[Draco-REX]

DISCLAIMER: There's no such thing as an Ultimate suspension for everyone. This is MY suspension and therefore it is MY definition of ultimate. Now that that's out of the way, let's begin:
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The Beginning

I thought I'd put down my plans and experiences with modifying my STI's suspension. I'm not a big suspension guru, nor do I have a ton of track time under my belt (yet). However, I do drive my car a lot, I know how it handles, and what I want different. I also have a very good working knowledge of how suspensions work, how the parts interact, and how to tune them on a mostly theoretical level. There is also a long history of watching the heavy hitters of IWSTI.com's suspension forum and paying attention to their decisions and experiences.

And so, I began.

My car is a 2007 STI. I bought it new so all mods have been done by my own hands. I want the car to be somewhat neutral in turns with just a bit of oversteer when I want to rotate the car more. I want to achieve this by INCREASING the grip in the front, rather than decreasing the grip in the rear. If I just wanted rotation at the cost of grip, I'd slap a 27mm rear bar on and go 3-legging all day long.

There's a reason my plate says "GRRRRIP"

And I want it ALL, while maintaining a ride that doesn't cause headaches.

So my list:
GroupN Bushings
TiC Clunk Killer (TiC diff crossmember bushings and Kartboy outrigger bushings)
Whiteline subframe lockdown bolts
Whiteline 24mm adj rear sway w/ Kartboy endlinks
Whiteline 27mm adj front sway w/ Kartboy endlinks (this may not stay on my car, more later)
RCE Black Springs
Ohlins Fixed Perch Struts
RCE Lowering Camber Plates
Whiteline Roll Center Adjusters
Whiteline Anti-Lift Kit

Currently I'm on the stock rims with stock-sized Hankook R-S2s. But that should change in the near future to 18x9s with 255/35-18 Z1*s or RE-01Rs.

I've just finished the bulk of these mods, so I'll be breaking my thoughts up into multiple posts. My goal here is to provide another POV (corner-carving DD) on these upgrades, why I think they're the best setup, and hopefully help some people understand that you don't need an F1 suspension for a world-class ride.

Recommended Reading

If you want to know the Hows and Whys of suspension, there are two excellent books I recommend. I read both of these because I wanted to know what I was doing to my car with the mods I planned. These were a big help and I now understand a LOT more about what goes on under my car.

How to Make Your Car Handle by Fred Puhn
Tune to Win by Carroll Smith

[Draco-REX]

Bushings and Lock Bolts

There are a number of bushings in the STI, and all of them are soft, squishy, and just plain bad for keepign yoru suspension straight. Anyone who's done serious upgrades to their suspension are not seeing the most out of their car if they haven't done bushings. They aren't as hard as many think to install; I've done all of mine myself with help from some friends, and only one specialized tool which is really cheap to rent.

I went with the GroupN bushings instead of Poly bushings for a few reasons:

1. GroupN bushings are about as stiff as Poly, so I'm not wasting my time, and they're easily available from SubaruGenuineParts.com

2. Rubber bushings don't need to be greased. Grease can hold dirt against the bushing and moving part which can prematurely wear both.

3. Most poly bushings only allow movement around one axis. The GroupN bushings allow slight movement in the other axis' without extra squish, allowing the suspension to move properly. The STI's rear suspension is located by lateral links and a trailing arm that is at a 90* angle to the movement of the links. This means that the links move forward and back slightly while the trailing arm moves in and out slightly through the range of the suspension's motion. I did not think it prudent to hinder this secondary movement.

So the GroupNs were the choice for me. Besides, they are called GroupN bushings because Subaru uses them in their rally cars that race in the GroupN class. Can't beat race-proven parts.

Why does Subaru ship their cars with the squishy bushings? Comfort. While the upgraded bushings don't increase NVH THAT much, they do a little which Subaru has decided is too much. Also, with the way the suspension is designed, the extra compliance (squish) of the stock bushings makes the car understeer more which is considered safer for the average Joe.

The Lock Bolts.
At some point during the construction of our cars in the factory, the rear subframe is bolted directly to the chassis. These are removed before shipping, however, to reduce noise. Instead, the subframe is connected to the body throguh four rubber bushings. That's more compliance, more vagueness, and jsut more softness for our cars.

The WhiteLine lockdown bolts have a tapered shoulder that fits the subframe and helps positively locate it under the car. WL has been running their bolts on their test car for a long time now, including tons of track days, with no ill effects. The disclaimer about increased wear in their instructions is just a CYA move.

Lateral Link bushings and Lock Bolts.
This was actually my very first suspension mod. A friend of mine in the local Suby club (Williaty) mentioned that he wanted to put together a tutorial on how to install the lateral link bushings. I wanted to do bushings in my STI, but figured they'd be too much of a PITA to bother with. But he assured me I could do them myself and would walk me through it. (As a side note, Williaty has been a HUGE help to me in working on my car. I wouldn't be where I'm at without him. He knows his stuff.)

This is his Lateral Link Bushing swap How-To.

Also, while I was under the car I figured I'd insert the Subframe Lock Bolts. Those are very straight-forward to install. Though you may want to make sure the threads are clean as they will often build up dirt/rust/undercoating. Otherwise the bolts wll be hard to get in all the way.

SO. Ever go to take a corner and feel the car shift its weight, and then seem to "sit" afterwards? That's the bushings, mostly the lateral links.

What goes on once the tires load up at the entry to a turn:
1. The bushings between the knuckles and the lateral links squish, allowing some lateral movement.
2. Then the bushings between the lateral links and subframe squish, letting the car move more laterally.
3. Then the bushings between the subframe and the body squish, meaning even MORE lateral movement. of the body.

It's amazing the stock car feels as good as it does with all that wiggling there. Addng the lock bolts eliminates #3, and the GroupN bushings minimize #1 and #2. The result? Less vagueness when cornering. Less upset from the rear when going over bumps in a turn. And a more solid and attached feel from the rear of the car.

These are easy to do, much cheaper than aftermarket links and feel great when done.

Differential Crossmember Bushings and Outrigger Bushings.

These I did next. They're very easy and there are a number of how-tos out there. These bushings were poly as there are no GroupN equivalents, but because these are not in places of articulation, I don't mind. I went with the comfort since there's not much difference between comfort a race as far as results go. I used the TiC Diff bushings and the KartBoy outrigger bushings. Just doing these bushings installs gets good results.

The biggest is less clunk when shifting. The rear differential is in a cradle under the car. When you shift hard, the cradle can move easily and it comes up and thumps the underside of the car. These two sets of bushings minimize that. The crossmember bushings also reduce some driveline lash by keeping the diff housing from twisting. If you ever do the diff bushings, you'll be amazed that the stock bushings even kept the diff in place!

The downside to these sets is NVH. There isn't much when cruising, but when downshifting, you will get a loud growling noise in the cabin. It's not anything wrong, just the bushings transmitting normal diff gearing noises into the body structure.

Trailing Arm Bushings

These are great to reduce driveline lash (pogo) and to make changes in speed more positive. The trailing arms are mounted to the subframe ahead of the rear wheels and connect to the bottom of the knuckles. Because they run front to back, they are the main suspension piece for transfering power from the wheels to the body. Remember how squishy the stock bushings are? Well you have to overcome that squish when you accelerate or brake. Replacing these bushings will make the car feel much more responsive when you hit the gas, and will reduce some of the low-speed pogo you may feel.

Again, Williaty has writeups on how to change these bushings (Have to go to DirtyImpreza.com for these:

Removing and Installing the Trailing Arms

Replacing the rear Trailing Arm Bushing

Now, here is where you will need a specialized tool. The Subaru tool for the rear bushing is costly, but BigSky (on IWSTI.com) has a custom tool JUST for replacing this particular bushing. It's an ingenius device and works incredibly well. As for the front trailing arm bushing, this poses a bigger problem. You can't replace the bushing itself unless you have a 10-ton press to do so. However, BigSky again has the means to do it and can sell you a set of OEM links with the GroupN front trailing arm bushing already installed. Or you could swap the trailing arm.

(To be clear, the front bushing is IN the arm, the rear bushing is in the KNUCKLE. SO swapping just the arm only changes the front bushing.

At this point, all but two suspension bushings are replaced, and those are the rear tophats. I'll cover those later though. Now, the rear of the STI feels much better. The RE070s have amazingly stiff sidewalls, but with the stock bushings the rear still feels like there's flex. With all of these bushings done, the car feels solidly planted and positively located on the road. No more vagueness, no double "sit" when loading the suspension in a turn. Just a solid, confidence boosting, sportscar feel.

No suspension is complete without doing bushings.

[Draco-REX]

Swaybars and Endlinks

Swaybars are the #1 Bang-for-the-Buck suspension mod you can do for your car. Just bolting on a rear sway bar will improve the car's handling drasticly. I took a friend for my shakedown run after just bolting a 24mm rear bar on and he was shocked. "Wow! The car actually TURNED!"

So... My bars:
For my STI I chose the Whiteline Adjustable sways. Whiteline has been a solid, dependable name in STI suspension circles for a long time now. I figured I'd go with them as a lot of people have had good experiences with them, and because there was a lot of info out there on them.

I currently have a 27mm front bar and a 24mm rear. When I originally spec'd out my suspension, this was the popular combo and many people have said they have good luck with a 27mm front. But right after I ordered my suspension, Stretch made a post about how he prefers the 24mm front. This got me thinking.

Originally, I felt that the STI's poor camber curve (the rate at which the tires lose negative camber to body roll) was a good reason for the stiffer bar. But after installing it, I now agree with Stretch under MOST conditions.

But lets start with the rear since that was the first bar I installed.

Rear Sway Bar:
The STI responds WONDERFULLY to a bigger rear bar. It reduces some of the designed-in understeer and really helps the car rotate. In the situation above, I had the rear bar at its softest setting (22mm equiv) and the car would rotate under throttle. It really improved the car and for someone who just wants a mild suspension upgrade, just a rear sway is a great place to start.

Installation is a snap, though I highly suggest replacing the endlinks. After just a couple winter months, mine were looking a little.. used. I'm sure they were good enough, but they just didn't appear to be capable of handling the new bars or the use the car would likely see. I went with KartBoy endlinks, again because of reputation and lack of issues. They are good solid pieces, and htough they are bushed, the bushing is so thin it might as well be a pillowball... but without the need to grease.

Front Sway Bar:
The front bar was another matter. I had heard stories about people installing the front bar WITHOUT dropping the subframe. Since Williaty had dropped the subframe on the first front sway install he did, we decided to try it without this time. Big mistake. Yes, it is possible to replace the front sway without removing the subframe. No, it is not easy, and doesn't save you any time. We could have finished the swap in half the time if we had just removed the subframe. So if you plan to do a front swaybar swap, saev yoruself the headaches and drop the frame. The ability to reach the bolts for the sway brackets is worth the trouble in and of itself.

Afterwards, the 27mm front sway was an incredible change. While the 24mm helped the car rotate, the 27mm bar flattened the car out. That big front bar made my car feel like a go-kart. It cornered so flat I was immediately impressed. But I did notice that the car felt more like stock as far as rotating in a turn. Applying throttle in the middle of the turn would make the front wash out like stock. But the flat attitude was really addictive.

It was later when I decided the 27mm was WAY too big. I often go on "fun runs" to the twisty roads in the area with other subaru owners. We have a blast and cover pretty much every kind of road surface imagineable. What I noticed was that on tight, bumpy corners, the inside tire would skip across the bumps. Not at all a good feeling, and definately a contributer to understeer.

Now, while I won't recommend a 27mm front bar for a mildly modified suspension, I will add that my car FELT great. The stock springs and struts are very well matched, and the ride is VERY good for a stock setup. Except for "bobblehead" (which can be fixed with an upgraded seat) the stock suspension, plus bushings and swaybars, is absolutely EXCELLENT for a DD. I really felt I could have been happy stopping here.

Little did I know what was in store for me. But at this point I stuck with my 27mm front bar because I had a lot of suspension changes to come, and I thought I might just need a bar that big in front..

Now, as of this post, I have installed my ALK, Struts, Springs, and Camber plates. The 27mm is perfect at this point in my suspension's build. Whereas I would not recommend a 27mm to most, I will say that it does work if you have EXTENSIVELY modified your suspension. But unless you plan to go whole-hog with an ALK, camber plates, and stiffer springs, go with a 24mm/24mm combo.

EDIT: I did forget to mention something. Though I feel the 27mm front bar is pretty much perfect at the moment, I have yet to install the Roll Center Adjusters. When that kit goes on, the 27mm bar may become too big once more. If that is the case, I'm going to go down to a 24mm bar. Now WHY the RCAs will do this is something for a post focusing on them.

[Draco-REX]

Anti-Lift Kit and the Roll Center Adjuster

This is a difficult section to write. Both of these mods deal with the actual Geometry of the suspension (angles of the mounting points in relation to each other), and one concens the elusive Roll Center. Yes, Geometry meets Physics; every highschool kid's nightmare.

"Anti" Suspension:

I'm gong to start here because it's the easier of the two to explain. "Anti" suspension (Anti-Dive, Anti-Squat/Lift) gets a lot of various opinions. It looks good at the surface, but when you look deeper there are some basic failings.

"Anti" suspension geometry uses torque, from either the brakes (Anti-Dive) or the axles (Anti-Squat/Lift) to keep the car level. This is done by angling the suspension arms in such a way that the lines drawn through their pivots converge. When this is done, the suspension essentially creates a lever that can reduce or eliminate the nose movement caused by braking and/or accelerating.

Because our front wheels are driven this "Anti" geometry can be used to counteract dive under braking AND lift under acceleration. If the nose doesn't move up or down, the camber doesn't change; which makes this "Anti" suspension seem like a great idea and a "something for nothing" design.

Unfortunately it isn't. To counteract the movement of the nose, the suspension needs to apply force in the opposite direction; and this force comes from the brakes or drivetrain instead of the springs. This means the suspension becomes stiffer. And as we've learned, a stiffer suspension is less able to handle bumps and irregularities in the road surface (i.e. the real world) which means the tires will not be able to maintain their grip. The end result is understeer.

Manufacturers use this sort of suspension geometry to reduce pitch changes which can frighten some drivers, and feel cheap to others. And the added understeer reduces lawsuits too.


Whiteline Anti-Lift Kit:

The Anti-Lift Kit is a bit of a misnomer, it actually removes the "Anti" geometry of the suspension. Whiteline has a whitepaper (no pun intended) on the ALK and its effects here. Essentially, it moves the virtual pivot point of the suspension lower and prevents the brake and driveline torque from messing with the suspension.

With the ALK installed there is no more Anti-Dive geometry, and the Anti-Lift geometry has been changed to "Pro-Lift" geometry. The result here is a more compliant suspension. When you get on the brakes or gas in a turn, your individual wheel rates (the amount of force needed to compress the suspension for a particular wheel; like spring rates, but total for the wheel) don't skyrocket, meaning the suspension can do its job and keep the tires in better contact with the road. Better contact = more grip.

Before the ALK, the 27mm front bar returned the car's tendency to understeer after installing the 24mm rear bar. On the exit of the turn, if I got on the gas the front would push wide. Some conteract that by using even more power and essentially overpowering the rear wheels to change the balance of grip from understeer to oversteer. As I said above, I want to increase front grip not decrease rear.

After the ALK the front grip improved dramaticly. I could feel the softer suspension as the tires would follow the road better and I could get on the gas sooner. Whereas the car used to have seemingly endless understeer, now I could use the gas on the exit of a turn. The car still pushed with too much gas however. But I feel that was the front sway proving to be too large again.

One note: When you install the ALK, it's good to perform the "Free Caster Mod" while you're under there.


The Roll Center

Roll Centers are the Quarks of suspension design; you never know exactly where those suckers are. But you can aproximate their location. I'm using plurals here because the front and rear suspensions each have their own roll center. There's a good article by Stretch here about finding the rollcenter of a car with an example using the STI. However, as you can see, when the suspension moves the Roll Center moves as well. So at any point in time in a race, the Roll Center can be nearly anywhere.

The Roll Center (RC) is important, because it's essentially the "hinge" that the car rotates around when it rolls left and right. Knowing basicly where it is helps determine how the car will roll, and how much it might want it. The height of the RC can actually control how much the car will roll. The difference in height between the RC and the Center of Gravity (CG) is called the "Roll Moment" or "Roll Couple." But the easiest thing to do is to think of it as a Lever. Just like a lever, the longer it is the more leverage can be applied to move a heavy object (car). So the larger the distance, the more roll the car will have. The more roll the car has, the faster you lose negative camber. The issue with our cars, as in Stretch's article, is that when you lower an STI your RC lowers 2.6 TIMES the amount you dropped the car. You've lowered the CG of the car, great. But you've just lengthened the "lever" that makes your car roll by nearly three times as much.


Does that mean if the RC is the same height as the CG (zero Roll Moment) the car won't roll?

Yes.

Then why bother with sway bars and other BS if we can eliminate body roll entirely?

This answer isn't so simple. Raising the roll center that high can cause a couple issues.

First is what's called Jacking. If you look at the image of the STI suspension in Stretch's article, you'll see a line from the contact patch of the tire to the RC. That is a line of force; the cornering force of the tires. Because it is going upward, it will literally try to push the car upwards. Increase the height of the roll center, and the upward push gets worse. (This is different from the Lift I talk about above in the ALK section) Jacking the front of the car up raises the CG (Bad), Raising the CG increases the Roll Moment (Bad), increasing the suspension's droop in the middle of a turn (Bad), and the drooping suspension ruins camber (Bad).

Second is that to get such a high RC, you end up with suspension geometry that does bad things to tires. With our suspension design (MacPherson Strut) the lower control arms would have be angled downwards drasticly (or the struts would have to be angled inwards so much we wouldn't have room for an engine). As the suspension compressed, it would scrub the tires (Bad), and you'd gain so much negative camber it'd be jsut as bad as having too little.

So! Too high of a RC is bad, and too low is bad. And we're just scratching the surface of what adjusting the RC can do (RC height can be used to controll weight transfer at different ends of the car for instance.)

And compounding these issues is that the RC drops because the angle of the lower control arm has changed. Now that the lower control arm is flat with the ground, or even above flat, as the suspension compresses it will pull the wheels in (more scrub) and that stands the struts up more which means you lose negative camber. Ideally, you want the lower control arm to be at a right angle to the chassis when the car is at maximum roll. That will get you the greatest amount of negative camber when you most need it.

Whiteline Roll Center Adjuster

The Whiteline RCA (and 6Gun BJE) counteracts the issues with lowering a Subaru by dropping the lower control arms to a more natural angle which also raises the RC.

I have not installed this yet, so I don't have any impressions.

[Draco-REX]

Springs, Struts, Camber Plates

Now to the meat and potatos of the suspension. When it all comes down to it, the springs and struts are the most important parts of the suspension. They keep the tires in contact with the road so the tires can do their job, and they keep the car stable so the rest of the suspension can do its job. If a strut or spring can't do this, then it's junk. I know I sound harsh, but if a part doesn't do what it's supposed to do, then what's it good for?

The Springs

This choice was helped by Stretch's Suspension Calculator. Now there are a lot of considerations when picking springs and different people have different priorities (hence the popularity of S-techs....) Now I wanted something that wasn't going to mess with the ride height too much (and the resulting issues from that) while giving me a good stance. But mostly, I wanted springs that would be a bit stiffer, but also comfortable. Basicaly, I wanted it all, but in moderation.

This really narrowed the choice down to a few different choices: Prodrives, Pinks, RCE Blacks, or Swifts

One great aspect of the SSC is the spring frequency calculator. You can input the spring rates of a set of springs and it'll let you know what the ideal rate for the rear is in relation to the front at a particulkar speed. The reason why I like this , is because you can input a cruising speed, feed in rates and see how the car will settle. If you get the frequencies right, the car will hit a bump at that speed and settle flat afterwards. Too high a rear frequency, and the rear will settle first. Too low and the nose will drop. A comfortable car is one that remains flat (not to mention this gives greater confidence too).

RCE Blacks, with their slightly higher rear rates over the Prodrives, proved to be spot on for the cruising speed I want. Then add the fact that they had a mild drop which is better for our geometry and that's another tick in their favor. Also, because I do plan to drive this car "enthusiasticly" once in a while, as well as run sticky street tires (RE-01Rs at the time), the higher rates were a better match.

Overall, the RCE Blacks were a perfect match to my requirements. Looking at the numbers, I think there was a small hole in the spring market that not many knew existed; and RCE filled it with their Black springs. Certainly without them, I'd have had to compromise on rate, ride, or height.

Now, if I had decided to go with Coil Overs, this would largely be moot. You can get pretty much any spring rate and height you want with a set of coilovers. But at the time I selected my components, there were no coilover options out there that weren't super-damped, requiring spring rates that would push the ride quality off the edge into track territory. So a set of coil-overs were not an opton for me.

Since then, however, TiC has come out with their SST coil over solution. I haven't played with the numbers yet, but from the reviews they appear to be a viable alternative for those who want a good ride, but would like the advantages the coil overs offer. Frankly, if I were to do my suspension over again, I would be giving the SSTs a serious look.


The Struts

Unfortunately, there really wasn't a great revelation concerning the Ohlins. Strut options are very limited for our cars. Considering this, it's very lucky that we have an option like the Ohlins available to STI owners that don't want to switch to coil overs.

Ohlins have a good history of provding quality dampers with consistent adjustment. Additionally, I don't think I've ever heard a bad review of them. One of the big things that gave me confidence in my choice of Ohlins was a webstie from a racing engineer that worked on dampers. This guy had taken apart and reassembled probably every major damper out there and Ohlins was one of about 6 companies on his short list of good dampers. I wish I could find that website again, it had tons of great info.

The ride from the Ohlins is great. I've ridden on rods with small bumps and expansion joints and roads that were miles of undulating tarmac. Never once did I think the tires were going to leave the ground, and always the ride was very comfortable.

As far as settings go, I'm running 12 clicks from hard up front, and 14 clicks in the rear. I've been distracted as of late, so I haven't experimented wth the settings yet. When I do, I think I'm going to end up choosing some that are a touch softer, but not by much.

Camber Plates

Camber plates are just a great addition to the front suspension. The biggest downside is that there is no compliance to them. Any energy that isn't absorbed by the strut will be transferred completely to the body of the car. They can make a suspension feel rougher than it is because the bumps will have more of a peak to them rather than being blunted by the rubber in the stock tophat. But when you watch the car, you can see that it's not moving as much as it seems.

The great thing about camber plates, other than the increased camber adjustability, is the improved turn-in. If it's one thing that reviews of the STI have often complained about, it's the lack of turn-in. Part of that is the fact that when you turn, the suspension has to move and "squish" all the bushings before the car will turn. One of those big "squish" points is the tophat. A camber plate with a pillowball at the top has absolutely no "squish". Couple that with the other improvements above and a good alignment, and the car will feel like it WANTS to turn.

One of my biggest reasons for choosing the RCE plates was that there is a "lowering" version that will lower the front of the car. The drop is about 3/8" or 10mm. Coupled with the black springs, that got me an ideal (in my opinon) 1" drop in front. I wanted more of a rake to get better aerodynamics, and to move the balance of the car more towards oversteer (though I'll need to get the RCAs installed to see this effect fully).

Now one thing I didn't realize, due to my inexperience with these parts, was build quality. The RCE piece is fantastic. I have since installed a set of Whiteline Max-C plates in my other car and I find the RCE plates to be better built and easier to adjust. And unless the STI control arme are THAT much wider than the WRX, I feel like I can get more adjustment from the RCEs before the upper perches hit the shock tower.

With the RCE lowering camber plates, and the stock camber bolt set for full negative, I was able to get -3.5 degrees front camber! Needless to say, I'm very happy with the available range.

[tyler_sti]

Sounds good draco, I really want the rear subframe lock bolts and anti lift kit. You're setup looks awsome for a DD car. And tear up the track!!

[Draco-REX]

My Conclusions

So where am I at? Right now, I'm very happy with my suspension. The car feels like it should have from the factory. Turn in is excellent, the suspension provides a level of confidence even higher than stock, and the car will rotate now.

Where to go now? I need to install the RCA kit and fit the new rims and tires. With those two pieces in place, the suspension will be ready for final tuning. I'll be able to make my final decision about the 24mm bar, choose the strut settings I want, and decide on my final alignment settings. I am also considering a set of camber bolts for the rear so I can even out the rear negative camber and maybe adjust it a bit.

What order should someone do all of this? Rear Sway first. That's the biggest improvement. Then I'd say rear bushings. Once the car is nailed down in the rear, drive it for a while and see if you REALLY want to go further. Then go from there. But I think a LOT of the DD only crowd would probably stop right at a rear sway and bushings if they started there. Just those will change the attitude of the car completely.


First AutoCross

I took the STI to my First Regional SCCA AutoCross. I've been RallyCrossing in my Bugeye, but this was very different, and not just in the road surface. There were 130+ pre-registered plus 30 walk-ups. I'm not sure if everyone showed since it looked like it might be bad weather-wise, but there were definately over 100 cars there.

I had a lot of fun, and got a good sunburn. I was also able to give the suspension (and my tires) a good workout. Unfortunately, there really was no opportunity to try different setups. That particular fact was rather disappointing. So some friends and I are looking into doing some of the smaller local car-club AutoXs where we can experiment some more.

Another, minor, issue is classing. The ALK put me in Prepared. I was given the option of running in FP, XP, or EMod. It appeared the EMod was made up of Prepared-Class Refugees, so I drove in EMod. However, EMod and Prepared are classes for Stripped-out, Caged, hardcore AutoXers. So I can never really be competitive with a DD.

But I didn't build this car to be competitive in AutoX.

SO.. My impressions of the suspension as it is at this point:
27mm Front Bar
24mm Rear Bar
No RCA
-2* F Camber
-1.4 R Camber
0 Toe all around

It's good, very good. But needs tuning. I was definately entering the turns too fast for my setup. The car would push. However, the suspension let me get the car back under control quickly and yank it back onto the line. The car is VERY responsive. I could dance it around cones and though the "Chicago Box" without trouble. There was one run where I cam in to the slalom WAY too fast. I was about to murder the first cone under braking, but lifted and whipped the car around it at the last moment and gunned it through the rest of the slalom. Also, in a long sweeping turn, I could keep the rear following the front with throttle input.

Now, I'm also not the best AutoX driver; this was my first AutoX after all. But I was happy with my times. However, this isn't about my drving. The car definately needs more front grip. I think the big front bar would prefer to have R-Comps as I felt like I was always searching for grip. Also, I definately should be running more Negative camber in the front. Such a tight, technical environment rewards agressive Camber also. I need to experiment with the bar settings as well.

You can see why I wish I was able to tweak the car during the day.

There was a very fast STI driver there. He was firmly in the BIG BAR camp. I understand his advice. However, a huge bar really is only good for RComps and a dedicated AutoX or Track car. I'm sure some could live with a 32.5mm front bar on the street, but if I were willing to put up with that, I'd have coilovers.

So it really comes down to tuning the suspension at this point. But overall, it's a hugely satisfying setup and it surpassed my expectations. Looking at the results for the day, I would have placed first in F-Prepared if I had stayed in that class, but placed 5th instead in EMod. Guess I should have stuck with FP.

[Draco-REX]

Originally Posted by tyler_sti

Sounds good draco, I really want the rear subframe lock bolts and anti lift kit. You're setup looks awsome for a DD car. And tear up the track!!

Fast reader, the board wouldn't let me post any faster.

As yo ucan see, this is an on-going write up. As of now, I jsut have the RCAs to go. But those may have other effects... More to be fleshed out... Now back to writing.

[blindfold]

add a front subframe and you should be complete, I have a very similar setup but still searching for that elusive TiC front subframe if it's ever released

[Drag-On]

I have nearly everything you named and a few other things. What you named is a great setup for the street and some track duties.

I agree with blindfold on the front subframe. I just recently installed a M1 subframe and I really like how it reduced a lot of the front end slop. The biggest drawback is that it will burn a hole in your wallet. An X-Brace is also a good investment if you don't mind spending a few dollars on bracing.

[Draco-REX]

Bracing (subframe, x-brace, etc) is definately in the future for me. After doing all of this, I can really feel (and sometimes I think SEE) the body flexing when I hit bumps. There's so much more energy being transferred to the bodystructure that it's become more evident. Considering how solid Subaru's unibodies are, it's amazing how much flex there is.

[Draco-REX]

Added some recommended reading to the first post.

[amg destroyer]

Can't wait to see the entire write-up. Sounds good so far!

[MeoW71]

Looks good. I'll be reading this more as I try and figure out how I want to do my suspension.

Originally Posted by Draco-REX

Differential Crossmember Bushings and Outrigger Bushings.

These I did next. They're very easy and there are a number of how-tos out there. These bushings were poly as there are no GroupN equivalents, but because these are not in places of articulation, I don't mind.

Actually, there are GroupN bushings that replace the front crossmember outrigger ones. They are just hard to identify, and probably a pain to replace since you have to drop the whole front diff carrier to replace them.

#5 in the lower right corner.
http://www.vtcar.com/prod/images/sti_lg.gif

[Draco-REX]

Originally Posted by MeoW71

Looks good. I'll be reading this more as I try and figure out how I want to do my suspension.




Actually, there are GroupN bushings that replace the front crossmember outrigger ones. They are just hard to identify, and probably a pain to replace since you have to drop the whole front diff carrier to replace them.

#5 in the lower right corner.
http://www.vtcar.com/prod/images/sti_lg.gif

Ahh, I see. However, they don't look like they solve the essential problem of the outriggers; vertcal movement.