Welcome to the North American Subaru Impreza Owners Club Sunday November 23, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Click here to visit TireRack
Brakes & Suspension Forum sponsored by The Tire Rack

Losing traction? Need new tires?
Click here to visit the NASIOC Upgrade Garage...
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Brakes, Steering & Suspension

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 12-16-2007, 04:26 PM   #1
Butt Dyno
Street's closed, pizza boy
 
Member#: 17301
Join Date: Apr 2002
Chapter/Region: MAIC
Location: Why do they always say the Evo
Vehicle:
is the "dark side"
06 Evo #7 STU, 03 IS300

Default The long awaited Coilover FAQ!

Well, this is about a trillion years late, but people keep buying Subarus, so it's still worth doing.

Suspension upgrades are quite popular. This FAQ is meant to cover one of those upgrades - coilover kits. As with all aftermarket parts, they may or may not make sense for your particular application. This guide should help you determine the answer to that question.

Please, please, please: first read the Lowering Spring FAQ as it covers a lot of important suspension related issues.

THEN please read Turn in Concept's "Regarding Coilovers" post:
http://forums.nasioc.com/forums/show....php?t=1701132

That should summarize how most of the regulars in here feel about coilovers

But naturally I highly recommend you read on...

What is a coilover?

There are two answers - the correct one and the "common usage" one.

The correct one:
http://www.norcalcrx.org/tyson/coilover.html
Quote:
What does coilover mean?
The term coilover describes a suspension design where a coil spring is placed around the shock absorber. In fact, your Honda probably already has coilovers as stock! Coilover design is used as opposed to leaf springs on trucks, torsion bars (like 1st gen CRX and Integra), and torsion beams (like VW rear axles where the coil spring is placed separately from the shock to allow more interior space). Kits from Ground Control and Skunk2 are often loosely called "coilovers" and is wrong. They are more appropriately called "adjustable spring" kits, and can be used to convert originally non-coilover suspension to coilover suspension (trucks do this all the time). These kits are mainly for those who wish to customize their suspension because of the adjustability that these kits offer.
But in common usage, "coilovers" "full coilovers" or "coilover kit" usually means a threaded spring perch with height adjustability, usually as part of a package that includes a full strut, and often includes top mounts (which may be adjustable camber plates).

[insert pic]

For the purposes of this document, it's the common usage

Why would I want coilovers?

Borrowing from the Lowering Spring FAQ:

Quote:
Why would I ever want to swap out my factory springs in the first place?

There are many reasons.

1. Aesthetics. Most cars look better with less wheel gap.
2. Handling. Lower/stiffer springs can reduce body roll and change the car's handling balance.
3. Ground clearance. Taller springs (say if you have a WRX and you go off road a LOT) can help on rough terrain.
4. Ride quality. In some cars, aftermarket springs may actually ride better than the factory springs.
You can accomplish these goals with coilovers as well.

The main benefit that a full coilover kit offers is adjustibility. What does that mean? First let's get one bit of terminology out of the way:

I see coilovers that say they're one/two/three way adjustable, but these Megan Racing coilovers are 32 way adjustable! That means they are 32 times better, right?

Not exactly. "adjustable" means a lot of things. When it's a really small number, it's usually on this scale:
Non-adjustable: height adjustment only (Tein Basic, KW V1. Sometimes referred to as one way adjustable)
1 way: height adjustment and one of the following: rebound adjustment, compression adjustment, OR a single knob that changes both compression and rebound (Tein Flex, JIC FLTA2, KW V2)
2 way: height adjustment and separate rebound and compression adjustments (RCE T2, KW V3)
3 way: height adjustment, rebound adjustment, and separate low speed and high speed compression adjustment (AST Raceline)
4 way: height adjustment, low speed and high speed rebound, low speed and high speed compression adjustment. (Motons)

When you see "32 way adjustable" it means that you can adjust the shock to 32 different positions, usually via "clicks" in an adjuster knob. This is either rebound, compression, or some combination of both. Most coilovers meeting that description are two-way adjustable, NOT 32-way adjustable.

Why would I want adjustable shocks?

The main benefit of an adjustable shock is the ability to change your shocks for different setups. You may buy a set of Konis, run them with stock springs for a while, and then swap out the stock springs for 400 lb/in springs later and need to run the shocks stiffer to effectively manage the stiffer spring. Or run softer for daily use. Or run softer for inclement weather. Or run harder for track use. etc etc.

It's important to note though, that you do not NEED an adjustable shock to have a good handling car. If you have good shocks already or if you upgrade to good non-adjustable shocks you may find it less necessary to "upgrade". But since there are very few strut options for our cars that aren't adjustable, you'll likely end up with adjustability even if you're not explicitly seeking it.

Also - you may find after having adjustable shocks that you aren't adjusting them that much. For me, my "street" setting and my "race" setting are the same - just happened to work out that way.

Why do I need height adjustment? I just want my car to be slammed.

The main benefit to having height adjustment is the ability to corner-balance the car. For more information about corner balancing, visit here:
http://www.nsxprime.com/FAQ/Performa...nerbalance.htm

Even if you don't get your car corner balanced, having a height adjustable suspension will still allow you to change the car's rake (the front being higher than the rear, or vice versa). Like alignment or swaybar sizing, rake is one tool you have at your disposal to change your car's balance.

But if you just want your car to be slammed, you can do that too. Just understand that most folks around here are "function over form" and will discourage you from doing this.

Other benefits to height adjustment:
* You can change the car's rake forward or back. This is one tool you can use to adjust the car's balance, or get downforce, or whatever.
* You can lower the car's center of gravity. This is, as a general rule, a good thing, but with a MacPherson strut car like the Impreza, there is a point where you can lower the car too far. Unfortunately, that point is where far, far too many people lower their cars to

Why do you keep trying to discourage me from slamming my car? I just want it to look good!

Please, don't slam your Subaru. It's not meant to be slammed. The automotive gods have cursed us with a MacPherson strut suspension with a very unfortunate camber curve. For more details on why slamming your Impreza is bad, check out the Tein S-tech FAQ. It discusses the S-techs, but also discusses why lowering too much is bad:
http://forums.nasioc.com/forums/show....php?t=1267918

So, in other words, my car is going to suck unless I have coilovers? This guy from SCIC said "go coilover or go home"!

No! There is nothing magical about coilovers. They are comprised of components that you can buy separately. A good strut/spring combination can be just as fast.
http://forums.nasioc.com/forums/show....php?t=1378003

And remember, each method of adjustibility you have is another way you can screw up your suspension. You can set the shocks wrong, you can set the height wrong, you can set the alignment wrong... A good strut/spring combination is a lot more likely to be easy to work with out of the box.

And I don't know why everyone in Southern California thinks you need coilovers. Maybe it's something in the water. Maybe it's a plot to stick it to the rest of the country because they are jealous of our 93 octane and the fact that we don't have the CARB. Who knows. Just ignore it when it happens.

I see these $150 coilovers on eBay all the time. Why would I pay $3000 for coilovers??

$150 will get you a no-name spring, typically of unknown spring rate, and a no-name adjustable spring perch. These may or may not match the valving of your shocks, may or may not sag, etc etc. You usually have no idea what you're getting. These kits are not "full coilover kits" as they only contain the spring/perch and not the strut body, shock absorber, camber plates, etc etc.

What is a Ground Control coilover setup?

A Ground Control setup (for instance, this one) typically contains the threaded spring perch and a 2.5" inner diameter coilover spring, but does not come with shocks/struts. You use these in combination with your factory struts and tophats. You adjust the ride height by moving the spring perch up and down.

The Ground Control kits generally come with Eibach ERS race springs. The tradeoff with these kits is that you cannot adjust preload independent of ride height.

This is what the eBay kits usually try to knock off.

What are the best coilovers? Something JDM, right? Or maybe some 7-way adjustable Penskes?

The suspension rules sticky covers this, but just for emphasis:
There is no best ANYTHING. There is only best for your application. And there may not even be a "best" - there may be several good options. Do not ask what the best is. This will get you nowhere. Repeat after me, there is no best coilover. There is no best coilover. Write it on the chalkboard 100 times, like Bart Simpson.

In the "early" days (circa 2001-2003) the JDM brands (Tein, JIC, HKS, Cusco, etc) were heavily worshipped. This is less true today as more and better options have hit the market.

I'm trying to decide between Brand X and Brand Y. Which one should I pick?

These posts do drive me a little nuts

1. Search.
2. If you're going to rule out 90% of the market you should have a reason. Please explain why you are focusing on these two.
3. Read the suspension rules sticky and tell us your goals.

I just installed my coilovers and they're really bouncy.

1) Contact the manufacturer to tell them the problems you're having.
2) Try adjusting the stuff you have.
a. Tire pressures. In some cases, going higher may help as it eliminates some of the bounce from the tires.
b. If you have adjustable shocks, try making them harder, AND try making them softer. Full soft might be nauseating (hit a bump and keep bouncing). Full hard might be just too damned stiff (headaches, sore kidneys, etc). Find something in between.
c. Preload. Some manufacturers have recommendations for how snug the spring should be.
d. Ride height. If you are too low you are going to be much more likely to be riding your bumpstops - bad for handling and for ride quality.
3) You can try going with softer springs. Please note that on a lot of the cheaper coilover setups this won't do a damn thing as all the harshness is in the shock.
4) If all else fails, buy something else. No one should put up with a suspension they don't like.

I bought coilovers, but I want to change out my springs. What are my options?

Since most coilovers use a 2.5" inner diameter coilover spring it's pretty easy to interchange them.

Coilovers known not to use 2.5" springs:
-DMS
-KW V3: 60mm (adapter available for 2.5")
-RaceComp Engineering Tarmac2: 60mm (adapter available for 2.5")
-Turn In Concepts AST Coilovers: 60mm
-Cusco Zero2R: 73mm (Swift sells 70mm springs)
-Bilstein / H&R: See kfoote's note in post 26
-Tein MonoFlex: 70mm (wrx wagone, PM)

(If anyone knows of a coilover setup that does not use 2.5" ID, let me know so I can add it.)

Probably the three most well known brands of 2.5" springs (that aren't included in an off the shelf "full coilover" kit):
-Eibach ERS
-Swift
-Hyperco

Eibach and Swift both post the spring specifications on their website. Hyperco just introduced a new line of springs ("OBD") and as of November they said they intended to publish the specifications for those springs as well.

Why would I change to different springs on my coilovers?

1. Ride quality. Shocks are typically valved to work with springs in a certain range, and going towards the softer edge of that range may help (or may not help at all, as described above).

2. Suspension tuning. You may take tire temperatures and realize that you need less body roll, and might decide to make your springs stiffer instead of going with bigger swaybars. You might decide you want a stiffer spring in the rear / softer spring in the front to make the car more biased to oversteer. Etc, etc.

3. Suspension travel / coil bind. It's possible that your springs are stacking up before the shock has run out of travel. Stretch has a great thread about it here:
http://www.iwsti.com/forums/suspensi...revisited.html
Your solution may be to run a longer spring, or to switch brands to something that has more travel before bind.

4. If you have a setup where the springs are rubbing on the adjustable spring perches, you can find a "barrel spring" (Eibach makes some I believe) that will be wider in the middle so that it does not contact the perches. These springs are not available in many spring rates, including most of the higher ones.

I snugged up my springs, but now my car rides like a monster truck. What gives?

If you are running a Ground Control or similar setup, you don't have the ability to adjust ride height and preload independently. In other words, the only mechanism you have for changing ride height is the spring perch. Base your ride height on what the car is when it's settled - NOT what is happening when the car is in the air. The spring does not need to be fully snugged at full droop, as long as the end result works out okay. Trying to snug the springs at full droop may give you monster-truck ride height.

My springs *aren't* snug at full droop and I want to make sure they're snug all the time. What can I do, other than monster trucking?

Buy helper springs (so that the helper will stay constantly snug). Or learn to deal with it

What's a helper spring? What's a tender spring? They're the same thing, right?

They're not the same thing.

A helper spring is typically something like 2-3" tall, and contributes no meaningful spring rate. At normal ride height, the spring should be fully compressed. A tender spring is typically about the same height, but it does have a meaningful spring rate. This can make suspension tuning quite tricky.

For a full explanation including pictures:
http://e30m3performance.com/tech_art...ings/index.htm
* Registered users of the site do not see these ads.

Last edited by Butt Dyno; 02-17-2009 at 07:49 PM.
Butt Dyno is offline   Reply With Quote
Old 12-16-2007, 04:27 PM   #2
Butt Dyno
Street's closed, pizza boy
 
Member#: 17301
Join Date: Apr 2002
Chapter/Region: MAIC
Location: Why do they always say the Evo
Vehicle:
is the "dark side"
06 Evo #7 STU, 03 IS300

Default

"OK, quit dancing around my question. I have money burning a hole in my pocket and I really want to buy coilovers because that's what it seems like everyone has and I want my car to handle really well!"

Zero - remember the rules above. Know what you need them for. Don't listen to anyone. When in doubt, search.

First - if you have to ask, you probably don't need coilovers. This is the Rule of Biggly (tm).

Second - you need to figure out whether you need and want coilovers. They are not always "maintainance free". Some will require intermittent rebuilds, especially if you are driving them on crappy roads. Certain coilovers are marketed as being more daily driving friendly. You may end up pissing off your significant other if the ride is too harsh. You might look silly if your car is bouncing down the highway. Etc etc.

Third - You need to figure out your budget. There are plenty of options in every price range. Remember too that dropping $3K on a set of coilovers can't save you if you don't know how to drive. Spending money on seat time (autox, track etc) is ALWAYS the best bang for buck on how to make the car faster. Would you rather be the guy in the cheap car driving fast or the guy in the fancy car who doesn't have a clue how to use what they have?

Fourth - you need to figure out how much adjustability you need. If you just want "better handling" with nothing specific in mind, you might not need 16-way adjustable dampers. There are plenty of good strut/spring combinations out there, like

-STi takeoffs (type RA, spec C, whatever)
-Konis + Prodrive springs
-Konis + Ground Control
-KYB AGX + whatever springs, etc etc.
A lot of the popular strut/shock replacements offer adjustable damping as well.

You should seriously consider these. Don't jump on the coilover bandwagon just to say you have coilovers. You can have a car with excellent handling without coilovers - camber plates, a good spring/strut combo, a good alignment and some swaybars is a good way to do this.

Fifth - if you just want the car lowered so you have less wheel gap, you can get by with just "lowering springs". If this is your only goal, well, this and "aggressive street driving" (), you can save the money you were going to spend on coilovers and put it into your car insurance.

I have searched once or twice. I know about the dangers of putting slam-tastic springs on the stock struts. It sounds like if I want to have my car really, really slammed, without compromising handling or ride quality, I need to buy coilovers, right?

Buying coilovers does not change the rules completely. You still can't completely slam your car to the ground, even with coilovers.

As Jon Bogert points out:
Quote:
Originally Posted by Jon Bogert
...even though coilovers may have several inches of thread on the strut body, there is only one correct ride height given the position of the piston in the damper. Coilovers are all designed for a specific ride height, and will not function optimally if adjusted far outside of that height (just like lowering springs on struts). So the typical noob thought process, "I'll get coilovers so I can slam it on Tuesday and jack it up for winter" is completely wrong.

The exception to the above is the very few and very expensive high-end coilovers that allow height adjustment at the spindle end. But since that's about 1% of what's sold, it's a small exception.
I have my ride height set to 12.75" in front. My axles are rubbing in places where axles shouldn't rub. What should I do?

Short version: you should absolutely not be that low.
http://forums.nasioc.com/forums/show....php?t=1377606


All feedback appreciated. This is just the first pass. If I kept trying to make it perfect it would never get done.

john

Last edited by Butt Dyno; 12-16-2007 at 04:46 PM.
Butt Dyno is offline   Reply With Quote
Old 12-16-2007, 04:27 PM   #3
Butt Dyno
Street's closed, pizza boy
 
Member#: 17301
Join Date: Apr 2002
Chapter/Region: MAIC
Location: Why do they always say the Evo
Vehicle:
is the "dark side"
06 Evo #7 STU, 03 IS300

Default

Knee-jerk "buy coilovers y0" thread hall of shame:

http://forums.nasioc.com/forums/show...highlight=scic
Quote:
Originally Posted by turb04
Niether. GO COILOVERS!!! u'll want them in the end..

Testimonial of people who have bought coilovers and regretted it

went coilovers, feels like being beat up in car.
http://forums.nasioc.com/forums/show....php?t=1691373

Last edited by Butt Dyno; 02-03-2009 at 09:02 PM.
Butt Dyno is offline   Reply With Quote
Old 12-16-2007, 06:50 PM   #4
Daishi00
Scooby Guru
 
Member#: 78952
Join Date: Jan 2005
Chapter/Region: MAIC
Location: BSG junkie
Vehicle:
2005 WRX
CGM

Default

I thought "xx-way" was simply in relation to compression/rebound in terms of high speed or low speed?

That would explain why Moton's and whatnot are 4-way adjustable as they do rebound/compression for both fast and slow speeds...

Or is this something that varies by manufacturer as to what "adjustment" is what?
Daishi00 is offline   Reply With Quote
Old 12-16-2007, 06:56 PM   #5
Daishi00
Scooby Guru
 
Member#: 78952
Join Date: Jan 2005
Chapter/Region: MAIC
Location: BSG junkie
Vehicle:
2005 WRX
CGM

Default

And possibly the difference between linear and progressive springs. Maybe you already have that in the Spring FAQ???
Daishi00 is offline   Reply With Quote
Old 12-16-2007, 07:07 PM   #6
boost junkie
Top Scoob 009
 
Member#: 68273
Join Date: Aug 2004
Chapter/Region: MAIC
Location: Silver Spring, MD
Vehicle:
2012 WRX
GD Race Car in progress

Default

As Alex was saying, I think that for our purposes it's easier to refer to the level of adjustability in this way:

Non-adjustable-height adjustment only
1 way-height and rebound or damping adjustment
2 way-height, rebound, and damping adjustment
3 way-height, rebound, low speed and high speed damping adjustment
4 way-height, low speed and high speed rebound, low speed and high speed damping adjustment.

It just keeps everything consistent, and when talking about coilovers it's assumed that they are all height adjustable. Other than that, this is a great writeup
boost junkie is offline   Reply With Quote
Old 12-16-2007, 07:43 PM   #7
Butt Dyno
Street's closed, pizza boy
 
Member#: 17301
Join Date: Apr 2002
Chapter/Region: MAIC
Location: Why do they always say the Evo
Vehicle:
is the "dark side"
06 Evo #7 STU, 03 IS300

Default

Quote:
Originally Posted by boost junkie View Post
As Alex was saying, I think that for our purposes it's easier to refer to the level of adjustability in this way:

Non-adjustable-height adjustment only
1 way-height and rebound or damping adjustment
2 way-height, rebound, and damping adjustment
3 way-height, rebound, low speed and high speed damping adjustment
4 way-height, low speed and high speed rebound, low speed and high speed damping adjustment.

It just keeps everything consistent, and when talking about coilovers it's assumed that they are all height adjustable. Other than that, this is a great writeup
Gotcha. Yours makes a lot more sense. I think part of my confusion is KW's labelling (i.e. the V1 is non-adjustable) and just in general I have heard the non-anything-but-height adjustable coilovers referred to as one way adjustable.

Would you mind if I switched "damping" to "compression" and used it?

john
Butt Dyno is offline   Reply With Quote
Old 12-16-2007, 09:25 PM   #8
paranoidWRX
Scooby Newbie
 
Member#: 156932
Join Date: Aug 2007
Chapter/Region: MAIC
Location: Fairfax, VA
Vehicle:
2006 WRX
Black Pearl

Default

Great job John!
paranoidWRX is offline   Reply With Quote
Old 12-16-2007, 10:24 PM   #9
Daishi00
Scooby Guru
 
Member#: 78952
Join Date: Jan 2005
Chapter/Region: MAIC
Location: BSG junkie
Vehicle:
2005 WRX
CGM

Default

Oh, sorry didn't say good job earlier I give you guys that right these FAQs big props as it takes a ton of time and energy.

Thanks for putting that into better terms Dan. I agree that it'll help keep confusion down especially when we have to talk about 32 way adjustable coilovers from BC (that's sarcasm if somebody doesn't understand right away).
Daishi00 is offline   Reply With Quote
Old 12-16-2007, 10:39 PM   #10
RaceComp Engineering
NASIOC Vendor
 
Member#: 54202
Join Date: Feb 2004
Chapter/Region: MAIC
Location: Elkridge, Maryland
Vehicle:
ASK ABOUT NEW RCE
SWAY BARS FOR STI

Default

Good job john!

Quote:
Originally Posted by ButtDyno View Post
Since most coilovers use a 2.5" inner diameter coilover spring it's pretty easy to interchange them. (If anyone knows of a coilover setup that does not use 2.5" ID, let me know so I can add it.)
KW's (and RCE Tarmac II's) use 60mm ID springs. They have an adapter available if you want to use 2.5'' ID.

I think TiC's new coilovers use 60mm springs too.

Those are the only ones I know of....I think just about everything else is 2.5'' ID.


- Andrew
RaceComp Engineering is offline   Reply With Quote
Old 12-16-2007, 11:19 PM   #11
boost junkie
Top Scoob 009
 
Member#: 68273
Join Date: Aug 2004
Chapter/Region: MAIC
Location: Silver Spring, MD
Vehicle:
2012 WRX
GD Race Car in progress

Default

Quote:
Originally Posted by ButtDyno View Post
Gotcha. Yours makes a lot more sense. I think part of my confusion is KW's labelling (i.e. the V1 is non-adjustable) and just in general I have heard the non-anything-but-height adjustable coilovers referred to as one way adjustable.

Would you mind if I switched "damping" to "compression" and used it?

john
Yeah man, go for it. KW's labelling is a little confusing in that regard...
boost junkie is offline   Reply With Quote
Old 12-17-2007, 01:00 AM   #12
BillJC
Scooby Specialist
 
Member#: 31002
Join Date: Dec 2002
Location: Sonoma, CA
Vehicle:
2002 WRX
Blue

Default

Quote:
Originally Posted by RaceComp Engineering View Post
Good job john!



KW's (and RCE Tarmac II's) use 60mm ID springs. They have an adapter available if you want to use 2.5'' ID.

I think TiC's new coilovers use 60mm springs too.

Those are the only ones I know of....I think just about everything else is 2.5'' ID.


- Andrew
Don't forget DMS uses larger springs as well. Even though a 2.5" ID will fit if you change the spring perch.

Bill
BillJC is offline   Reply With Quote
Old 12-17-2007, 10:10 AM   #13
Turn in Concepts
NASIOC Vendor
 
Member#: 93646
Join Date: Aug 2005
Chapter/Region: MWSOC
Vehicle:
Many Track Records
Let us help you go fast!

Default

Quote:
Originally Posted by RaceComp Engineering View Post
Good job john!



KW's (and RCE Tarmac II's) use 60mm ID springs. They have an adapter available if you want to use 2.5'' ID.

I think TiC's new coilovers use 60mm springs too.

Those are the only ones I know of....I think just about everything else is 2.5'' ID.


- Andrew
That is correct - we use 60mm springs on our setup.
Turn in Concepts is offline   Reply With Quote
Old 12-17-2007, 01:45 PM   #14
STI4ME
Scooby Specialist
 
Member#: 6034
Join Date: Apr 2001
Chapter/Region: BAIC
Location: Fresno, CA
Vehicle:
2002 WRX
It's Soo-BAH-roo

Default

The front springs for the Cusco Zero2R (GDA application) are 73mm ID. With a little machining on the bottom spring perch, a slightly more common 70mm ID spring can be used. Swift makes 70mm springs.
STI4ME is offline   Reply With Quote
Old 12-17-2007, 09:53 PM   #15
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
QuickSilver Metallic

Default

Replace the word "shocks" with "dampers" or "struts" everywhere. We don't have shocks.

Other than that, looks good.
Patrick Olsen is offline   Reply With Quote
Old 12-18-2007, 05:47 PM   #16
Butt Dyno
Street's closed, pizza boy
 
Member#: 17301
Join Date: Apr 2002
Chapter/Region: MAIC
Location: Why do they always say the Evo
Vehicle:
is the "dark side"
06 Evo #7 STU, 03 IS300

Default

Quote:
Originally Posted by Patrick Olsen View Post
Replace the word "shocks" with "dampers" or "struts" everywhere. We don't have shocks.
Well, I always thought "shock" was short for "shock absorber" and that struts contained shock absorbers, no? When you change a rebound setting, you're not adjusting the strut (unless you're changing the ride height or something), you're adjusting the shock absorber.

http://en.wikipedia.org/wiki/MacPherson_strut

That's how I interpret it at least. I'm certainly open to changing it but I thought it made sense the way it was used.



john
Butt Dyno is offline   Reply With Quote
Old 12-18-2007, 06:03 PM   #17
Butt Dyno
Street's closed, pizza boy
 
Member#: 17301
Join Date: Apr 2002
Chapter/Region: MAIC
Location: Why do they always say the Evo
Vehicle:
is the "dark side"
06 Evo #7 STU, 03 IS300

Default

Updated the 1-way, 0-way etc part after feedback
Added list of non-2.5" coilovers
Added a note about barrel springs
Added something to post #2 (feel free to submit candidates )
Butt Dyno is offline   Reply With Quote
Old 12-19-2007, 04:15 AM   #18
Patrick Olsen
NASIOC Supporter
 
Member#: 120
Join Date: Jul 1999
Chapter/Region: AKIC
Location: Where the Navy sends me...
Vehicle:
1997 Legacy 2.5GT
QuickSilver Metallic

Default

Quote:
Originally Posted by ButtDyno View Post
Well, I always thought "shock" was short for "shock absorber" and that struts contained shock absorbers, no? When you change a rebound setting, you're not adjusting the strut (unless you're changing the ride height or something), you're adjusting the shock absorber.

http://en.wikipedia.org/wiki/MacPherson_strut

That's how I interpret it at least. I'm certainly open to changing it but I thought it made sense the way it was used.
Struts carry the load of the car, shock absorbers do nothing but act as dampers. We have struts. When I adjust the damping, I'm adjusing the damping of my Koni struts.

But then again, Wikipedia is always right, so...
Patrick Olsen is offline   Reply With Quote
Old 12-19-2007, 08:04 AM   #19
Daishi00
Scooby Guru
 
Member#: 78952
Join Date: Jan 2005
Chapter/Region: MAIC
Location: BSG junkie
Vehicle:
2005 WRX
CGM

Default

When I think shocks I think the tubes that sit next to the springs on off road trucks personally (Hey, Xtreme 4x4 was actually good for something ).
Daishi00 is offline   Reply With Quote
Old 12-19-2007, 06:32 PM   #20
niksuspect
Scooby Newbie
 
Member#: 144707
Join Date: Mar 2007
Location: Eureka, CA
Vehicle:
1995 Legacy L
green

Default

so I am curious...if I want my car to be higher off the ground instead of lower....am i going to have to get much more expensive coilovers?
niksuspect is offline   Reply With Quote
Old 12-19-2007, 07:20 PM   #21
zzyzx
Scooby Specialist
 
Member#: 815
Join Date: Jan 2000
Location: Florida
Vehicle:
2013 Boss 302 White
2000 2.5 RS Coupe Silver

Default

Quote:
Originally Posted by Patrick Olsen View Post
Struts carry the load of the car, shock absorbers do nothing but act as dampers. We have struts. When I adjust the damping, I'm adjusing the damping of my Koni struts.

But then again, Wikipedia is always right, so...
I think some more clarification is in order here.

First off, a KONI shock/damper insert is not a strut. Is is, however a damper that was designed for a strut application. The primary design difference is that it can take side loads, whereas a non-strut damper cannot. The most visible difference is the diameter of the shock shaft, which is about 22mm in a KONI insert and similar is most other non-inverted dampers for strut applications.

A strut is the structure that bolts to the upright/hub, and contains a damper. In most cases that damper is a "wet" setup where the internals of the damper are not self contained in another structure, but in the case of the KONI "insert" the opposite is true. It's self-contained.

The combination of the KONI insert and the surrounding strut housing is often simply referred to as a "strut", which is fine, because functionally it is. the point here is that a KONI insert itself, is not a strut. It needs the surrounding application-specific strut housing to make it functional.

Last edited by zzyzx; 12-19-2007 at 07:37 PM.
zzyzx is offline   Reply With Quote
Old 12-19-2007, 07:32 PM   #22
zzyzx
Scooby Specialist
 
Member#: 815
Join Date: Jan 2000
Location: Florida
Vehicle:
2013 Boss 302 White
2000 2.5 RS Coupe Silver

Default

Quote:
Not exactly. "adjustable" means a lot of things. When it's a really small number, it's usually on this scale:
Non-adjustable: height adjustment only (Tein Basic, KW V1. Sometimes referred to as one way adjustable)
1 way: height adjustment and one of the following: rebound adjustment, compression adjustment, OR a single knob that changes both compression and rebound (Tein Flex, JIC FLTA2, KW V2)
2 way: height adjustment and separate rebound and compression adjustments (RCE T2, KW V3)
3 way: height adjustment, rebound adjustment, and separate low speed and high speed compression adjustment (AST Raceline)
4 way: height adjustment, low speed and high speed rebound, low speed and high speed compression adjustment. (Motons)

When you see "32 way adjustable" it means that you can adjust the shock to 32 different positions, usually via "clicks" in an adjuster knob. This is either rebound, compression, or some combination of both. Most coilovers meeting that description are two-way adjustable, NOT 32-way adjustable.
I would not agree with this characterization of the situation.

It seems the issue revolves around considering the damper and strut as a single entity. I think this is an incorrect approach.

Damper:

Single adjustable: Rebound or compression or both adjust together and are not independent. In the case of KONI, a single adjustable damper adjusts rebound. Some adjust both in some predefined ratio.

Double adjustable: Rebound and compression can both be adjusted independently of one another. Some shock designs have some "crosstalk", so that adjustment is not truly independent.

Triple adjustable: Rebound and compression can both be adjusted independently, and either rebound OR compression is separated into independent "low" and 'high" speed adjustments. It's invariably bump that has high and low speed adjustments on a triple adjustable damper. What velocity constitutes high and low speed is manufacturer dependent.

4-way adjustable: Rebound and compression can both be adjusted independently, and rebound AND compression are separated into independent "low" and 'high" speed adjustments.

A lot of low-buck Asian coilovers refer to their adjustments as "32-way". This refers to the number of detents on their (invariably needle valve) adjusters and almost all of these are single adjustable dampers.

Strut:

There are two possible adjustments for a strut:

The lower spring perch. This is what the spring seats into. Often referred to as "spring preload". Some would call this "single or 1-way height adjustment".

The lower flange. This is the application specific component that bolts to the upright/hub on the suspension of your car. Some would call this "2-way height adjustment".

Last edited by zzyzx; 12-19-2007 at 07:42 PM.
zzyzx is offline   Reply With Quote
Old 12-20-2007, 12:30 AM   #23
arfrce
Scooby Newbie
 
Member#: 126130
Join Date: Sep 2006
Chapter/Region: South East
Location: North Western Arkansas
Vehicle:
06 Subaru STi
WRB

Default

I thought it was a good write up. SO you used shock. Everyone knows what you mean. If they are so nit picky to call you out on that. I hope they never take the time to research and the time to write up a DIY thread or anything for that matter. I would think you guys would say thank you. I learned something that will help me out when I decide to change my suspension.
This is directed at the nit pickers. No one else.
Keep up the good work. Thanks Jeff
arfrce is offline   Reply With Quote
Old 01-03-2008, 07:11 PM   #24
grippgoat
Scooby Specialist
 
Member#: 62182
Join Date: May 2004
Chapter/Region: NWIC
Location: Kirkland, WA
Vehicle:
2005 STI
White

Default

Tein Flex uses 70mm ID springs.

Also, longer springs will not eliminate spring slack in droop. It'll just make you move the lower spring perch down.

-Mike
grippgoat is offline   Reply With Quote
Old 01-17-2008, 09:17 PM   #25
mxpop
Scooby Specialist
 
Member#: 103776
Join Date: Dec 2005
Chapter/Region: SCIC
Location: BFE
Vehicle:
2006 STI
silver

Default

Quote:
Originally Posted by ButtDyno View Post
Why do I need height adjustment? I just want my car to be slammed.

The main benefit to having height adjustment is the ability to corner-balance the car. For more information about corner balancing, visit here:
http://www.nsxprime.com/FAQ/Performa...nerbalance.htm
OK, you guys are definitely thinkers so I hope to get a definitive answer to a burning question that has even the smartest guys perplexed. I have heard good and sound logic for all answers but none that thouroughly disproves the other. Even the link above has contradictory information and I couldnt find much better info here or with Google.

Q: To adjust your corner balance %, is it better to adjust the pre-load on the spring (adjusting the perch) or by changing the overall length of the coilover (adjusting the ride height)? This assumes that relocating weight is not an option.

SPRING: Some CO's only have spring adjustment so you have to do it with spring adjustment on these. But, what happens if you run out of adjustment or if you end up with drasticaly different settings?

RIDE HT: This tends to have more influence on cross percentages (turn for turn) than adjusting the springs. Unfortunately, this can upset the loading of the chassis and can effect the geometry.

PROBLEM: What happens if 2 diagonal springs need 4 turns of preload while the other 2 need zero turns of preload to get an ideal 50% cross? Should you adjust the CO lengths to get the springs back to equal preload all around or do you run with the springs that far off from one-another? Or, do you split the difference like 1 turn on one set of diag springs and 3 turns on the other and THEN adjust the CO's to get your desired cross%.

Bottom line: do you ajdust just the spring preload, CO length, or both. For bonus points, explain why....


mxpop is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
The long awaited pics of the new AMS facility! AMS Member's Car Gallery 54 10-04-2007 10:09 PM
El Camino Productions now presents the long awaited sequel... El Camino Off-Topic 81 07-03-2006 04:02 PM
The long awaited selling RS thread... Fido Tri-State Area Forum 1 10-23-2002 06:15 PM
the long awaited pics.... Bill.B South West Impreza Club Forum -- SWIC 5 02-13-2001 09:52 PM


All times are GMT -4. The time now is 03:37 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.