What to look for and WHY: Coilovers

MaysEffect

The amount of vague information here is pretty surprising. Springs in relations to ride quality and ride height is barely mentioned here, yet so much is blamed on the dampers and price. Yet no one is questioning how the spring comes into play here....

9 times out of 10 what makes or breaks a suspension system is the capacity and quality of the springs and its implementation of supporting the weight of the vehicle. At the end of the day it is the spring"COILover" that facilitates the working motion of a suspension system. All other items and factors are secondary to this.

Most kits that have bad road feel, improper wheel travel and bump problems comes from a improperly matched spring for the ride height set by the user and overall compression capacity for the weight and and subsequent load during harder driving situations. The damper is not suppose to support the weight of the vehicle, its job is to absorb road imperfections and harmonic imbalances the SPRING creates. Having shocks with valve rates set stiffer to mitigate spring binding and bump is a poorly formulated solution for bad wheel rates. In most cases the damper should be as free flowing as possible without limiting spring travel.

There is a reason springs are usually the only object in the suspension system that has the [force per travel (ex. KG/mm)] information listed in the details of the product. You'll probably never see the shocks value of measurement because its extremely variable based on several factors.

It was mentioned earlier in this thread, but even though the defining factor of the kit is the spring rate (and overall load rating), the overall cost for a kit is defined by the quality and features available on the shock. Where as springs generally have a fixed price, the design of a shock is dependent on its tune-ability and build quality, most of which are unnecessary additives for road cars once you get passed the basic ability to change ride height and compression and rebound.

Way too much emphasis are put on the design of the shock here and its function. The tube design does play a role in overall cost and implementation, little of its capabilities are a defining feature. On average, a normal road car such as the 370z will only get up to about 5 inches and compression and rebound from static ride height. Any version of monotube or twintube damper can support this wheel travel. But in almost every case, a twintube shock is the cheaper option. This alone is the primary reason behind it being used more in OEM and lower priced shocks. In either case, neither design should have to bare the load of the vehicle and the bending forces of the wheel.

I can elaborate further for those who care. With regards with some problematic information -

This is so vaguely uninformative. For one - If you are going for the "stance" setup, its even MORE important to have the correct setup. With a lower suspension than advised, you are dealing with decreased wheel travel. Secondly - Saying the dampening is WORSE is horribly vague. What defines worse here? Way too stiff? Way too soft?

Well if its too stiff then that would actually make sense, as you have reduced travel and in turn reduced time for absorption. Instability can come from a plethora of factors in this instance. Bottoming out, not enough travel before bumpstops, Improper corner rates, and overloading the tires from any of these reasons.

Saying the dyno figures are off from "coil to coil" doesn't exactly mean anything either. Was the preload values the same? Was the temperatures the same? Was it tested with or without a spring? Saying this gives zero emphasis one what the ACTUAL problem could be. A company simply having horrible consistency between products doesn't truly argue bad quality but incompetency of the technicians of assembling the products.

Spooler

Really???? You are going to come to a stickied thread and provide no useful information. Just self imposed chest pounding on how smart you think you are.

This post needs to be deleted.

MaysEffect

Please elaborate on what wasn't useful? Or was everything i said completely obvious? Given the previous discussions, no one bothered to go over anything i said in great detail.

The topic is called "what to look for and why" Most of what was previously stated was about the quality of dampers, the price and which company. In the original question of type of driving, i'm not sure that was covered fully either.

Very few people, if at all, discussed how the springs come into play, how they effect the overall suspension dynamics and geometry.

I'm not trying to be a smarta$$. I just want people to be sure on what they are buying instead of marketing BS that has plagued the aftermarket industry for years. I'm coming from the BMW and VW scene and the information and vagueness i found in those forums were equally non-informative.

Why wouldn't this information be important on a stick'ied thread appose to some random question? I realize this is several years old, but these cars are still being sold and people are still heavily modifying them.

MaysEffect

In order to appease Spoolers disgust of my rant. I'm linking this thread that was going around the same time this thread was started. With the intentions of figuring out the spring rate and overall car balance. Given the fact it was discussed in the "track,Ax..." topic. The information revolves around maximum grip settings and balance.

Spring rate help?

I hope people will continue sharing proper information and there views on the matter.

Spooler

I think you missed the point. This thread was about basic coilovers and why cheap ones were actually a downgrade from the stock suspension. The track thread is a much better guide for a track setup and will give you great tips for a quality street setup. I remember reading that one a few years ago.

MaysEffect

The OP poised several questions, with the global discussion clearly stated on "what and why" makes a coilover setup good. None of the questions were focused directly on cost per quality compared to the OEM specifications. However it was asked, why and what made high quality kits worth the price. Throughout the previous answers and advisories, spring rates matched to the potential balance wasn't really discussed with any detail. As i stated before, most of the "blame" for what was bad or improper revolved around the dampers.

But in any case i don't see why buying a cheaper kit would warrant an argument of why its bad. That can easily be solved by the age old answer "you get what you pay for". The bigger question would be why a expensive coilover may perform poorly, and their are several cases like this. Who is to blame here? The user or the manufacture?

If we were to even make a basic calculation on even a reasonably spec'd coilover kit we would be over 1000 dollars at the very least.

Here is my breakdown.

Swift, Hyperco, Eibach have competitively priced linear springs at about $60-80. With an average cost of $70 per spring we already have a total of $280 for springs alone (basic spring kits are closely priced to this figure on average). Lets throw in a set of tender springs for good measure so that we can tune preload in fine detail. Tender/helper springs in most cases cost more than their linear spring counter parts because of relatively complex rates and design (flat coil, thinner wall). A average cost for a set will go for about 360 dollars ($90/per).

We are already at 640 dollars. This is typically half the cost for a basic coilover set, buying a coilover kit for anywhere around the price of the quoted springs alone means somewhere along the line parts, engineering or technician wages were significantly under funded. In any of these cases i hope cheap parts was the cause. An improperly trained technician assembling a product or a poorly engineered design of vital safety components for a car can be significantly more catastrophic of a failure than cheaper pieces IMO.

DAMPERS -
Given the increased complexity of any basic damper unit (considerably more parts/consumables per unit- oil, shims, piston(s), piston rod, bolts, seals,etc) We can already guesstimate a single damper would be more expensive than a spring. Internals alone for a basic monotube damper can be as much as 65 dollars (from actual price figures of a Bilstein monotube shock). This doesn't even include adjustable parts for a simple 1-way tunable damper like adjustable bypass valves, compression adjustment springs and so forth. in total a single 1-way damper can cost up to 120 dollars a piece, and if both front and rear dampers are of the same design, a set is about $480 alone.

Linear springs - 280
helper/tender springs - 360
Damper set (monotube 1-way) - 480
Total - 1120

This would be for dampers and springs alone. We haven't factored in assembly cost, accessory pieces and any potential R&D.

So in this case i would 100% agree that a cheap system COULD be worse than OEM.

On a completely different corner of this table i have a complete breakdown on the cost of a single Ohlins ILX 2-way damper and how it cost 940 dollars (no spring or external pieces). Without the discussion of springs based on the cars weight and potential load, this same damper system would ride equally horrible to a 666 dollar kit if not setup properly. So how or why exactly is the cost of the damper system a good bases of ride quality? Without springs they are just fancy umbrella's, and that was my point about how emphasis of dampers was the wrong primary priority.

Instead of bad mouthing companies and putting all the blame on them how about we figure out a bases for complaints? In reality, almost no one in history who took the time to write a piss poor review also took the time to measure the shocks performance in relation to spring setup, preload and other external factors.

In a notable case a few years ago, a clubracer bought one of the most expensive Moton kits on the market for a M3 e36. Without any practical testing and setup analysis the customer went on to completely slam Moton by saying it was absolutely horrible to drive. After having it sent out to a professional to have it "fixed", the technician found out the damper was set to FULL stiff (oil bypass completely closed) and a gas pressure over 150psi (not untypical or the source of problem for Moton's, but high). How long it was like this is unknown, but the customer gave zero notice to anyone before making these complaints. Was this the absolute fault of the damper? In almost all cases having a damper set to full stiff means you are compensating for a separate issue outside of the dampers control.

In a recent situation, a time attack team with a BMW 135i had a custom Nitron 2-way kit. A full review was made about the car setup (some may have read about this). Within this article the driver/mechanic lodged a small complaint that the kit was not working to their standards and was considering tossing it for something "better". Also within this review, pictures showed clear details of both the front and rear spring perches adjusted with well over 1 inch of spring droop when unloaded. There was NO PRELOAD on these springs, even with both F/R having helper springs on the setup. From this, we can discern the car would've been practically riding on bumpstops if this was truly how the car was setup in normal conditions. I have yet to here back from them for whatever reason after trying to ask about the issue.

Examples like this show where misleading statements can manifest improper analysis for anyone else looking to potentially work with companies.

Sorry for writing so much (not really ) rant over....

Spooler

This is a much better response than your first one.

Jordo!

The biggest obstacle (other than price) is getting interpretable data.

Probably the easiest way around this is to find someone who is a good auto-x er in your make and model, with a nearly equivalent set up, and then buy what they have and set it about where they have it set. Same goes for tires, etc.

You might dial things in ever so less "aggressively" if it's street only, but its not as if folks in sports cars don't drive a wee bit more spiritedly day to day than the average driver (tho' hopefully in a safe and responsible manner...).

Failing that, the best OEM option on the table is as likely as not to be a superior (if over priced) set up that has actually undergone some real testing.

Just throwing down a bag of money on an aftermarket set up that has many options and configurations is useless if you aren't able to take advantage of it, and may even be counterproductive if you don't know what you are doing and/or the effect of a given adjustment cannot be validated (i.e., shock dynos, track day data, etc.).

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MaysEffect

Sounds like copying, not interpreting. Also cost here is open for interpretation as well. What if this hypothetical Ax driver has a 8k$ 4-way damper system ,sway bars, chassis bracing, etc, intended to support up to 2g's of lateral force at 80-120mph?

Opposing to this, what if a similar car in said field had a much simpler and cheaper coilover system with arguably worse tires, but comparable lap times? Do we just settle for the cheaper option because it's good enough?

How are we suppose to easily copy this setup? What if both drivers have no idea what the suspension system is actually doing and are just going off of what they bought and how some technician said it should work best at. And BLAM, it's fast, they're fast, and no reasonable amount of data was logged to truly understand what made said car and driver fast in those particular situations.

OR in another case (most cases), both drivers have lots of data logged and understanding of their systems, but given the fact competition...is competition. They don't want to share any of their knowledge and setup with you or anyone else. How do we go about copying it then? Break in to their race shop like Brian O'connor lol.

To be fair on the last point. There are several race shops and tuners that would charge upwards of $200/hr to setup your car and teach you how to tune a car and what to look for in a suspension setup. On top of the cost you already will have to spend for parts, this may or may not be sound investments if you have no intentions to recoup this cost through competitive racing/promotion. I for sure wouldn't turn around and just mouth out that knowledge to some guy looking to just flat out copy my setup.

sirnixalot

Proprietary information aside any vendor on here that also competes with the same platform would probably supply you with a reasonable amount of setup information once you explain what you're after.

949 racing did with my Miata. Why buy without support?

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2012 Frontier - BTWTuning VK56DE swap

MaysEffect

100% agree! None the less, we go out and buy "recommended" parts without getting all the information about what exactly we are buying and how to set it up. In most cases we have to rely on professionals to help us with these unknowns. Professionals generally don't do work for free though.

949racing are indeed very helpful from my experience with the group. But information and proper setup are two different things. Shops like 949racing can setup your car with alignment specifications with accuracy up to .01 of a degree across an axle if you have all the right parts. They can also probably setup a near perfect corner balance. But you still have to start with the right parts and you still have to pay for their service if you want them to do it right. Or pay for it one way or another (publicity work, street cred?,sponsorship, exchange services(prostitution?)).

Speaking of 949, those guys also provide excellent information with regards to the products they offer and how and why one kit may be better than another. But they are a specialty group dealing exclusively in Miata's.

direct pull from there ND Xida kit - ND Xida coilovers Miata
So not only do they offer coilover kits in several variations, but they also have recommended TESTED primary spring rates that would work best for the particular driving situation and the TIRE that can induce a high corner load. The tire specification being a important reference irrespective to the dampers and springs abilities to control wheel travel. If a tire can only support a maximum of 1000ibs of force but you have a corner load of 1050ibs at a simulated .96g from CG, the tire is beyond its limit of traction, in most cases you are sliding off the road into a pole or a tire stack if you persist at this simulated level of force. And if for whatever reason you haven't slid off the road and still have grip, you are working in a range of stiction, this principle is where road racing tires generate its cornering grip. It's also the reason slick tires have a uncanny ability to lose control of traction at unreasonable levels.

Most companies are not going to take the time to test several spring rates to counter the corner load double its static weight. For one, any potential tire capable of supporting the weight won't likely fit without major modifications. Secondly in order to produce such a load you'd have to be going uncharacteristically fast for public roads.

At most you'd hope a company did basic calculations to come up with a spring rate based on the corner weight in relation to its motion ratio while taking the potential wheel travel into consideration. Things immediately start becoming more complicated when you have to assume how much force passed this a tire is capable of accepting all while keeping the car from bottoming out or hitting something under the wheelwell. OEM specifications don't take lateral forces over 1g into consideration at all. The primary focus is to keep the car from bottoming out under normal driving conditions and weight restrictions. Thus the GVWR. Most aftermaket companies simply try to replicate this load rating in relation to the static ride height change you hope to achieve.

Jordo!

Nissan tuned all the 370Z motor the same way. They don't give you a blank ECU. Its all copying based on an empirically validated model. The end user can then fine tune to the best of his or her ability.

The other option is massive amounts of datalogging -- which is ideal -- but impractical for someone who hasn't got the resources.

Consider the simple principles in chassis stiffening -- you can make educated guesses on a set up by knowing whether bracing one region over another is likely to induce more over or understeer.

For things like shock valving and spring rates, it's more complicated, but modeling your car after one that is highly similar (i.e. same make, model, weight, tires, power/torque, etc) is better than starting from scratch or choosing items with many, many options of adjustment where the end user will either have no idea or no time to work it all out for their unique situation.

How do you decide on tires? You look up what the hotshoes are running on GRM and decide if that will work for you, given price and typical road conditions. Same for alignment, and so on.

What's wrong with copying? It just can't be done blindly. Each person has only so much time to embark on a "project car" journey, and having done many such projects, I can tell you pioneering stuff is exciting, but not for everyone. Copying a good working model is more likely to work than traversing a steep learning curve aimed at preparing a singularly unique car for track use that will mostly serve as a DD (see further threads on my problem with those who over-cool their oil...).

I am not suggesting someone blindly shell out for and set their car for track conditions if its primary use is the road -- brakes that don't work well when cold and tires that can't handle wet are no good, but you can still copy more modest set-ups that will map onto a spirited DD with a modicum of research.

The whole point of sharing knowledge is to not waste time reinventing the wheel. You can adjust as needed from the established model or scrap it entirely if you have a good reason, but typically, the average end-user won't.

Someone who buys expensive highly adjustable parts who can't adjust them is probably as likely to ruin their handling as improve it. Not everyone has the time, resources or background knowledge to innovate -- and often that will be based on an existing design anyway, not one specially developed for their unique personal car.

This is the same concept behind sharing dyno tests for various bolt on mods and so on. It's so someone can copy that on his or her own car without starting entirely from scratch.

I'm more put off by people putting parts on their car or setting things based on name recognition without any data to go on. Show me the data, and I'll buy it if I can afford it, otherwise, I'm skeptical (see my verrrrrrry detailed commentary on this stuff regarding tuning in the Proven Power Dyno Thread).

I like sharing data and am happy if something found to work well can be copied. We're not all competing with each other in F1 or rally cross, right?

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MaysEffect

This is apples n oranges. Engine management is worlds ahead of basic suspension systems. Not every car is making the same power based on several factors. There is an optimal base map which has to work in a field of operating parameters. The engine has levels of VVC and A/F parameters to work with depending on operating temps and air density.

Mass produced cars/bikes just recently starting using VVC to change compression/rebound parameters depending on road conditions and response timing. Even still its not the end all be all for perfect ride, where you still have to rely on the spring for the overall support of weight.

Thoroughly disagree. Chassis stiffening is considerably more complex than damper settings and spring rates. Companies spend millions of dollars alone in validating structural integrity, mapping out where there needs to be absorption and crash resistance independent of each other. Altering this is a matter of safety. Doing it for suspension characteristics is an impractical validation of chassis control and money is best spent else where first.

This may be a good point of reference, but as you said, in the end it has to work for you. Simply copying it tic of tac is a matter of following someone else blueprint. This isn't valid interpretation of data. There are several parameters behind tires that someone else may be able to exploit, but maybe you can't. Heat ranges being one. You may live in a cold climate area, where as i may live in a hot climate. RS3's may work better between 50-70F, where as a RE-11 may work better between 70-90F. Why get the same tire you have if my climate doesn't suit your option any better? What if all of the Utah hotshoes swore by said tire no matter what?

You started off by saying an obstacle is finding interpret-able data. Then followed up by saying simply copy someone else tic for tac is the easiest thing to do. The solution doesn't solve the problem at all.

Copying is not interpreting, and in most cases it is done blindly. I can copy an entire photo album from google and submit it as my own. I don't have to understand the parameters of a single image for it to be positively accepted by others or for me to make some vaguely blanketed statement about what it is.

If you are always under the wing of someone else, you will never fully be able to interpret information accurately. Being in a constant state of following others based on positive results isn't a winning formula.

Without the actual understanding of the potential options available, we'll never truly get what is actually best for our exact needs. You'll most likely get what sounds/looks the best for your money. In all cases this just doesn't always pan out to be the most reasonably philosophy to live by.


This is contradicting within itself, In order for me to even know something is best in one condition or the other, i have to be remotely knowledgeable about what works where. Business marketing in some cases is intentionally misleading to people and prescribes what is best for their needs simply because they need to sell what they have for offer. Or in other cases go overboard in the reminders of safety in the cases where some idiot might still try to use said product in the wrong conditions and subsequently try to sue them.

If a coilover kit has the words "comfortable for street" in its details but hides the fact the springs are 2000ib/in with 2 inches of spring travel. I may end up buying it off the false pretense that its comfortable. Same thing when marketing associates the words "soft" as a bases of suspension control. In most cases SOFT isn't exactly the best solution either. In everyday lingo, we usually associate "soft" with plush and comfortable. Are we supposed to accurately interpret this to real life terminology? How is soft or hard accurately measurable and where is the line where softer turns to hard? Does Hard mean my a$$ won't work after 20 minutes of driving?

100% agree.
BUT...If you don't have the time to understand what you are changing even on a basic level, why are you even messing around with it in the first place? How long will it take for someone to read this page? In my guesstimation, significantly less time than installing a coilover kit or wait in your installers lobby looking at sports illustrated or Motortrend.

You don't need to be a innovator to comprehend things you are willing to spend money on modifying or using. I don't need to know how to make a iphone to understand a battery that stores energy powers a motherboard and its subsequent pieces to turn pre-written codes into visual/audible applications. I also don't need to know the exact ratio in my air/fuel charge to know more of it will result in a larger explosion in a cylinder chamber (although it would be helpful so that i don't blow a hole through my engine block when a gauge reads 14.5:1)

At the end of the day, having a basic understanding of what you will be working with is better than having no understanding and just hoping it works best based on someone else performance capabilities. If you don't know, being mislead into false knowledge isn't helpful. Its even less helpful than not understanding at all. And that is exactly what happens when false pretenses are published on marketing pages on how something will make blah better, or works period for daily usage. "Better" implies all one needs to know to make a decision. You throw in some mouth watering scripts like "great value, more agile, comfortable, faster, more blah" and my money has already escaped my pocket book. Throw some eye catching beauty shots in the mix. MAN!!

I disagree, although a valid topic for discussion. Sharing data is so you can have a bases of understanding of what should be expected. Not so you can just go out and copy it. Again, what if copying said changes meant you had to spend an arm and a leg to get said performance gains? What if you could make it better? or get comparable gains with a completely different set of parameters and cost? The guys over at OnPointDyno (Sasha) were able to extract over 375whp on a N/A engine. You can also make that much by simply bolting on a basic supercharger kit. Completely different parameters. Comparable results.

Shock dyno's are rarely posted because people generally have no comparable data. What does this information actually tell me?



All of this has to be interpreted to some base of information.

In the case of a dyno graph for engine performance we all can gather that a higher curve value would generally mean a higher power output. But without a bases of understanding of what is happening where within that curve, how would we know one value is better than another?


Here we just see values of how different setups work, just a approximation of how much and potentially where. No exact data between specifics in tunes. Do i just get the one that has the highest total value?



Here we see comparable values between several kits and its subsequent gains and drawbacks over stock and competitor kits. This gives us a much better representation of what i have or could have purchased in relation to other kits. or what i could possibly do with my own custom kit.

With regards to the shock dyno's, what exactly can we interpret without comparable data of other plots from competitor profiles? Someone simply telling me its better than blah and showing me its "adjustable" can be all i need to throw down cash for something i still don't understand.

Jordo!

I think you are taking me too literally. I am opposed to overly adjustable parts where the end-user cannot easily determine acceptable (let alone ideal) settings, and for which there is no clear working model to use as a guideline. Informed, not blind, "copying" is actually pretty useful in a pinch. I had already stated that this would serve as a starting point from which further adjustment could be made, but often little further changes are needed if the parts, settings, and motor, etc. are all approximately equal, and instead it becomes a problem of consistency across measurement tools as much as anything.

Maybe I should just make this audacious claim: For a typical DD, a set of non or only lightly adjustable set of dampers and a set of (probably, progressively wound) springs with similar rates that just lower the car a wee bit will suffice. There are numerous auto-xers on here who do not have insanely complicated and unique set ups, and in the absence of massive end-user testing and data-logging, their results are as likely to be helpful in making decisions on one's set-up as any.

If that still doesn't satisfy: Advise everyone who can't re-valve their shocks as needed following track and/or dyno data logging to just stick with the best OEM set-up available, or to only modestly adjust from that (e.g., similar advertised spring rates, but sits a bit lower or something), because at least we know that was tested by people with the know-how and the facilities.

A track dedicated car is going to be tuned quite differently than a DD; HOWEVER, a dual purpose DD and moderately successful auto-x car is likely to have settings an enthusiast can use as a starting point.

If you disagree, then I can only assume you are an advocate against "casual enthusiasts" even bothering to modify OEM (suspension) set-ups unless they are experts (we'll leave the magic and mystery of engine tuning, tire selection, brakes, etc etc out of it).

That's certainly defensible.

Perhaps you could post a lengthy thread on what the upper and lower boundaries for settings are, with data, and offer recommendations. Some of us on here endeavor do that -- if imperfectly at times -- and it is always greatly appreciated.

Yes, of course, comparisons between set-ups, and explanations with details. Again, some of us take the time to do that. Maybe you are one of those sorts. It sure seems that way...

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MaysEffect

My original point was never fore or against the idea of the end user having to be experts in order to make changes. Just being properly informed and knowledgeable to limit the chances of disappointments and complaints if things are not as intended. Companies have both ruined and been ruined by vague information the public received and took as face value. That was my initial point. OP asked for almost specific clarification years ago, yet, over this time, we had sponsors and installers making vaguely inaccurate statements on what they should do oppose to what actually makes a difference between one design vs another. Some of the best information came from users that had to do the R&D themselves.

My stated disagreements and disappointments were over the fact some companies and sponsors were being misleading, as if they assumed "you have know idea what to do, so why even bother trying to find out, just buy ____ if you do ____". Ultimately that is what i believe is the problem. The user can not properly find or get the right information if the designer/definer does not publish the right information. This is blind copying, partly on behalf of the designer, and not the fault of the user. We all have the right to follow and copy whatever we choose, but an independent user has no obligation to teach you or define the proper recommendations.

Even in recent car forum history, their are users still jumping through fences dealing with unidentifiable flaws in aftermarket products they buy. I don't believe this is their fault. It is the fault of the seller for not noting all the procedures, changes and recommended steps to make the modification as seamless as possible.

Sometimes the best products can be viewed and warned as horrible simply because the company failed to list basic information on proper use. Where as some cases an average run of the mill product can be reviewed as excellent simply because the instructions, recommended changes and features were clearly noted for the user to use properly. That doesn't make the user an expert, it makes them well informed. You said it perfectly the first time about the biggest obstacle is getting interpret-able data.