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STi Suspension Buyers Guide

Suspension/Stiffening 
126K views 98 replies 67 participants last post by  S2000_Europe 
#1 · (Edited)
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
Perrin
Whiteline
STi

Springs:

JDM Pinks
Prodrive
Swift
Swift R Spec
RCE Yellows
RCE Blacks
Tein
Tanabe
Cobb
Skunk2
Eibach
Perrin
Crucial Racing
Work Tuning
twiSTies soopah doopah springs
http://www.iwsti.com/forums/suspens...4-2007-sti-aftermarket-springs-rate-drop.html

Swaybars:

Swift
Cusco
Whiteline
Cobb
Hotchkis
RCE
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
Tein Flex
Tein Mono Flex
Megan Racing Street
Megan Racing Track
Helix
BC Racing BR series
BC Racing RAM (inverted BR) series
BC Racing ER series
Tanabe
Cusco
Apex'i
HKS
H&R
Eibach
KW V3
RCE Tarmac 0
RCE Tarmac II
Bilstein PSS-9
AST 4100
Whiteline G4
Ohlins Sportlines
Ohlins Flag Series
STi
Moton
RS&SP
ZZYZX
TiC SST
Prodrive

Chassis Braces:

CLdevelopment X-Brace
Fender Braces
H Brace
Subframe Brace
V Brace
twiSTies BAMF 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. Just something to note, if you are running larger than stock sized bolts for your camber plates, the Perrin bar won't fit. For example, my Vorshlag plates use 13mm sized bolts and nuts. The Perrin is made for the stock 12mm size and the holes wouldn't line up right with the 13mm sized ones. Just a friendly tip to anyone looking to run those two brands together.

Springs:

The stock springs on the STi are matched for the stock strut valving. The issue is that the stock struts lack sufficient bump travel, which causes the car to bounce up and down off of the bump stops. In the past, the remedy to this was to put a lowering spring on the car, which would stabilize the ride. What it really does is bury the car into the bump stop so that you really don't have any bump travel anymore, just a bump stop. The best way to fix this issue is to simply CUT your bumpstops. Remove the first progression of the bump stop, which will increase your strut travel without any negative side effects. It should also reduce bobblehead a bit too.

If you want to increase the spring rate for less bodyroll, then there are several options for springs all geared for different uses. JDM Pinks are a nice mild upgrade that will help smooth the ride out and give you a little bit more performance over the stock springs. They also match up to the factory struts rather well. The basic Swift Sport springs give similar performance to the JDM Pinks for a little bit less money and give a little bit lower of a stance. Keep in mind that this lower stance eats into your strut travel!

If you're looking for more performance, the RCE Yellows and Blacks 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 mitigate brake dive and improve turn in response. The difference between the Yellows and Blacks are about 6lbs in spring rate (very neglible) and the ride height. The Blacks lower the car very minimally, which is GREAT for strut travel and ride comfort without a major loss in performance enhancing spring rate. The Yellows lower the car a bit further for a lower cg and better looking profile, but at the expense of strut travel. I'd buy Blacks for a street car, personally.

The Swift R Spec springs are very similar to the RCE offering if you want an alternative. At this level you're getting the best springs out there for what the STi is built for: Performance.

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 in 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 a slight 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 bump travel 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 was 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.

New to the market are the RCE swaybars. These pick up from where Whiteline left off and its apparent that RCE did their homework. They utilize washer tabs to prevent the sway bar from "walking", which often results in a nice clunk noise over bumps or turns. They also use a much higher quality paint, unlike the Whitelines which are known to rust pretty badly. To top it off, the sizing of the RCE allows for a good adjustable range for street (soft-25.5mm front and rear) to "OMG I'm on crazy R compounds" (hard 28.5mm front 25.5-28.5mm rear). This versatility and quality put the RCE bars in the lead for most applications.

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. The lowering version is able to keep precious bump travel while lowering the car, but running the lowering version on a spring like the RCE Yellows, 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.

The Vorshlag plates are heavy duty and dead silent. The bearing is where they truly shine over a lot of the competition. It will operate quietly and for a longer period of time than some of the lesser models out there. Theres a reason why they cost what they do, you're getting heavy duty components that will last you for quite awhile without making a squeak (and trust me, if you drive your car a lot, squeaking is the last thing you want to listen to).


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 propriety 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.

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. The downside to this is that if you aren't mechanically inclined or know anyone that is, you're probably not going to feel comfortable hacking up strut housings and mixing things together.

For most people, the Ohlins are still the only way to go if you want to keep a strut and spring setup.

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 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.

BC Racing ER Series:
These are two-way (rebound and compression) adjustable coilovers. They use a lot of the BC BR series components to keep costs down, such as the camber plates, strut housing, locking perches, and they have the same amount of strut travel. Each adjuster has 30 clicks to cover a wide range of valving in theory. These come with external canisters to keep heat low (which is a nice feature since I personally overheated the BR series) There just isn't a lot more information on these at this time and no shock dyno sheets to show what the valving looks like at each click. They have been used on other car platforms and are getting some rave reviews from the track. They may be the answer for a budget two-way, much like the BR series is the budget answer for a one-way adjustable coilover system.

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 with SHOWA dampers, therefore the higher cost.

H&R/Tanabe/HKS: The H&R budget coilover set is non-adjustable but uses Bilstein parts inside to help make them a viable candidate for a total budget coilover. You can adjust their height, but not the valving, so these are ultimately fairly limited, but can be a nice introduction to driving the STi with a higher spring rate. The downside to this is without adjustability, something as simple as a tire change can result in unfavorable ride quality changes with no way to change it.

JIC/Zeal: Old school coilovers that were "awesome" about 3 years ago. Haven't heard of many people still running them today since the market has shifted favorably to the European suspension brands.

RCE Tarmac 0: RCE's budget answer, these are non-adjustable but use KW internals. These also utilize the INOX coating to keep rust away from your investment and RCE-specific valving that is catered for a comfortable ride quality, but capable track performance with proper linear springs. The Tarmac 0 offers a lot of what the T2 comes with, minus the wide range of adjustability. These are built more for the 'set it and forget it' crowd and should be considered by anyone looking into upgrading their strut and spring combo, but not wanting the complexity of a coilover. As an added bonus, RCE will preset the height on these so that you can just install them, get an alignment, and go to the trackday or the office without needing to touch anything.

KW V3/RCE T2: The gold standard for 2 way adjustable coilovers offering great 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. The T2 coilover from RCE uses RCE-specific valving that is better suited to the trackday/autox enthusiast. The T2 also separates itself from the V3 by using double locking perches and stiffer LINEAR springs front AND rear. Well worth the small price difference to just step up to the T2. These really are the gold standard for properly valved two-way coilovers in the Subaru market. They offer enough flexibility with the valving to be comfortable on the street, but still kick ass on the track with some clicks of the adjuster.

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. Quite possibly the lowest priced coilover you should consider buying.

Ohlins Sportlines: Potentially better valving than the Bilsteins, but has been shown to be JDM-like with heavy rebound valving. They come with camber plates and pillowballs, and have 5 more settings on its single adjustable damper than the Bilsteins 9 way. Rebound adjustable-only. Very streetable, very nice on track. Has had very good reviews.

Ohlins Flag Series:All aluminum, all components are clear anodized, threaded strut body, threaded lower flange: offers bump/droop travel adjustment independent of ride height, double-adjustable external reservoir shocks: independent bump and rebound adjustment, high speed compression damping is fixed, low speed is adjusted, comes with ~440/330 8 inch springs. Appears to work with rates up to 600/500. The downside is that these have 105mm of strut travel, which is less than any known coilover on the market (including JDM options). The other downside is the cost is roughly twice that of the T2s with less strut travel and comparable features. What's the advantage to these again?

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 anodized, 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. NOTE: ZZYZX is out of business.

Moton/RS&SP: 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.:lol:

TiC SST: 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.

Prodrive: Made by HKS. Theres really not much else to say. Spring rates are ridiculously high for a street car and the valving is unknown. There also doesn't look to be much strut travel either. If someone can show me real differences between these and the HKS coilovers other than colors and spring rates, I'd be happy to add that to this column.


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
 
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#66 ·
Already subscribed, but thanks for the heads-up! Now, are you going to give us any hints or do we all have to live in suspense??? :D (The correct answer is the former, NOT the latter...) ;)
 
#73 ·
Damn good info! Just joined iwsti and this was the first thread I read. Great timing w/the update LOL. I've been on tons of websites trying to get myself educated before buying my coilovers and was looking at the TIC's and Tein SSp. Thought the EFDC and included camber adj. were easier for me. But I will reconsider. Much Mahalos!
 
#78 ·
I have them on mine. The coilovers in general are great. You have 1-32 rebound settings from soft to hard, which is from what I see one of the widest ranges in dampings among the other coilovers. However, I'm facing a lot of problems in the damping remote control unit. Any wiring problems will give errors and will not let you apply any damping settings. Also the electronic motors have less age and will not last for long. If one motor is gone, the whole remote control system is gone !
 
#92 ·
I just wanted to add one thing on strut bars that the OP didnt mention and I'm not sure if its been covered on previous pages.

The point of the strut bar is to help with roll, very similar to sway bars now if you got the "ebay" route most likely it is made out of a cheap aluminium and it is hinged at the ends this is a piece of crap and not even worth $5. The hinged ends offer no increase resistance to roll and are compliant under load.

Even expensive brands like Cusco has hinged strut bars which is retarded. What you want to look for is a one piece bar made of a high grade aluminium (5051,T6 etc) and preferably a bar that not just connects to the struts but also another contact point at the firewall. This helps in both bending and torsion.
 
#93 ·
Wow, I just came back from a long hiatus and see that not only is this still stickied at the top of this section, but it has also been commented on quite a bit since I left the STi scene!

I sold my T2 and RCE equipped 05 back in October of 2009. It was wrecked within a month by the tard that bought it from the dealership. :( I really loved that car.

I got an Evo X GSR which was a nice step up for a DD at the time, but eventually got bored with how easy it was to drive and got an E46 M3 (my dream car) to replace it with. I've now almost completely restored the M3 and my buddy at AREA1320 has given me the STi bug again.

I can't say for sure if I'll be back, but it's on my mind and a possibility. One of the things I'd have to do is to learn about all the new suspension products that came on the market after I left.

In the meantime, I highly suggest anyone with questions to contact Myles at RCE. It's been a few years since I was his customer, but he always surpassed my expectations as a customer and as a source of knowledge.

Thanks,
Dave
 
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