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A-man's 07 STi: Taming the Beast

207K views 892 replies 118 participants last post by  A-man 
#1 · (Edited)
I bought my 07 SWP STi in Jan 2007 sight unseen from a Subie dealer in Birmingham, AL. The older gentleman who delivered it to me (a little over 100 mi to my office) got out of the car with a smile on his face, handed me the keys and said, "nice little car." :)

This car replaced my 05 WRX (totaled) as my daily driver and after a year I had racked up almost 40,000 miles commuting. Gas was approaching $4/gal and I was tired of dropping $60 for a tankful so I bought a Honda Fit for a DD and decided to make the Subie my fun car. I had already learned from the WRX that these cars really need at least Stg 1 tuning, so during that 1st year I added the Cobb AP and shortly thereafter a Cobb TBE to go Stg 2.

Now I have found the direction I was looking for thanks to AnorexicSti and his incredible lightweight STi. This project will take quite awhile as I am very busy with job and family and mostly only have every other weekend to work on the car.

Update 09/01/2011: Engine build and tune finished by EFI Logics.

EFI Logics tune



Mod List

Engine/Bay
Power
EFI Logics built and tuned
Stage 1 EFI shortblock w/11mm oil pump, nitrided crank
Forged pistons (99.5mm), Swain coated (TBC) piston domes
Garrett GT3076 turbo w/Tial 0.63 SS turbine housing
EFI fabbed rotated uppipe w/EWG
Tial MVS wastegate - open to atmos.
Litespeed UEL header, Swain coated (White Lightning)
EFI customized KSTech 73mm CAI
ID 1000 injectors
Aeromotive fuel rails with EFI fuel system
JDM TGV deletes
Cobb XLE BOV
Invidia DP (catless) - EFI conversion to V-band
Burns Stainless ultralightweight muffler
Cobb lightweight crank pulley
NGK 1 step colder plugs
Spearco TMIC
Walbro fuel pump
Stock heads and cams
Killer B Motorsport Ultimate Oil Pick Up
Cobb AP

Miscellaneous
Shorai LFX36L3-BS12 Lithium Iron Battery - 5 lbs.
Rob's upper coolant tank delete
Saikou Michi catch can

Dress Up
Gates blue belts
Gates blue radiator hoses
SPT aluminum oil filler cap
Ixiz Concepts hood dampers
STI Pink radiator cap
Samco blue intercooler hoses

Driveline
ACT HDSS clutch
ACT StreetLite Flywheel
ACPT CF driveshaft
Litespeed aluminum outrigger bushings
Kartboy tranny crossmember bushings
Group N tranny mount
Group N rear diff mount
Group N engine mounts
Group N pitch stop
WL steering rack bushings

Suspension
AST 4100 coilovers 7k/5k Swift springs Vorshlag camber plates(with high-caster al plate upgrade front) front/rear
Caster-adding 05 LCA swap
Whiteline Plus front LCA bushing (thanks TiC for the install)
Whiteline RCA kit
Whiteline front sway, 24mm adj (set to stiff)
Subaru OEM rear sway, 20mm (DIY adjustable to 21mm)
Whiteline ball front endlinks/Kartboy rear endlinks
Whiteline Anti-lift kit - standard
Free caster mod
TiC Giuyngmyo front fender braces
Whiteline KSB700 H-brace (thanks Eric "jagstyle" Houts)
FHI Spec C Titanium front strut bar
STi Pillowball Lateral Link bushings
STi Pink Trailing Links - pillow ball front bushings, Group N rear bushings
Kartboy rear subframe lockout bolts
Litespeed Rear Chassis Bridge


Wheels/Tires
Kosei K1-TS 17x9
Bridgestone Potenza S0-4 245/40/17
McGard Spline Drive lugs - black

Brakes
The Brake Man 2 piece lightweight front rotors
The Brake Man #93 street pads front/rear
Girodisc 2 piece lightweight rear rotors
ATE SuperBlue Dot 4 fluid
Techna-Fit SS brake lines
OEM Brembo calipers

Exterior
DRL delete
Front license plate delete, "STi"
"Keep Attacking the Nurburgring" door decal
Spec C aluminum trunk lid
APR GTC-200 CF rear wing
RavSpec CF roof vane
Custom painted tails (thanks all4bspinnin)

Interior
JDM S203 shift knob
Prosport Premium Boost gauge
Prosport Premium Oil pressure gauge
Limited red hazard switch
Sony CDX-GT130 headunit
Interior Flair red LED swap on climate controls

Weight Reduction
Extensive removal, modification or swap out of parts (need to read journal to get the full picture) including:
Litespeed Performance rear bumper beam
No front bumper beam
Removal of U-Subframe
Trunk cleanout
Under/behind rear seat cleanout
Sound deadener removal
Air pump delete
Removal of tow hooks, plates and many, many brackets all over the car


As of 02/21/2009...stock except Cobb Stg2

 

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#2 · (Edited)
Re: A-man's 07 STi: DD to Street Weapon

Started to day with the lightening.

Removed the beam under the rear seat as well as the considerable rear seat and third seatbelt bracketry/hardware along with all child seat anchors and the rear seat pass through. Lost about 27 lbs here.



Also took out the spare tire, bolt/cap and jack/tools for an additional 36 lbs.

The Cobb TBE and deletion of the heatshield has saved me 17 lbs already so I'm up to 80 lbs off the car. The butt dyno says definitely :tup:, though the rear end feels a little light and the front end feels relatively less responsive. Need to get some weight off the front.
 
#3 · (Edited)
Re: A-man's 07 STi: DD to Street Weapon

Ordered the ACPT CF driveshaft last night from sojdm.com. They are having a $1099 special on them and shipping to US addresses is only 19.99. Couldn't resist as this is one of the top mods I've been wanting to do since deciding to go this way. It'll be a couple of weeks before I can get it on the car but man I can't wait.

Cobb lightweight crank pulley to follow soon thereafter.
 
#4 · (Edited)
Re: A-man's 07 STi: DD to Street Weapon

Took off the U-shaped subframe this evening - heavy piece. Another 25lbs off so 105 lbs lighter now.

Driving impression: acceleration continues to improve but the best change is in the low-speed responsiveness of the front end. Doesn't feel nearly as ponderous and turn-in is better. Steering feels quicker. I can only imagine what going to lighter wheels, tires and brakes is going to do :tup:.

Of course, the plastic undertray stays off now as the front of it bolts to the subframe. Without it the car is noticeably louder standing outside at the front, but no big deal. I wonder about the airflow under the front of the car but I think a V-Limited front lip will solve that issue. Only thing that concerns me here is the oil filter is rather exposed and the possibility of water/dirt coming up. Will have to monitor. It wouldn't be difficult to tie up the front of the undertray to the radiator support beam if I felt I needed it though (the rear bolts to the triangular bracket).
 
#6 ·
Re: A-man's 07 STi: DD to Street Weapon

Okay, Finished up the ACPT CF driveshaft tonight so that's 10 lbs off there + 4 for the protection plate + 3 for the front undertray I didn't add in last time and +1 more for all the bolts that i hadn't included = an additional 18 lbs off the car or 123 lbs lighter so far.

ACPT CF Driveshaft driving impression: I'd pretty much echo what has been written before - you rev up a little faster with a most noticeable difference in the upper gears. Shift quality is improved as there is a noted lessening of load when easing off the clutch pedal and nearly eliminating that "loaded up" feeling, or you might call it a decrease in driveline snatch. Either way this is a very nice mod that would probably be even better for those with power beyond stage 2.

Install was done on ramps and jackstands. Not too bad but it would be much easier on a lift...what wouldn't.

Is it worth $1100? Comparitively I'd say probably not, maybe 1/2 that, but if you got the dough to blow it is a really cool mod. :tup:
 
#825 ·
Re: A-man's 07 STi: DD to Street Weapon

Okay, Finished up the ACPT CF driveshaft tonight so that's 10 lbs off there + 4 for the protection plate + 3 for the front undertray I didn't add in last time and +1 more for all the bolts that i hadn't included = an additional 18 lbs off the car or 123 lbs lighter so far.

ACPT CF Driveshaft driving impression: I'd pretty much echo what has been written before - you rev up a little faster with a most noticeable difference in the upper gears. Shift quality is improved as there is a noted lessening of load when easing off the clutch pedal and nearly eliminating that "loaded up" feeling, or you might call it a decrease in driveline snatch. Either way this is a very nice mod that would probably be even better for those with power beyond stage 2.

Install was done on ramps and jackstands. Not too bad but it would be much easier on a lift...what wouldn't.

Is it worth $1100? Comparitively I'd say probably not, maybe 1/2 that, but if you got the dough to blow it is a really cool mod. :tup:
I think its worth 1100, my favorite mod personally even over my turbo i just like seeing my rpms rev quick !
 
#7 ·
Re: A-man's 07 STi: DD to Street Weapon

So yesterday I spent quite a bit of time with the car and removed the rear bumper beam.



Doing this eliminates mounting points for the far left muffler hanger and a bracket that holds up the charcoal box over on the right side (at least I think its called a charcoal box). Solutions were pretty easy, just used a couple of zip ties to mount the charcoal box through the frame rail and I used electrical wire for the muffler hanger, also through the frame rail holes, to give the muffler some play as it moves around some naturally. You can see neither from the back of the car.



So with the removal of the rear bumper beam, rear tow hook, leftmost muffler hanger, left tow plate and all attendant hardware plus the spare tire cover that I decided to to remove as well, that's another 37 lbs lighter or 160 lbs off the car.

I removed my wrecked front bumper cover as well, ridiculous amount of plastic pop rivets :crying:, but only got half way with the bumper beam as I didn't have a long enough 1/2" extension to finish. I got to really looking at the bumper beam though and decided I couldn't just go bare. It obviously offers enough front crash protection, at least at low speed and possibly at higher speeds, that I dont want to leave it off entirely. So I'm deciding on ordering the JDM beam or modifying my USDM beam. In either case it'll be awhile before I can drive the car on the road. Not to mention, I have to order a new right wheelwell skirt as that got torn up when I hit that dog and its required to mount the bottom of the bumper cover.

At least I can continue with mods :).
 
#10 · (Edited)
Re: A-man's 07 STi: DD to Street Weapon

Looks like a fun project. :)

You can ditch the front subframe and side-impact door beams for some additional weight savings if you are willing to give up more crash protection.
I have ditched the subframe. I couldn't tell it really added anything to crash protection (other than overall weight) and it definitely helped the handling without it. I don't think I'd waste $500 on a lightweight aluminum subframe. The only thing you lose is some mounting points for the undertray.

In general, the lighter you make the car, the stiffer it gets. I wouldn't add an aftermarket brace anywhere on this car as I very seriously doubt you could prove faster lap times all else being equal (EDIT 5/2010: this statement is totally false). Sti are plenty stiff already and if you start shedding weight you'll see how much stiffer they get pretty quickly.

I wouldn't give up the side crash protection of removing the bars from the doors. I ain't that brave...not on the street. I finished taking off the front bumper beam this AM and I'm more convinced that I don't want to leave it bare. Not even considering safety, there would be massive monetary damage to the front of the car without the beam and there would be no chance of having insurance cover it if an adjuster noted it missing.

I also removed the windshield washer jug (about 8 lbs with current level of fluid) and used a plastic T-fitting to join the IC sprayer line to the windshield washer hose right by the cowl/wiper section at the left of the engine bay. The IC sprayer button now sprays the IC and the windshield simultaneously :lol:. Thanks to Anorexic for this idea. I added some of the windshield washer fluid, about 2 lbs, to the IC sprayer jug in the trunk, so 6 more lbs total off and that came from the very front of the car, so 166 lbs total, not counting the front bumper beam which I'm going to replace with something lighter.
 
#12 ·
Re: A-man's 07 STi: DD to Street Weapon

I've been busy under the hood. Since removing the front bumper and bumper beam and therefore unable to drive the car, I've begun attacking brackets. I've removed several already on the driver side and several to go. Thing is, one leads to another and you need to remove this that and the other thing like the battery to get others, well a lot of stuff is half on and half off. I'll have to complete much more that I had planned to get it rolling again, but that's fine.

Things to do include removing more brackets, changing the coolant and I bought some Mishimoto silicon hoses, some Gates blue belts, Cobb blue lightweight crank pulley. Have the JDM bumper beam on the way and will see if it can be further lightened or bolt it on as is. Order a Braille lightweight battery. Also will be getting my new bumper painted and putting that back on. Would like to remove the air pump altogether if I can get Cobb to tell me how to remove the CEL's that will result (if possible). The air pump is a heavy, in-the-way MFer - we'll see. Pics to come too.

Other things on the very soon to do list is replace the diff and tranny fluids (Motul fluids on the way). The most expensive thing I want to do is get new light wheels and tires and rotors. This will be some pretty change but will save a ton of weight and improve handling and responsiveness. Additionally will eventually do an APR wing, a CF trunk and I think an APR front splitter over a V-limited lip (actually cheaper). Maybe seats one day too.

Something I'm going to have to think about very soon is coilovers. With only 166 lbs off the car + the bumper beams, the ride height is 1" higher than stock all around (looks like a rally stance) and its getting too stiff with the stock crappy dampers. Oh yea, Cobb sways too - already have the front.
 
#13 ·
Re: A-man's 07 STi: DD to Street Weapon

Ordered the Braille battery, the B129 ( Braille Battery USA - B129 ) which weighs 9.5 lbs and will save a whopping 22.5 lbs over the stock battery and obviously take more weight off the front end. I really need to get weight off the front as I've taken so much off the back that my weight distribution is very skewed right now (would really like to get the sound deadener off the firewall if it can be done without removing the dash). Also bought the 2 amp trickle charger for peace of mind.

Also I'm very excited to have been let in on a group buy for The Brake Man front rotors which will save another 20 lbs off the front and reduce unsprung weight at the corners. This'll really help acceleration and handling. Also upgrading to Brake Man street pads and I expect my braking performance to be very much improved as well - I reeeally need new pads. Staying with the stock calipers for now. Wish Brake Man had lightweight rear rotors that didn't require ditching the e-brake. Just can't do that.

I need to edit post #1 with a mod list and maybe a price list too :eek:.
 
#15 ·
Re: A-man's 07 STi: DD to Street Weapon

The air pump, while ugly and in the way, is not heavy. The whole thing is about 10 lbs.
I'd definitely consider 10 lbs heavy, particularly if you add it to the whole of what can reasonably be removed/swapped. If you've read AnorexicSti's journal or follow this one, you'll see that by taking off 1-2 lbs here and there in addition to many items 10 lbs or more, you can easily remove 300-400 lbs off an STi. Monster difference.
 
#16 ·
Re: A-man's 07 STi: DD to Street Weapon

Prepping this evening for some new stuff going on in the engine bay. Bay is dirty as hell, good thing I bought some engine cleaner.



Look at the rust on the pulleys...nappy. What I usually do with a rusty part I'm not going to paint is clean it up with a wire brush or sanding and apply some clear coat paint. The alt/AC housings are funky too. Will clean this crap up tomorrow and put on new blue Gates belts, blue Cobb lightweight crank pulley, and red silicon Mishimoto radiator hoses. If my Braille battery comes in tomorrow I'll put that in too.

Here's what a wrecked fender skirt looks like:



You'll note that I've done the airbox silencer delete as well.

Full frontal nudity:



Supposed to get JDM bumper beam tomorrow and new fender skirt. It'll probably take me the rest of the week to get all this done. We'll see if I get lucky weather and delivery wise.
 
#17 ·
Re: A-man's 07 STi: DD to Street Weapon

Today I received the JDM bumper beam but that was it. Installed:



The beam and foam absorber were a combined 8.5 lbs which is 16 lbs lighter than stock!

Installed the Cobb lightweight crank pulley, 4 lbs lighter, and also the Gates belts and cleaned up the other pulleys:



So with what I've finalized this evening, I've taken 186 lbs off the car. I've actually taken off more, but when I finish up in the engine bay I'll tally it all.

Can't wait to drive it again.
 
#20 ·
Re: A-man's 07 STi: DD to Street Weapon

Received the new fender skirt and replaced the torn one. Not a bad job at all, just a handful of plastic pop rivets, 1 metal screw and a couple of clips. Worse part as usual is dealing with plastic pop rivets that are in exposed places are always dried out and they crack apart easily. Would be a good idea to buy a bunch of new ones for this kind of work.

Also picked up my new bumper. Guy said the white pearl gave him a tough time matching it up but he did a good job. Matches perfect. It ought to for $460. He told me to wait a day two prior to putting it back on to let it finish curing.

Hadn't received the Braille battery yet so I called Braille. The trickle charger I ordered was on back order until today so it won't be shipped 'til tomorrow. This means probably next Tues I'm guessing :(.
 
#21 ·
Re: A-man's 07 STi: DD to Street Weapon

Today I received no presents from fedex so I had to actually work. I changed the radiator hoses (bottom one a bit of a PITA), took out the driver's side fan and slightly relocated the coolant reservoir.



The red hoses are just okay to me. I think I would have preferred blue. Gates makes some blue hoses that match the belts - may do this in the future with a clamp upgrade too. Comments welcomed.

Don't know if I'm nuts or not living in Alabama and removing a radiator fan, but I'll bet one will be enough. Its easy enough to get on/off. I'll see soon enough.

The fan weighs 4.5 lbs so we'll just call it 190 lbs off the car.
 
#26 ·
Re: A-man's 07 STi: DD to Street Weapon - evil shows its face

The Braille battery showed up today and I was able to put the new front bumper on.

What Gulliver felt like upon arriving in Lilliput:

:lol:

Installed:


Took a page fron Anorexic's book and used industrial strength velcro - major sticky stuff. An aggressive drive moved it not in the least.



Before: After:

Note the new ride height (looks like its on jackstands):



An issue brought about by the all the weight loss is front end lift. With the car riding an inch higher all around, the front begins to lift noticeably approaching triple digit speeds - not what you want. Soooo, coilovers and a front splitter are a must. OTOH, acceleration and response is getting :devil:. You guys with 400+ whp are nuts. The combo of the CF driveshaft and the lightweight crank pulley is sweet.

I've taken 5 lbs of brackets out of the engine bay (there's more to come too, not to mention the air pump) + 1.25 lbs for the intake resonator box + .75 lbs for the battery cover/mounting bracket/hardware -.5 lbs for the battery terminals and mounting + 22.5 lbs for the Braille battery = another 29 lbs or 219 lbs off the car.
 
#27 ·
Re: A-man's 07 STi: DD to Street Weapon - evil shows its face

I'd been overlooking the floor mats. I took out the rears at 2 lbs apiece or 223 lbs so far. Leaving the fronts in until I find a lighter alternative. I get a lot of dirt/leaf clutter in there.

I've about gotten my wheel choice narrowed down to these two:

OZ Alleggerita HLT in Titanium Tech (17x8)


SSR Type F in Bright Silver (17x8)


I like both quite a bit. Both weigh right at 15.5 lbs - really light - and will save 3.5 lbs per wheel over the OEM BBS's or 14lbs total. Just can't decide on dark or light to go with my SWP. Opinions welcomed.
 
#37 ·
Re: A-man's 07 STi: DD to Street Weapon - evil shows its face

OZ wheels manIve got the same car and IMO the OZ will look better and probably be lighter!!!!!!!!
I'd been overlooking the floor mats. I took out the rears at 2 lbs apiece or 223 lbs so far. Leaving the fronts in until I find a lighter alternative. I get a lot of dirt/leaf clutter in there.

I've about gotten my wheel choice narrowed down to these two:

OZ Alleggerita HLT in Titanium Tech (17x8)


SSR Type F in Bright Silver (17x8)


I like both quite a bit. Both weigh right at 15.5 lbs - really light - and will save 3.5 lbs per wheel over the OEM BBS's or 14lbs total. Just can't decide on dark or light to go with my SWP. Opinions welcomed.
 
#28 ·
Re: A-man's 07 STi: DD to Street Weapon - evil shows its face

It appears I'm talking to myself :rolleyes:. Anyway, I've decided on the OZ's when I do decide to get wheels.

Also ordered Kartboy endlinks from TiC and a Cobb rear sway, already have the Cobb front though not on the car yet. With any luck I'll get them by Fri for install. Have a whole weekend for myself. Going to spend it with my Subie and :beer:.
 
#33 ·
Re: A-man's 07 STi: DD to Street Weapon

i'd go 17x9.5 ssr type f's...good stuff. i'm gotta start eliminating some weight to. my recaro's gave me a taste of the anorexic diet :lol:
I really like SSR's. Quality wheel - I have them on my other car currently. My biggest concern with the bright silver Type F is having to clean them all the time to keep them decent looking. The brake dust from the stock pads has all but ruined the OEM gold BBS's. I thought about a wider wheel but I don't autox and I feel like I've got plenty of grip with the 8" and 225 config. Besides, more width = more weight and less weight has been quite rewarding so far :).

Great journal thus far. This is definitely something I'd consider doing right away when buying any vehicle. Random weight savings is the best first DIY mod.
Thanks. Funny thing is you don't feel the quicker acceleration with lighter weight as you do with increasing engine power, you know, that shove in the back...it just moves faster if that makes sense. But its all good.
 
#36 ·
Re: A-man's 07 STi: DD to Street Weapon

if i get an is-f, weight reduction will be a BIG factor for me. gotta do it while keeping the luxory tho LOL plus there's like 4 aftermarket parts for that car, so i gotta find some way to molest it :domo:
That'd be fun. I'd love to have a 135i with 400hp as a daily driver, that way I could take the STi to 500whp and 2700 lbs :D. But I guess I'll keep going with the STi as I am and keep the Fit for a DD. There are definite benefits to keeping a low cost car that gets 37 mpg.
 
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