great info about coilovers vs springs..i may jus save up for coilovers instead

res0zsfa

its pretty long... but for those springs/coilover newbies...this is some good information! let me know what you guys think

from Pure_adrenaline - OEM springs and struts are designed to work together. This means that the load rate on the springs are matched with the damping rate of the struts. Without struts, the car will bounce on the springs. Without springs, the car will drop to the ground. Therefore, the strut and the spring have to work in unison to soak up road irregularities while providing comfort and good handling.

Of course, there is an infinite number of ways to tune the strut and spring. It all depends on the vehicle's purpose.

Now what happens when you introduce an aftermarket spring to an OEM strut? Most likely, the load rate and the height are now different. This will make the spring and the strut out of sync from each other. However, in most cases and based on my personal experience, the ride does not suffer too much from the stiffer and lower springs because the OEM struts are able to handle the wider range of specs. That is assuming that the struts are in good working condition. But it is almost a certainty that you will shorten the life of the OEM struts.

You also need to consider the different designs of springs. For instance, there are springs that have a single rate throughout the length of the spring. Then there are springs like H&R that have progressive rates. Wider and softer usually, then as compression is applied to the springs, the narrower and harder coils kick in and provide a stiffer feel. You can see the progressive rates at a glance because the gaps between the coils are different top to bottom.

Contrary to popular beliefs, springs do not need time to "settle". Almost immediately after installation, as soon as the weight of the car is fully on the suspension, that's pretty much it. Also, springs from reputable companies explain the amount of the drop so it should be no surprise to anyone.

One thing to keep in mind is that, depending on the drop by the springs, you will inevitably shorten the travel height. This means you will be more prone to bottoming out the struts.

Now let's pair up an aftermarket spring with an aftermarket strut. Let's take Koni adjustables and Eibach springs, since they were mentioned in this thread. This is really not much better than, and certainly not the answer to, the OEM strut + aftermarket spring combination. Why? Because I doubt Koni and Eibach got together to match their engineering specifications. The Koni struts are simply designed to handle a more extreme range of specifications because most buyers buy them because they want stiffer ride with most likely a lower ride height.

So in essence, it is better than the OEM strut + aftermarket spring combination, but not THE answer. Oh, and, it is just fine to use these two combinations on the track. I have seen plenty of people using spring + strut combination at the tracks... even all-OEM suspension.




There is, of course, a better answer to the question than the aforementioned two options. It is the coilovers. Coilovers are an integrated unit consisting of a strut and a spring that are typically accompanied by other nice features such as camber plates, ride height adjustability, damping rate adjustability, etc. They also look nicer than OEM.

They naturally cost more because of the added engineering, materials and features that are involved. But often times, if you need these features, it's well worth the money. The strut and the spring are designed to work together at a lower ride height with adjustable preload and damping.




Now having ridden on adjustable coilovers for years, I can tell you that you really won't be changing the height setting much after the initial installation. Why? Because you have to get an alignment. It's a pain in the butt and costs time and money. Plus if the locking mechanism fails or rusts, you are looking at some bloody knuckles or costly repairs.

If you just want the dropped look with a slightly sharper ride, then I think springs on OEM struts will do just fine, especially if you are on a budget.

If you are on baller status and want the bragging rights, then by all means, the coilovers are your best bet because along with those two things, you also get the extra engineering. Or maybe you just don't settle for anything but the best for your car.

ClemsonWill

This article is layed out very well. It's great for a newbie. Maybe stickie material.

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Red__Zed

I don't really agree with the opinion in there on an aftermarket damper paired with a set of springs-- for most cars, you can easily find a set of matched rate springs and dampers, and it will be the same way for the Z once the aftermarket catches up.

In addition, it is not too hard or expensive to have custom valving done. I had a set of custom valved Koni yellow's matched to the ground control springs I had on the Civic I autoXed. It honestly made very little difference since they were already such a good match.

kenchan

i read maybe the first 2 paragraphs and stopped. it sounds like some kid with little to no experience wrote it from reading car forums, yet never touched a wrench. lol

Nikon FM

To the OP. Thanks for taking the time to write the post

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CFZ

So give me an example of a matched spring and shock coilover. You would be surprised what you will find with whats out there in the market. Also Most coilover manufacturer will tell you that you can go up or down 4KG. which is about a 447lb difference, how do you match that.

Also with the shock and spring, There is a valving range with the stock shocks. A good spring manufacturer will test out the shock and figure out for us what will work and what wont. Also they will figure out the useable stroke of the shock.

Yes springs are not supposed to settle but if you do enough research you will see that springs do indeed settle after a few months, this is what is called spring sag which is never wanted (Eibach, H&R), better spring manufacturers will never sag. Usually there is about 2-3 days needed for the height to settle and this is normally because of the rubber seats in the tophats that needs to be broken in. because the seating of aftermarket springs are slightly different from oem.

I have seen OEM shocks with aftermarket springs beat the crap out of vehicles with coilovers and vise versa.
Pros of Oem shocks and springs- comfort, and a preset performance out of the box. coilovers will never be more comfortable.
Pros for coilovers- adjustability. and being able to fine tune with your setup.

In other words I don't agree with your post.

wilsonp

Is it possible to just get shock/strut upgrades to dampen the bounciness in the Sport suspension?

I put Bilstein shocks on the NSX and it made a nice ride/handling difference without (much) lowering.

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Red__Zed

In the bolded part...I think your math is off....

CFZ

How is it off?
lets say we start at 6kg=335lbs
4 up from 6kg
10kg= 558lbs
4 down from 6kg
2kg= 111lbs

So total difference is 447lbs

Let me know how you calculated it out. kg/mm divided by 0.0179= lbs/in.

Liquid_G

"They also look nicer than OEM."

That's why I bought my coilovers.

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djpathfinder

Z's should roll off the production line with less wheelwell gap, that's for sure.

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Knives

I disagree. I like the "Green Bay Packers" look when you combine Tein springs with Koni Yellow shocks. Performance be damned, I want my suspension to co-incide with my fantasy team having Aaron Rodgers and Greg Jennings.

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BeauNC

The other thing the article doesn't mention is that the average driver will never really notice the difference between a "good" aftermarket shock and a factory shock. Most people just don't understand what a "good" suspension feels like because they've never ridden in a car with one, so anything that is stiffer is understood to be "better".

Then with coilovers, the average Joe has no idea how to properly tune them and will never even get them corner weighted. If you have a finely tuned sniper rifle, but you don't know how to dial in the scope, you still won't hit anything. A lot of coilovers have very stiff rates, not always good in the real world where roads have expansion joints and some pretty nasty irregularities sometimes. I've witnessed stiff coilovers cause accidents while driving on the mountain backroads. The road was too bumpy for the stiff coilover to keep the tire in constant contact with the road, car bounced into a guardrail.

Then cost is a consideration. Cheaper really sucks in the world of coilovers. I've seen many dyno tests by reputable shops on forums and not a single shock from the same box will dyno nearly the same. Plus, the adjustment knob doesn't produce the same curve from shock to shock. 8 turns on one shock, may be 10 on another shock. And its not always linear as you turn the knob. From shock dyno's I've seen, the curve (as you turn the adjusting knob) gets radically stiffer the more you turn it. So 1 turn on the soft side, could be like 2-3 turns the closer you get to full stiff.

Cliffs notes: Average driver on normal roads will be satisfied with springs and good shocks (Koni/Bilstein). If you insist on coilovers, don't go cheap and pay a reputable shop to set them up properly so you get the most for your money. Then LEAVE IT ALONE!

BeauNC

Another thing is that your tires are a part of your suspension as well. If your stiff coilover severely overpowers your tires sidewall stiffness, you could get some odd handling. The whole package needs to be tuned to work together. The relative stickyness of your tires also comes into play. Talking about this any deeper, I think, is outside of the concern of a street driving enthusiast. You shouldn't be going fast enough on any road to have other stuff come into play.

kevr6

DITTO!

I've been through a half dozen cars using coilovers, aftermarket spring/shock combos from a bunch of different manufacturers driving over 300,000 miles throughout. Old news (opinions)!

Next!

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