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?:driving:,sponsorship, exchange services(prostitution?:wtf2:)).

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.

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? :icon17:

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!!:yum::happydance:

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?
http://www.hyperracing.com/Assets/fi...s/image005.jpg
http://www.hyperracing.com/Assets/fi...s/image006.jpg
https://d1oglr07rm6q0i.cloudfront.ne...358f.large.jpg
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?
http://www.cjponyparts.com/skin/fron...urve-graph.jpg

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?

http://www.mazdamaniac.com/images/misc/rx8club_hp.jpg

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.

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...

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.

Data by sellers are automatically suspect. I refer only to independent tests by knowledgeable end-users, ideally addressing the advice in terms of design and measurable output over a specific brand.

Now, to be fair, that usually ends up with a short list of brands unless you go custom built (which some do or have done for various projects, myself included).

Anyway, all I'm really advocating here is for making decisions based on data over brand name; interpreting whatever data is available is something inherently fallible, even in dealing with assembly line automobiles, but ignoring that data entirely means you have only crossed fingers and dubious testimonials to go on.

I know this post is ancient, but it is one of the most detailed, thoughtfully-written, and informed explanations about dampers that I have ever encountered. From a chassis design engineer, I thank you [Fishey] for your contribution!