[twiSTies]

I'm writing this because all too often there are posts on here asking which part the person should buy that's the best. The answer is that it depends on what you're looking to do with your STi. First, let's go over the options:

Strut Bars:

APR
ebay
Carbing
Cusco
Tein
Whiteline
STi

Springs:

JDM Pinks
Prodrive
Swift
RCE
Tein
Tanabe
Cobb
Skunk2
Eibach
Perrin
Crucial Racing
Work Tuning
twiSTies soopah doopah springs
2004-2007 STi Aftermarket Springs Rate and Drop

Swaybars:

Swift
Cusco
Whiteline
Cobb
Hotchkis
Strano

Tophats:

STi Group N

Camber Plates:

Noltec
PDE
RCE
Whiteline
Ground Control
Cusco
Tein/BC/Helix/Megan (They look identical)
Vorshlag

Struts:

Koni inserts
Ohlins
Prodrive/Bilstein RB320
STi 4-way Pink

Coilovers:

Tein SS-P, Flex, Mono Flex
Megan Racing Street and Track
Helix
BC Racing BR series
Tanabe
Cusco
Apex'i
HKS
H&R
KW V3
RCE Tarmac II
Bilstein PSS-9
AST 4100
Whiteline G4
Ohlins Sportlines
Ohlins Flag Series
STi
Moton
ZZYZX
TiC SST

Chassis Braces:

CLdevelopment X-Brace
Fender Braces
H Brace
Subframe Brace
V Brace

Anti-Lift Kits:

Perrin
Whiteline (Comfort/Sport/Race)
GT Spec

Swaybar Endlinks:

Kartboy
Whiteline
Cobb/Hotchkis(same thing)
Pol-Tec
Helix
Perrin

Strut Bars:

Not the best place to spend your money at the start for performance. They HAVE helped with cutting down on windshield creaks and rear window creaks though. If you're unsure about how much they benefit, try the cheapy ebay bars. At the $30 price point, they're practically disposable and would let you see if you can notice a difference on your car. If you want something that may be stiffer and look better under the hood, try out any of the premium brands like Carbing, Cusco, Whiteline, or STi.

Springs:

The stock springs on the STi are too soft for the stock strut valving. The rate doesn't match. To remedy this, there are several options for springs all geared for different uses. The proper match to the stock valving are the JDM Pinks. However, they leave some people desiring for more performance, which is where the Swifts and RCE springs come in. The RCE springs are designed with a higher rear rate to help balance the cars handling out at the limit. The front rate is also higher than the Swifts or Pinks to help with dive and turn in response. On the other end of the spectrum from the performance springs are the springs made to lower your car and look "good". These springs are a joke for performance because they lower the car too much and will spend an inordinate amount of time on the bumpstops. Tein S Techs, H Techs, and anything that lowers beyond the Swifts (which are low) will fit into this category. Not only do they lower the car too much and cause the A arm geometry to be pointing upwards, they also don't have stiff enough spring rates for this amount of lowering to keep the car from bouncing around. In the middle of these two extremes are the Prodrives. These are the springs to buy for ride comfort and an improvement over the stock springs in handling. Anything not mentioned are simply unknown or not highly recommended. There are people happy out there with every spring on this list and they will defend their purchase, but its up to you to filter it all out and see what has the proven following. At the end of the day, no spring will cure the horrendous valving of the stock struts. Here is a listing of known spring drops and their rates.

Swaybars:

The best bang for the buck suspension mod you can do on a stock car. The Swifts and Cusco bars are great for a daily driver, street car, but the Cobb/Hotchkis are a step up. For the ultimate in adjustable bars and the benefits of large sways, Whiteline is the way to go. A popular choice of Whiteline bars are the 27-29mm adjustable front bar with the 22-24-26mm adjustable rear bar, but as spring rates get higher, the bar size will probably need to be adjusted lower. The 32mm Strano bar has had problems with fit and breaking off the front endlink tabs from the front LCAs.

Tophats:

STi Group Ns offer a harder rubber compound over the stockers and this results in less deflection under load. A highly recommended mod for anyone who touches struts, springs, or coilovers.

Camber Plates:

This is the way to go if you need to dial in extra negative camber for track days. The stock camber bolts and aftermarket camber bolts can not give you nearly as much negative camber as a good set of plates will. The plates are also more durable than camber bolts (to say the least, my bolts are rusting after a year). The RCEs have a big pillowball that lets them remain relatively quiet and last a very long time, but they lack a true caster adjustment. You can swap sides with them to gain additional caster, but it comes at the expense of not being able to get as much negative camber. Also keep in mind that any changes to camber with the plates will affect your toe. Make sure you get an alignment after putting these on. I've seen rusting issues with the Tein/Taiwanese camber plates. Camber plates from Noltec and PDE will also raise the car 3/8ths of an inch, so keep that in mind. RCE offers two flavors, a non-lowering version and a lowering version of their plates. The lowering version is intended for the JDM Pinks and coilovers. Running the lowering version on a spring like the RCE, Cobbs, or Swifts will result in messing up the front a arm geometry much like if you ran S Techs. Ground Control plates use a dual bearing setup, but not much info from the field is known about them. Cuscos have tended to make noise. PDEs allow for caster adjustment separate of the camber, as well as the Whiteline plates. Vorshlags look to add .75 degrees of caster with the biggest bearings in the industry, but not much else is known yet.


Struts:

If you have an '04, get the Koni inserts in WRX housings. You won't get a better bargain than that.

If you have an '05, you have Ohlins, Prodrive RB320, and GC-sleeved Konis. The Ohlins are amazing for a fixed perch strut, but cost prohibitive for a lot of us. They will match up great with a wide range of springs on the market, and the adjustments allow for great control on the street or track without sacrificing a lot of comfort. They're recommended for the daily driver who doesn't track their car much. Pairing Ohlins struts with Prodrive springs will give the STi its best ride quality combination currently available. The RB320 Bilstein fixed perch struts are released, but due to Prodrive USA closing their doors, very rare and hard to find. They contain PSS-9 internals, but require their propreity springs in order to work on your car since they changed the spring mount on the struts. These will also only be for the 05+ STi. RCE is also working with KW on a new fixed perch solution for the STi as well, but no information is really known by the public about this yet. Stretch has found out that there is now an option for the 05+ STi owner with Koni inserts using Ground Control Housings. This setup allows you to run single adjustable or dual adjustable Koni struts in GC sleeves on the 05+ in any spring rate you want.

Coilovers:

Let's start by breaking these down into their price categories. For around $1,000, you can buy the Helix/BC Racing/Megan Racing/Stance/K-Sport group of coilovers. The BC and Megan are known to be produced by the same manufacturer, Bor Chaun Racing. There are people happy with these coilovers. They have won a bunch of autocross classes. You still get what you pay for. These are not recommended if you value a smooth highway ride or don't like bounciness. The valving of these coilovers reflect the traditional JDM method of using high spring rates with high rebound valving to increase road holding and feel. The problem is that roads have dips, bumps, separations, and divots in them. Another problem with these coilovers are the quality control may cause the valving in the same set to vary. Shock dyno sheets have confirmed that the K-Sport dampers do not have repeatable valving across the set. This is pretty bad. For someone on a budget, who doesn't mind a stiff ride or the ridicule of everyone with European dampers, and doesn't care if the valving may not be the same between his left and right shocks, you can buy the $1,000 coilovers. Just realize the old truth, you get what you pay for. If they look great on the outside, they probably don't on the inside at this price point. Buyer Beware.

Tein/Cusco: If you like the JDM style of valving (see above), go for these. Both have been used in winning race car programs. Both may not work great over bad roads. Some people love them, others think they're too stiff for American roads. YMMV. Both come from reputable manufacturers. The Cuscos are built a little better, therefore the higher cost.

H&R/Tanabe/HKS: Not enough reviews to make any conclusions on them. For other car platforms, H&R has been really good.

JIC/Zeal: Old school coilovers that were awesome about 3 years ago. Haven't heard of people still running them today.

KW V3/RCE T2: The standard for 2 way adjustable coilovers offering good ride quality due to the German style of valving. Both use INOX technology to keep rust to an absolute minimum. Both have very good support inside the U.S. and both have proven themselves many times on the track. Currently, the best way to go for someone at the $2k price point who needs to have a serious track car on the weekends and a daily driver on the weekdays.

Bilstein PSS-9: A little step below the dual adjustability crowd, but better geared for the daily grind since the single adjustability allows for the high speed bump and rebound to be turned down. Inverted design, lifetime warranty like the KW/RCE set, stainless steel construction. A tiny bit cheaper than the KW/RCEs, but won't give you the 10/10ths performance.

Ohlins Sportlines: Potentially better valving than the Bilsteins, come with camber plates and pillowballs, has 5 more settings on its single adjustable damper than the Bilsteins 9 way. Rebound adjustable-only. Costs close to a grand more. Very streetable, very nice on track. Has had very good reviews.

Ohlins Flag Series:All aluminum, all components are clear annodized, threaded strut body, threaded lower flange: offers bump/droop travel adjustment independent of ride height, double-adjustable external reseviour shocks: independent bump and rebound adjustment, high speed compression dampening is fixed, low speed is adjusted, comes with ~440/330 8 inch springs. Appears to work with rates up to 600/500. Comparable to the ZZYZX.

AST: Recently back in the USA with AST-USA forming. Their entry level coilover is the 4100 series that is 12 way adjustable. This coilover is the basis for the TiC SST coilover, and is well-respected for providing a good single adjustable option other than Bilstein and Ohlins.

Whiteline G4: Discontinued, but were the ultimate DD coilover option on the market. Used AST for the damper technology, but valved differently. Had a lot of strut travel, which absorbed bumps better than other coilovers. Very low spring rates for a coilover, but had an optional Race kit that would allow them to be more competitive on track. Overall, a great coilover for the hobbiest.

STi: 4-way adjustable coilovers come with Group N tophats. These are offered by Subaru for 04 and 05+ owners that desire more performance. They utilize the JDM "Tuned by Arai" springs (346F/280R) and are the only option for people who wish to keep their car All STi. All the time. The problem with them is that they cost upwards of 2 grand or more which puts them in KW/RCE territory. At that price range, the valving of the STi coilover isn't that good. Each adjustment is pretty limited as the coilover is only single adjustable. Plus, the valving will be JDM in nature, which often means undesirable ride quality characteristics. As with most aftermarket things from STi, too little performance for too much money.

ZZYZX: - all aluminum, all components are clear annodized, fully threaded strut body, threaded lower flange: offers bump/droop travel adjustment independent of ride height, double-adjustable Koni 8611 shocks: independent bump and rebound adjustment, your choice of spring rate and length. This info has been taken from the company web page.

Moton: I put this in as a joke. Maybe 1% of the people reading this would be able to even set these up correctly, let alone use them and if they can do that, they wouldn't be listening to me or reading this.

TiC SST: This coilover is the baby of the Subaru form community, which spent many months helping TiC out with design ideas and mathematical equations to try to find the best balance of a comfortable street ride with the best performance. These are based off of the AST 4100 series damper, but have AST's Race valving inside of them in order to hit the desired damping requirements. Quite possibly, these are the most comfortable coilovers that you can buy for your STi, and won't give up any performance vs. the other single adjustables on the market. Through superior valving and the use of Swift lightweight springs, these are a tremendous entry on the market that should be considered by everyone looking to put coilovers on their car.


Chassis Braces:

CLdevelopment X Brace: Probably the best received brace on the market. Manufacturer tests claim .1 increase in skidpad and the reviews have been pretty favorable. Promotes a stiffer chassis and lets the rear end follow the steering wheel input a lot tighter. The downside is that its not cheap and is the 2nd most expensive brace you can buy.

Fender Braces: Only applicable for the 04-06 STis. The debate on whether they do anything or not may still rage on, but even Subaru acknowledged they do something by putting them on the 07 STi from the factory. On my car, they stopped a lot of the shock from bumps in the road from reaching my seat. The theory is that they connect the front chassis together better which redirects the force back into the suspension and into the a pillars/firewall.

H Brace: Connects the front LCAs to each other and the subframe. This mod helps tighten up the front chassis a little bit more. A good bargain mod, but not a world-beater. An aftermarket subframe will usually incorporate this into its design.

Subframe Brace: There are now a handful of these on the market that are designed for different things. Some reduce a lot of weight over the stock U brace, while giving more strength. Others give more strength. Others tie together more points of the car, while others focus on certain sections (Gt Spec). The M1 and Carbring braces are gaining popularity since they're a single piece, incorporate the H brace geometry, and are receiving good reviews. Bruce Chapman loves his GT Spec design. YMMV.

V Brace: This is a Cusco designed part that mounts in the trunk and connects the rear strut towers. If CLdevelopments' testing is correct, this brace doesn't do anything. Not enough reviews of a noticeable difference with this brace compared to a regular strut tower bar to really make a solid opinion.

Anti-Lift Kits:

The Perrin has had fitment issues. The Whiteline has had too many questions devoted to it. The Comfort is stiffer than stock and will be the best choice for most people due to the NVH involved with this mod. What does this mod do? Well, it does NOT stop lift. It actually creates it by removing the factory anti-lift geometry. This is a good thing. It helps improve front end traction and adds additional caster to the front of the car. The Sport spec is a harder compound than the Comfort and some people will want it for autocross. The Race spec is the hardest compound and has a lot of NVH over bumps on the street. Since NVH is impossible to accurately gauge from internet reviews, your best bet is to stick to the Comfort if you're concerned with it. The GT Spec kit isn't as widely used as the Whiteline kit.

Swaybar Endlinks:

Practically required for people who want to change out their swaybars on the STi. While the stock endlinks have held up reasonably well for people on the front swaybars, the rear endlinks are known to flip, even with the stock bar. While there are people out there that haven't had the stock endlinks flip and take a chunk of metal out of their nice aluminum arms, there are enough to make a recommendation to not cheap out on the rear endlinks. The standard for the Subaru community has been the Kartboy endlinks. They offer noise-free operation, are extremely beefy, and don't flip. They're also competitively priced and won't break the bank. The Whiteline endlinks, Pol-Tecs, Helix, Perrin, Cobb/Hotchkis(they're the same), offer you the ability to have a spherical bearing, but oftentimes this will result in noisy operation, especially as the bearing gets worn and dirt enters the equation. Kartboy keeps it simple, so most people run them.

If you'd like to add or make corrections, please feel free to PM me and I'll give you credit with your additions. This has bias in it, but I feel its a decent enough of a representation of what the collective forum here believes to be the most true from the past 4 years of discussion. As always, YMMV.

Thanks,
Dave

[RaceComp Engineering]

That's acutally really really good. Nice and informative, non-biased, non-speculative, and very helpful.

Good job!


- Andrew

[upncummr]

Moderators - Should this be made a Sticky?

Gary

[evilSTi7]

excellent job twisties, thank you for writing it!

you also might want to throw Zzyzx in there. a couple people run them.

[twiSTies]

Thanks guys I have to add Chassis Braces and those ZZYYXXXXsss too

[RaceComp Engineering]

Originally Posted by evilSTi7

excellent job twisties, thank you for writing it!

you also might want to throw Zzyzx in there. a couple people run them.

Also, mentioning Ohlins Flag seperately from Ohlins Sportlines.


- Andrew

[jaydow11]

Thanks a lot! Very good info!

[Glycerin]

yes this is excellent! what about ALKs!?!?!?

[twiSTies]

I don't know enough about the Flags or XXYZZ's to write about them, unfortunately.

[kts262]

For 05+ struts, Spec-C Type-RA 4-way adjustable struts from Subaru/STi.

These are also sometimes known as the Arai struts and are the same ones used on the S203/S204.

4 way damping adjustable from 1 (much softer then WRX) to 4 (uber stiff). Stock STi is between 2 and 3 from what I read somewhere. I'm currently running 3. A little stiff for daily driving but I have no major complaints.



These pop up from time to time from various JDM importers with low miles in the $1000-1400 range, usually complete w/ the JDM Tarmac/Arai springs and stock tophats. You can also buy them new from some vendors ($$$) or from places like japanparts ($, but less then most of the US guys.)

22k miles on them so far and they are running strong. Had thought about upgrading to Ohlins but changed my mind, no need for it for me at this time.

[thermobox]

a few more

strut bars:
greddy
rigid
mas
hks kansai
do-luck
rs*r
zero/sports
black rock
wangan
beat rush
ganador
be free

springs:
blitz
apexi
trust
corazon
espelir
eifel
racing gear
tommykaira
d cuatro
rs*r
zeal
garage ohno
wangan

sway bars:
zero/sports
carbing
arc
avo
eibach
wangan
do-luck
rs*r

camber plates:
ia concept
dog fight pro

struts:
bilstein presto
bilstein premium order line
zowie auto studio

coilovers:
zero/sports
dog fight pro
project k
bilstein bps
bilstein bbs
bilstein motorsport line
aragosta
fightex
racing gear
liberal
rocket dancer
eibach
eifel
blitz
jspeed
arc
kpower's
quantum
garage km1
apexi
gab
rst
biot
ia concept
kyb
car service hiro
zeal

chasis braces:
floor brace
trunk pillar bar
rear bulk head
floor support bar
harness bar

anti-lift kits:
avo
beatrush

others
bushings
engine mounts
tranny mounts
sway bar mounts
trailing link
lateral links
end links
lower arm bars
roll bars
roll cages
camber bolts

[sti robot]

Getting nitpicky here but...

JDM pink "Tuned by Arai" springs

[twiSTies]

thanks for that list! unfortunately that is a lot more products than have been reviewed on here so it wouldn't be good to offer an opinion on any of them.

[stretch]

*cough* Ground Control
Ground Control / Koni Coilovers (incuding 2005+ STI's)

[Mykl]

Originally Posted by twiSTies

I don't know enough about the Flags or XXYZZ's to write about them, unfortunately.

I'm taking much of this off of the web site...

ZZYZX - all aluminum, all components are clear annodized, fully threaded strut body, threaded lower flange: offers bump/droop travel adjustment independent of ride height, double-adjustable Koni 8611 shocks: independent bump and rebound adjustment, your choice of spring rate and length. This info has been taken from the company web page.