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11-09-2007, 08:38 AM | #1 | |||
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
The Lowering Spring FAQ (including the NASIOC spring database)
(Disclaimer: this isn't done yet. I figured the best way to get it done was to put it out here for comments. There are probably sucky parts. I will fix them )
(Disclaimer2: this does not discuss shocks/struts or coilovers in much detail. Those will be done in separate FAQ's.) Two quick rules to remember before buying lowering springs: 1) Most lowering springs suck. 2) If it looks sweet, it's probably too low. Here in the suspension tech forum, by far the most popular question is: "What springs should I buy?" While no static document can give you a definitive answer, we can definitely help you go in the right direction and ask the right questions. This document is intended to do just that. So... What springs should I buy? Jumping the gun a bit, eh? Here is some background reading: -Suspension/Brake forum rules: read this before posting http://forums.nasioc.com/forums/show....php?t=1326482 No, seriously, read that first. If you post a spring thread and you haven't read it, we'll know - How car suspensions work, including a definition of Macpherson Struts: http://auto.howstuffworks.com/car-suspension.htm - High performance handling handbook - Don Alexander - if you are after something that is technical, yet pretty readable, this is pretty good: http://books.google.com/books?id=BJUVdn5SMBgC And finally, and perhaps most importantly: - Canonshooter's guide: "Lowering your Impreza?" - lots of specific firsthand experience in here as well as good technical background. http://forums.nasioc.com/forums/show....php?t=1030221 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. Most people's reasons involve some combination of #1 and #2. Why would I bother with just getting springs when I can buy coilovers? Sport Compact Car convinced me that if I don't have coilovers, my car will never handle well, I will never get any dates and my dog will die from brain cancer. This is crap. If anyone tells you this, you should slap them silly. A "full coilover kit" typically includes camber plates or at least some sort of hardened strut top, a coilover spring, a shock, and a strut body with height adjustment. While coilovers are a convenient way to get everything you need, they are NOT the only way and definitely NOT the only good way. You can get all those things separately. A well thought out strut/spring combination can absolutely 100% hang with a coilover kit. What should I look for in a good lowering spring? 1) Something that's designed for your goals! This means: -designed for your car (sedan vs wagon; see wagon-specific information below), -compatible with your shocks (stock or aftermarket) -appropriate for your application (street vs track/autox) in both spring rate and height. 2) You are reasonably happy with how it looks. Not too happy though, because then it's probably too low. What should I look to avoid in a lowering spring? 1) They should not be Tein S-techs. http://forums.nasioc.com/forums/show....php?t=1267918 2) They should not be "too low". As a general rule, if it looks sweet - it's probably too low. Going too low (especially combined with not going sufficiently stiff) means that you won't have much shock travel, which will make you ride on the bump stops a lot. This will have negative impacts on both handling and ride quality. 3) They should not be too stiff for your struts. Stock WRX struts generally start having problems somewhere around 250 lb/in. Stock STi struts can go a little higher, maybe 325 lb/in or so. Most aftermarket struts can go to around 400 lb/in or higher depending on valving and intended use. (NOTE: this is a section where I could use help!) So... how low is too low? This is a point of some debate. It also varies by car. While no Impreza likes to be lowered, the STi's situation is a little different than the rest of the Imprezas (see post #2 for details). BigSky again with an explanation of how lowering a MacPherson strut car hurts the handling: http://www.wrxtuners.com/forums/show...?t=9954&page=2 And I'll say it again - read the Canonshooter thread listed above. I have opinions about which springs (other than the S-techs) are too low but I don't want to slam specific companies/specific products in here. Just research it and evaluate the reviews critically. update! New information about the 08/09 cars: http://forums.nasioc.com/forums/show...ghlight=travel Short version: lowering the 08-09 cars with springs only is a bad idea with the products on the market today. This is not to say that lowering it with bad coilovers is much better It seems like you guys are really conservative. C'mon pops, kids lower their cars. Deal with it! MacPherson struts suck. They have a really low threshold for sucking more with bad lowering springs. And there are lots of bad lowering springs out there. That's pretty much why. What's a bump stop? http://www.hrsprings.com/technical/m..._jounce_bumper Quote:
http://www.wrxtuners.com/forums/showthread.php?t=17337 In short - once you lower the car, you are likely putting it in a position where you're more likely to be on the bumpstops. A common thing people do with lowering springs is to trim a nub or two off the bottom of the bumpstop. It's a tradeoff: you're less likely to hit it, but it will be harder (and less progressive) when it happens. How can I tell when I'm hitting the bump stops? Riding the bump stops and bottoming out are not the same thing. http://forums.nasioc.com/forums/show...ight=bumpstops Quote:
Here's a good writeup from Swift that silverF4turbo found: http://www.swiftsprings.com/faq02.html Quote:
For the WRX, maybe. Check out these threads: http://forums.nasioc.com/forums/show....php?t=1642099 http://forums.nasioc.com/forums/show...ight=bumpstops Some lowering springs may come with instructions that say to cut them however. For the STi, check these threads: http://www.iwsti.com/forums/suspensi...advantage.html http://www.iwsti.com/forums/suspensi...t-springs.html Do I need a camber kit when I lower my car? If you lower your car too much, you may want to look into getting camber bolts or camber plates if you end up with excessive negative camber. What's excessive negative camber? That will be covered in an upcoming alignment FAQ. But for most folks, you probably don't want more than -2 or so. (massive generalization) Do I need an alignment when I lower my car? Yes! Your new, lower springs will affect the car's camber and toe, if you were to stick with exactly the same settings. Plus, the installation process involves removing your eccentric bolts and you're probably not going to put them back exactly where they left. You can mark them with paint to get them approximately where they used to be, but you still are going to want an alignment afterwards. (shock FAQ): How can I tell how much shock travel I have? * Todo
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Last edited by Butt Dyno; 02-12-2009 at 08:48 PM. |
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11-09-2007, 08:41 AM | #2 |
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
Specific Springs
What springs fit my car? A list of what parts fit what cars is here: http://forums.nasioc.com/forums/show....php?t=1303381 The cliff notes version is: 02-03 is mostly the same, and 04-07 is mostly the same, and you can make springs for one fit on the other as long as you use the right tophats. But that is ONLY the cliff's note version. Read the whole thread! Make sure you research whatever you buy! What lowering springs exist? I want a really big list! Here's a Google spreadsheet that contains most of the ones we know about: http://spreadsheets.google.com/pub?k...eL_KhwEw&gid=1 North Ursalia also has a good reference that contains a lot of the factory cars: http://www.northursalia.com/techdocs/spring/spring.html What's lb/in? What's kg/mm? What's the difference? Lb/in and kg/mm are different ways of measuring how stiff a spring is. lb/in is how many pounds are necessary to make the spring compress one inch. A 100 lb/in spring with 200 pounds of weight on it will compress 2 inches (assuming there are two inches of travel). kg/mm is the same thing, but metric, like they use in Canuckistan. More info here: http://forums.nasioc.com/forums/show....php?t=1083184 Rule of thumb'ish: Divide lb/in by 55 to get kg/mm. Multiply kg/mm by 55 to get lb/in. I have an STi. What do I need to know about lowering springs? You're probably already on your bumpstops http://www.iwsti.com/forums/suspensi...ump-stops.html What does that mean? Your car is MUCH more sensitive to bad lowering springs. Lowering without going stiffer means that you are going to be even deeper into the bumpstops - not good for handling OR ride quality. IWSTI has done a lot more work on the specific STi woes than we have here so you should definitely spend some time there reading threads. http://www.iwsti.com/forums/suspensi...ng-stiffening/ I have a wagon. What do I need to know? Here is the master "wagon setup" thread (not just lowering springs): http://forums.nasioc.com/forums/showthread.php?t=478371 1) Camber differences and how springs change them: Wagon struts on a sedan will make it easier to get negative camber. Sedan struts on a wagon will lose you negative camber. (need more) 2) Saggy butt: myth or fact? (help!) I hear a lot about "pink springs" or "the pinks". What are those? The "JDM pinks" are 252/217 rate springs originally designed as lowering springs for the Spec-C. There are a bunch of pink springs, but those are the most famous ones. The SPT pink springs are sold by your dealership http://forums.nasioc.com/forums/show...light=jdm+pink I'm thinking about buying SPT Pink springs for my WRX. Are there any cheaper alternatives? You can get USDM STi takeoff springs at a small fraction of the price. The fitment rules above still apply, though. http://forums.nasioc.com/forums/show...ght=difference Last edited by Butt Dyno; 12-16-2007 at 02:14 PM. |
11-09-2007, 08:41 AM | #3 |
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
Expansion slot 2
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11-09-2007, 10:21 PM | #4 |
Scooby Newbie
Member#: 156965
Join Date: Aug 2007
Chapter/Region:
E. Canada
Location: Toronto
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you can add information from this extremely informative post:
http://forums.nasioc.com/forums/show....php?t=1030221 |
11-13-2007, 01:04 PM | #5 |
Scooby Specialist
Member#: 101898
Join Date: Dec 2005
Chapter/Region:
SCIC
Location: So Cal, Long.Beach, Whittier
Vehicle:1905 NINETWO EX AIRO Prodriv.Hotchkis.Stromng. |
could not update your google spreadsheet, here , i had to do some heavy searching, and even called tokico to get this info
Tokico 205/170 1.25 F/1.25 R |
11-13-2007, 05:17 PM | #6 |
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
I added it but I still have no idea which springs those are
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11-19-2007, 10:55 AM | #7 |
Scooby Guru
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MAIC
Location: Silver Spring, MD
Vehicle:Dad- Core OG |
Prodrive WRX springs are blue, but the STi springs are red.
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11-19-2007, 11:03 AM | #8 |
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
^ Fixed
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11-21-2007, 04:48 PM | #9 | |
Scooby Newbie
Member#: 157079
Join Date: Aug 2007
Chapter/Region:
MWSOC
Location: Ky
Vehicle:2007 Impreza 2.5i Obsidian Black Pearl |
Quote:
Also, maybe you can put something in the FAQ about what springs are "good" and the others that are not. Which springs that will need you to purchase more than just the springs; ie: camber bolts, camber/caster plates, etc. Last edited by zsimpreza; 11-21-2007 at 04:57 PM. |
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11-21-2007, 05:07 PM | #10 | |||
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
Quote:
Quote:
Quote:
In general you don't want a lot of negative camber in the rear but there are no hard and fast rules about "too much" because everyone uses their cars for different things. Something in the -1.5 to -2 degrees range is nice and safe. You may want less if you're racing (depending on a lot of other things of course) john |
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11-27-2007, 11:35 PM | #11 |
Scooby Newbie
Member#: 53846
Join Date: Jan 2004
Chapter/Region:
E. Canada
Location: Laval
Vehicle:2004 WRX Satin White Pearl |
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11-29-2007, 08:12 PM | #12 |
Scooby Newbie
Member#: 165288
Join Date: Nov 2007
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i'm going to buy lowering springs. can someone post pictures of their car with just lowering springs. I'm looking to drop about 1.7 in front and 1.4 in back. i want to see if it is worthwhile. thank you
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11-29-2007, 10:15 PM | #13 |
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
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12-01-2007, 11:17 PM | #14 |
Big Ron
Super Moderator Member#: 18062
Join Date: Apr 2002
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Location: I can save you a ton of cash
Vehicle:on car parts so PM me b4 j00 buy |
Where's the questions about cutting a coil out of springs or heating them up?
<-----actually cut a coil on Subaru springs for a buddy of mine once, though I will deny it in a court of law. Oddly enough, it worked out well and we were both pleased and shocked. |
12-13-2007, 11:09 PM | #15 |
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
Made some revisions to make stuff a little more organized.
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12-13-2007, 11:15 PM | #16 |
Scooby Newbie
Member#: 164416
Join Date: Nov 2007
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BAIC
Location: Sacramento CA.
Vehicle:05 WRX Wagon Stg 2 03 Yamaha R6 |
lol i have done that b4. it was easy cheap (free) but the bad side was when i jacked up my car and lowered it back down the spring popped out. lol went to buy another set right away. really bouncy also.
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01-17-2008, 05:53 PM | #17 |
Scooby Specialist
Member#: 101898
Join Date: Dec 2005
Chapter/Region:
SCIC
Location: So Cal, Long.Beach, Whittier
Vehicle:1905 NINETWO EX AIRO Prodriv.Hotchkis.Stromng. |
the spreadsheet needs some love, and organization
example : Subaru OEM 2002 WRX Sedan 163-163/119-132 0 2002 WRX wagon 163-163/132-144 people reading this will wonder why is there 2 different numbers for front and back. this is because of the trans choice AT / MT Espilir ASD 35mm / 20 mm 196 / 161 (calculated) GT 30 mm / 20 mm 280 / 230 Also I can has Whiteline springs info peaz?? hope this helps |
01-23-2008, 07:15 AM | #18 | |
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
Quote:
I don't know much about the Whiteline springs... maybe Arnie does tho Doesn't seem like anyone buys them. john |
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01-23-2008, 01:12 PM | #19 |
Scooby Specialist
Member#: 101898
Join Date: Dec 2005
Chapter/Region:
SCIC
Location: So Cal, Long.Beach, Whittier
Vehicle:1905 NINETWO EX AIRO Prodriv.Hotchkis.Stromng. |
I liiike , I liiike , High 5 !!
( good job bro !!! ) |
01-23-2008, 10:40 PM | #20 |
Scooby Newbie
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South East
Location: VIR, CMP, RRR
Vehicle:2013 WRX Hatch |
ok, help me. Where's the spreadsheet, how do I get to it?
-Matt |
01-24-2008, 08:15 AM | #21 |
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
Look for the text "here's a google spreadsheet" in post #2.
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01-27-2008, 05:04 PM | #22 |
Scooby Specialist
Member#: 92706
Join Date: Aug 2005
Location: Cambridge, MA
Vehicle:2000 Swapped 2.5 RS Silverthorn Metallic |
Now, i don't have an engineering degree or anything, but i think the description as to why linear springs are tougher to drive with is flawed.
The description operates under the assumption that a linear spring and a progressive spring will compress identical amounts under similar cornering forces...but that's simply not true. A progressive spring that has a rate that ramps up to higher rates than the linear spring will compress less for the same corner, effectively absorbing and reacting with the EXACT same amount of force a linear spring would, assuming all other factors (cornering force/style) are all the same. In fact, the progressive spring would result in way LESS body motion, and a more stable/easier to control drive. In fact, the whole point of having Progressive springs is so that you can START with soft spring rates that are comfortable when cruising, but they ramp up to stiffer spring rates so that the car stays flatter under hard driving. I'm pretty sure it's what prodrive used in their P1, which was supposed to be both the most-plush and best-handling GC ever made. I ask that you please reconsider the linear/progressive description used in the sticky, as it's VERY misleading and could push people who don't have the time to think about it in the wrong direction. |
01-27-2008, 05:47 PM | #23 |
Street's closed, pizza boy
Member#: 17301
Join Date: Apr 2002
Chapter/Region:
MAIC
Location: NoVA
Vehicle:2018 Focus RS 2006 Evo #17 STU |
Yeah, that's fair. I'll keep the factual parts and whack the "characteristics" section.
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01-28-2008, 08:22 PM | #24 |
Scooby Specialist
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Join Date: Aug 2005
Location: Cambridge, MA
Vehicle:2000 Swapped 2.5 RS Silverthorn Metallic |
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01-29-2008, 02:17 PM | #25 |
Scooby Specialist
Member#: 101898
Join Date: Dec 2005
Chapter/Region:
SCIC
Location: So Cal, Long.Beach, Whittier
Vehicle:1905 NINETWO EX AIRO Prodriv.Hotchkis.Stromng. |
TANABE
Code:
GF210 Application Chart Impreza (GC6/8) 98-01 3.5K / 2.9k 1.3" / 1.0" TGF031 Impreza WRX 02-03 3.0K / 2.8K 1.5" / 1.0" TGF045 Impreza WRX 04 4.3K / 4.0K 1.3 / 1.0 TGF092 Impreza WRX 05-06 5.8K / 4.4K 1.0" / 0.5" TGF107 Impreza WRX STI (GDB) 04 4.3K / 4.0K 1.3" / 1.0" TGF092 Impreza WRX STI 05-06 5.8K / 4.4K 1.0" / 0.5" TGF107 Legacy Sedan 05- 4.6K / 6.0K 1.1" / 0.8" DF210 Application Chart Impreza (GC6/8) 98-01 3.5 / 2.5 1.0 / 1.1 TDF031 Impreza WRX 02-03 3.5 / 2.6 2.0 / 1.5 TDF045 Impreza WRX 05-06 4.7 / 4.4 1.3 / 0.8 TDF107 Impreza WRX STI 05-06 4.7 / 4.4 1.3 / 0.8 TDF107 NF210 Application Chart Impreza (GC6/8) 98-01 3.0 / 2.4 1.3 / 1.1 TNF031 Impreza WRX 02-03 2.5 / 2.0 1.5 / 1.0 TNF045 Legacy Sedan 05- 3.7 / 5.4 1.1 / 0.8 TBA |
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