Coil-overs vs upgraded struts/springs?

Alright, guys. Remember, I come from a world of solid axles on both ends, with leaf springs and shocks. This new car is nowhere near that world, and I need some advice. 

For my 2002 Mazda Protégé 5, what are the advantages and disadvantages of each setup? I’m looking to have a good handling daily driver that will see much spirited driving and the occasional autocross, if I can find a local one. I’m not looking at adding a bunch of go-fast to the car; rather, I’m looking at making the stop and turn bits more effective. I want it to handle!

So please, if you would, educate me on suspension, because I’ll cheerfully admit that I know precisely squat about performance tuning a suspension system...

Edit to add: car needs to remain at or as close to factory ride height as is feasible. The roads around here are garbage, and I already have to be careful on certain streets.

Your car already has coil overs.

The accepted terminology for 'coil over' means adjustable height perches. Which is the only advantage.

If you want to adjust ride height or corner-weigh the car  - that's the only difference/advantage.

Be cautious if you want to retain stock ride height, as many aftermarket units are designed for a lowered ride height.  

It all depends on what's available that fits the car or can be made to fit.  If you've got good choices for springs and shocks, there may not be a need to go to coilovers.  But if you don't, coilovers will give you more universally sized springs, so you'll have more choices of spring rate, etc. 

Depending on the car it can be hard or very hard to increase spring rate without lowering the car with commonly available aftermarket springs. In those cases, adjustable perches and springs the proper stiffness/length will let you keep all that precious height and travel will getting closer to the ride you want. Shocks is a whole different issue. What are available for your car? 

Eibach + Koni FSD (if available for your car). 

It will likely be around a 1" drop. Unless there is a specific budget option that's been developed for your, regarding coilovers like say the VMaxx for the Miata, I wouldn't bother with coilovers. 

All the BC stuff is junk and will likely ride worse than stock. Quality coilover setups are much more than you'll want to spend.

The best part about having adjustable perches and adjustable struts is that you get an almost infinite number of adjustment values to get wrong!

Kidding, sort of.

If you can get a good strut and match it to springs that fit on the regular perches, there's no real disadvantage to that.  An adjustable perch setup gives you a wider selection of springs since you can choose your height and rate from a checkbox in the catalogue, versus having to measure from all different cars to find something.

Another advantage is that it might give you the ability to fit a wider or taller tire.  If the stock spring perch is what's in the way, getting rid of it will open up the area a bit and give you more wheel and tire options.

In reply to wae :

You joke, but without scales, your handling will always be more or less 'eyeballed' quality. I have seen quite a few cars get slower after ride height adjusters were installed. 

But that said, no 2 springs compress the same, look at a spring dyno sometime. Even oem setups suffer from uneven weighting quite often just due to mfg tolerances. Going with a quality spring mfg helps a lot here. Progressives tend to be worse about this.

Just food for thought. I will +1 the ubiq koni setup. Had good luck with tokico illuminas too, but people dislike em because all other tokico shocks seem to suck and blow (oil).

If you want an accurate progressive spring setup, you might want to run very stiff tender springs that don't fully compress under the weight of the car. Then it's like a dual-rate setup. The Ariel Nomad runs springs like this.

If the secondary springs aren’t fully compressed at rest, you get really weird damping characteristics unless you have bypass shocks. Been there, tried that. You have to lock them out if you do that. 

I love that this forum understands what coilovers are and that they’re not inherently magic like most marketing-fed forums. 

One thing to watch for - coilovers with adjustable bodies cannot package as much shaft travel as a fixed-length body. If your car is travel limited, this is a significant problem. Ideally, your coilovers (or struts) will have as much shaft travel as stock. 

On our old Protege5, we had some BG coilovers that worked surprisingly well. Not BC, this was 15 years ago. 

Know nothing about Mazdas
.  But a little research produced something like this.  Megan Racing

^Megan Racing/BC are part of the crop of Taiwan junk.

About the best entry level coilovers you can get away is calling the guys at FEAL and having them do a custom built to your needs 441 setup. That's still going to run your $1500 once you add in Swift springs over whatever no name garbage is there. 

Or if TEIN has extended their Flex Z along to include OPs vehicle.

Most everything today is from the land of tea.   Trouble is between suspension and possibly tires, you can easily exceed the value of your every day driver.

The easiest way to do this is see what shocks are available for your car. And find the valving specs. Then build backwards from there. If you can’t change the valving, you’ll need a certain spring rate to work correctly with the shock. Once you know your spring rate range needed, you can find what length and diameter of spring you need. Once you have this information, hop on over to afco or hypercoil springs and buy the springs that have the correct diameter, length, and rate. Now you are set. 

The other option is to chose what spring rates you want and ride height you want, and then pay a fortune for custom valves shocks. Bleh. 

I was coming back to recommend a set of Koni STR.T (oranges) but it looks like they don't make them for that car.  In fact, a quick look through the tubes gives me the impression that there isn't really anything out there.  You could get some KYBs, which are good stock replacements, and try to find a spring that's a little stiffer and a hair shorter.  Maybe even just swapping out to brand new stock replacements would give some improvement over the springs that have been bearing the weight of the car for the last 16 years.  But I don't think you're going to get anything amazing out of it.  It looks like KW makes a setup that fits, but I have no idea what the quality is like.  

If you want to get a little crazy, you could open up your strut bodies and find a cartridge for another application that would fit.  I'm not sure how you go about determining what dimensionally-correct inserts have the valving that you want/need though.  And then you still have the spring problem -- but you could grind off the perches and install sleeves from Ground Control so that you can pick from the available 2.5" ID springs that are out there.

KW makes quality stuff, but their spring rates tend to be on the soft side for the current crop of TW200/Rcomps.......but that extra comfort could be nice since the car will mostly be a street driver.

Probably an unpopular opinion but if it's going to be a DD I would go springs/struts instead of adjustable for the simplicity. 

The car was designed with a good handle and C&D said it's a stable platform.  I would keep the stock springs and replace the dampers with stock, IF they were worn out.

I'm not 100% sure about the P5 in particular, but typically the "sport" spring and damper packages available for cars in this class are all aimed at lowering the car for a sporty look, without totally ruining the streetability in the process.  They add a little stiffness in the process but it's a secondary effect.

If I wanted to bump up the handle on this car, I would spend up for some 300 treadwear summer sport radials to go on the stock wheels.

I am a coilover fan.  Do your homewprk on spring rates and dampening.  You will find a that a disturbing amount of folks selling them cannot tell you what they are actually selling in regards to rate and dampening. 

I have landed at hybrid setups from ground control and a mix and match approach to struts on the last few I put together.

 The adjustment is great to put them where you want them.  With that said they typically get adjusted manually by me a few times to figure out where I like them at height wise.  From there it's off to a ~400 alignment where the heights get adjusted to corner weight.  At that point they typicall never get changed.

There are some really nice upgraded damper spring setups out there that are likely 95% of what you would get from coilovers. 

I make that statement based on a ~1000 dollar budget for a full setup before alignment.  There are likely very nice high dollar setups that are much better but mostly irrellevant to me on a cost basis.

I’ve been trying to learn up on this very topic as of late.

Another general question about aftermarket coilovers (in the vein of the Megans mentioned above).  Is it possible to interchange the dampers as well as the springs?  Or would they have to be sent back to the manufacturer to do this kind of thing?

Keith Tanner said:

One thing to watch for - coilovers with adjustable bodies cannot package as much shaft travel as a fixed-length body. If your car is travel limited, this is a significant problem. Ideally, your coilovers (or struts) will have as much shaft travel as stock.

Interesting! Why is this the case? I figured there was no difference in travel as you're essentially just adding threads on the outside of the body?

I know this is somewhat off topic, but do you know how the Bilstein B8 is supposed to cope with lowered cars better than a B6? The manufacturer literature is quite vague other than 'its better.'

I've been in two cars with Vogtland/KYB, always just really enjoy the way they drive, so I always recommend that combo. Very comfortable, and just enough sporty for a daily driver. 

Most spring sets on "modern cars" (i.e. 2000ish, when cars started using progressively larger wheel/tire diameter) don't lower them enough to cause ground clearance problems, but check the forums for that car. 

In reply to Blaise :

Because when you lower it, the threaded body goes up, and that, eventually, takes up room where the shock shaft operates. 9 out of 10 times it occurs when some kid wants that slammed look, and then nails pot holes and complains that his dumped Miata broke down at Walmart. 

paranoid_android said:

I’ve been trying to learn up on this very topic as of late.

Another general question about aftermarket coilovers (in the vein of the Megans mentioned above).  Is it possible to interchange the dampers as well as the springs?  Or would they have to be sent back to the manufacturer to do this kind of thing?

Not at all. In fact, you’ll find that most coilover manufacturers use a shock from an already reputable shock manufacturer. Same with the springs. You can rebuild them your self, or take it to a race suspension guy and they can custom revalve it or just rebuild it. 

But that’s why you buy from a reputable company. Not “eBay” or etc. FYI- you can build your own coilover setup for much cheaper and it’ll be custom, set the way you like, and be rebuildable. The only time it starts getting near the “buy it now” prices is when you factor in pillow ball upper mounts. 

Trackmouse said:

In reply to Blaise :

Because when you lower it, the threaded body goes up, and that, eventually, takes up room where the shock shaft operates. 9 out of 10 times it occurs when some kid wants that slammed look, and then nails pot holes and complains that his dumped Miata broke down at Walmart. 

You're referring to just moving your static height to have no bump travel left.

I'm asking why the total travel would be reduced.