette!)
and the rated load of the coil springs is only 5lbs more on the TA springs

the advertised weight of a 78 TA is slightly lighter than my Camaro

in total all four springs are costing about $200 (compared to about $600 to get Z28 ones shipped over! shipping and import duty is a killer on anything that weighs more than a peanut) and I'm doing the work myself, I'll try the TA's and if it does sit too high I'll see if I can freshen the camaro springs and switch back, then just add the TA springs to my ever increasing pile of hardly used american car parts that I might one day sell!

I'll let you know how I get on in a few weeks, my shocks are coming directly from the Koni factory in holland because I have a friend who works for them so I'm paying a 3rd of the normal retail price (£100 rather than £300)