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Old 11-02-2011, 12:31 PM   #1
ScoobyAddict14
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Default Tyler's 2005 Boppity Bopp STi ASP Build

This is my winter build and I'm sure it will be an ongoing build. I should have started a thread a long time ago. I'd like to get some input on the direction my build is going.

Sponsors for the build:
TiC
TRU Motorsports
Fort Wayne Subaru

Here is the specs of the car right now:

2005 Subaru STi

Engine:
JDM TGV Deletes
Perrin Turbo Inlet
K&N Typhoon Intake
3 Port Boost Solenoid
Deatchwerks 850cc Injectors
E85 Tune
GTSpec Header & Uppipe
Cobb DP
Ansa Cat Back
Megan Racing Motor Mounts
Megan Racing Trans Mount
Megan Racing Pitchstop
Lightweight Battery

Suspension:
TiC AST Coilovers (8k/7k)
Vorshlag Rear Camber Plates
PDE Front Camber Plates
32mm Niles Front Sway
29mm Whiteline Rear Sway
Outrigger bushings (TiC)
Shifter bushings (Perrin)

Wheels:
17x9 5zgen FNOR-1C w/ 265 Star Specs

Brakes:
Hawk HP+

Interior:
RS Driver's Seat
Defi Boost Gauge
AEM UEGO

Winter project:

8mm Phenolic Spacers
Intake Manifold Port by TiC
Throttle Body Port by TiC
New Tie Rod Ends (front)
New Ball Joints (front)
New Wheel Bearings (all four)
285 / 30 / 18 Hoosiers
Golan Fuel Filter
PURE Tune
Corner Balancing
Heavier Swift springs
Damper revalve
Karlton fender flares
Lateral link bushings (TiC)
Trailing arm bushings (TiC)
Front control arm bushings (Whiteline)
Rear control arm bushings (TiC)
MSI Housings
Steering rack bushings (Whiteline)
Deathscwerks 1000cc injectors

I am going to nationals next year for ASP so I am looking at ways I can mod more to be competitive.

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Last edited by ScoobyAddict14; 02-18-2012 at 05:34 PM.
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Old 11-02-2011, 03:15 PM   #2
subydude
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The list of things to do is pretty much what I was going to suggest for it to be even close to ASP competitive. Spring rates are in the ballpark at least and the tires are good. 18x10 +35 would be just about right as well, although I'm sure TiC will let you know.

Off topic, but is that pic from an OVR event at OSU?
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Old 11-02-2011, 04:07 PM   #3
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Nah I believe that's the Subaru Challenge at SIA this past August. Great lookin build T. Hopefully I can make it to some Ft wayne events next year and see how it runs.
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Old 11-02-2011, 08:28 PM   #4
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It looks to me that you are too stiff on swaybars and too soft on springs. I'd go to 12k/11K springs with those bars turned down a notch.

What is your alignment? Alignment is often the cheapest, most overlooked suspension tuning tool available.
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Old 11-03-2011, 07:30 AM   #5
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Quote:
Originally Posted by speedyHAM
It looks to me that you are too stiff on swaybars and too soft on springs. I'd go to 12k/11K springs with those bars turned down a notch.

What is your alignment? Alignment is often the cheapest, most overlooked suspension tuning tool available.
The front is nonadjustable so it stays at 32. My buddy and I are going to calculate the best spring rate for the car based on a couple of variables. Alignment is -3.2 camber front and -1.6 camer rear
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Old 11-03-2011, 09:47 AM   #6
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lightweight seats?
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Old 11-03-2011, 09:48 AM   #7
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Nice car, nice build!

One question, and I apologize for my ignorance, I thought the STI was in BSP?
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Old 11-03-2011, 09:57 AM   #8
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Quote:
Originally Posted by Annihilator817 View Post
Nice car, nice build!

One question, and I apologize for my ignorance, I thought the STI was in BSP?
The class change proposal puts it in ASP with most of the current ASP cars going up to SSP (Super Street Prepared).

I agree with SpeedyHam, you'll end up fighting the bars a decent bit, and I'd add in a good rear diff as well for a more complete package.
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Old 11-03-2011, 09:58 AM   #9
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They're creating a SSP class and doing some redistribution of the classes. New ASP = old BSP essentially.

November Fastrack has the break down for what they're changing:

http://www.scca.com:8090/assets/11-fastrack-nov.pdf
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Old 11-03-2011, 11:56 AM   #10
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Quote:
Originally Posted by thunderbird View Post
lightweight seats?
Throwing in the RS seats which are significantly lighter than the STi seats

Quote:
Originally Posted by subydude View Post

I agree with SpeedyHam, you'll end up fighting the bars a decent bit, and I'd add in a good rear diff as well for a more complete package.
What suggestions do you have for the rear diff?
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Old 11-03-2011, 12:01 PM   #11
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+1 on the rear diff or this will be the death of you.

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Old 11-03-2011, 03:25 PM   #12
subydude
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The Cusco RS is always a popular option. I have a Carbonetics that I got on closeout. It basically requires fluid changes every 3k miles for hard use so not something I would suggest for a heavily used daily driver. For me though I usually change the fluid 2-3 times a year and absolutely love the diff. Smooth with great progression in locking.

The Cusco is spring loaded so you have to put a certain amount of torque through it before it starts locking. This is to prevent popping in low speed parking lot type turns. Only downside I've ever heard of that is it can occasionally lock more suddenly as you overcome the springs.

If OS Giken made a diff for our cars I'd be interested in that, but the Carbonetics is as close as I could find at the time (2-3 years ago). And like I said, the only reason I have one is a shop was closing and they were selling the last few parts they had. IIRC the diff was like $1,600 new or something and I got it for $800 with enough fluid to last till now. I was going to buy the Cusco since it went for roughly $1k.

Still, long story short, you want the diff first as it will dictate your suspension setup. If you setup everything else first, then do the diff you'll find that you have to go back and change a lot of things to bring it back to "just right".
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Old 11-04-2011, 10:27 AM   #13
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We picked up a Guard rear unit for the race car from Matt Monson (here on the boards).

At first we were rather apprehensive given the price and the cusco unit we had in the past seemed to do ok. Oh, man, the price is worth it. So very happy with that diff.
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Old 11-04-2011, 10:46 AM   #14
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Not from personal experience, but I do a lot of reading and talking with people on different suspension ideas/theories/ etc. A guy in SC races an RS and is going through the process now of redoing the suspension after upgrading his rear diff to a Cusco.

At first, he was fighting to get the car to rotate while keeping the car level to minimize rear tire lift. Now that he has a proper diff that can distribute the power as needed, and let the drivetrain help rotate the car, not jack up the weight transfer through bars and/or springs, he is going to try a wagon rear bar or none at all.

Good luck. Also, what are the current SP rules on a splitter? I would think there is some aero work that could be done, as IIRC have seen some of the CSP cars and such with splitters and I know huge rear spoilers.

Travis
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Old 11-04-2011, 11:37 AM   #15
subydude
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Quote:
Originally Posted by T_Racer69 View Post
Not from personal experience, but I do a lot of reading and talking with people on different suspension ideas/theories/ etc. A guy in SC races an RS and is going through the process now of redoing the suspension after upgrading his rear diff to a Cusco.

At first, he was fighting to get the car to rotate while keeping the car level to minimize rear tire lift. Now that he has a proper diff that can distribute the power as needed, and let the drivetrain help rotate the car, not jack up the weight transfer through bars and/or springs, he is going to try a wagon rear bar or none at all.

Good luck. Also, what are the current SP rules on a splitter? I would think there is some aero work that could be done, as IIRC have seen some of the CSP cars and such with splitters and I know huge rear spoilers.

Travis
Ok, I have to ask, are you talking about me? I'm the guy that picked up the wagon bar from you at Georges shop back in the spring and that just sounds an aweful lot like what I did earlier in the year
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Old 11-04-2011, 11:52 AM   #16
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Quote:
Originally Posted by subydude View Post
Ok, I have to ask, are you talking about me? I'm the guy that picked up the wagon bar from you at Georges shop back in the spring and that just sounds an aweful lot like what I did earlier in the year
Mayyyybeee. Yeah, and echoed what my buddy at SOJ was telling me too. When I went down to get an alignment, I got on the subject of what bars, setups, etc. And he is a big proponent of a proper diff, then you are not having to run bars to get the car to rotate, but let the diff help power the car through the turn, not over load the tires.

He mentioned that when he was running a 22/24 bar, that he could hear the rear end clunking when the car would hike the inside tire, and then drop back down, and hear the rear diff clunk from the sudden load as it was basically weak enough that it was very close to an open diff. I have had this personally happen a lot as I am still on stock bars, and stock diffs.

Travis
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Old 11-04-2011, 10:42 PM   #17
ScoobyAddict14
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Quote:
Originally Posted by Turn in Concepts View Post
We picked up a Guard rear unit for the race car from Matt Monson (here on the boards).

At first we were rather apprehensive given the price and the cusco unit we had in the past seemed to do ok. Oh, man, the price is worth it. So very happy with that diff.
Quote:
Originally Posted by subydude View Post
The Cusco RS is always a popular option. I have a Carbonetics that I got on closeout. It basically requires fluid changes every 3k miles for hard use so not something I would suggest for a heavily used daily driver. For me though I usually change the fluid 2-3 times a year and absolutely love the diff. Smooth with great progression in locking.

The Cusco is spring loaded so you have to put a certain amount of torque through it before it starts locking. This is to prevent popping in low speed parking lot type turns. Only downside I've ever heard of that is it can occasionally lock more suddenly as you overcome the springs.

If OS Giken made a diff for our cars I'd be interested in that, but the Carbonetics is as close as I could find at the time (2-3 years ago). And like I said, the only reason I have one is a shop was closing and they were selling the last few parts they had. IIRC the diff was like $1,600 new or something and I got it for $800 with enough fluid to last till now. I was going to buy the Cusco since it went for roughly $1k.

Still, long story short, you want the diff first as it will dictate your suspension setup. If you setup everything else first, then do the diff you'll find that you have to go back and change a lot of things to bring it back to "just right".
Quote:
Originally Posted by T_Racer69 View Post
Not from personal experience, but I do a lot of reading and talking with people on different suspension ideas/theories/ etc. A guy in SC races an RS and is going through the process now of redoing the suspension after upgrading his rear diff to a Cusco.

At first, he was fighting to get the car to rotate while keeping the car level to minimize rear tire lift. Now that he has a proper diff that can distribute the power as needed, and let the drivetrain help rotate the car, not jack up the weight transfer through bars and/or springs, he is going to try a wagon rear bar or none at all.

Good luck. Also, what are the current SP rules on a splitter? I would think there is some aero work that could be done, as IIRC have seen some of the CSP cars and such with splitters and I know huge rear spoilers.

Travis
Thanks for the suggestions on the rear diff. I will be looking into the options to replace my rear diff for next year.

Working on more of the teardown tomorrow!
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Old 11-05-2011, 02:20 PM   #18
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I have everything off the car except for the two inner rear lateral links. I need to get 6 point combo wrenches to get them off.

Could someone please explain the need for a new/better diff?
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Old 11-06-2011, 11:03 AM   #19
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The factory diff(s) becomes open when one rear wheel is lifted off the ground and all the power goes to that hanging wheel. The car will slow down till the hanging wheel (that's now spinning pretty fast) comes back to earth and jolts the rest of the car. If you search you'll see there's a lot of other autox drivers who have the same problem. They call it "bouncing out of corners". The wheel lift is very common, especially with big bars. With a proper clutch pack diff you can still put the power down to the other three wheels and mitigate the bouncing.
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Old 11-06-2011, 02:40 PM   #20
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Subydude is right on. Potentially you could have this wheelspin/loss of power to the ground on almost every corner exit.
Say you loose .05 secs per corner exit from wheelspin X 10+ corner exits that .5secs you lost. This could be on the extreme side but just an idea.
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Old 11-06-2011, 03:57 PM   #21
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Quote:
Originally Posted by subydude View Post
The factory diff(s) becomes open when one rear wheel is lifted off the ground and all the power goes to that hanging wheel. The car will slow down till the hanging wheel (that's now spinning pretty fast) comes back to earth and jolts the rest of the car. If you search you'll see there's a lot of other autox drivers who have the same problem. They call it "bouncing out of corners". The wheel lift is very common, especially with big bars. With a proper clutch pack diff you can still put the power down to the other three wheels and mitigate the bouncing.
Not to mention that with the '05 car I drove with stock diffs, when that wheel came down, the car would tend to take off in whatever direction the front wheels were pointed at that moment. I was not told this before I drove the car, and it resulted in one of the scariest moments I've had while autocrossing.

I didn't have quite that kind of problem with my '06 WRX, but then again, the drivetrain is completely different. Instead, I would just get a lot of wheelspin. Changing out the front and rear diffs really helped my car a lot.
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Old 11-06-2011, 08:16 PM   #22
ScoobyAddict14
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Quote:
Originally Posted by subydude View Post
The factory diff(s) becomes open when one rear wheel is lifted off the ground and all the power goes to that hanging wheel. The car will slow down till the hanging wheel (that's now spinning pretty fast) comes back to earth and jolts the rest of the car. If you search you'll see there's a lot of other autox drivers who have the same problem. They call it "bouncing out of corners". The wheel lift is very common, especially with big bars. With a proper clutch pack diff you can still put the power down to the other three wheels and mitigate the bouncing.
Quote:
Originally Posted by 04trailsti View Post
Subydude is right on. Potentially you could have this wheelspin/loss of power to the ground on almost every corner exit.
Say you loose .05 secs per corner exit from wheelspin X 10+ corner exits that .5secs you lost. This could be on the extreme side but just an idea.
Thanks for the explanations guys. I feel like I'm going to have to learn a whole new car next year, but going to have one setup all year long. Can't wait for the new parts to come in; it's going to be a long winter.
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Old 11-13-2011, 10:04 PM   #23
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Just some updates and I know it was debated earlier in the thread:

Spring rates - is there a way to calculate what I am going to need or is it merely just trial and error? I'd like to get some other input on this before I go ahead and order my springs.
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Old 11-13-2011, 11:34 PM   #24
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I co-drive my buddy martins bsp car (06 sti soon to be asp) at national tour and pro-solo events and he put the Cusco RS diff in it and man did it make a night and day difference. but let me tell you!!! it is not a diff you want to drive around on a daily basis... we drive the car to and fro events and man when you are pulling out of a gas station it will pop/crack and sound almost broken. Its funny though, the second you launch and are on course the diff feels amazing, the car responds 10000X better than the stock diff. On show case sweepers the car does not feel like its gona wash out or understeer and it pretty much eliminates "bouncing out of corners." I personally own a 06sti the i am building for stu class and it takes a bit of adjustments(suspension) to keep all 4 wheels on the ground, i feel i am finally getting there now lol. Now putting the RS diff in is pricy but in the end you will be happy, just wish i was aloud to in stu class.
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Old 11-13-2011, 11:44 PM   #25
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o and p.s. not to scare you but i snapped a rear axel in the Atlanta National tour. Surprisingly didn't happen on the launch but rather after when i was in a 3gear high speed slalom, according to my video it happend when i was transitioning from left to right and the diff locked a little harder than usual. In all honesty i would not let this deter you from buying it. Martin and i estimate that our times improved by about 1.3sec with the diff in. O and thanks again CamaroFS34 (karen) for hooking us up again in Atlanta with a new axel you were a life saver!
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