9krpmrx8

iTrader: (46)

I need some enlightenment. I haves searched and read and it seems many recommend certain coilovers over others but there is not a lot of technical info or detail on the lower end coilovers versus the more expensive ones. I know these are not in the same price class but I have personally installed a set of Bilstein PSS9's and a set of Tanabe Pro S-0C's and honestly the Tanabe's were much easier to adjust once installed versus the Bilstein's which were kind of tough to turn the adjusters on.

I know when you step up to the big boys you get several options and i know that some brands such at K sport have been shock dynoed and they are crap and are not truly 32 way adjustable. I am also aware that many "JDM" coilovers are made in the same Chinese plants as much cheaper alternatives.

So, what are differences in coilovers typically? Some adjust the spring perch top, some adjust from the bottom, some are 5 way adjustable, some are 32 way adjustable (supposedly). I realize there can be a difference in build quality but honestly IMO, the $700.00 Tanabe's I installed seemed to be of the same quality level of the Bilsteins that cost much more. I realize the Bilsteins have more features obviously but I just wonder if the prices really reflect the quality.

For example, I found a set of coilovers on Ebay that have detailed pictures and appear to be of decent quality and do have a warranty comparable to more expensive coil overs. These are 24 way adjustable (supposedly) and you can actual specify the spring rate you want when ordering.

So what are you really paying for? The quality of the spring? because I have had name brand springs sag. The quality of the dampener? That to me seems to be it but without testing who is to say one is better than the other? The quality of the threaded assembly and adjusters? The bushings used? Some have tops and some use factory parts.

I would like some of you more knowledgeable guys to try and point out what you have seen in your experience. Not what you prefer just because you like a certain brand, so try and be unbiased if you can. If you have any links to any testing please post up some of us who are uneducated in this area can learn a thing or two

paimon.soror

iTrader: (15)

Based on the research I have done on the stance coilovers, there are a couple differences between different sets of C/O's

One is the adjustability of the perches. Some are linked which means that you adjust the height via the spring perch instead of a separate height adjustment perch. I am trying to be bias here but I would advise against these as they are not "true" coilovers. Basically you are sacrificing compression for height, and preloading the spring. By doing this, you actually start killing off the life of the spring, no matter what kind of spring it is. Thats when we start to get into the discussion of spring coefficients and the effect of resonant frequencies that come from certain loads.

Another difference is the external tube as opposed to monotube. This allows you to adjust the damping/compression rates and rebound separate from eachother by adjusting gas pressure. With monotube, you cannot really adjust rebound, but by turning the adjustment line you are changing the damping setting by compressing the air inside of the montotube. Although this adjusts the dampening rate, it also adjusts rebound. 2way allows you to adjust each a bit more freely by having a separate reservoir.

Then comes a three way which is the same as the 2 way, except you now have an extra adjustment for low speed vs high speed compressions.

With non-monotube you are able to adjust the rebound rate far more vastly with each compression setting, and they are an inverse of eachother, which means the less compression, the more rebound. With monotube, you are unable to adjust rebound rates, so whatever setting for rebound you are given with your compression setting is what you are stuck with

Main difference? If you plan on tracking the car a lot of drivers love to have rebound adjustments available to them. This allows them the ability to do corner bumping a lot easier with more traction (aka, hitting the warning strip on the corners, allowing a rebound to get them nice and tight on the turn).

Hope that helps some.

9krpmrx8

iTrader: (46)

^ Great info, that's what we need. We should put up some pictures of the adjustment differences to give a visual.

So like these "cheap" coilovers the ride height on the Stance coilovers is achieved by turning this lower shock mount, right? maybe we should compile a list of the different brands and what features they offer? The Tein basics do not adjust this way correct?

paimon.soror

iTrader: (15)

Right so thats the lower adjustment perch, so that would help you adjust your height. Might be easier to see the application here:



Looking at the assembly on the left, from the bottom, the first collar is your height adjustment collar, so that you would adjust independant from the spring perch to get your height set. The next collar up is the lower spring perch which allows you to adjust the preload on the spring, which on a default application that hasn't been cornerbalanced, should just be making contact with the spring and more more (aka you should be able to wiggle the spring a bit and be able to spin it when the car is lifted up. Next is the spring, which then touches the upper spring collar, nothing to adjust here, but there should be a washer in between. So this particular assembly is a one way monotube. There is no external reservoir so all adjustments are made from the clickers at the top of the shock assembly. This adjust dampening which inversely adjusts the rebound

paimon.soror

iTrader: (15)

here is the mazda speed coilovers. As you can see here, from bottom to top you see only one adjustment collar, which is the spring perch. Theoretically you are at a set height with these "coilovers", but many people will adjust the height by increasing spring preload.

paimon.soror

iTrader: (15)

This here is a 3 way coilover. They call it 3 way because the extra tube is specially designed to have two adjustment *****, one for low speed and one for high speed dampening. You need to use a special tool to be able to release and add gasses to the tube. In this example, you have the same adjustment perch variations as the first image i posted.

This particular type of multi-tube assembly is removable for distribution purposes. Most have the tubes attached directly to the shock housing.

paimon.soror

iTrader: (15)

Here is another variation of a 2way adjustable. As you can see, there is a tube that in this case is actually linked directly to the shock tube. This "2way" allows for separate damping and rebound adjustments.

9krpmrx8

iTrader: (46)

Great thanks, so what does the helper spring do on the type of coilover that are adjustable on the car?

paimon.soror

iTrader: (15)

Also, to set the record straight. A Coilover is simply a shock assembly that comes with the spring. A "Coilover" doesn't necessarily have to have any adjustments. The word was developed to separate the ideas of a shock assembly, a set of springs, and a package with both the springs and the shock (coilover).

Anything that comes with a spring around a shock is a coilover. That's why there 300 dollar coilovers and 3000 dollar coilovers, because you can have a coilover that has 0 adjustments, and a coilover that has 30 adjustments.

paimon.soror

iTrader: (15)

A helper spring is something that was designed for cars that had a large stroke in their coilovers. Basically, people would take the helper spring to "move" the spring closer to the center of their stroke. For example, the higher you go on stance coilovers, you are actually bringing the height adjustment perch lower on the shock assembly, which in turn, causes your spring to sit higher up on the whole assembly. By using a helper spring, you are adding a few inches to the stroke of the spring for a more even distribution across the entire body. This helps to prevent super bouncing on some cars.



Here is a good example. Notice in this application, because the shock body is so long, that it would make the spring sit very high on the assembly. In this picture, helper springs are added to bring the actual spring lower so that it has a more even stroke to compression ratio. If you didn't have this, you would be compressing more than you would be rebounding. This would cause your shock to do far more work than it should.

9krpmrx8

iTrader: (46)

Okay, I thought the helper spring was specific to the types of coilovers that are adjustable on the car.

paimon.soror

iTrader: (15)

They are basically just small springs that add some length to the overall spring height. Not all applications require them depending on the length of the shock. I haven't come across an instance of our cars where someone had to use one.

I think a lot of 240sx drifters liked using shorter springs while adding a helper spring to prevent some spring rattling. By using shorter springs they were able to go nice and stiff without having to worry about their ride height.

BRODA

iTrader: (7)

There is a lot of incorrect information in here. For anyone seeking accurate information on damper design, I would suggest looking elsewhere.

paimon.soror

iTrader: (15)

incorrect information?? care to explain

9krpmrx8

iTrader: (46)

How about you enlighten us? That's the purpose of this thread.

I searched an searched and all I really found is people bashing the cheaper setups just because they were cheaper setups. I only found one shock dyno of K sport coilovers that showed adjusting the dampening made no change on the shock dyno. Kind of the way people bashed the OBX catback and cheap and shitty when in the end it is as good as exhausts costing three times as much. I just want to try and understand all this because I found a lot of conflicting info.

paimon.soror

iTrader: (15)

I am more interested in seeing where my information was flawed. I would be embarrassed to find out that all the stuff that I have researched over time has actually either A. become incorrect, or B. design has changed over the past few years.

BRODA

iTrader: (7)

I think you are confusing the fundamental differences of mono-tube vs. twin-tube as well as the reasons for and benefits of external reservoirs.

I am not a suspension engineer, but there are many great acticles written by engineers published on the web. I would start by reading some of those. If this forum does not have the information you are looking for, try searching other forums. There is a great thread on the corner carvers forum with tons of good information, including links to other very informative resources.

Hope that helps.

paimon.soror

iTrader: (15)

Yea, i mean there is a whole theory between pros and cons of mono/twin tube but I really didn't want to get into that. I basically generalized that aspect of it since the guys that would best comment on that are the ones who are actually using them for race applications unlike myself. I assume what you are talking about is the whole idea between having the piston of the shock external to the primary tube, allowing stable compression while mono allows better heat transfer and all that jazz? In essence you can generalize that by having a twin tube setup you get the added benefits of having more control over rebound and compression.

http://www.ek9.org/forum/suspension/...info-tein.html

Here is a pretty good example of the differences, in this example they compare models that do not have the external res.

9krpmrx8

iTrader: (46)

Thanks guys, I am learning (I think )

BRODA

iTrader: (7)

I'm not sure where you are getting this (mis)information from that article.

9krpmrx8

iTrader: (46)

Hmmm, sounds like monotube is the way to go for me since the roads around here are pretty smooth. Sounds like the best best or smooth street/occasional track use.

hoss -05

iTrader: (4)

Dave Coleman wrote a Great article on this subject for USCC but I cant seem to find it... If I was home I would scan it in for all. Its a great read that lays the info out so its very easy to understand.

Dampeners are so different from company to company. What can seem like the same "shock" specs from two different manufactures can turn out to be very different from the internal shock valving, spring tolerances and any number of other manufacturing variations. I generally don't think one should get hung up on Mono tube, twin tube or otherwise and should go for a spring and dampener set that fits there needs will be serviceable in the future.

I like the ability to be able to adjust my rebound and compression settings independently and externally. It takes me a very long time to figure out the settings I like best and I really don't want it to be a hassle to make adjustments. In my case that feature far outweighs the great debate between mono twin or any other kind of tube arrangement. All the different kinds of coil overs have there pros and cons and I believe the end user needs to go with what is the best fit for there needs and not settle on sub standard untrusted parts.

9krpmrx8

iTrader: (46)

My main concern is once you compare features, then what sets aside the good from the bad? I guess brand reputation goes a long way at determining which to buy if there are no negative reviews of the alternatives.

Check out these Greddy's and the way they adjust in the rear.

BRODA

iTrader: (7)

The most important “features” you really need to compare are the dyno plots, not the number of ***** they have or how many "click" sounds those ***** make (i.e. "32-way adjustable"). Some good shocks don't click at all... are they infinity-way adjustable?

The problem is that shock dyno results are not readily available for most coilovers until you get into the really high-end and/or custom-valved stuff. And even if you got your hands on a shock dyno graph, most people wouldn't know what to do with that information (including myself).

This makes it very difficult to be an informed consumer.

In most cases, that leaves you to buy based on reputation or reviews on the internet. If you are racing, and you don’t have the money to test and re-test different products (whether shocks or tires or spring rates), just run what the fast guys are running. That should get you in the ball-park. For the street, that does not really apply, so it’s even harder to make an informed decision.

I will refrain from giving specific product advice, as I don’t have much first-hand experience, but hopefully the above information is at least marginally helpful.

9krpmrx8

iTrader: (46)

BRODA, thanks for the input, you have some great points. There are so many factors and honestly the best parts don't necessarily make you the fastest anyway. I have followed some guys with far better tires, suspensions, etc. and I have yet to be left in the dust by another RX-8. But mainly I just do canyon runs and I am going to do some sessions at our local road course. I just want my monies worth.