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Homebuilt GC8 for Time Attack

63K views 269 replies 24 participants last post by  bue car 
#1 · (Edited)
Hi!
Always wanted to start a build thread but never had enough time or interesting things to write about. Now looking back I thought that I have something to share, some ideas for this season in local racing series, and it will be good to start a journal just for my own record and as a motivation to move forward.

Short background story.

It all started in 2013, by that time I already owned Impreza STi type-R for couple of years and found myself a bit confused with it. Here I need to mention that I live in Cyprus. It's rather small island in Mediterranean Sea :) Cars are RHD here and before country joined EU lots of JDM cars were imported. So, sometimes you can spot quite rare japaneese cars here. When I saw my Type-R I was amazed because in Europe you rarely could see 2-door Impreza. At that point I wasn't even aware of existence of these models, I thought that type-R sticker is just a bad joke of some honda fan. Also, I wasn't big subaru fan at that time. Imprezas were just much cheaper than similar vintage EVOs.
So, after owning this car for some time I was confused. It was old (1997), poor market value, not very reliable but eating money really fast. Insurance was expensive, fuel costs were crazy... Then I ran into head gasket problem while trying to sort out mess with vac routing. I had engine rebuilt only to get a dropped valve 6 month later (the next week after I got car mapped after prolonged break-in period). So, I just put in used engine from salvage yard and thought "what to do next?"
I wanted to mod the car but I kept questioning myself, why do I need to do that? Well, at that point I ran onto local time attack series and it was perfect. Owning this car become full of sense in one moment and participation in "Street" class with strict regulations promised to save me from expensive mods. Basically I had to keep engine stock and no lightweight parts were allowed, so I could only get suspension. I was happy with this because I wasn't excited in modifying good and quite a rare car extensively. I even bought DZ03G tyres in size that fits without any modifications like arches rolling.
On local track where all time attack events are held I got lap times around 1:18 after I changed some shitty lowering springs for stock sti ones and I managed to get nto 1:15.xx on the first event I took part with coilovers and group N bush kit installed. It was mid-season 2013 and I even managed to win that event in my class although I knew that there's one EVO 6 lapping the track in low 1:14.xx, he just wasn't taking part in that event.

Then my Dunlops arrived. That was the day when I realized that tires are probably the most important single thing that will define your lap time. This time fast EVO came to the event and did low 1:14.xx lap again. I managed get to 1:13.xx. (he had same tires btw ;)) It was a shock, for me in the first place. The next event was on the next day and some guys came to check the car asking if turbo was stock and so on, because such time for street class car was rather surprising :)

Long story short, this car took me to second place overall in 2013, and win in 2014 in AWD (Unmodified) Street class. The car won every race it participated in. In 2014 I managed to set fastest unmodified street awd class time ever and if I recall it right - second fastest time among all street cars time loosing more than 0.5 sec to GDB from senior "Street Modied" class (engine mods allowed + removing aircon and stuff) and winning just 0.03 sec from Corvette ZR-1 in third place.

This is how it looks like




And this is one of the most fun videos - free ptactice session before final 2014 event, in wet

2014 Time Attack 5 Practice:


At the end of 2014 season I decided that keeping a track dedicated car in good looking condition capable for driving around city is hard, expensive and not worth it. I promised myself to stop tearing good rare car in competition.

So, this journal will be about this one:


I don't plan anything extraordinary, it's not going to be record breaking project, rather story full of pain and suffering about fixing old cars :)
hope you like it.
 

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#28 · (Edited)
Under the bonnet the car is as stock as swapped car can be

there are no mods except for turboback 3 in exhaust...
but plans are v3 intake manifold and vf28 turbo.
Need to think about exhaust manifold, but if I go for it, it's rather will be some cheap ebay stuff. Some of those work well, but some can even make worse...

regarding 245 section tyres, Dunlop doesn't make 245s in 17 inch :(
I had to choose between 235/45 R17 and 255/40 R17.
245/40 would be perfect, but...

v-mount... there is something magical in this word :)
unfortunately, it's beyond both my budget expectations and my fabrication tools/skills..
 
#34 ·
Every time I saw bandoned car journals I was thinking like "WHY YOU NOT WORKING ON YOUR CAR?!!!" Well, turned out that it's not that easy. My day job is as far from working on cars as it may be and this summer in Cyprus is really turned out to be too hot to work outside on weekends.
Also not helping progress with the car is that I bought myself a motorcycle :) Not sayint that it stole much time from the project since it was too hot to work on it but I spent couple of saturdays riding in the mountains :)

Car is standing without wheels and brakes for couple of months now and serves as really good anchor for the bike. Chaining bike to the towing hook lets me sleep much better becasue my friend's R6 was stolen recently from his house :(

Lazyness as it is:
 
#36 ·
Thanks! I'm trying :)
So, yesterday I got from work very excited to do something on the car. Finally. Probably had too much coffee. Anyway, I opened a hood and started thinking what to do.
It’s really hard to decide where to start. During quite long period without updates in my journal I managed to remove aircon compressor, so now it was a mess and after couple of month I hardly could remember where did I put my tools…

BTW, that's WTA intercooler CORE mock-up from carton. Without endtanks.. V2 maniford is really not cool for top mount options...
Also my new tyres arrived - same Dunlop DZ03G as I had before, but in 235/45 R17. Size is a bit odd for GC8, but I have other problems to solve before it will become top priority.

So, quick update on my TO DO list:

Brakes.
Delete ABS, install brembos. Simple. More below.

Engine. (electronics)
V2=>V4 conversion. Should be pretty simple, but I’m a bit nervous about it. patch harness arrived, so I hope that major harness splicing will be done there, keeping it as clean as possible. Cmon, who am I fooling? it will be a mess, for sure...

Engine (mechanical)
Strongly tied with v4 ECU swap. Engine has loud valvetrain noise, leaky valve covers and cracks in almost any rubber hose on it. Idea was to keep it on budget, so I didn’t wanted to go deep in it planning to get as much as I could from stock unit. But common sense suggests some preventive maintenance. I have all the parts to do valve cover job and might try to adjust the valves. Tricky part is that it might be rare V2 STi engine with unique shim under bucket design and shims might be hard to find.. Otherwise it’s HLA and they are just noisy…
Also on the list - v4 manifold swap (if necessary), 440 injectors, parallel fuel rails mod+AEM fuel pressure regulator, VF28 turbo. I have all the parts, just need to put it all together.

WTA Intercooler
Decide on base kit
get it
install it :)
If I get full v4 manifold conversion I might use spare v4 intercooler I have as tempo solution.

Misc - finishing touch
Walbro fuel pump,
Complete AC delete
Audio delete/Central console with all the stuff that I need (datalogger, WTA IC controller, remote brake bias adjustment)
Wheels/tyres issues
Mapping


Since car is currently is on jackstands without wheels and brakes, I decided to finish with the brakes first.

I was trying to decide where to put brake bias valve and which front lines I might use.



Ended up with idea to put it where ABS unit is located. Since i’m not 100% sure about engine configuration and which intake will be used on the engine, this spot looks like the only place which might not cause fitment issues in the future with both intake components.

Previously I was stuck because some bolts were missing to mount front calipers and some flares were stuck on ABS unit. Luckily hot weather and soaking two months in wd40 did helped and ABS unit is out!



Now I need to clean up working space for fabricating brake lines, the plan is to have both front lines made from scratch and re-use only rears.
Also I have universal Allstar aluminium brake disc cooling ducts. They’re not really fitting great on the hubs from the first look, but I’ll try to figure it out...
I hope next update will be this year :)
 
#37 ·
Some parts popped up on local marketplace. I'm interested in exhaust manifold, but I don't think it's any better than stock.. What do you think? Any good?




Ad says "For sale : stainless steel exaust,down pipe ,up pipe Twister, carbon rear lights , adjustable rear wing spoiler ( 4 ways) , unequal length manifold, intercooler,alloy rims,full glas front lights and many more. " Looks like somebody is parting up his project.
 
#38 ·
^ I wouldn't put any of that stuff on the car, especially the exterior bits. You guys are lucky because your cars come stock with the best exterior styling. Here in the US we have to buy all the crap to make the cars look the way they're supposed to look.

I love your type-R. Such an awesome looking car and a great setup. Are there any updates?
 
#39 ·
Thanks! My Type-R is now my daily driver since I gave my Forester to a friend while his car is being repaired. It really reminds me what a great car it is but also to-do list on it is growing... Some strange clicking noise in suspension, loud transmission whine and scratches/paint chips all over.. Some interior parts are showing their age and gauges lighitng started not turning on sometimes, probably relay is dying...
Car almost has 150k kms on odo... And I keep noticing it in every spot I look at :(
After all money and time spend on it it needs basically full resroration :( That's very discouraging.
Anyway, I managed to spend couple of hours on weekend working on car... Most of it was wasted searching for tools and stuff, but I managed to wash the car, get all brake parts together and mock-up some of the components under the bonnet.


Here how brake bias walve will probably be installed:




Unfortunately it will not clear V2 intake, so no way back
 
#40 · (Edited)
2015 season is over, so I'm not in hurry now :)
The fastest car in my class was still ZR1 with crazy 1:09.3, but second fastes as of the end of the season is.. GC8!
This one:




Haven't seen the car in person this year but I heard it runs GDB internals and 255 R17 Hankooks Z221...
Also some rather big turbo setup is spoted under the bonnet:


these guys have a team running bunch of GC and GD cars and as I can see this car got some parts from their badass green hillclimp coupe car... Probably they used not only exterior and aero parts ;)

Well... Taking into account my current progress, making any estimations on my future lap time will be ridiculous, but I would really like to get into 1:10.xx, which is light years away from 1:15 in opening event this year.

My plans are the same. Get brembo brakes and adjustable bias valve in, abs, stereo and aircon out. Install water-to-air intercooler setup, wire in V4 ESL ecu and datalogging, get VF28 turbo in instead of td04 and kinda tune it, put 235/45 R17 dunlops on and adjust suspension. That's all for now.

Working under the bonnet I found that almost any vac hose under the bonet become cracked, so probably I'm gonna need kind of "gaskets and stuff" maintenance since oil is all over the place from valve cover gaskets...

Doing this I will also try to measure valve clearence (because it' quite noisy) and I need your advice on how can I tell from looking under the valve covers if engine has HLA setup or this is early STi shim under bucket valvetrain?
 
#41 ·
Great build thread! I love reading about these home built time attack cars and what all is done to them. Got plans to rebuild my Type RA in similar fashion when I get the parts back stateside next year. That MapDCCD is awesome! I'm glad to see something that works so well with the older versions with all the data logging and sensor inputs it has. Keep up the good work. Can't wait to see how it progresses.
 
#42 ·
Yep, MapDCCD is really great. It helped a lot to make it trough that 1:13 barrier, you can really feel how it works and see it in the log :) Too bad I had not enough track time to play with different maps/strategies.
As I said, my tranny/diff in coupe are quite noisy, well above the level you wand it to be in street/daily car and nobody wants to rebuild them here... Everybody just saying to keep it until it blows and then replace. So, if i would ever get involved in rebuild/restoration of the coupe I planned to swap all transmission from my coupe into the track car to have DCCD/R180/big hubs...
And then just get 6 speed or fresh 5 speed tranny for the coupe...
 
#43 ·
I know all about a noisy DD ha. I've got the R180 swapped already with a Cusco RS LSD and subframe locking bolts, but with JDM bugeye STI 5x100 hubs. I love the short 5S from the RA though and would rather build that then swap a 6S. Plus it has DCCD so that's already there for me.

Your coupe is gorgeous by the way.
 
#44 ·
Thanks! :)
Managed to make first connections yesterday. Now two rear lines are connected together via T-fitting. Once I get this T connected to bias valve my rear lines will be complete.


Flaring lines appeared to be not an easy job. In fact every second flare I did was a failure. And since every line has two ends, 50% success rate was really not enough :)
I really want to think that problem is not my skill but rather the fact that I bought one of the cheaper ebay kits like this:

It does the job, but it's really important to keep stuff alligned and squared when you press it and pipe itself straigt when you cut it or fix it in the tool... And it's really hard to achieve because of tool design. Heating the tube kind of helped, plus I improved a bit after failing 3-4 times. Time will tell... Hope it will not leak.
 
#47 ·
Well. Tried to mout brake booster and mc to see how it all fits together. Also installed actual brake pressure sensor to see how it's harness connector will clear solenoid bracket. Here is the result:




Looks like for now it clears fine, but one big question remains. How to route lines from MC to bias valve? They need to enter from the top of the valve and only oblious way to do this is to route them abovethe valve. But I don't like it since 99% it won't look clean, might be at the same height if not higher than max fluid level in MR reservoir and probably will mess up with the adjustment knob...
And there is not much space on the bottom either to route lines there because I need to connect three lines to the ouput pots and squeeze them between the valve and wheel well. Not even saying that pressure sensor will be in the way if I somehow get the lines under the bracket from the RH wing side...

Will be trying to solve this today.
 
#49 ·
Not much done with the car since last update...
Took Type-R for a spin to the track, basically in full stock specs, except for DCCD controller. Made a video just to remember how it all works ;)
Became a bit rusty behind the wheel...
anyway, it was fun! :)

 
#50 ·
So, it's been a while since my last post.
First round of 2016 TA is scheduled on March 12, and I'm quite sure that I'll miss it :(

Couple of recent weekends turned out to be quite productive even with weather trying to mess things up.
I almost finished with brake lines but got kind of short on supplies, so ordered more line tube... Basically I still need to finish making two front lines and assemble the system.
Here is longest line 50% completed using original one as a guide. Still needs to be cut to length and final bends, as well as second flare...

I wonder if this was a good idea since it's not 100% as OEM for sure, so I expect fitment issues. Maybe it would be better to make it from scratch. Engine was in the bay at the moment, so I thought it's a good idea to copy original line...

My fake Advans are not clearing brembos :( Just a tiny bit..

Major disappointment since I didn't plan to by another set of rims...
Temporary fixed by adding cheap 5 mm spacer, but I don't like it. Looks like I will end up with some Rota or JR budget stuff, needed 17x8 rims for 235s anyway..

Engine is out! It was first time for me doing anything like this (messing up the car that bad :)) so it was a challenge. Everything went smooth and it looks like I haven't even broke anything.


Whoever did this last time did it pretty rough. One of the dowel pins is missing, in two bottom holes bolts are used instead of studs, so I can't get them out from bellhousing without removing CV joints, and some of different length bolts are kind of mixed up...


Will try to get some hardware to mount the engine to the stand and get valve covers out today.
The idea is to clean everything, check valve clearances and adjust it if it's possible, replace bunch of seals and gaskets, replace all cracked and worn hoses, install front entry turbo, yellow injectors, connect fuel rails in parallel and convert it to be controlled with V4 ECU.
I still have most of the parts to convert intake to V4, but as I started pulling parts from the shed I found that some stuff is missing.. Like throttlebody :( Who knows what else. So it's one more decision to make - should I convert it to V4 manifold or not?..
For now I stripped V4 intake, got yellow injectors out (what a PITA!) and sent them for cleaning.. There were plenty of metal shavings in the manifold (after snapped valve on old engine) - another risk of putting it on the car...

Anyway, it's good to be back! Got tired of watching it under dusty cover.
 
#51 ·
This weekend I worked on engine to prepare order for engine parts.
Engine suffered from a old power steering fluid leak, so I decided to clean it and probably reallocate PS tank somewhere. Or at least replace some seals to stop the leak…
Also crankcase vent hoses become hard as plastic and all connections were leaky and dirty.
Before:


As the result I washed it three or four times every time removing more and more bits that were not allowing to clean it better.. Many cans of engine cleaner later, kind of semi-finished result:

later I removed timing bits and coolant tubes over cyl 2 ad 4 and cleaned it once again

Timing belt was off on all cams except for RH intake (1 and 3). Here’s pic of LH cams with crank marks alligned:

I wonder if this could be a cause of poor performance comparing to my other car.
most of the pulleys are toast, so gonna replace them and timing belt
Initially It wasn’t planned but I think it’s worth it. Oil pressure was solid and seal looks clean, so pump will stay on..
Water pump… Probably good idea to replace it because that looks scary:

Any idea is there a way to clean the block inside? I rinsed it with water, but maybe there’s some trick or solution for this specific job?
Another surprise was the turbo. While removing I found it hard to remove one nut right under the center section, so I decided to take the turbo out from hot housing to reach it. Result:


I didn’t broke it, it just fell apart.. crack is quite old and looks like it wasn’t leaking. Anyway, I didn’t planned to use it. Despite this turbo looks fine btw, no play or leaks…

By the way, is there a flex section in stock uppipe? Turbo mount flange is kind of loose on mine and it feels like joint is somewhere under the heat shield, can’t see. Wonder if it leaks..
Also question, does it makes sense in keeping stock heat shields? Mine are kind of reusable but they weight a lot.. I wonder if wrap works better or not?

Finally after final stage of cleaning I managed to pull out valve cover from LH side (2+4).
It’s for sure STi, not HLA heads.


Shims are 9.65 mm (? my caliper is crap) diameter with 6mm hole on the other side and have numbers on them written by hand.

Buckets are 30 mm diameter. This one seems to have worst wear although sits a bit tighter than others.

Are these (buckets+shims) similar to V3-4 and later bits? because I never seen them but by part numbers V1-2 STi shim setup looks different and unique although similar by design.
Cam journals are fine for me, which sounds funny because I never did anything like this before :)
I just never heard of anyone doing any polish/repair stuff on these, so I will just try to put it back together as clean as possible to not to cause more damage.
Exhaust cam, worst bearing:

respective cam journal

Intake cam caps, cam looks mint.


Still need to measure the other head and order correct shims plus some other stuff to put it together.
Now, questions:
Before final assembly would it be good idea to turn engine on stand till head will face downwards and spray it with some intake cleaner stuff? I will lube everything with fresh oil during assembly anyway and I wanted to get rid of any dust or stuff that may got there since I have to work outside… It wasn’t windy or anything yesterday and it’s not F1 engine but it’s not the best condition to work on engine and I don’t want to harm it in any way...
There was some silicone inside including in some threads… I will try to do this job better when I will put it together. Is there a simple way to clean old silicone out of threads?
Also if anyone has advice on valvetrain setup or coolant passages cleaning on assembled engine tricks or exhaust stuff that I questioned about, please share!
Thanks for reading! :)
 
#52 · (Edited)
nice work. the shims you need to measure the inside were it rest on valve. They are rarely out of spec so just put them back exactly where you got them

you heads look like v2 sti heads. v3 and v4 are the ej20k engines with cloverleaf chambers, the valve buckets are different diamteres. the early wrx heads wre HLA lifters, were yours are shim under buckets sti heads. O dont see any closed deck casting marks on block, usually v2 sti's were closed deck

looking again i think i do see the casting. Thats a closed deck v2 sti engine. not sure if you knew that or not
 
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