How do you choose the perfect spring height?

[Yanchik]

Hello and Happy Holidays!

I'm trying to decide on what springs to get (1inch drop/2inch drop, etc) but it's honestly a shot in the dark for me. Looking at pictures online doesnt help because everyones drop looks different. Some look perfect with a 2 inch drop while others dont look as good.

Is there a safe way to choose a spring? Should I purchase a 2 inch drop spring and continually add spring spacers to achieve desired height? Any input is greatly appreciated! Thank you



Edit: I cant even compare to "stock height" because the springs on my Skylark are 50 years old and saggy as f*

[Zspoiler]

It all depends on the "look' you want .You can do with springs height (such a as coil overs}and or tire size .And what you want to do with the car.Check with the manufacturers,Spring and Speed shops are a few resources. Good luck to you.

[Typhoon1015]

Coilovers are the preferred method to dial heights in if that is in your budget. Everything else will be a trial and error depending on your desired results.

[Yanchik]

Thank you for the response guys. I’ve thought of coil overs but the reason I didn’t choose them is because I read that it limits the full travel of the shock/spring. There’s apparently a better travel and effective range of having individual springs and shocks.

Lowering the ride height will increase the spring rate, making the ride harsher. I think drop springs would work better, but I honestly don’t know.

[marolf101x]

Properly designed coil over systems do not lose stroke. Look at it this way. . .the wheel/tire needs to move 5" total. The coil over will move some fraction of this based on motion ratio. So even a motion ratio of 2:1 means the shock (coil over) moves 2.5", but the wheel moves 5". I don't care if you put a 10" stroke shock in that set up, it still only moves a little more than 5" (bump stops or ball joint bind will limit travel if the shock does not).

Lowering does not necessarily increase spring rate. You can keep the same rate and lower a car. You can lower a car and use a lower spring rate. . .but you will have more preload on the spring.
If you want an explanation with numbers let me know and I'll toss out a few examples.

[Yanchik]

Properly designed coil over systems do not lose stroke. Look at it this way. . .the wheel/tire needs to move 5" total. The coil over will move some fraction of this based on motion ratio. So even a motion ratio of 2:1 means the shock (coil over) moves 2.5", but the wheel moves 5". I don't care if you put a 10" stroke shock in that set up, it still only moves a little more than 5" (bump stops or ball joint bind will limit travel if the shock does not).

Lowering does not necessarily increase spring rate. You can keep the same rate and lower a car. You can lower a car and use a lower spring rate. . .but you will have more preload on the spring.
If you want an explanation with numbers let me know and I'll toss out a few examples.

Holy smokes thank you for that info. All of this is new to me, so I'm doing my best to gain as much info as possible and I appreciate your help. If you dont mind steering me in the right direction, which set-up will give me the best results for street use? (Not just regular driving to and from destination. But more like spirited driving and hard turns).

Should I go Conventional Springs (550/150) or Dual Rate Springs (ridetech)?
Should I go Monotube (ridetech/UMI) or Double Adjustable Shocks (Viking)?
Or should I just go coilovers and call it a day? (And save up money for the Lower Strong Arms lol)

[marolf101x]

First you should know that I ran the Engineering department for ridetech for nearly a decade (now handle special projects) so I'll be a bit biased. However, my opinions are based on product knowledge and personal experience.

If it were me I'd go coil overs and call it a day. It gives you everything a basic kit will give you and more, for not that much more money.
If budget is more of a concern and priority then you'll have to give up something. In most cases that's a bit of geometry (only tubular arms and spindles/ball joints can change geometry), and the ability to put the height where you want.
If height adjustment is priority, then coil overs for the win.

As far as shocks I would not use any twin tube typically used in our market (Viking, QA1, etc). There are really good twin tubes, but they are crazy money. Monotubes (ridetech/Fox, Bilstein, etc) are a much better option in our market.
Obviously I prefer the Ridetech units as I worked with Fox on the parts and valve codes. We do a lot of custom valving at our place, so we know what these cars like and more importantly, what the customer expects. Throw in the 1,000,001 mile warranty and I think it's a no brainer.

Dual rate/progressive springs are nice in the "standard" size springs, but I don't think they are needed for coil overs.

[Interceptor5588]

From personal experience it is a giant PITA to get the ride height correct on a front coil spring setup. Mine is SPC, need to disassemble the whole thing to change shims and bolt length under the spring. Too many variables -- engine weight, control arm configurations, balljoints, spindles, etc. Unless everything else is dead stock -- go with coilovers.

This is assuming fronts. Rear coils are easy to change and pretty straightforward to get right the first time.

[pitts64]

I have SPC uppers and lowers. I crank the coil spring up into the frame with a piece of all thread and a plate I made and change the SPC plates in the lowers with everything still connected..

If I were the OP, I would just get 2" lowering springs all the way around with Bilstine shocks. I used BMR springs from Summit on my 69 el Camino. The 2" lowering spring will put that Buick pretty close to stock height. For some reason stock height has changed over the years into making these cars look like 4x4s. Look at factory photos of your car when new.

As far as looks go, it depends where the cars parked, ride height is always changing with terrain, at least it does on these hills around here..

[Yanchik]

First you should know that I ran the Engineering department for ridetech for nearly a decade (now handle special projects) so I'll be a bit biased. However, my opinions are based on product knowledge and personal experience.

If it were me I'd go coil overs and call it a day. It gives you everything a basic kit will give you and more, for not that much more money.
If budget is more of a concern and priority then you'll have to give up something. In most cases that's a bit of geometry (only tubular arms and spindles/ball joints can change geometry), and the ability to put the height where you want.
If height adjustment is priority, then coil overs for the win.

As far as shocks I would not use any twin tube typically used in our market (Viking, QA1, etc). There are really good twin tubes, but they are crazy money. Monotubes (ridetech/Fox, Bilstein, etc) are a much better option in our market.
Obviously I prefer the Ridetech units as I worked with Fox on the parts and valve codes. We do a lot of custom valving at our place, so we know what these cars like and more importantly, what the customer expects. Throw in the 1,000,001 mile warranty and I think it's a no brainer.

Dual rate/progressive springs are nice in the "standard" size springs, but I don't think they are needed for coil overs.

Damn, that's some impressive experience you got under your belt, and thank you for the response!

Judging by the information you gave me, I feel like I should "do it right the first time", and my gut is telling me that Ridetech Coilovers are the way.
Unfortunately, I just dont have the bank to afford the Strong Arms which are necessary to run their coilover. Im only 21 and in college lol.
So the only other option at the moment would be to get some 1" drop springs and some Tubular Uppers w/tall ball joint to correct the geometry. Later on I'll save money for the Coilover/StrongArm conversion.

You previously mentioned that spindles correct the geometry as well. Are you referring to tall spindles, drop spindles, AFX? Thank you again for all the help

[Yanchik]

From personal experience it is a giant PITA to get the ride height correct on a front coil spring setup. Mine is SPC, need to disassemble the whole thing to change shims and bolt length under the spring. Too many variables -- engine weight, control arm configurations, balljoints, spindles, etc. Unless everything else is dead stock -- go with coilovers.

This is assuming fronts. Rear coils are easy to change and pretty straightforward to get right the first time.

Yeah it seems that coilovers are the way. Thank you

[Yanchik]

I have SPC uppers and lowers. I crank the coil spring up into the frame with a piece of all thread and a plate I made and change the SPC plates in the lowers with everything still connected..

If I were the OP, I would just get 2" lowering springs all the way around with Bilstine shocks. I used BMR springs from Summit on my 69 el Camino. The 2" lowering spring will put that Buick pretty close to stock height. For some reason stock height has changed over the years into making these cars look like 4x4s. Look at factory photos of your car when new.

As far as looks go, it depends where the cars parked, ride height is always changing with terrain, at least it does on these hills around here..

Yeah I've been googling stock height for the Buick to see what drop srpings to get. I think I'll go with the 1inch drop for now. Btw, your el Camino sits pretty nice

[Skip Fix]

I agree it is a crap shoot for where the ride height ends up and a little involved to swap regular springs.Pull the shock, getting a floor jack under the lower A arm, a ball joint separator that pops the ball joints apart(large bolt/coupling nut appearance) much easier than a pickle fork and does not destroy the ball joint boot. Leave the upper ball joint and spindle connected. Spring compressor(often not needed in short stiff springs). Can do it as quick as a brake job and repacking bearings!

Global West does have some spring spacers for fine tuning side to side.