I was wondering what are the lentghs for the front and rear springs on an 86 Camaro,and the spring rates?

 

What suspension do you have?

JamesC

 

i dont know what suspension... but it is an 86 sport coupe... it seems to be the base sport coupe... if there was any better sport coupe... anyway yeah... its completely stock...

 

The following link may provide some useful info:

https://www.thirdgen.org/forums/susp...ring-info.html

JamesC

 

https://www.thirdgen.org/camaro_spring_rate

 

one question... what do the numbers mean? they certainly are not pounds... or any measurement of height since it says spring rates... i cant get to the other link since i an using my cell phone, so my internet is limited to certain pages... thanks for the info!

 

Part of my link--very useful.

JamesC
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Moog part numbers for OE replacement.

JamesC

 

ah yes... it makes sense now... well... i wanted the info just to know what the stock length and rates were... so i would know how much shorter and stiffer i could get without scraping the floor and feeling every little piece of dirt on it... i want to build my car for road racing...
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ah yes... it makes sense now... well... i wanted the info just to know what the stock length and rates were... so i would know how much shorter and stiffer i could get without scraping the floor and feeling every little piece of dirt on it... i want to build my car for road racing...although i dont mind a stiff ride at all...

 

Don't bother with what the stock rate and height were. That info is not particularly helpful.

You need a spring that installs at about 10¼" - 10½" height with about a 2300-2500 lb load on it, with about a 700 lb/in rate. You will observe that there are 2 Moog springs that fit that description, the 5662 and 5664. Your choice will be between those 2.

Other aftermarket stuff such as Eibach, Ground Control, Global West, Intrax, etc. etc. etc. may offoer other possibilities. But those Moog #s are ones you can buy at GOBS of places; any CSK store, Advance, maybe PepBoys, NAPA, "real" parts stores", etc.

The spring rate IS NOT the "suspension" rate; the "suspension" has about a 2½ or 3:1 mechanical advantage on the spring. In other words, if you took a 700 lb/in spring and put it in the car, then adding a 250 lb weight on that fender, would push the car down about 1 inch (2.5:1). Likewise, a 2400 lb load IN THE SRPING, corresponds to about a 900 lb load ON THE SUSPENSION (about half the front weight of one of these cars).

 

i was thinking qa1... and i an gonna be taking quite a bit of weight of the front too... aluminium heads... hood, aluminium radiator, take of power steering, anything that i dont need will come off... so will that still lower the car one inch with those springs? and i dont quite understand the suspension rate opposed in relation spring rate... i was thinking about a 350 pound spring rate, but i guess that was really low...

 

Look at your suspension.

Notice that it has these "control arms", that the springs sit in; they have a pair of pivot bolts in one end where they attach to the "frame", and a ball joint in the other, with a tire stuck out in space on a spindle somewhere out beyond that.

Looks suspiciously like a lever, doesn't it?

The long arm of the lever is from the tire contact patch to the control arm bolts; the short arm is from the spring pocket to the CA pivot bolts. The ratio of "rate" at the tire (car weight) to "rate" at the spring (spring load), is the same as the ratio of those 2 lever arms, except it's the inverse.

 

i see what you are talking about...

 

One more thing... If I was to get a kit such as an eibach one, which lowers the front 1.6" and the back 1.3", and take off a bunch of weight on the front end will it not stay 1.6" lower than stock?

 

No, of course not. That's kind of tied up in the definition of "spring". Less weight = compresses less = sits higher.

Which is one reason why those "lowers the car by 1.47983" " kind of things are ridiculous. Every car is a little different, once they get modded a bit. And every 20-odd year old car with TOTALLY collapsed stock springs on it, will ALREADY be sitting lower than they did when new. So we've seen posts on here where people have taken their old worn-out stock junk out and put "lowering" springs in, and their car actually sat HIGHER than before.

As I said, the "rate" of the suspension in these cars, can be guesstimated by taking the spring rate and dividing it by about 2.5. So for example if you get 750 lb/in springs, divide that by 2.5, and you will see that the car height will vary by about 1" for every 300 lbs, more or less. That's not exact, but then, nothing else about any of that is either; but it'll get you into the right ballpark.

Most people tend to VASTLY overestimate their projected weight loss.... and completely forget for some reason to include weight GAIN. Most of that loss that they claim is not significant anyway until ALOT of other stuff has been shed. For instance, changing to manual steering hardly matters, probably about a 6 lb "savings; people "forget" conveniently to include weight gain when they take off a 32mm sway bar and put back on a 35mm one and a "wonderbar", or when they add a transmission fluid cooler, or they put in a bigger radiator, or a strut tower brace, or SFCs, or a couple hundred pounds of amps and speakers and boxes; so in the end, most of what you see on here about "weight loss" for cars that are driven on the street, is mostly fantasy land. The "numbers" people give are highly selective and represent only what they've hacked (as if that's something positive to do), and not the TOTAL package.

 

I see... I am gonna be putting stuff on as well... with that said... I read that the ID of the stock replacement MOOG springs was around 4"... I was looking at QA1 Springs but they are 2.5" ID... where can I find aftermarket springs of that diameter? And would 9" long spring be too short? By the way thanks for all the info, I have learned much!!

 

The QA1 I believe is a coil-over; that is, it's actually wound around the strut. Not a stock configuration at all. Requires significant bracing to the car in order to use, because the place it puts the car's weight on the chassis (the strut tower), isn't where it was originally designed to be (spring pocket). Pretty much race-only. Looks somewhat similar to the setup on this car here https://www.thirdgen.org/forums/cama...g-chassis.html

To put a spring in the stock location, it pretty much has to be within a few .001"s of the stock size. Nice thing about that is, GM has used the same size springs in ALL KINDS of vehicles, for literally DECADES; there's literally HUNDREDS of models with springs that will interchange directly with these cars. All manner of chassis from Chevelles and Monte Carlos and Cutlasses and so on, to S trucks, to F bodies, from the 60s to the present, use the same configuration of springs. For just about any weight and ride height you want, you can find a stock replacement one to get it.

9" installed is MIGHTY short. Going back to the lever thing, if the stock spring installed height is let's say 10½", and you put a 9" spring in, you will lower the car by the lever factor of 2.5, TIMES the difference in spring height. Just like moving a long wrench: if you have a breaker bar that's 2.5 feet long, and you move it so that a point 1 foot from the end moves 1½", the far end of the breaker bar will move 2.5 times 1.5 inches. Meaning, a 9" installed spring will lower the car by 3¾" !!! Might be a bit "too much club".

I can tell you from experience though, the Moog 5662 front and CC635 rear combo works well. Other people have used the 5664 on the front, or the 5665 on the rear, and also get good results. The 5662 is probably more appropriate for a lighter Camaro, and the 5664 for a heavier Firebird, but the difference is really just fine-tuning. You probably wouldn't be able to notice a difference in most cars. Likewise, 5665 is constant rate, while CC635 is variable rate; each has advantages and disadvantages. All of those are known to work well, and cost quite a bit less than the "name" brands.

 

I see...well I am kinda going for a race car disguised as a street car type vibe... so I was considering a coil over kit... will the 5662 and cc635 give me a stiffer/not overly stiff ride? ands handle as good as, say, a Corvette? Obviously with the whole front and rear suspension re-worked...