Correct spring rate for QA1 coilovers

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dragbaron

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I recently got back into the A-body game with another Scamp. It has a 4-link rear and tubular upper and lower control arms on the front with QA1 coilovers all around. The rear rides good, however the front hits very hard over sharp bumps. I've noticed that there doesn't seem to be very much gap between the front spring coils, and I'm thinking the spring itself is "bottoming out". I have no idea what spring rate is on it, so just wondering what other A-body guys are running.
20200322_154748.jpg
 
Holy crap. That looks like you’ve got about a 1/2” of suspension travel before the spring bottoms, if that.

How low is the front sitting? Do you know what suspension set up you’re using?

Maybe @HemiDenny can shed some light...
 
20200317_130910.jpg
It's sitting pretty low in the front, lower than I'd like. I could raise it up, but won't help the coil gap any.
20200404_175830.jpg
 
That spring is either the wrong rate, too short or both. I don’t mind cranking the platform up for more stored energy, but you can’t do what you have going on there.

Who made the shocks?
 
They're QA1 shocks. This is how I got the car, and all this stuff was done 2 owners previous to me. I haven't owned anything other than stock suspension cars, so this is a learning experience. Definitely didn't think that coil gap looked right though!

I never thought to lower the adjustment to possibly raise the car. Guess if it lowers the car further, I'll definitely know they're the wrong coil springs.
 
I'd pop the springs off and see if you can find the spring rate printed on them. At least then you'll know the rate and length and use that as a baseline for choosing the correct ones.
 
No, you can'[t raise it up. There's zero room between the coils to do that. If you tighten the spring nuts any farther, you're going to have a solid spring on the front. You think it rides bad now..........

You need new springs. Those are either worn out or the incorrect springs. Look how far the spring nuts are screwed up. I would take the springs off and see if there's a number on them. If not, I'd get in touch with QA1 and see what they say.
 
They're QA1 shocks. This is how I got the car, and all this stuff was done 2 owners previous to me. I haven't owned anything other than stock suspension cars, so this is a learning experience. Definitely didn't think that coil gap looked right though!

I never thought to lower the adjustment to possibly raise the car. Guess if it lowers the car further, I'll definitely know they're the wrong coil springs.

So first off I misspoke, if you lower the collar you'll gain back some suspension travel but that won't raise the car. It may lower it some, but not much given how little room there is to move it to begin with. It'll depend on the springs.

Looking closer at your pictures it looks like what you have there is some kind of hybrid coilover conversion kit, it's using the stock upper shock mounts with a modified LCA. There's a hoop welded in to reinforce the upper shock mount, because it was never designed to carry the weight of the car. The hybrid coilover conversions that use the stock K member like that are cheaper, but because they're using all the mounting points for the torsion bar suspension they're pretty limited in what they can do. Namely, they have to run a very short coilover, which limits suspension travel.

One of the previous owners cranked up the preload on the springs. Which would raise the car a little. Coilovers aren't ride height adjustable to the same extent as torsion bar systems though, so you can't raise the car a ton that way without significant consequences. The ones on your car are almost completely bound up, so basically there's no suspension travel at all in the front.

I would start by lowering that adjustment collar and seeing what you get. At the very least you'll get some suspension travel back, which should soften the ride up some. If the springs are actually right for the car, it shouldn't lower it a ton. If they're way too soft for the car then it may lower it too much, but if that's the case then you know what the problem is. The tires look really close to the fenders though, so it's possible that the tires were rubbing on the fenders so somebody cranked up the collars to try and raise the car some to stop that. If that's the issue then the tires will start rubbing when you lower the collars, and again you'll know what the problem is. The other thing is, if the springs aren't completely wrong for the application then the coilover is probably fully extended with the spring compressed like that. So if the springs aren't super soft then just adding stiffer springs won't raise the car any because you're already at the maximum extended length of the coilover.

Some of those conversions come with drop spindles, so, you'll need to look into that. If you've got drop spindles on there then you may need to swap them out if you want to raise the car up any.

I would lower the collars and see what happens. That's pretty easy to do, and it should give you a better idea of what's going on without completely tearing everything apart.
 
I recently got back into the A-body game with another Scamp. It has a 4-link rear and tubular upper and lower control arms on the front with QA1 coilovers all around. The rear rides good, however the front hits very hard over sharp bumps. I've noticed that there doesn't seem to be very much gap between the front spring coils, and I'm thinking the spring itself is "bottoming out". I have no idea what spring rate is on it, so just wondering what other A-body guys are running.View attachment 1715500784

To cut thru all the b.s. , I went thru the same thing on ride harshness , and had virtually no front end lift on acceleration. The coils were 500# springs, I changed them to 300# springs , and helped some , but was still too stiff.
I then went to 250# springs and had to raised the adjustment collars up a fair amount to get my ride heigth back so my front end alignment would still be right.
It is way looser than before and rides mo betta , havent had it back on the dragstrip to see how much a little front end rise would help my traction problems tho.
Ur spring rate depends on ur cars front end weight and how long those shocks are , I even changed shocks out eventually. Mine are 12'' shocks .
 
I believe I have 9” 350lb springs on my 64 Valiant. I remember the springs were 1” longer than the recommended length for the shocks. Had to compress the springs to get them on my shocks, but i think that extra energy helps keep the ride height up and still offers suspension travel
 
Does your shocks have any travel? The shocks maybe to short. Jack the car up under the K member and make sure you have enough shock travel.
 
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I recently got back into the A-body game with another Scamp. It has a 4-link rear and tubular upper and lower control arms on the front with QA1 coilovers all around. The rear rides good, however the front hits very hard over sharp bumps. I've noticed that there doesn't seem to be very much gap between the front spring coils, and I'm thinking the spring itself is "bottoming out". I have no idea what spring rate is on it, so just wondering what other A-body guys are running.View attachment 1715500784
Remove one of the springs you should find the spring rate scribed on the spring flat that sets on the shock collar.
 
Ok guys, got a few things now to check out on my next day off. Thanks for all the advice so far!
 
looks like coil bind to me. likely (for starters) the spring is wayyyyyy soft. Also looks like the Dilinger LCA coil over conversion???

Need more info to get into the ballpark at what spring rate you should have. What engine? and is there anything done to take ar add any weight?
Qa1 guidline.....the spring, at installed height should collapse 25%-30%....or, a 10" spring should collapse 2-1/2" to 3" once installed and all the weight on it.

good luck with the build,
Denny
 
Go to the QA1 website, they have a good video about choosing springs as well as a chart for choices. I just got the video via email because I signed up on their site.
 
looks like coil bind to me. likely (for starters) the spring is wayyyyyy soft. Also looks like the Dilinger LCA coil over conversion???

Need more info to get into the ballpark at what spring rate you should have. What engine? and is there anything done to take ar add any weight?
Qa1 guidline.....the spring, at installed height should collapse 25%-30%....or, a 10" spring should collapse 2-1/2" to 3" once installed and all the weight on it.

good luck with the build,
Denny

I'll get some better pics of the suspension so maybe someone here will recognize it and tell me who made it.

It's a small block with aluminum heads and currently has no heat or A/C system. I plan on adding vintage air at some point. Other than that, I would think it's close to average weight of most small block A-bodies.
 
on the majority of street driven small block HDK builds, a 12" 300 lb rate or 325 lb rate spring does the job (Qa1 #12HT-300 or 12HT-325). Be helpful to know the installed height (eye to eye) of your shock mounts and the specs (compressed / extended lengths) of your current shock. If you have the spring out....also the full length of the coil spring.
 
on the majority of street driven small block HDK builds, a 12" 300 lb rate or 325 lb rate spring does the job (Qa1 #12HT-300 or 12HT-325). Be helpful to know the installed height (eye to eye) of your shock mounts and the specs (compressed / extended lengths) of your current shock. If you have the spring out....also the full length of the coil spring.

not an expert , but I`d go w/ 275# springs to start with. I have the 300# springs on mine , and its 440/505 w/heavy raised port heads on it , probly quite a bit heavier than ur 340 w/ alum heads .-----------jmo
 
Ok guys, I'll get a wheel off and get some pics. Then pull a coilover out and get some measurements.
 
Ok, here's what I got.

The coilover mounted in the car and at ride height is 10.5 inches(eye to eye)

Shock by itself is 13.5 inches extended and 9.5 inches compressed(eye to eye).

The coil is 9 inches fully extended.
 
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