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Discussion Starter #1 (Edited)
"...because anything worth doing is worth overdoing." -Mick Jagger

Table of Contents:
Interior
Suspension
Engine
Drivetrain
Chassis
Heat Managment
Brakes
Wheels/Tires
Cadmium Plating
Vendor Experience/Reviews
Tuning/Dyno Sheets
Perrin Gauge install
Polished Intercooler
Moroso Air Oil Separator



Before...




After... (not much of a change on the outside lol)



This build was a dream come true for me. After years of research and planning I finally had the opportunity to build what I envisioned to be the perfect STI. I tried to maintain the car's balance and nature while kicking everything up a notch or two.

For me the calling came when I saw the headlights on an STI slowly power up at an autocross in 2004 one cool, dark, misty, morning. I have wanted one ever since. Finding a clean near stock 2006 took months because so many of these cars are poorly modded and that's not what I wanted. I found this STI in Salt Lake City. It had about 37,000, was in good shape, and the price was right so I flew out. It was stock with Tein springs. It had taken a light hit in the front right corner, but the carfax was clean. Assessing body damage is not my strong suit so a few things got by me that were either covered up or I just didn�t/couldn�t see when I initially inspected the car.

When I started taking it apart I noticed things. It was rougher than I had originally thought. It had been curbed on the right side. And it looked like the left side had been repainted. It also looked like the strut had been bottomed out on the left front which coned the strut tower a bit. I also noticed clues that it must have had a cat-back on it at one time. Oh and someone drilled a hole in the spare tire probably when installing a subwoofer box or something. So this is also kind of my rescue car. Anyway it all worked out though since I got a good straight car. Had I noticed all that stuff though I may not have bought it and could still be looking.

So then, the idea was to build this STI with the best parts I could find. From the beginning this car was built with an eye towards STU class autocross as my guide. A lot was done with the suspension, but it's a mild build power-wise which if fine with me. I feel it has enough power so I chose to work on power delivery. My focus was on consistency and response. I tried to carry this theme throughout the entire car. Since the direction was always going to be a dual-role street/STU car I also wanted to try and keep the car as quiet and comfortable as possible. This way I could enjoy it as much on the road as I did on course.


A great deal of research went into every part installed in the car as well as the car itself. I decided on an �06 because they seem to do the best in STU and I also think they are the best year released in the US. I wasn�t crazy about the aesthetics at first, but the look has really grown on me. It�s very easy to detract from the performance of these cars and I wanted to avoid that. For me it was about taking what was good about the car and making it better. Due to my nature of always trying to do things the best way I can you may see some things done here not usually seen.

I naively though this would be a bolt-on affair, but boy was I wrong. It�s a good thing I know a great machinist, because I made many trips to his shop during the build. Sometimes just to modify an existing part, other times to make new parts. I�ve even designed and had built a bunch of special tools and fixtures. The most tedious part was all the bead-blasting that preceded the plating. It took months. Next time (if there is one) I�ll just pay to have it done.

The most difficult part turned out to be installing the Group N bushings in the rear suspension. It took the machine shop four hours to remove then install the rear subframe bushings. I did the rest myself with some help. I had to design then have made fixtures that would compress and push at the same time so the bushings wouldn�t tear themselves apart. It took a couple revisions to get them right, but in the end they worked great! All part of the fun!!!


It took about 8 or 9 hours of blasting to clean each knuckle.




It was worth it though.




At it's most dissembled the car was basically a tub.




Some assembly required!

 

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Discussion Starter #2 (Edited)
Interior

SPA dual digital gauges- Oil temp/pressure, Boost/EGT (Subtle Solutions gauge pod), Lathewerks boot collar, reverse ring, hybrid shere shift knob, toggle for ECU test mode, Schroth quick fit harnesses for driver and passenger seat (modified to fit in an �06).

I guess I can be a little like Howard Hughes. I ended up buying three Subtle Solutions gauge pods before I got things just right. The gauges didn�t fit so I tried to enlarge the holes myself. That didn�t work too well. The second one I had done at the machine shop, but the placement for the buttons didn�t work out. Once the pod was installed in the console one of the buttons were partially covered up. So the third time was a charm on that one. I also went through five shift knobs before I found one that felt right. Doh!


Perrin gauges have since replaced these SPA Techniques gauges. You can check them out here.




I did a red light conversion on the interior lights. The red/green mix bothered me.




...and another shot




I had to get some custom work done on the harnesses. For some reason in 2006 they changed the seat belt buckles. I had known about this so it was no big deal. Just a matter of shaving the sides of male ends the go into the buckles on the front seats. The surprise was the stub belt that mounts at the anchor point for the front seatbelt. I had the machine shop make a bushing and press it onto the original bolt so it would all work properly and it did.




Since the gauge pod took the place of the ashtray and 12v power plug I added a 5V USB power port to the inside of the center console. I should�ve done a double recep, but hindsight is always 20/20.




I added a switch to put the ECU into test mode to make it easier to change between the STU and Stage 2 maps. This was the original configuration. The problem was I kept fiddling with the switch. You know Grimes switch cover... "Too close for missiles, switching to guns!"




I ended up going to a locking toggle. It works just as good, but I'm not tempted to mess with it.




Someone decided dynamat was a good idea. It took a while to get it all out.




After finding the dynamat I decided to strip the interior completely to make sure there were no other surprises. I found some change, a couple tuner style lugnuts and some kind of dried white powdery substance. Ah, the joys of used car ownership.




Since the interior was out I thought a speaker upgrade would be a good idea.

 

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Discussion Starter #3 (Edited)
Suspension

AST 4100 coilovers, Hyperco springs, Vorschlag plates, Whiteline Swaybars, mounts, endlinks.

These went in pretty easy. I did have the machine shop add some graduations to the front camber plates though. Vorschlag makes some really nice stuff, but the graduations they put on the plates were useless if you were actually going to use them.

 

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Discussion Starter #4 (Edited)
Engine

Cobb Accessport, Constant torque clamps used throughout, Killer B header/oil pan/pick-up, AVO turbo-back (machined and coated). Perrin engine mounts, Kartboy pitch-stop. Redline 5W30 oil/ Subaru synthetic P/S fluid/ Subaru Super Coolant.
I also did all the maintenance items like belts, hoses, and the timing belt/pulleys while the engine was out. I had to replace much of the intake system too. At first I was going to go with and AMR hard inlet pipe and Cobb intake with airbox. They never got installed and will eventually get sold. The reason being is that you need TGV deletes for the AMR pipe to fit properly. The Cobb intake was another issue. I really wanted it for the turbo noise, but autocross is unique since you run the car hard then it sits. In this one specific circumstance the cold air system on the OE intake works better. So in the end I bought a new OE inlet pipe (old one was split) and a new lower filter box (old one was broken) then covered it all on gold foil. I also bought a new snorkel. At that point I was like why not. It was a similar story on an ATI Superdamper I bought. I found out they have to be press-fit and are really only an advantage when you increase HP or change out internals. Otherwise the OE damper does the job.


Things are very shiny here...




The oil temp and EGT sender were fairly easy to install, but...




...the oil pressure sender was a tight fit so I had to get creative and have a special fitting made with an angle of about 22�.






I wanted to keep the OE heatshield since I think it is more effective then aftermarket options. I tried to keep as much of it intact as possible.



 

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Discussion Starter #5 (Edited)
Drivetrain

Group N tranny mount and crossmember bushings. OE short throw shifter with TiC, Kartboy bushings. Subaru Extra-S in the transmission. Subaru LSD oil in the rear diff.
This was pretty straightforward. Most of it was bolt-on. The car came with a Kartboy short-shifter which I didn’t care for. I replaced it with a brand new OE short shifter. I reused the Cobb shifter bushings and the Kartboy rear bushing. I also replaced all the bushings in the new shifter with TiC and KB bushings. At first I got the wrong trunnion bushings and they did not fit at all. Once I got the right kit they went right in, but the steel sleeves were a little too tight. I had the machinist make some new ones that fit better then covered everything in Formula 5 grease. It’s very smooth and positive. What a joy to row through the gears!
 

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Discussion Starter #6 (Edited)
Chassis

Rear suspension bushings (including rear subframe) all replaced with Group N, Diff carrier Poly TiC bushings, Outrigger bushings replaced with Whiteline poly bushings. Front Suspension bushings were replaced with new OE bushings. Kartboy XL exhaust hangers. Whiteline Front tower brace, STI rear tower brace.
The group N bushings were the biggest challenge. Why are rubber parts so uncooperative?!
It took a couple months to get this sorted out. Most people just go poly, but I really wanted rubber and was told it would work better. I�m not sure how well the poly works, but yes group N bushings are awesome! The are tight and quiet. I�m glad I put in the extra effort ( Lots of extra effort!). I was told they could be installed by freezing the bushings and heating the lateral link to gain some tolerance. My hands don�t work as well as they used to and that method is just too inconsistent for me. So I had some fixtures made. It took a while to get them right, but once they were they worked like a charm. After tearing up two bushings trying to install them the conventional way it was cake in comparison with the fixtures I had made. It took a while, but no problems, no tears. Just happy bushings. While I had everything apart I also had the aluminum parts anodized. You can�t really change the appearance of an STU car much so this was my attempt at a little customization. In addition to the red lateral links and LCA�s, I also anodized the Diff cover gunmetal.


The fixture I designed for pressing in the bushings...








Liberal amounts of Sil-glyde...




Then they went right in. Piece of cake. :)












The bushings in the knuckles were a different size so second larger fixture was also made once we knew the first one would work...



 

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Discussion Starter #7 (Edited)
Heat managment

DEI gold foil, Swaintech White lightening, 2000� �turbine� coating.
I used a lot of gold foil on this car. In addition to the intake I also used it on the the firewall and part of the tunnel near the cat to keep heat out of the cabin. I completely covered the A/C drainhose and bracket so it wouldn�t melt. Swain coating was used on the Killer B header. I really wanted inconel heat shields from turbosource.com, but didn�t have the room. Turbine coating was used on the bellmouth, downpipe, and two intermediate pipes. Only the muffler stayed shiny. I also had my modified OE turbo heatshield coated. I would�ve liked to have done the turbine housing too, but that�s not allowed in STU.









2000ºF "turbine coating"
 

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Discussion Starter #8 (Edited)
Brakes

Front- DBA 5000 two-piece rotors, Project Mu B-Force pads
Rear- Stoptech Cryo-stop rotors, Project Mu B-Forcepads
Goodridge stainless lines, Pentosin Super DOT 4 fluid

The brakes didn't really need much work for my purposes so I just tried to increase performance a bit and shave off a few pounds.



I actually got a little grief from some of my fellow autocrossers because the rear rotors didn't have the gas slots like the front rotors. There's just no pleasing some people... :rolleyes:

 

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Discussion Starter #9 (Edited)
Wheels/ Tires

Street- Team Dynamics/BFG Comp-2's/ Autocross- Mach V Awesome/Hankook RS3 V2/ Winter- Rota Grids/ Hankook Ventus S1 Noble 2

I love the BFG Comp 2's, but I must say I'm not too happy with the Rivals. I may be trying some different race tires very soon.
update: Rivals have been replaced with Hankook RS3 V2's which I really like.



 

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Discussion Starter #10 (Edited)
Cadmium Plating

All hardware and many brackets plated in aerospace grade cadmium.
This was a long process. Some of it went quick, but the knuckles for example took forever. It was worth it though. They look great even though it's only me that really sees them.

I suspect the car's life in Salt Lake is what did a number on all the hardware. The body had only very minor rust which I easily fixed, but cadmium being a sacrificial metal had been eaten off much of the hardware and brackets. I guess I could've just got new hardware, but I wanted to plate some parts (the knuckles for example) that didn't come plated plus I was rebuilding a tire machine too and I had a bunch of it's parts plated at the same time. In the end it was about 250lbs of parts, brackets and hardware.

I ended up replacing a lot of other OE parts too. All the plastic covers under the car as the old ones were tore up. I also replaced the front and rear subframes for fear they may have been bent from the curb hit. There were many other small parts that were either damaged or worn that got replaced too. Lots of parts I wouldn't have even thought of. Plus I also had to get a new spare tire.







It took me two days to get all the bolts sorted out and figure out where they went.


Yea... I plated just about everything whether it needed it or not. :cool:
 

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Discussion Starter #11 (Edited)
Vendor Experience/Reviews

Killer B- ***** Awesome! Chris is very helpful. Every part I bought from him was extremely well made and fit perfectly with no modifications.

Cygnus Performance- ***** A great deal of my parts came from here. Suspension, brakes, Cobb AP, and some other stuff. Geoff is a great guy to deal with. This has been a long project and some parts I had for a couple years before getting to them. I had one odd issue with the Whiteline endlinks. The shafts are supposed to be 10mm, one came with 12mm. Even though it had been a long time since I bought the parts Geoff got right on it and helped me get the right part quickly. Whiteline's customer support had a role here too and they resolved my issue very quickly. So they get a thumb's up too.

The BoostCreep ltd.- ***** Harvey is an awesome guy and did a great job! He took the time to work on the details. After the dyno tune we jumped in the car for real world data with me driving and Harvey in the passenger seat with a laptop to make sure everything was perfect. I would go there again in a heartbeat!

C&G Machine- ***** I could not have built this car without them. I've known the owner for about 12 years and he's a great guy. He is also a car guy and built his own rock crawler so he has a good understanding of what's needed when it comes to the automotive realm.

Subi-mods- **** Another good company to deal with. There was a part I had been waiting on for a while. Hood struts They ended up upgrading my order and sent me a couple shirts to boot.

AST- *** I like their stuff. The valving on their dampers are awesome for our crappy roads here in the US. You wouldn't know my car had coilovers. I do have some minor gripes. I'm a fairly intelligent person, but had zero experience with coil-overs so then some instructions would have been nice, or even a link to instructions. Also when I called AST about a minor issue they weren't as helpful as I hoped they would be. Lastly the extenders for the rear adjusters are these rigid rods. It's great if there is a straight shot down to the damper, but that's not the case with the STI. It get's wedged between the rear deck lid and up right seat-cushion. This pushes the rod sideways and makes it very difficult to turn. I figured it was only a matter of time before it broke the adjuster tab off the damper so I bought the cable adjusters. You'd think for as much as AST's cost they would just include them or at the very least offer them as an option. Lastly it would have been nice if they would have included spring bushings so the springs don't dig into the aluminum adjusting collars. Again minor gripes from a critical person.

Wheeldude- ** I bought a set of 17 x 9 Rota Grids back in September. I noticed one of them was very out-of-round on the inside lip. The whole return process is ridiculous. You have to take all these pics then email them to wheeldude to get the process going. I probably called them 50 times or more throughout the process. They never called me back with an update. It took the better part of a week just to get the return label after Rota approved the return. At that point I was calling them everyday for a tracking number except the one day I couldn't get through. They had told me seven times they thought the wheel shipped, but couldn't get a tracking number. I figured it hadn't shipped and there is nine different ways to get tracking with a fed ex shipped package. Finally I pinned them down and got the wheel shipped. I will say the people at wheeldude were nice and polite, but very, very slow in getting my problem resolved. All in all it took a month and three days to get the new wheel from my first phone call to them about the bent wheel.

I had the advantage of my own tire mounting and balancing machines otherwise it would have cost me more money in mounting and balancing. In the end it cost me time, packing materials, some stick on weights and a tire valve. To anyone looking to purchase from this company be warned. You can't be in a hurry and if you're having someone else mount the wheels ask them to run them up on the balancer before mounting to check for trueness. It will still probably take a month or more to replace a defective wheel, but at least you can save the cost of mounting and balancing. This is the second set of Rotas I've purchased from this company although before they were still subydude and I had no issues. I knew what I was buying and the fact that a wheel wasn't quite right didn't really bother me. However the character of a company is in how they handle customer service and returns. I'm not sure what's going on over at wheeldude, but they didn't do a very good job at all. I won't be dealing with them again. I just wish there were more reasonable choices in a 17 x 9" et42 wheel.

AVO- ** My experience with them was somewhat less satisfying, but I still like their stuff. They make a nice exhaust, but it's not perfect. The bellmouth is separate and made of cast iron which is great. It also has a tongue that goes all the way in to the turbo between the wastegate and turbine. I had to get this machined for proper clearances which is OK since the engine was out and it wasn't that difficult to remove the turbine housing. Since different turbos have different depths there would be no way to fit them all. I also had to get the flange machined. It wasn't parallel to the gasket surface and I'm sure would have eventually cracked the ears off the turbine housing. I wish I had realized this before having the part coated so I didn't have to do it twice. Again no big deal, but I would have expected they would have thought of that at the factory. I was however displeased with the cat in the downpipe. It looks like the cat comes from a third party supplier. The welds on the downpipe are nice tig welds. The welds that hold the cat together are not. It's like a cheap fusion weld (not sure what it's actually called). It's not what you would expect on a $7-800 downpipe. Anyway the cat developed a crack on the weld very shortly after the install (less than 100 miles). The rep suggested that I get it welded locally because he thought that would be a quicker solution. This wasn't that easy to do. I finally found a guy to do it, but the whole process took about two months for the repair. The rep was right though. Initially it took me three months to get the system. I would buy these parts again because I really like the design on AVO's bellmouth. I think they have since changed it though probably because machining the tongue is too involved for most just looking to bolt on a down pipe. So it's not a truly divorced system anymore. However I would just get the cat welded as a matter of course if they're still made with those cheap welds. That would save me money on coatings since I had to have it coated twice also.

Some more machining after I had the part coated... :(


The cracked weld on the downpipe...


I tried three different shops before I finally found a welder who could fix the cat. He's aviation certified and I think he may have even done some welding on stealth aircraft. That's just cool. Anyway he did a great job!
 

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Discussion Starter #12 (Edited)
Tuning!

Getting the car tuned was really exciting. I had it done by Harvey at TheBoostCreepltd. I had been taking it easy on the car up until that point. I was a bit nervous. At the car's most disassembled point the only things left in the car were the dash, wiring harness and A/C system. I was worried I had missed something on reassembly. The car ran great all the way to his shop though so that was inspiring, but once he started running it up I was bit nervous. It was all fine though. Harvey said he had never seen an STI like this before which I had taken as a high compliment knowing some of the amazing machinery that has passed through his shop. He asked me if my goal was to build the perfect stock STI. I said yea pretty much. To which he said well you succeeded.

The reaction was similar at my first autocross recently. I hadn't driven in an autocross in 2-1/2 years so it had been a while since I had seen my autocrossing brethren. A few tried to crawl under the car to see what I had done and kept teasing me that the car was too clean to autocross. I guess if there's one thing you can say about me is that I believe anything worth doing is worth overdoing. Since I had only finished the car about a week before I was worried about making a fool out of myself especially in my region where we have a lot of very good drivers and many national champions and repeat national champions. Turns out again all the worry was for not. The car was awesome. It almost drove itself. I managed third in class and 41 out of 163 drivers. I was 1.1 seconds behind the leader and a half second behind second. This happened in a brand new car with a driver that hadn't been on course in over two years. It was a pretty amazing day and I couldn't be happier with the result! I also could not be more happy and satisfied with my car. I love my STI!!!

Here's the STU map... (stock boost targets) 247.5HP -266 ft/lbs torque


...and the stage 2 map. 258HP -290.5 ft/lbs torque
 

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Re: Project Silverstreak: The Perfect Build (or as near as I could get it)

Impressive...you did indeed do a few things no one has done...lots of sweat there.
 

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Discussion Starter #15
Re: SubySal's '06 STI STU build...

Well The Rivals are up for sale. Some people love 'em, but I just couldn't get them to work for me. I just had my first event on Hankook RS3 V2's yesterday and it was a night and day difference right out of the gate. Most noticeable was the significant increase in straight line braking. The RS3's remind me of the old Direzza Star Spec's which I loved. I've heard that the sidewalls are softer, but on 9" wheels they seemed fine on my runs. They do howl over the road like a pack of wolves in heat though. I can't see taking any long trips with them.
 

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Re: SubySal's '06 STI STU build...

I am totally Impressed! I suffer/delight in a mild form of OCD as well, I love to make everything as perfect as I can regardless of the project. I don't have the skills/experience, talent you clearly do. I love the photo of your garage/work space! That is totally Awesome! Clean, bright and well organized. I'm afraid if I had those conditions available to me, my wife would never see me again!

Well Done! Enjoy the car!
 

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Discussion Starter #18 (Edited)
Re: SubySal's '06 STI STU build...

...got some HP all-season tires and wheels for the cold winter ahead. It was hard to choose between the DWS's and Noble 2's. I finally decided on the Hankooks because they have a slightly stiffer sidewall and the car isn't going to see snow. Also they were $35 cheaper per tire.

The wheels are Rota Grids. I got a great price on them and have had good luck with Rota's in the past. I like the way they look on the car, but after the fiasco in getting an out of round wheel replaced this will be my last set of Rotas. It just sucks that 17 x 9" wheels in GD fitment are getting so limited.

 

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Discussion Starter #19 (Edited)
Re: SubySal's '06 STI STU build...

I'm not really into the frequent updates, but I figured I'd do a year end review. I bought my STI back in March of 2011, but it took a back seat until November of 2013. The project wrapped up with a protune on April 4,2014. The build itself was fun and challenging if not a little maddening. However, it has been a wonderful experience since driving the car. In some ways it turned out better then I expected. For example it's more streetable then I thought it would be. I've ran 7 autocross events with the car, but it didn't really come together on course until I switched to the Hankook RS3's. They gave me the consistent grip I was looking for so I could push the car right to the edge and keep it there. Though I still have issues with reading the course I was very happy with the results of the last event. Things really came together. And as an added bonus a good friend of mine let me take his car on my last run.

This car...


It was awesome! Obviously very different then the STI. The car was super-composed on course. The steering was the thing that really stuck out to me. It was sublime. Perfectly weighted and consistent. It makes me wish my STI's steering was a bit more like it, but I still love my car anyways. All in all it was a great end to a great year!
 

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Re: SubySal's '06 STI STU build...

It was awesome! Obviously very different then the STI. The car was super-composed on course. The steering was the thing that really stuck out to me. It was sublime. Perfectly weighted and consistent. It makes me wish my STI's steering was a bit more like it, but I still love my car anyways. All in all it was a great end to a great year!
I would agree with this 100%. Any 997's steering is going to make an STi's seem less than ideal in comparison. I am just talking from experience of driving run-of-the-mill CS2s. I'm sure a GT3 RS probably feels even better than that. That is why at least with the GRs I've tried to focus so heavily on improving steering feel. There are things that can be done to make it feel significantly better than it does off the showroom floor, but every time I drive a 997 or Cayman it makes me wish that my STi's steering felt more Porsche like as well... but then I put all of my skiing equipment on my roof and all of my gear in the back and remember that while my STi may not be perfect it is as close as I'm likely to get in a car that I can actually use for everything.

-Geoff
 
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