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Homebuilt GC8 for Time Attack

64K 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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#53 · (Edited)
Yes, I knew that it might be STi engine with closed deck block. But now it's finally confirmed.
I can't measure buckets since i don't have proper tools like micrometer. I have only basic cheap caliper which does the job for most of the time. So I'll trust the numbers for for now, but when I'll do second head I'll pull some buckets and give them to my mechanic to check and confirm sizing.
The clearances measured on LH head are too tight, around .17-.20 mm for intake valves and around .22-.28 for exhaust. The specs if I'm not mistaken are 0.25/0.35.
This is kind of strange because valvetrain was a bit noisy so I was expecting to see clearances above the nominal. Although as valve seats wear out clearances should decrease, so results that I got look realistic.
Will check second head and decide.. Maybe switch some of the shims to even the clearances a bit, or order some new ones.
 
#54 ·
So, I got second head measured this morning before work and most of valves seem to be tighter than specs which is probably normal considering normal wear for 20-year-old engine :)

Since Subaru was kind enough giving nice description for shims in parts catalog that included shim "number" and thickness, I ended up with spreadsheet with calculations of required shims:

I initially set up "target" clearences to 25/35 and to get those calculations suggested me to get 8 new shims... I adjusted my target to .21/.33 as you can see in the table and this got me to the option to get only 6 new shims:


Looks fine for me :) Now I need to figure out other parts I might need to put engine back together and make an order.
 
#57 ·
Ok, it turned out nearly impossible to order V2 STi shims by OEM part numbers.
Well, it may be possible but list prices are 50 USD and more. I never tried ordering them.
Instead I found the way to get them from independent manufacturers. These shims are kind of widely used in different applications and there are companies that can make them in sizes you need. Also I found that correct specs for this engine are not 0.25/0.35 but 0.2/0.25 (in/ex). This was much closer to what I had in the engine so in the end I needed only three new shims. Now I think that it would probably be a good idea to replace all shims so they would be from one manufacturer, same design (in case there will be any slight differences).
I ended up ordering three missing shim sets in two different places, I'll decide when I receive my orders.
Tried to strip old paint from the manifold and paint it over the weekend but weather messed it up again :(

by the way, 1st Time attack event of this season was held this weekend. Best time in my category was 1:11.3x, which is 1.4 seconds below my PB in my Type R and some 4-5 second less than my PB in this specific car. Quite a challenge...
 
#59 · (Edited)
It seems that some versions of SR20 also had similar shims..
Anyway, photos from opening event arrived... I don't know why one needs to upload all the photos, but... here they are: Time Attack Championship by EKO -

First event traditionally is not the most attendable, some cars are not ready yet... ;) I heard that track was dusty and there were less grip than usual. But in any case there were couple of nice and rare cars there. Like, I personally was surprised to see Baur E30 in classic cars. Rare one by all standards.
Also I'm pretty sure I used to testdrive that specific blue RX7. It's seen better days but engine was pulling great. love the looks of those cars...

Just small memo for myself:
TA1-2016
Entrants: http://i810.photobucket.com/albums/...651_739275596176045_2917819755995625445_n.png

Times: Event results - details - MYLAPS Sports Timing
 
#61 ·
How to tell that your project is taking too long to complete?
Well…

So, I’ve done couple of things on the car. Some part orders arrived.


Since most of the hoses are crap and in any case I will be converting it to V3, I decided to go full silicone kit. Found this G-Plus brand being really cheap.


Got intake pipe, intercooler kit, and coolant kit... For 130 bucks. Free shipping. Couldn't resist :)
With this stuff from China sometimes you can’t be sure what you get, and I wouldn’t advise anyone to do this if they are not ready to loose their money. But sometimes, when for example new brand is being launched, you can get some good quality for amazing price. I really like to think that this is the case because for now I like it and some parts I tried fit great.
Decided for blue for intake parts and red for coolant ones and coolant hoses came with STi labeling on them.

Not a fan of this, but if it’ll work, whatever :)

Still expecting for major engine parts order to arrive. But since all suspension parts are here, I have some stuff to do before I can finish with the engine and put it back. But before that I wanted to fininsh with my brakes..

I really regret for getting this flaring kit. It's just impossible to get it aligned for consistent results.
The only thing that works fine from the kit is tube cutter. The rest is crap. I don't know if it's me or this specific kit quality, but I'm quite pessimistic about this design in general.

I’m not happy with 50% of flares I got on the car now, but I simply couldn’t waste more time with it. I hope there will be no leaks, still need to test it. Ordered another flaring tool and more supplies in case I will need to replaces some of the lines. Anyway, what I got now:


DBA rotors+EBC Yellowstuff pads+Goodridge hoses.
Fronts are ready, in rear still need to fix some issues… I got calipers adaptors, thick drum brake shoes to use with newage discs, but dust shied rubs again brake disc, will try to figure it out today.

Thought about painting the calipers but dropped the Idea, just gave them a good clean. I spent last week (evenings+weekend) to get V3 intake manifold cleaned and primed which took enormous time and effort because I couldn’t get old paint off. Tried two different paint strippers and have major collection of wire brushes now. So those memories kept me from messing up with this stuff again.


I hope that I’ll be able to forget this feeling by the time I get rear subframe down for bushings installation because i wanted to clean and coat them and underbody.
 
#67 · (Edited)
Yesterday second time attack event took place. Here is onboard video of third fastest time in my class:


Results were pretty close with first three cars being as different as they can be:
Classification - details - MYLAPS Sports Timing

1. Evo 6
2. Civic EG
3. M3 CSL

Once I considered this day as pessimistic scenario project finish date :)
Here's how my car looks now
 
#68 ·
removed from the car:
Front arms
Diff
Diff carrier with front bushing
Rear Subframe

parts sent to sandblasting, and probably spot welding for rear ssubframe because I wasn't really impressed with how it looked. Initially I though that I saw some cracks on welds, but it turned out to be only rust flakes on weld seam. Anyway, asked a friend to look at it after sandblasting and spot weld if necessary...
After that whiteline bushes will be pressed in.

issues: one fuel tank strap is not original, too short and strapped to a subframe instead of body, two triangle-shaped brackets on front diff bushes are missing, need to find those because they look structurally important ))
 
#72 · (Edited)
hey man question:

why you didn't do the union connection with
the front brakes lines like you did on the rear?
Missed that one.
In fact Wilwood has two entry ports, for front and rear lines separately and three exit ports - one for rear lines and two for fronts. Taking into account that it's usually mounted somewhere near to master cyl it may be wise since it saves you from getting one more T with three potentially leaky connections )))
So, in any case you need either use two front ports on wilwood and run separate lines from unit or block one of the ports and use T later.
 
#70 ·
I got 5 meters of 4.75 mm kunifer brake line (stands from Cuprum-Nickel-Ferrum if I'm not mistaken), it's same size as 3/16 in US. All OEM fittings have threads M10x1, I believe Wilwood valve has those as well, but I'm not 100% sure since it comes with it's own fittings and I used them.
I ended up buying this type of flaring tool for double flares:

It's for single size and single type of flares, but it works.
Also brake line straightening and bending tools might be useful if you want to make it look nice and clean. Otherwise you can bend it with your hands.
 
#71 ·
new style of update - pictures only ))
in two words, things are moving really slow.








Not again.. I'm tired of cleaning and painting....


racing update.
Civic won time attack event in my class... beating M3 CSL, quick Evo 6 and Turbo S2000...
Claimed to have 208 h.p. and no window wipers ))) Need to learn Greek to read those damn regulations... Someday...

 
#74 · (Edited)
Well, since car was with ABS, front lines end at the spot where ABS unit originally was. They are long enough to be bent to my bias valve location and I believe that with proper tool they can be cut and flared. As is they will be too long for this unless you will bend them in a way to route excessive length somewhere. Then again you need to check if threads match on OEM lines and in this case wilwood unit. Also they seem to be a bit harder to bend than kunifer line that I got, so I never tried to re-use them. Rear lines connections I used originally were OEM bias valve connections. At first I wanted to rote new line to the back or use some part of one of OEM rear lines and put T-connection in the back since brakes are no longer connected in X-pattern with independent circuits, so I believe there are no reasons to keep two OEM lines... but looking at all the work I need to get done to remove that one extra line I decided that it's not worth it )))
 
#75 · (Edited)
there are some people out there who can do stuff in well planned and scheduled manner, it doesn't work like this for me really much :)
My suspension is in pieces, still need to get cams out and adjust the valves, need to figure out how to wire up engine to run on different gen ECU, but my mind gets obsessed with water-to-air intercooler design for some weird reason )
Well taking into account that it will take some time to get parts shipped, maybe it's good thing that I have motivation to do something...
The system will be based around Type 13 frozenboost cooler unit. Site says it's rated up to 350 hp which I believe will be enough considering that I don't have any plans running anything other than stock turbo lineup.
Anyone knows some freeware software to design electrical circuits? I want to make a plan for activation system, pump will be activated either by temp differences in radiator and IC core or by pressure switch and will go through off delay relay.
Also might need to document some of the stuff in wiring conversion...

I also have an idea to use engine coolant for the system. It should be quite simple to unite both systems so they will be running with single expansion tank but with two separate radiators, pumps and different working temps.
 
#76 ·
Really looking forward to your plans for a water to air. I was tossing around the idea for a while, but most my friends who have them only run 1/4 mile at a time, not time attack. Really curious to see how the long term cooling effects are. I've researched both the closed loop system and the engine cooling integrated version. Run the second radiator under the trunk.

Frozen boost was the site I was sent to as well, so I'm actually super excited you're planning WAIC. I've got some time to decide if I want to ditch the Mishimoto FMIC.


Sent from my iPhone using Tapatalk
 
#77 ·
Hey, looking through your journal I think you probably will get in done faster than me! :)
In many places I've seen that ATA intercoolers are more simple, lighter and quite effective in road racing environment. But in this particular case I'm really excited to have it because it might be more effective than ATA and in Cyprus weather it counts, plus I can delete scoop and engine compartment pressurization, e.g. increase flow trough radiators.
I really like this setup: Air to water intercooler setup, one of a kinda!!!! - NASIOC
Involves some fabrication though because there is no such core and it will be hard to stuff bypass valve in without modifying of the core. But chargecooler is moved away from turbo and maybe it will be possible to get bigger unit in.
A bit of a problem that all V2-V6 intake manifolds leave less room compared to newage ones, so this basically limits available chargecooler units to smaller ones... Don't know if it's a big loss though.
Might also try consider rotating manifold and getting this type of chargecooler:
 
#79 ·
Ha, unfortunately my build is on hold a couple months until I move back to the states. I think for the time being, I'm going to stick with my ATA and option to swap down the road. Still excited to see how everything goes together for you. I'll be running a V8 EJ207, so theoretically I would be able to run it standard like the pics in that NASIOC thread. But like you mentioned, the charge cooler size shouldn't matter for the power outputs were shooting for. That track day looked like a great deal of fun! I'm anxious to get onto a real track down in Atlanta eventually.

Keep up the good work!


Sent from my iPad using Tapatalk
 
#78 ·
Not really an update on the car.
Yesterday I took a part in local Autosprint event. Really liked that guys did interesting layout on loal track using some karting sections and part of the drag strip.
So, here is the layout:

Car is still in pieces so, for this occasion I got Type-R out of garage, put Dunlop semis on and took her for the alighment.
On stock ride height and semis for me car looks strangely appealing :)

The only downside was that event used usual telemetry for timing, so it was limited to one car on the track at the time. With times aroud 2 minutes for a car and 40 participants it was lot of waiting... In fact I spend all day on the track to do one practice and two timed runs.
I was really shocked how rusty I become working on the car instead of spending time on track. I could see my line and felt the car but I kept screwing things up like braking too late or steering too aggressively. Or forgetting things.
Anyway, in practice I took my wife with me :) It was fun, time we got was 2:11, she reminded me to turn AC off but we forgot to start the recording on GoPro. :)
On first timed session I forgot to turn AC off but managed to shave more than two seconds from our practice pace, got 2:07.
On third run I massively screwed things up at least twice, almost crashing on second one and got only 2:11.
But it appeared that 2:07 was good enough for a class win!
here is the video of best time, later I will do data overlay for second run with time gap to see the mistakes. I did datalogs on everything that I could :)

I was really happy, mostly because no matter how I tried to screw things up, Type-R managed to save it's reputation and remain victorious :) One guy did 2:06.xx, but he smashed the cone and they cost +3 sec each.
Overal winner was another GC8 with 1:58.xx


First time in Street modified class went to Civic again. 2:01.5, fourth overall - fantastic time. I'm gonna compete with this it when I finish this build. Spoke with the guys who built it and they said that they got the car for 200 EUR and build it in 15 days. Crazy! 900 kg, B18 engine and same Dunlop semis that I use. Dunlops FTW!
But the only reason why it got first place is because another GC8 was really cone-hungry! :) Without counting penalties, this 1:59.xx would have been second fastest of the day. This guy had enough power to spin all four wheels in 255 Hankook semis that from my experience are really close to Dunlops in grip. No aero at all. Car is a bit rough, but crazy fast.


So, that was a nice weekend. Good to be back, need to finish the car
and get it to the track! )
Couple of more photos of other cars.


 
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