Subaru Forester Owners Forum

Subaru Forester Owners Forum (
-   Suspension and Handling (
-   -   How to turn better than an STI for cheap! (

wadejg 12-01-2006 04:31 PM

How to turn better than an STI for cheap!
2 Attachment(s)
I'm going to try to cover a number of the often discussed subjects on making your Forester handle better. I will try to touch on goals, costs, and a little bit on installation.

I will only be talking about the SG body style Forester 2003-2008, although some of this does apply to the earlier SF body style.

For some great SF suspension information check out:
SF5 ultimate all around low suspension? - Subaru Forester Owners Forum

You basically have a tall 2004 WRX STI. Really, I’m not joking. For the most part, if it fits on a 2004 WRX STI it fits on your car. Pat yourself on the back for a great choice in cars.

I strongly suggest reading the following FAQs written by UNABOMBER on NASIOC for lots of general Subaru/WRX handling information that applies to our cars:
Suspension & Driveline FAQ: Read if you are thinking about upgrading! - NASIOC
Spring/Strut/Coilover FAQ: Read if you are thinking of buying them! - NASIOC

Here is a good thread about effects of suspension geometry changes on Foresters:
Lowering your Forester? - Subaru Forester Owners Forum

I will try to make this handling FAQ Forester specific. However I strongly recommend reading the above FAQ as much of it applies to our car.

I am making this information geared towards a mostly street driven Forester. If you track your car on a consistent basis then your knowledge should be high and your needs specific to your venue. Because of this I will give minimal discussion to such things as coil over suspensions.

Here is a link to my current suspension setup, as you can see it is pretty extensive:
Ultimate FXT street suspension? Look inside - Subaru Forester Owners Forum

You can look up SPT/STI part numbers for our Foresters at:
SPT - Subaru Performance Tuning (Performance Parts) | Lookup Parts

I have attached diagrams and pictures of the suspension at the end of the thread for identification of parts and terms used in this thread.

1. Tires: This is without a doubt the first handling upgrade you should make. It is the biggest bang for the buck and will let you take the most advantage of any subsequent modifications. You should get a set of 3 season tires for maximum performance. All season tires make a huge performance compromises in order to have snow traction. If you live where it snows your best performance will come with a set of snow tires and a seperate set of 3 season tires. Sorry it is just the way it is. I have a seperate set of rims/tires for snow tires and 3 season tires. I used to just have the tires taken on and off the rims 2 times per year. I actually kept the tires in my dorm basement during college, so it can be done:icon_wink:

I won't cover plus sizing, aspect ratios, tire brands, etc. It is just too large of a subject. But you can get killer 3 season tires for $100 per tire from several manufacturers.

Here are some links for specific tire discussions:

Tire Rack - Your performance experts for tires and wheels
Edge Racing - Home
Tire & Wheel - NASIOC
Tire and Wheel Tech - Subaru Forester Owners Forum

A tire size calculator (one of the handiest links on the web):
Tire size calculator

Here is a link to seeing what tires fit on the Forester (Thanks Porter):
SG Forester Tire Options: Master Document - Subaru Forester Owners Forum

I personally run 225/45-17’s (stock STI size) on my lowered Forester. Before it was lowered I ran 225/55-17’s. A good size to run on the stock rims would be 225/55-16.

2. Wheels: I’m putting this second not because they would be my second upgrade, but because they go with tires. Honestly, on the bang for buck scale, wheels are pretty low. Sure you can get wider tires on a wider wheel, and larger diameter wheels give you a lower tire aspect ratio and better turn in feel, but wheels aren’t cheap and bigger wheels are heavier. So, I suggest making this a later modification.

One of the cheapest, highest quality wheels you can get for your Subaru are the 2004 WRX STI wheels. For $750-1000 you can get used STI wheels and tires and BAM, bling and handling all at once. Keep in mind, only 2004 STI wheels will fit the Forester because after 2004, STI’s went to 5x114.3mm bolt spacing. All 2002-2007 Foresters and WRX’s have 5x 100mm bolt spacing.

The sweetest wheel available for our car, IMHO, is the OEM JDM Forester STI wheel. Check them out:

Here is the quick list:
2004-2007 FXT: 16x6.5” ET48 (17x7” optional in 2007) (ET is offset in mm)
2002-2005 WRX 16x6.5” ET55
2006-2007 WRX 17x7” ET55
2004 WRX STI 17x7.5” ET53
1999 Impreza RS 16x7” ET55 (will clear JDM 4 pot front calipers)

A great Subaru wheel info link (thanks Peaty):
Wheel info (offset etc.) - ScoobyMods

3. Sway bars: This would be my second modification, and a good bang for the buck. The cheapest option is getting a rear swaybar and sway bar bushings from a 2004 WRX STI along with the rear STI sway bar mounting brackets. The front bar on the Forester is the same size as the STI so there is no upgrade. Our endlinks are the same as the 2004 STI. If you use your stock FXT mounts and don’t upgrade to the STI mounts you will tear the mounting ears, maybe not today or tomorrow, but eventually.

STI rear swaybar upgrade part numbers:

[email protected] 20451FE100 Sti 20mm rear sway bar
[email protected] 20466FE000 Bushing bracket (U shaped clamp)
[email protected] 20540FE200 Right STi mount
[email protected] 20540FE210 Left STi mount
[email protected] 20464AE050 STi bushing
[email protected] 902350013 Nuts

A link to the install (thanks again Peaty):
20mm US STi rear sway bar retrofit - ScoobyMods

The better option is to get aftermarket swaybars. There are many options out there. Perrin (made by Progress), Cobb (made by Hotchkis), Cusco, Whiteline, etc. I will wholely endorse using Whiteline for swaybars. And I even suggest getting them from Helping you to enjoy your car - Turn In Concepts (great service and price). Whiteline bars fit correctly, where as several others have reported fitment problems from other companies. I have yet to hear of a significant fitment problem for any of the Whiteline products.

Swaybars for 2004 STI’s fit 2004-2007 Foresters correctly both front and rear. The only exception to this seems to be the Cobb/Hotchkis bars which may need to be Forester specific. 2004-2007 Forester rear swaybars are actually slightly shorter than the 2004 STI rear bar and for some reason with the Cobb/Hotchkis bars people have reported getting the bar for a 2004 STI and having a problem. I’m not sure if people actually got a WRX rear bar, or what else is the factor, but just be aware.

There are many options for swaybar sizes and many technical discussions regarding what size to get. In general, match your front bar to your rear. I like adjustable bars because you can select your roll stiffness to the situation. Here is a link listing percent changes in stiffness based on change in swaybar diameter: Swaybar Sizing Chart

If you get a rear swaybar stiffer than the STI 20mm swaybar, you WILL break the stock Forester end link mounting brackets on your lateral links. There are three options. First, upgrade your lateral links to STI or aftermarket pieces (see item 5 for more information). Or get the Mo_Boost (username on the forum) lateral link reinforcements. Links to Mo_Boost reinforcements:

LLWS (Lateral Link Weldment Supports) FXT - Subaru Forester Owners Forum
Lateral Link Weldment Supports (Mo_Boost) - ScoobyMods

Or lastly get a completely different style of endlink which attaches to a machined aluminum box that inserts under the bolt which holds on the lateral links at the hub. This “boxed endlink” is made by PolTec Homepage You then simply “flip” your lateral link so the endlink tab points down, since the endlink attachment point on the lateral link is no longer used. HUH? Check them out here:
Box endlink install(Pol-Tec) - Subaru Forester Owners Forum
Rear End Links

“But….I was thinking maybe I can just weld the endlink tab to make it stronger.” Think again. The welding may weaken your lateral link and SNAP:
If you have welded your Sway Bar link tabs PLEASE READ! - Subaru Forester Owners Forum

I have a significant bias towards getting upgraded lateral links, which offer improved performance and handling at the same time as avoiding the issue with breaking, but on a budget, the reinforcements are the minimum that need to be done.

So you have larger aftermarket swaybars? You would also be well served by getting heavy duty swaybar mounts. Bigger bars have greater forces on the mounts and even the STI mounts can break. Several companies make heavy duty mounts. Whiteline, Cobb, Perrin, all come to mind. They are all pretty similar, but Cobb makes a really sweet set that are adjustable to allow them to change mounting forward to backward to compensate for an adjustable rear sway bar. Check them out here: - Adjustable Rear Mounts

“DAMN, I just installed my new swaybars and now they creak!” This common complaint can be fixed by a couple of methods. First, try properly lubricating the swaybar mounting points where they meet you new bushings. If this doesn’t fly, clean off the grease and try wrapping them in Teflon plumbers tape. Preferably the the thicker yellow kind.

4. Swaybar endlinks: The front and rear endlinks on our car are the EXACT same as the 2004 WRX STI. They are nice solid spherical endlinks. For many swaybar setups on a lowered car they will work perfectly and do not need to be upgraded. This is especially true of the front endlinks.

So when should you upgrade the endlinks? If you are running a suspension that is stock height or only slightly lowered you may bend your rear endlinks with a larger than stock rear bar (even just the 20mm STI rear bar). The forces on the endlinks with our high stock ride height can be very large when combined with a large rear swaybar. However, if you drop your car using WRX/STI struts and springs, you well might get away with the stock endlinks in the front and rear (assuming in the rear you also upgrade your lateral links).

Also, you may find benefit in upgraded endlinks that are length adjustable when running an adjustable swaybar. Having end links that adjust in height allows you to take out swaybar preload from side to side when moving the swaybar.

There are lots of companies out there that make endlinks. They generally fall into two categories: spherical bushings and urethane bushings.

Poltec, Cobb, Whiteline, Perrin, and Hotchkis make endlink styles with spherical bushings. Of these the Poltec, Whiteline, and Hotchkis are length adjustable. Endlinks with spherical bushings are more likely to groan/clunk. I’ve seen complaints from owners of all of the above brands except for the Whiteline (which are pretty new on the market). I personally have Poltec box style endlinks. They began creaking/groaning after a few months. They recently sent me warranty replacements (hassle free) that are of a different bearing design. We shall see.

Kartboy, Whiteline, Noltec, etc. make endlinks that are of the urethane bushing variety. This style may be better for your average daily driver because of the lack of noise. The Kartboy endlinks that are Forester specific are slightly longer in length than stock in order to help prevent swaybar “flipping” which is more likely on a stock height car. And of course Kartboy makes a quality product.

The Poltec endlinks with the box mounting system are the only ones that get rid of problems with breaking the mounting tab on the lateral link.

People with upgraded RSB end links (of any type), make sure you check to see how close the end of the bolt holding the top of the link to the bar gets to the bolt on the banjo fitting for the rear caliper's brake line. Here is the link for more information:
Rear Sway Bar (RSB) upgraded end link watch-out - Subaru Forester Owners Forum

5. Lateral links: Here is another area where the best option for your average daily driver comes from Subaru IMHO. Subuaru makes beautiful aluminum lateral links that fit the Forester and STI. They have solid spherical bushings with very well made rubber seals that appear to be very durable. They have very stout endlink mounting tabs for upgraded rear sway bars. They are NICE. The only downside is that they aren’t adjustable.

You can get these aluminum lateral links used from a 2004-2007 STI (although the bushings will be rubber) , or you can get them from SPT (with the spherical bushings). The part number for the SPT 2004-2007 Forester and 2004-2007 STI is the same: B0250SA000.

Supposedly the 2004 STI had slightly shorter lateral links, however, some have said that this is not true. Link to the thread discussing this:
Could someone please measure their lateral links - Subaru Forester Owners Forum

I don’t know for sure, but I do know that the upgraded lateral link listed for a 2004 STI is different on the SPT web site (it is the pink steel style). To be safe if getting your lateral links used, get them from a 2005-2007 STI. Of course if you get a set from a 2004 STI on the cheap, they might work fine.

Aftermarket lateral links are also available for your car. The only reason to get these is if you want adjustable lateral links. These allow you to make toe and camber changes in your rear suspension more easily and you can avoid rear camber plates which are limited in selection and are reported to have clunking problems. These are most readily available from Poltec and are the same parts used on 2004-2007 STI’s. You can get them with spherical bushings or polyurethane bushings. You can get them with box endlinks or standard endlink mounting tabs. On my car the spherical bushings have been quiet so far. These are also available from Cusco, but they are noisy and expensive.
You might be able to get the pieces from Whiteline or Hotchkis that are made for a standard WRX (different swaybar endlink mounting system) to work as well. If you are trying this, you already know what you are doing.

Lateral link install:
Poltec Adj. Aluminum Lateral Links installed pics - NASIOC

6. Springs/Struts: Any spring that fits a 2004+ WRX or STI will fit your Forester. Of course just because they fit doesn’t mean that they will work well.

On stock struts there are three available springs. The most commonly used are either the JDM Pink SG Forester STI springs or the just released Swift SG Forester Springs. Both of these springs are pretty equivalent, giving a 1” drop and a firmer ride with slightly higher spring rates. The Pink STI springs are JDM only so they are pretty expensive. The Swift springs give more even fenders front to back because the front drop is relatively more than the rear drop (by a couple of mm) and they are significantly cheaper. I would probably get the Swifts. Also available are the Whiteline Forester specific springs.

JDM Pink link:
JDM Forester STi pink springs for SG (03 - 08) - ScoobyMods

Swift link:
Swift Sport Springs - Forester Specific - Subaru Forester Owners Forum

If you put springs intended for the WRX or STi on your stock Forester struts they will wear out quickly because of the huge drop and higher rates. A few others may disagree with this statement. Tough nuts. I’m right. :icon_wink:

“I want to keep my ride height but I want my car to handle like a Porsche, Ferrari, EVO, Miata, STI, etc.” Good luck. :lol: There is a reason that a Porsche GT3 has 4” of ground clearance. But you can get it to handle really well. For this goal your only choice are getting JDM Forester STI spring/strut takeoffs. This gives you a 1” drop and springs that are matched to an inverted Forester specific STI strut. Pure sweetness. $750, what a bargain.

Link for the JDM Forester STI springs/struts:
JDM Forester STi Suspension (Take-off) - ScoobyMods

Link of a Forester STI being flogged:
YouTube - 5thGear - Subaru Impreza WRX STi vs Subaru Forester STi

So you don’t mind a dropping your Forester 2.5-3.5.” You are in luck. The WRX struts/springs give a nice ride/handling compromise with a 2.5” drop. The STI struts/springs are more performance oriented and give a 3.5” drop. Any 2004-2007 WRX or a 2004 STI spring/strut combo will bolt right up to your car without any problems. Now your car will handle like a WRX or STI. Really. The WRX struts are conventional KYB struts. They were revalved in 2005 and by report this gives better handling and ride quality. If getting WRX takeoffs, look for 2005+. If you don’t mind a harsher ride, then get 2004 STI springs/struts. ONLY the 2004 STI struts will work with the SG Forester because the hub mounting was changed for 2005. The 2005+ STI struts can be made to work, but it isn’t likely worth the effort. The STI struts are fancy inverted struts. They are pretty darn stiff and actually give better ride quality and handling with stiffer than stock aftermarket springs that match the valving better.

Also, if you are doing STI struts, make sure you remove the grease in the struts and replace it with a higher quality lubricant such as Mobil 1 synthetic grease. This will decrease the likely hood of the dreaded STI rear strut clunk that has lead to so many warranty strut replacements. Here is the link:

If you want aftermarket struts for the Forester there is one option that I know of, and is the KYB GR2. They are reported to be slightly stiffer than the stock strut.
KYB GR2s with JDM Forester STi pink springs for XT - Subaru Forester Owners Forum

You can also use aftermarket struts made for the 2004-2007WRX or 2004 STI. They are made by Koni (inserts), Tokico Dspec, KYB AGX or GR2, and Ohlins. The Ohlins are the ULTIMATE strut for your street driven Forester, of course they cost $2000.

If you are using struts for a WRX or STI, and you want aftermarket springs, you should get springs made for those struts, and don’t get springs that slam the car. I chose Prodrive 2005 STI springs to go with my 2004 STI struts. The springs made for 2005+STI’s give slightly less of a drop than springs for the 2004 STI because the 2005 + STI have a little less suspension travel available so the springs aren’t as effective with more of a drop. Here is a great link listing WRX/STI spring rates: Spring Rate Chart

Here is a link to give you an idea of your Forester ride height with various spring/strut combinations (thanks Richard):
What is your ride height? - Subaru Forester Owners Forum

If you are getting lowering springs for either the STI or WRX struts, you need to cut off 1 “bump” from the bumpstops (or in the case of Prodrive springs install the provided shorter/stiffer bump stops). Here is a link on changing the bumpstops on the STI struts which are inside the strut body:
STi prodrive bumpstops - NASIOC

7. Coilovers: Coilover suspensions give you the ability to adjust ride height using threaded bodies to mount the spring perches. Sounds like a great idea. However, as you raise and lower your car the alignment gets changed and you should be prepared to account for this. And the struts used in many or most coilover suspensions are not made to last very long between rebuilds. Because of this they tend to get clunks clanks moans and groans. My wife doesn’t like this and neither do I. I don’t really consider them to be a wise choice for a street driven car. Some others may disagree. Okee dokey. Just be warned. If I was getting coilovers, I would get Bilstein PSS9’s.

There are no coilovers currently available in the US market that are made specifically for the Forester. These would allow you to keep a closer to stock ride height rather than the large drop provided by WRX/STI specific coilover.

Megan Racing has a Forester specific coilover almost(?) done. Here is the thread for more information:
Update on MeganRacing Coilovers for SF/SG - Subaru Forester Owners Forum

You can get some JDM Forester specific coilovers. Contact for information. Brand new looking JDM JIC MAGIC FLT-A2, $1200. Sweet deal. Clunking? Maybe.

Any coilover made for a 2004+ WRX/STI will work on our car. A cool option that would keep some respectable drivability at a low cost would be using Ground control threaded perches on a Koni converted WRX strut body. Check out this thread for information:
Ground Controls and shocks discussion - NASIOC

If you want a really cool coilover setup check out these:

8. Camber bolts: These are bolts that are in the lower bolt hole where the strut attaches to the hub. They are “eccentric”- that is not round to allow “wobble” in the strut that allows changes in camber. You already have camber bolts in the UPPER front strut mounting hole, giving the stock front strut camber adjustment. The front strut Upper mounting hole is an oval to accommodate this wobble. Here is a link with picture:
And another link on getting even more camber adjustment on the front:
Does any one use two sets of OEM camber bolts? - NASIOC

Your aftermarket camber bolt would be used to correct increased negative camber in the rear of the car encountered when lowering the car. The UPPER bolt holes in the rear struts are round so this eccentric bolt is of a different design and must “lock” into place. Here is a link (fill in Subaru Forester)to see what I’m talking about:

These camber bolts are made by several companies with slightly different designs including Ingalls, H+R, Whiteline, etc. I’ve only seen the Ingalls in person. Their design is sturdy and they are cheap ($15 at JCwhittney). Ingalls P/N 35420 for a single bolt or I-81260 for the pair.

Camber bolts are a cheap method to allow one of two things: correct/compensate for too much negative camber on a lowered car, or allow for increased negative camber on a stock height car.

The advantage is that they are cheap. The disadvantage is that they can slip and allow changes in alignment. This can and does happen. It might or might not happen to you.

9. Upper strut mounts or Caster/Camber plates: Aftermarket upper strut mounts serve the purpose of giving your suspension a firmer mounting point to give improved handling response and the expense of ride comfort. SPT makes rubber of a harder durometer than stock. These are identical to stock except for the rubber durometer (even using the same molds that have the stock part number molded into them). They are the same parts for all 2004+ WRX/STI/Foresters. Part numbers front: B0310FE000 and rear:
Don’t buy stock STI strut mounts because they are identical to your stock mounts, and don’t let anybody tell you otherwise.

Caster/camber plates serve two purposes. The first is the same as the stiffer upper strut mounts. The second is allowing changes in alignment by allowing movement of the upper portion of the strut. I’m stealing this straight from UNABOMER’s FAQ because I can’t do any better writeup specific to our cars:

“Camber plates replace the suspension top hats and allow for the adjustment of camber and/or caster. Typically, they feature a spherical bearing for the strut top to bolt through, and the hat portion bolts into the stock locations on the strut tower. Some feature an all metal "race only" design whereas others have some kind of damping built in to allow for some modicum of NVH absorption (lets be honest here, if you're running these then NVH probably isn't on your top list of concerns). The basic premise is the same for all of them; they allow for moving the top of the strut assembly to differ from the stock geometry. This changes the angles of the whole assembly to allow for the addition or subtraction of camber and/or caster.

Sounds simple right? Well, yes and no. While the theory is easy to understand there are some design factors that need to be considered when looking at these plates. There are two prevailing designs, one that allows for just camber adjustment and one that allows for both camber and caster adjustment. Here's how they work:

For just camber adjustment we have to look at the main parts. Aside from the various nuts and bolts there are two pieces that do the work. The first is the strut carrier. This is the part that actually bolts to the strut top. It will typically feature the spherical bearing that the top of the strut goes through and has a shape that makes it look like it has "wings." These wings are what bolt to the adjustment plate. The adjustment plate is typically triangular in shape and at each corner is a captured stud. These studs are what bolt it to the strut tower. In the face of the plate will be three rectangular slots. A large one in the middle, and parallel to this on each side is a narrower slot. The large middle slot accommodates the spherical bearing of the strut carrier, and allows it to stick through the plate. The more narrow slots line up with threaded holes on the wings of the strut carrier. When the assembly is bolted together, it bolts through these slots and into the wings that hold the strut carrier to the adjustment plate. When the entire assembly is bolted into the car, the rectangular slots run perpendicular to the centerline of the car. By sliding the strut carrier along the slots the assembly allows the top of the strut to move in toward or out away from the centerline of the car. This allows for the adjustment of camber by changing the angle of the strut assembly inward or outward relative to the centerline of the car.

It is important to note that while this design allows for just camber adjustment it is possible to install them to allow for camber and caster adjustment, but it will not allow for independent adjustment of each. When installing the adjustment plate, it is possible to turn the plates 120 degrees so that the slots are no longer perpendicular to the car's centerline. Instead by orienting the slots so that they run at an angle to the car's centerline it is possible to adjust the strut top at an angle. This has the effect of moving the top of the strut in/out and back/forward to increase or decrease camber and caster at the same time. Because of the nature of the design when you install it in this manner you cannot adjust camber without affecting caster. While it seems that this configuration may at first glance be the holy grail of caster/camber plates there are some things to consider. First, you cannot adjust one setting without affecting the other (for truly hardcore suspension geeks this is a bad thing). Second, in this configuration you will not be able to set as much camber or caster as you would by going with the second type of plate explained in this document. Racecomp Engineering, Hotchkis, and Cusco make plates that follow this camber only design.

The second type of plate is one that allows for independent adjustment of both camber and caster. The key word here is independent. It's possible to adjust either camber or caster without each affecting the other. There are many different designs when it comes to this type of setup. Some use a "floating plate" design. Some use an elliptical locating plate design. Some use a compound philosophy of the camber only plates. These are the
most common ones, and we'll look at each by specific manufacturer.

The Noltec (MRT units are rebranded Noltec) units use a floating plate design. In this case the strut carrier is a large plate with a spherical bearing in the middle. This plate is sandwiched between two rings. The rings have bolts through them that attach to the stock mounting points on the strut tower. This plate "floats" between the rings until the desired adjustment setting is reached. When the strut tower bolts are tightened the rings clamp on the strut carrier, and hold it in place, thus keeping the floating plate from moving.

The PDE and DMS units use a rather unique elliptical plate with a locator pin to hold the settings. On the strut carrier is a plate with holes bored into it according to an elliptical curve pattern. The strut carrier sits on a strut tower plate, and allows the strut carrier to float in place. By choosing a hole on the elliptical plate it is possible to choose a variety of settings that allow you to set camber and caster independently by predetermined amounts.

The Ground Control plates are very similar to the camber only plates listed above. Just like the camber plates they have a strut carrier that slides in the adjustment plate. The difference is the adjustment plate does not have captured studs. Instead a ring that mounts to the bottom of the strut tower holds the captured studs. The adjustment plate sits on top of the strut tower, and has slots parallel to the car centerline. So essentially, the strut carrier slides in and out on the adjustment plate, and the adjustment plate slides forward and back on the mounting studs.

When considering camber/caster plates there are a couple of other things to think about. Almost all the designs will add ride height to the vehicle due to the thicker than stock design. The two exceptions to this are the units made by Racecomp Engineering and Hotchkis, which are designed with this in mind, and will not raise the overall height on the vehicle. The other thing to consider is alignment settings. You can't just go shoving the top of the strut all over the place without affecting toe, which up until this point we have not mentioned. Before you jump into getting camber/caster plates please understand their full effects, and the principles of alignment adjustment.

Camber plate manufacturers: Racecomp Engineering, Cusco, Hotchkis, MRT/Noltec, PDE/DMS, and Ground Control. I’m personally using the PDE units and am very happy with them.” Thanks again UNABOMBER.

PDE camber plate install info:
PDE or DMS Camber Plate Question. - NASIOC

10. Bushings: Basically any bushing you can make stiffer on your suspension you can buy from SPT in harder rubber or Noltec in Polyurethane.

The only one you should do for sure is the bushing where the trailing arm attaches to the hub. You will either have to remove the hub and take it to a machine shop or get the special tool from BIGSKY at NASIOC to press the old bushing out and new one in while the hub is still on the car. You can get this bushing from SPT in harder rubber, part number: B0220FE010, or you can get a solid metal one from PolTec Homepage Here is a link for the rear trailing arm bushing:
Anyone have a spare rear hub around to take some measurements - NASIOC

11. Trailing arms: These are available from SPT, Poltec, Cusco, and a couple other JDM companies. You have two choices. Upgrade the stock trailing arm bushing with a stiffer SPT rubber bushing or a Noltec polyurethane bushing. Have the old ones pressed out and new ones pressed in at a machine shop. Cheap and effective.

Or get an SPT “pink” trailing arm. Part number: I don’t think the other companies make a rear trailing arm that is worth getting compared to the SPT part. What you get with the pink arm is a stock trailing arm painted pink with a really nice rubber sealed pillowball bushing. $250 is a lot to pay for a stock arm with two nice bushings in them. And they are so pink.

Trailing arm install info (For Poltec but works for any of them): sheet metal trailing arms install/how-to... thank Poltec! lots of pictures! - NASIOC

12. Front lower control arms and ALK: The 2004 STI aluminum front lower control arms bolt directly onto our car. They are lighter, stiffer, and give an increase in caster. All are benefits. You can get them new or used, it doesn’t matter. I got a used set for $250. New is about $425. An upgrade that is towards the end of the list.

Link to install the Aluminum lower control arms:
Aluminum control arm install - ScoobyMods

The ALK for the 2004+STI works on our cars. I accidentally got one for a 99+JDM STI which fit correctly but one of the bolts that fits through the subframe spacers was too short. I fixed it by getting a bolt the correct length from a hardware store. There is some debate as to whether the ALK should be used on the Forester. Here is the link to the discussion:
Whiteline ALK - Subaru Forester Owners Forum

I can tell you, holding both bushings side by side, the ALK is different than stock and should be one of your first upgrades for increased performance on the cheap.

I recommend considering only the genuine Whiteline ALK, as other manufacturers have had reported problems.

Here is the ALK FAQ:
Anti-lift Kit FAQ - NASIOC

More ALK information:
Whiteline Anti Lift Kit - NASIOC

13. Steering rack: The stock Forester rack is 3.0 turns lock to lock with a variable ratio. It sucks. The first upgrade is to install urethane steering rack bushings. It is kind of a pain in the *** but it is a cheap, effective upgrade to improve steering feel.

The real upgrade is a rack from a 2004 STI . Only the 2004 rack fits as the mounting design changed in 2005 and won’t work. The 2004 STI rack fits on all 2004-2007 Foresters. The WRX rack from 2002-2004 will also work but doesn’t give as quick of a steering ratio.

The specs:

04 STI 15.2:1 and 2.7 turns lock to lock.
02-04 WRX 16.5:1 and 3 turns lock to lock.
Forester 19.1:1 in the center to 15.2:1 near the ends and 3 turns lock to lock

Costs about $300 used and $550 new for the STI rack. I’ve seen WRX racks sell for $25. No joke. Now that is a big bang for the buck.

The link:
STI/WRX steering rack install instructions, anyone, anyone.... - Subaru Forester Owners Forum

14. Strut tower bars: They all stiffen the chassis by connecting the upper portions of the strut towers which are under corning load. They all probably work pretty equally whether they are the $25 STI knockoffs or the $500 Carbon fiber fancy JDM blingerific bars. I chose the JDM STI titanium strut bar for the front. Usually about $200.

In the rear you can get a fixed brace for cheap, spend a little bit more on a quick release Whiteline, or try to get the ultra sweet Mo_Boost quick disconnect triangulated rear bar. The Whiteline is the best affordable alternative. I have the Mo_Boost bar because it is a work of art. Check it out:
Mo_Boost Forester Quick Release Rear Strut bar - ScoobyMods

15. Bracing: The most common braces used for the Impreza platform are the underbody H brace, the fender braces, and subframe replacements. Guess what? The fender braces don’t work on the Foresters because we are missing two threaded holes at the door piller. It is possible that the GT spec fender brace would work because it also uses the bolts for the door hinges, but I haven’t heard of anybody trying.

I don’t recommend the subframe replacements as I don’t see any real evidence they stiffen the car and they could seriously effect the car’s crash worthiness. Also, I don’t think that the Impreza braces would work on our cars since our subframes are two separate rails rather than one large U shaped piece as on the Impreza.

Which leaves the H brace tying the subframe to the lower control arm. This might actually do something. There is a catch on the Forester. In the following link you see the mounting point with the circles attached to control arm bushing and the mounting points that are “ears” attached to the subframe.
Cusco Lower Arm Brace for STi - NASIOC On the Impreza platform both of these parts are mounted by removing then reinstalling the bolts. Simple. On the Forester the two “ears” attached to the subframe have to go UNDER the subframe rails. This requires loosing several of the subfram bolts to slip it under. IT WILL NOT FIT IF YOU DON’T DO THIS. Trust me. I stripped and gouged one of those 19mm bolts trying. 600lb/ft of impact wrench. Slip the brace under the subframe and it goes in like butter…if you haven’t stripped and gouged the 19mm bolt trying the wrong way.

The H brace fits fine with the Whiteline ALK.

There are lots of other little odds and ends braces to try. Let us know. I doubt they do diddly.

16. Alignment: After tires, this should be your next handling mod. Cheap, simple, incredibly effective. Guys that race in any venue are obsessive over tires and alignment specs because they make such a huge difference in handling.

Read this thread about Subaru alignments:
HowTo: 4 wheel alignment (toe and thrust angle) - NASIOC
I don’t have a lot to add to this thread. When your done reading it, read it again. It is a great read.
And a couple more:
Alignment Thread - NASIOC
DIY Alignment Method - NASIOC

My recommended specs for the street are:

Front: -1.5 to -2.0 negative camber 0 toe as much positive caster as you can get
Rear: -.75 to -1.25 negative camber 0 toe

Yes that is a lot of negative camber for the street, however, with neutral toe, you should not kill the inside of your tires. What eats the inside of tires is toe out, more than negative camber. I have specs in this range and my tire wear is completely even.

To get a good alignment you have to do a careful job yourself or go to a GOOD shop that specializes in performance alignments. I can’t emphasize this enough. Your average Goodyear/Firestone/Les Scwab/etc. will do a crap job. Talk with some high level local autocrossers. They live and breathe alignments.

I’m going to lay out what suspension modifications I would make for the following cash amounts:


I am going to hold myself to a couple of objectives. The first is that the car must remain highly streetable. To me this means no coilover suspensions. You may disagree with this, but they have a tendancy to make noise and need to be rebuilt on a regular basis when driven on grimey streets, particularly in the winter. You can buy a fabulous set of coilovers for $2000, no doubt. If that is what you want, cool.

Also, within the first couple of categories, I’m going to include tall ride height and much lowered ride height as this is a major decision you must make based on your use of the Forester. You can’t lower the car 3” and expect it to be an “SUV.” At that point it is a tall station wagon. Fine with me, but some people want to maintain ground clearance.

I’m going to allow myself the use of SOME used parts. These are typically going to be readily available takeoffs. I follow used part prices pretty closely but there is a range depending on condition, so keep this in mind. $100 for a set of blown struts isn’t a bargain, it is a headache.

I’m not including the price of install. If you need this done for you, it will cost a bunch of cash. It took me 16 hours to replace my entire suspension, but I’ve got air tools and a nice garage. It is very worthwhile, because then you really know what you are talking about and you might do a better job than most shops, because you really care about your car. Most of the install instruction can be found at
And as a hint, install instructions for a WRX work fine for the Forester.

Also, I’m going to give myself a free $100 for a GOOD alignment. This should be your first suspension modification. Period.

1. New 3 season tires ($100 per tire-$400). Lots of good ones out there. Consider some less known brands like Avon, Hankook, or Toyo. On stock wheels I would get 225/55-16 size. This size will be 1.6% smaller than stock-pretty close.
2. Used STI swaybar and mounts ($100) You might be able to find the bar for free, but you might have to buy the STI mounts and brackets new if you can’t find used ones easily.
With these mods you are going to get much better handling, but you’ll still have lots of body lean. It won’t be a sports car, just a more fun SUV.

Stockish ride height 1” drop:

1. Tires ($400)
2. Used STI rear swaybar and mounts ($100)
3. Forester specific lowering springs ($250)-Swift, STI, Whiteline
4. Whiteline Adjustable front swaybar ($200)- Either 22mm or 24mm adjustable
5. Camber bolts ($25)-might not be needed for this much drop

Lowered 2.5”-comfort:
1. Tires ($400)
2. Used STI rear swaybar and mounts ($100)
3. Barely used 2005-2007 WRX takeoff springs/struts ($200)
4. Whiteline Adjustable front swaybar ($200)- Either 22mm or 24mm adjustable
5. Camber bolts ($25)

Lowered 3.5”-sporty:
1. Tires ($400)
2. Used STI rear swaybar and mounts ($100)
3. Used 2004 STI takeoff springs/struts ($300) –they really are this cheap now
4. Used 2004 STI Prodrive springs ($150) or Grp N tops ($150)-dealers choice-helps with the STI struts bounciness known as the “bobble head”
5. Camber bolts ($25)

The stockish ride height will give you a nice handling car. The lowered comfort will give you a WRX clone with a bit extra zing. The lowered sporty will give you a car that can keep up with most sports cars- this is where things get exciting.

Stockish ride height 1” drop:

3. JDM Forester STI takeoffs ($750)-
the ultimate in stockish ride height suspension
4. Whiteline Adjustable front swaybar ($200)- Either 22mm or 24mm adjustable
5. Camber bolts ($25)-might not be needed for this much drop

Lowered 3.0” drop-comfort:
1. Tires ($400)
2. Used STI rear swaybar and mounts ($100)
3. Used 2004 WRX struts/housings ($100)
4. 2004 WRX Koni strut inserts ($600)
5. Used 2004-2007 STI springs ($50)
6. Whiteline Adjustable front swaybar ($200)- Either 22mm or 24mm adjustable
7. Camber bolts ($25)-might not be needed for this much drop

Lowered 3.5” drop-sporty:
1. Tires ($400)
2. Used STI rear swaybar and mounts ($100)
3. Used 2004 STI takeoff springs/struts ($300) –they really are this cheap now
4. Used 2004 STI Prodrive springs ($150)
5. New Grp N strut tops ($300)
6. Whiteline Adjustable front swaybar ($200)- Either 22mm or 24mm adjustable
7. Camber bolts ($25)-might not be needed for this much drop

Now I would start adding the following in this order to any of the above depending on what you want for height and ride quality:

1. Whiteline ALK-comfort or regular ($175)
2. STI aluminum lateral links ($400)
3. Whiteline adjustable rear swaybar 22mm or 24mm ($200)
4. Kartboy rear swaybar endlinks ($100)
5. STI rear trailing arm-hub-bushings ($50)
6. Noltec polyurethane front bushing of the rear trailing arm ($50)
7. Used STI steering rack ($300) (oh and for $25 you should have put in Whiteline steering rack bushings when you bought the car)
8. Used STI aluminum front control arm ($250)
9. Front strut tower bar ($150)
10. Rear strut tower bar ($150
11. PDE front caster/camber plates ($250)
12. Undercarriage H brace ($75)
13. Kartboy front endlinks ($100)
14. Ohlins struts ($2000)
15. 17” wheels ($750-$2000)- don’t buy crappy wheels- the minimum are used 2004 STI wheels, they might even come with nice tires.

Special thanks to:
The Wraith
Turn in Concepts
Everybody else who cotributed to this information.

I’m out of breathe. Time to chime in now folks.Feel free to PM me or post suggestions as I work on finishing

Justin Wade
2004 FXTi

Aleksey 12-01-2006 04:43 PM

From my experience 17" wheels seem to be an optimum size in comfort/handling/price ratio.

3. 20mm Impreza STi rear sway bar, arguably Ze biggest bang for the buck along with the tires.

Once you've covered these basics you can start looking at lowering your Forester. There are quite a few options here - you can change springs, or springs+struts, you can get coilovers. At least for 04/05 model year Foresters the full 04 Impreza STi suspension was a direct swap. Some people that prefer the best medium between comfort and handling install JDM Forester STi pink springs. They lower the car for about 1" and a bit stiffer but not stiff in comparison with the STi springs. Also there are people that install swift springs. Search this board for them and you should find a few interesting threads with details.

ten80 12-02-2006 08:04 AM is dirt cheap.

rktwgn 12-05-2006 06:05 AM

I'm running the '02-03 WRX wagon struts with '02-03 Prodrive springs (not WRX wagon-specific) and Koni inserts. I had to use '04+ rear strut mounts but this setup otherwise came directly out of my '02 WRX wagon and went right onto my FXT. I love it and the ride is very nice. The Prodrive springs are universally praised as giving the ideal street/light track ride and perfect drop (on the WRX). The Koni's are terrific (enough said). The install in the strut housing is well-documented. I'll post up some pic's in a few days.


skforester 12-05-2006 02:28 PM

Whiteline springs
I'm quite happy with the Whiteline "Control" springs and some top-rated A/S tires on 17x7 light alloys recommended by TireRack. The springs lower the car about 1.5", a little more in the front than rear for a nice appearance. The cornering and overall stability is so much improved with hardly noticeable comfort loss that I see no need to get into the rear sway-bar morass! :icon_wink:
Note that this is a general-use car that is now much more enjoyable for spirited forays, while still being a very versatile vehicle, exactly the reasons I waited a year for the '04 XT. :icon_biggrin:

DOHCammin 12-05-2006 10:40 PM

awesome information, I, like most have gone the STi strut/takeoff route and am extremely happy with the "bang for buck" performance. If anybody is trying this route, definately swap out tires and/or wheels at the same time. Most of the bounce in the suspension is associated with the fat geolanders.

another way I reduced bounce and lost a little more ground clearance was swapping the stock STi springs to Tanabe GF210 springs (similar spring rates to the wrx STi pink springs).

This suspension setup, along with the STi 20mm Rear sway bar, poltec endlinks and Cusco rear strut bar makes the forester stick like glue in the turns.

I would also agree with the 17" wheels being an ideal choice for the forester but some of us require the "stock rolling diameter" to keep the same gear ratio and use of the spare. you would have to run a 225/55 series tire on a 17" wheel or a 225/45 series tire on an 18" wheel. I stuck with the 18" wheel for a shorter sidewall, and, IMO better traction in the turns.

uh8myvtec 12-09-2006 04:23 PM

Is there much difference between 05 and 04 STi parts? I have frindes with 05 parts that I can get cheap i.e. rear sway and springs.

wadejg 12-09-2006 04:34 PM


Originally Posted by uh8myvtec (Post 122876)
Is there much difference between 05 and 04 STi parts? I have frindes with 05 parts that I can get cheap i.e. rear sway and springs.

The rear swaybars and springs are the same 2004-2007 STI. The front swaybar design changed in 2005 on the STI. Also, the struts are different with different hub mounting as the STI hubs were changed in 2005. They can be made to work but it requires quite a bit of effort. But as I said above, I don't recommend simply putting STI springs on the stock Forester struts.

Justin Wade
2004 FXTi

The Black Box 12-09-2006 06:12 PM

Wow! Nice write up! Definitely sticky material. Now I can reply "Do a search Noob!" and refer to the sticky at the top of the page.:lol:

You also might want to add that one of the advantages of using camber bolts is that they allow you to eek out a bit more clearance between the strut and tire if necessary. Not true with the plates.

Also big ups for mentioning alignment as a huge factor in improving handling. I see so many threads on NASIOC where someone spends thousands on their suspension or ask a lot of questions about swaybar sizes and a year later are asking what alignment specs to run or are satisfied with "within spec". *** over?:crazy:

You can easily spend a grand on mounting and balancing a set of summer tires yet I don't understand why people balk at paying $20-$30 more for a "to spec" alignment versus a "it's good enough" alignment when they have every "Mad tyte JDM yo" part on their car. :lol: Plus you rarely have it done more than once during the life of your tires which is usually two years or so.

Forester 2.5 XTi 12-09-2006 06:25 PM

Thanks for your time and effort. It'll be a great deal of help here now andin the future!


VincenzoL 12-13-2006 01:09 PM

Now if I could only figure out how much of this applies to MY01 SF5 chassis. A lot of information and my head is spinning! I basically want my car as low as I can go with a decent ride.

wadejg 12-24-2006 04:09 PM


Originally Posted by VincenzoL (Post 124611)
Now if I could only figure out how much of this applies to MY01 SF5 chassis. A lot of information and my head is spinning! I basically want my car as low as I can go with a decent ride.

I added a link for the SF guys at the top of FAQ:icon_cool: . Here it is:

Justin Wade
2004 FXTi

Mann Engineering 12-24-2006 06:50 PM


Originally Posted by wadejg (Post 122884)
The rear swaybars and springs are the same 2004-2007 STI. The front swaybar design changed in 2005 on the STI. Also, the struts are different with different hub mounting as the STI hubs were changed in 2005. They can be made to work but it requires quite a bit of effort. But as I said above, I don't recommend simply putting STI springs on the stock Forester struts.

Justin Wade
2004 FXTi

The rear bars on the 04/05/06/07 are all different rates between model years, but all with the same fitment. This means that they made damper and spring rate changes through the different model years. The 04STI uses I believe a 21mm and the 05 used a 19mm. The 06 went back to a 20mm and the 07 went back down to a 19mm again.

This is why when we were testing out the Swift Stabilizers for the STI we were trying to see how much of a difference the bars made for each model year. Because we did not want it to be at a point where the bars created any ill handling affects. So it took awhile to find the necessary model years to test the reactions on each model. Another reason why Swift did not originally want to design the bars for the STI because of the rate changes for each year. They warned us before we began any testing on the bars.


wadejg 12-24-2006 09:30 PM


Originally Posted by Mann Engineering (Post 128523)
The rear bars on the 04/05/06/07 are all different rates between model years, but all with the same fitment. This means that they made damper and spring rate changes through the different model years. The 04STI uses I believe a 21mm and the 05 used a 19mm. The 06 went back to a 20mm and the 07 went back down to a 19mm again.

I know that the 2004 STI rear bar was 20mm (not 21mm). Can't speak for the other model years though. They are definitely all the same fitment and interchangable between years, but certainly size could vary my 1mm.

The struts were changed different model years for the STI with different valving, however, it is my understanding that the spring rates and heights stayed the same for all the model year STI's which is why nobody tries to swap stock springs between model years. It is interesting that Prodrive and Tanabe both changed spring designs for the 2005 and later model year STI because the struts have less travel and don't work well with dramatic height drops.

Justin Wade
2004 FXTi

Mann Engineering 12-25-2006 02:06 PM


Originally Posted by wadejg (Post 128557)
I know that the 2004 STI rear bar was 20mm (not 21mm). Can't speak for the other model years though. They are definitely all the same fitment and interchangable between years, but certainly size could vary my 1mm.

The struts were changed different model years for the STI with different valving, however, it is my understanding that the spring rates and heights stayed the same for all the model year STI's which is why nobody tries to swap stock springs between model years. It is interesting that Prodrive and Tanabe both changed spring designs for the 2005 and later model year STI because the struts have less travel and don't work well with dramatic height drops.

Justin Wade
2004 FXTi

Yeah I knew that the 04STI has something like that but was not sure. I know that the 07s have a 19mm because I measured it the other day when I was installing a catback system on our 07STI. I think that all these small changes make it annoying for us. :P


All times are GMT -8. The time now is 05:12 AM.

Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.

vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.


Title goes here

video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome