Coilovers vs lowering springs

[mrr1999]

Aside from adjustability, what are the differences between the two performance wise? I am looking at QA1 coil-overs and Hotchkis or DSE lowering coils for the front. Pros? Cons?

The car (69 Camaro) will for cruising 99% of the time. I really don't see racing in its future.

Thanks.

[Blake Foster]

Adjustabilty !

Nufsaid :thumbsup:

[redfire69]

Do the QA-1s need to be reinforced in the stock arms? How much lower can you adjust them from stock, 2-3 inches?

[GregWeld]

Do the QA-1s need to be reinforced in the stock arms? How much lower can you adjust them from stock, 2-3 inches?

Be careful with this "adjustability".... And I'm not trying to step on what Blake said. Adjustability is the reason for coil overs. The shock rebound rate can be dialed in etc - and there is LIMITED height control. Coil overs are ordered and installed with rather "tight" tolerances for total travel. You can cause the shock to bottom out by lowering the spring on the body too far. That will wreck the shock in nothing flat. Of course you don't have much control on a leaf spring - but you can get adjustable shocks which can work just the same as a coil over... and a leaf spring can be mounted many ways and at many heights (with some work of course).

When ordering a coil over - they have very specific travel specs -- and "as installed" heights. One thing you'll discover with a coil over is that while they are great for handling and installation etc - they are really rather limited in their ability to be "adjusted" for PROPER ride heights/operation.

One of the reasons I chose to do inboard mounted leaf springs on my '37 Ford chassis was that I wanted to have it sit nice and low - but still be able to load the trunk up (it has a HUGE trunk!) - have a full tank of gas - and me and the wife could get in and go and still have a nice ride. I might risk bottoming out a coil over doing this. The coil overs would be my preference for the car - but the USE should also be factored in.

[realcoray]

Aside from adjustability, what are the differences between the two performance wise? I am looking at QA1 coil-overs and Hotchkis or DSE lowering coils for the front. Pros? Cons?

The car (69 Camaro) will for cruising 99% of the time. I really don't see racing in its future.

Thanks.

I debated this a lot before going with coils & adjustable shocks. There is no adjustability you get with a coilover setup that you can't get with coils/shocks. That being said out of the box it's easier to adjust coilovers.

I think the adjustment on the QA1 coil overs is like max 1.5" before you get into a dangerous area.

[redfire69]

Thanks guys, that's what I was getting at. I wasn't sure how much "ride height adjustment" you get with QA-1s out of the box. No question on the tuneability (sp?) of the shock.

[Vegas69]

Coil overs every day of the week. If you're like me, you want a car that is reasonably the same ride height side to side. These old cars can be off a little after 40 years. With springs you're left dealing with it or cutting springs. Neither are good options.

[realcoray]

Coil overs every day of the week. If you're like me, you want a car that is reasonably the same ride height side to side. These old cars can be off a little after 40 years. With springs you're left dealing with it or cutting springs. Neither are good options.

With spring adjusters you can adjust them to get the exact height you want, although obviously it's not something you can do very easily once the car is all assembled.

[Vegas69]

Good point but I'm lazy. Popping a ball joint loose to change ride height isn't servicable for me.

[Bryce]

The other thing to consider, once you get into a good shock, double adjustable, you might as well get the coilovers. The cost difference is nothing. The coil springs are cheaper and lighter weight. And a lot easier to change if you want to change spring rates. Plus there are a ton of spring rates to choose from. For a track car I would stay away from the QA1 "sorta" coilover.

[mrr1999]

Just so I understand this correctly, QA1's pretty much have a (safe) ride height adjustability window of 1.5"? That being said, does it come out of the box with a lower ride height than a stock spring and you can drop it 1.5" from there? Or does it start out with a similar height as stock spring?

Oh yeah, and do QA1's work with stock arms? Thanks.

[GregWeld]

They come out of the box "how you ordered them". There is a good explanation of all of this on their (QA1) website - or consult an expert.

Coil overs - regardless of brand - have an extended length - and a collapsed length --- and an "as installed ride height" length. It's the installed ride height length that will wreck havoc on you if you think you can install a set and then just crank the car up and down with the spring adjuster nut.

If you want the car to set low -- then you need to set it at the ride height you want -- then measure the mount points -- and order a coil over accordingly. Of course this is oversimplification - because there is also bump steer issues if you get your A arms and rack out of whack... and there are clearance issues for turning radius and a bunch of other stuff that comes into play.

One of the reasons people do air bags -- is because they want to raise the car for driving - lower it for slow speed cruising - or slam it in the weeds for a show etc. They make that super simple. Coil overs however - are really not for doing that.

If you want to just lower your car - and I'm assuming it's the mustang in your avatar.... then you can do a set of lowering springs and the accompanying shocks and or struts. My daughter has a 2006 Mustang and it's been pretty aggressively lowered.... so low using the Eibach lowering springs -- that it ruined the ride. I had to have her take it to Fesler in Scottsdale (she's down there in college) and have him "fix it". Now it's low but rides 10X's better. Not sure what he did. I just paid the bill. :willy: :D

[realcoray]

Just so I understand this correctly, QA1's pretty much have a (safe) ride height adjustability window of 1.5"? That being said, does it come out of the box with a lower ride height than a stock spring and you can drop it 1.5" from there? Or does it start out with a similar height as stock spring?

Oh yeah, and do QA1's work with stock arms? Thanks.

I think it's 1.5 drop from stock but again this is just what I recall hearing, I know it's a narrower range than they list.

The QA1 coilover conversion will work with stock arms although I would probably suggest at least looking closely at your arms. The conversion changes what is holding weight from the lower spring pocket to the T bar mount area. A 40 year old stock arm may not be the most ideal thing to rely on.

Speedtech and DSE both have true coilover conversions that allow you to change your lower & upper mount to an eye mount, and you can also buy whatever coilover you want.

[GregWeld]

I should have gone back to check the original post... I see you're questions are about your '69 Camaro -- not the Mustang in the avatar.

Either way - What I have said above is the same.... you have to "set" the stance you want FIRST - then order shocks and or coil overs / springs to fit that rather than try to adjust a too long set to make it sit lower.

There are so many '69 Camaro builds on here - it should be fairly easy to find a thread with a build you like -- and ask the builder / owner how they got there.

Although - there are plenty of people that have ordered them all wrong and learned the hard way that there are a few things to consider BEFORE you order... I know I have at least two complete sets (4 ea) on the shelf from a couple builds that either changed along the way - or didn't sit quite right!

Spring rate - and LENGTH is just as important as the length of the shock they're going on or around.... Most of the shops and manufacturers that sell this stuff should be more than happy to help guide you thru the process. I seriously doubt you're doing anything "new" regarding what look you're trying achieve.

[mrr1999]

Thanks Greg-

Yes, it's for my Camaro. I'm only looking to drop it roughly 2 inches but I wanted to get it right the first time I tried it, so thanks. I'll establish the ride height I need before ordering. My concern now is whether the stock arms will be ok with the coil overs. If it isn't a good idea to use the stock arms, I may have to reconsider the DSE or Hotchkis lowering springs so I don't break the bank (for now).

[GregWeld]

Mike --

Try SpeedTech also.... they have options for Arms / Spindles / coil overs etc.

I don't know about stock arms and coil overs... since that just isn't an option I would have ever tried. A simple upgrade is to use aftermarket A arms - and get much more benefit than just the strength!

[SLO_Z28]

Greg is the first person ive ever heard make sense when talking about coil overs on the internet.


The short story on coil overs is if you have to ask about them, you don't need them. They are not intended for ride height adjustability, although that's what they get used for most of the time, its not the reason or the purpose of said adjustment. They are solely to cut weight and for corner weight adjustment. There are other benefits too but that discussion can get rather technical rather quick. Most coil overs wont work very long with stock lower control arms, but a little metal and a welder can fix that.

Get a set of Hotchkis springs and matching shocks, dont cut them and 99% chance you'll love the results. make sure and toss in new bushings and ball joints when you have the arms off.

[JRouche]

So true!! Many folks see adjustable and think ride height. Ride height is based on the control arms, NOT the springs, if you want performance.

Same think with air springs. Folks see products like air ride springs (I have shockwaves, think progressive coilover) and think there is some adjustment for ride height.

Not so. There is no adjustable ride height suspension out there that doesnt compromise performance.

When I market my variable upper control arm mount to the public then you will see a truly variable ride height system. Yes, it will be fast and completely independent unlike fixed upper arm mounts. Caster and camber will be computer controlled and bump steer will be a thing of the past.

Want a look into the future think electromagnetic fluid. JR

[Bryce]

One other advantage of coilovers:

If you have a determined your ride height and measured the shocks at that height and order them and decided on a spring rate and the car sits too high or too low, you can dial in the coilover spring nut adjuster to get the car back to the predetermined height.

If this was a conventional spring you would have to cut the spring or shim it or order new ones.

[GregWeld]

One other advantage of coilovers:

If you have a determined your ride height and measured the shocks at that height and order them and decided on a spring rate and the car sits too high or too low, you can dial in the coilover spring nut adjuster to get the car back to the predetermined height.

If this was a conventional spring you would have to cut the spring or shim it or order new ones.

Well..... yes...... and no.


If the spring rate is wrong for the car... you can thread the nut up and put yourself into a coil bind situation.

Really, the best part of coil overs is IF you ordered the wrong springs - or the car changes and you need different springs is, they're relatively inexpensive - and super easy to replace! Which is the CORRECT way to solve the issue(s). :D

[Bryce]

Greg,

You are right. I was saying you order the right springs but the weight of the car was 50 lbs heavier/lighter than you planned for. The car sits a 1/4" too low or too high. You could adjust that back to correct. Sometimes you can only get a spring rate to the nearest 25lbs.

This is what I use to determine spring rates:

--------------------------------------------------------------------------------

When I choose spring rates I do (two) calculations.

First what is the weight of the car at that axle. Divide that number by 2. this gives you F (force or weight)

Since F=kx next is to determine the amount fo droop you want or the shock has. This amount of droop gives you the minimum preload on the spring at ride height. If you have 3" of droop you dont want the spring to become unloaded. take F/x=K. K is your MAXIMUM spring rate.

Now this is where personal preference comes in. I design around a 1G bump. How much travel do you have in your shocks from ride to full compression, this is your x for the next equation. Take F times 1G, or whatever number you want to design around. F/x=K this is you MINIMUM spring rate. Now you have a range.

The only way to adjust this is to adjust your shock length and your shock length at ride height.

[GregWeld]

Yes Bryce --- you're right of course....

1/4" or even a bit more.... but you're post might lead a guy to believe he could crank the car up or down an inch or more maybe.... since you didn't mention the "1/4". An INCH up or down in a coil over is way too much - as you know.

Many people just don't understand how little a coil over actually travels... and you start dropping a coil over an inch - and you could be bottoming out. This gets worse as a guy is trying to correct for a wrong spring rate/length.

When I post here (on Lat G) I try to make sure that ANYONE reading the posts is getting the right info because there's so many people reading without commenting etc... That is NOT to say I know what I'm talking about... and I get corrected often by people with far more knowledge than me. I try to post from my perspective - which is many years of fixing many of these very (Vari? LOL) issues on my own cars as well as those of my friends. :rofl: