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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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#135 ·
Things are moving!
It was raining all the weekend but I was determined to get engine in. Realised that I need to put clutch on, found that one of the whywheel dowel pins whas missing. Made new one out of old cam cap bolt with appropriate shoulder using hand saw, file, sandpaper, and drill as lathe :)))
It was fun, kind of... I made something )


Long story short, engine is now installed ) Achievement unlocked ))



Before installing engine I drilled and tapped O2 plug before uppipe for EGT sensor and changed spark plugs... now I'm ready to start working on fuel lines and wiring...
Still waiting for two more intake manifold gaskets to put manifold on finally with install thermal insulation spacers I got last week...
There will be sprint event next Sunday, not regular time attack configuration. Stage will be about twice as long as regular lap, using some of the lap sectors twice in different directions. Should be fun, thinking of getting Type-R for a ride to get some seat time before the season...
 
#137 ·
Nope, I have two now... They are 90 degrees apart. I believe there are no spare holes on my flywheel to put a third one...
One of original pins got lost somehow. I tried to pull it from my spare engine but only lost about two hours.. Cam cap bolt shoulder was just a tiny bit larger than I needed, so I filed it down using drill, cut it to length and polished :)
 
#140 · (Edited)
Awesome cars!
Finishing a rally blue pearl v4 STi R replica myself engine is swapped (with billet turbo & v2 RA semi el oem exhaust manifolds), 3" tbe, v4 front & rear bumpers, type r lip, STi option suspension, alloy hood, gd sti interior ;)

I had a couple of 95 STi RA engine swaps in the past - ecu was SB code, tmic was silver w an aluminum / silicone intake (one of the best if not the best flowing tmic (tested by an australian mag)), exhaust manifold was cast iron el "y" on left side & had longer runners on right side (odd semi el sounding) of course tranny was dccd.

Odd the your car had the standard z5 ecu & black tmic w plastic inlet (worst flowing tmic) - looks good now!!!

Also turbine housings seem to be cracked most of the time but they are 7cm, your turbine housing had a 6 stamped into it was it a td04 or td05?
 
#141 ·
Thanks!
original turbo was TD05:


Progress update.
Managed to mount Aeromotive FPR and figure out the layout of fuel system.
Did my first ever AN hose end...

Well... I must say that they might be a really cool system, but It's not that easy. Especially without proper tools.

These stainless steel braided lines are real pain to work with, literally.. Cutting lines with angle grinder makes such a mess, but I couldn't find better way to do it. Will need to figure out how to clean them properly before final assembly.
Once cut braiding starts to open up and it's real pain to put it in the nut... Also not having proper AN wrenches I scratched all the nuts :(
well, it's not going to a beauty contest anyway...

Also I noticed that after tightening the fitting hose moves back in the nut about 1mm. I read that it shouldn't move back, but I believe that 1mm doesn't counts really as a failure...

Please correct me if I'm wrong before I spray engine bay with fuel :)

In general, final assembly is not such an easy step as I thought. Maybe it would be easier with OEM parts, but all those silicone hoses and aftermarket stuff create packaging issues. The more stuff I put in the engine bay, the more question I have :) I thought that fuel plumbing will be easy, but that FPR is so big! And looking on nice AN plumbing setups I couldn't even imagine that those fittings need so much space. Nice learning experience :)
 
#143 ·
Almost managed to finish fuel lines yesterday, got more and more stuff mocked up in the engine bay to confirm fitment. Got to AEM methanol kit. Originally I wanted to mount nozzle straight under the intercooler outlet which would be perfect, as I understand, but heater core lines are in the way.
Will it work if I'll mount it offset to the side like this?


That's the mock-up of nozzle length, need to have hose as well.
Maybe I could arrange some kind of bung with 45 degree angle to be welded in closer to outlet, that would be perfect.

Also got an opportunity to buy 5 speed DCCD gearbox with R180 rear diff.
R180 means that I will need driveshafts and uprights as well. I can get them from the same guy, but then I don't know what to do with brakes. Because parts for sale are form Ver 5 STi RA car and they seem to have pretty unique rear brake setup. Basically it's the same as my Type-R, there are GC8 STi 2 pots with vented brake discs and odd handbrake shoe size. I probably can't use my rear brembo calipers and DBA rotors... Need either get complete assembly with brakes or get only tranny and diff and look for more common newage STi uprights that will work with brembos and discs I already bought.
Need verify this and find more to not to buy stuff that I'm not going to use...
 
#148 ·
Wow, it's not even a semi-annual update anymore... Why does it have to be so slow? :(
A lot of things happened, but car is still in pieces :)
Diff I was going to get with gearbox I bought appeared to be R160, so I ended only getting gearbox. one less problem to worry about. :)
Now I have spare 5 speed DCCD gearbox to play when get car running...
Engine-side fuel system is assembled, still need to replace fuel pump but this time do it without having starvation issues in turns afterwards.
ECU harness modification was not as exciting as I expected. Still need to finish it and get ESL ECU from another car.
The main issue I'm having now is power steering. It appears that V2 ps lines do not really fit with v3-v4 style manifold and v3 style lines I got don't fit my steering rack.
I ended up getting bunch of AN fittings and ptfe line to make custom one, but in RHD car where steering shaft is at the same side where line connections and downpipe are the space is really minimal an I'm struggling with high pressure line routing.
Anybody has good pics of clean custom PS setups on RHD gc8?
My best looking option so far is to run the line from 45 deg fitting downwards along subframe. It will be between subframe and downpipe with minimal clearance which I don't like but for now it looks like cleanest if not the only possible way I see to get it done.
P.S. nice one: :blow_money_original
 
#150 ·
couple of pics
90 deg Barb fitting for return bolted up fine, but SS fitting for high pressure is challenging.
Here is 90 degree one pointing upwards. Fitting clears ok, but space for hose is tricky.

45 deg fitting upwards - better fitment for hose, but fitting is too close to uppipe

45 deg facing forward looks like enough space to the uppipe.

Plan to fit hose like this:
 
#152 ·
Tried to mount it like that, don't like how it turned out.

Basically have to either revise the bracket so hose will be tucked in crease of subframe or try something else...
It's not the lowest point of the car, but that loop facing down and edge of subframe pointing against the hose... This is asking for trouble.

I had straight, 45 deg and 90 deg stainless fittings for this project.. Ordered some 120 degree fittings from UK, should be here next week. Managed to find only aluminium ones, but I thing it would be fine. Will try to route it in more conventional way.
By the way, PTFE hoses and fitting are much easier to work with. Compared to regular rubber ss braided ones I had for fuel system, these are much easier to assemble.
 
#153 · (Edited)
Spent some time working on car this weekend.
120 deg fitting arrived, so I finally came up with this high pressure hose routing:


Hose is going up over clutch master and then mounts on RH frame rail with OEM bolt. Long and high, but for me it looks the safest way possible.
Initially I tried to rout it right after the uppipe but then it was interfering with steering shaft and uppipe was really close.
Will probably use cluch master heatshield mount bolt as second mounting point as well.
Reservoir is below the pump and below this high pressure loop, hope it will be OK.. It looks like that's the same height in relation to the pump as in newage cars anyway. If there will be any issues with high pressure hose height, I believe I can route it along the firewall a bit lower, but for now it's easiest way to mount it securely...
Finally got most of engine bay components mocked up to check general layout of intake and other stuff:

Idle control valve port on turbo intake pipe is slightly hitting bonnet when closed... Probably because of intake spacers, although they are only 10 mm, I believe... Not that bad, probably will leave it as is just keeping eye on it.
Still need to get 45 deg elbow for intake, finish with crankcase venting, cooling plumbing and exhaust and try to start this Frankenstein :)))
 
#155 ·
Had absolutely no time and motivation to work on car :(
I mean.. I had some time and I had huge motivation, but these two never came together, so almost nothing was done. Although I managed to find what I think is good routing for high pressure PS hose finally. Hope I'll do something this weekend and make some pics..

Last week went took my daily car to the track joined by another Type-R GC8 that was preparing to next event.
Was trying to catch him up for several laps, overheated tyres a bit and generally was too excited to get a gap on him after we finally met, so got off the track...
Nothing too exciting, it's completely stock car after all now (except for MapDCCD), on 215 Federals RS-R. Stock car is really fun though. Rotates really nice, tail happy and fun!
Mapdccd is great too, changing maps really helps to control the car.
Spend most of the time in most "fun" auto mode though :)
 
#157 · (Edited)
The time has come to revive this old journal ))
Life made it's corrections to my plans and I have to move to another house. Or rather to the apartment, so I can't work on the car on my driveway anymore. I count this as positive change, because having car by the house didn't actually helped me much putting it together in past three years.
Now car has to move, and I'm committed to make it move on it's own power.
I rented two car garage nearby to be able to isolate this kind of activities from my living space because situation with tools and spare parts all over the living room was getting out of control recently...
Engine is assembled, oil is in, trying to start it now... Found some glitches in wiring that I made. My merge of v2 and v4 wiring harnesses didn't gone as planned. I finished patch harness, but car refused to start on first try. I started checking signals on ECU pins and found that something is sending 12v to sensors ground pin..
On older 4-plug ECU there were several separate ground wires for different sensors, on newer 3-plug almost all grounds and shields are on single pin. And it has 12v now (
For now I isolated this problem to MAP sensor and temp sensor grounds having 12v and it seems to come from dashboard.
Further investigations got me thinking that I probably messed up temp sensors wiring because on V2 temp sensor (1-pin one?) is going to dash and ECU at the same time while on V4 dash and ecu use separate sensors... I also need to confirm that V2 has two temp sensors because having some conflicting wiring diagrams not helping either... My V2 ECU diagram shows only 2-pin sensor, but dash diagram shows grounded 1-pin sensor that is shared by dash and ECU (and same pin used as in case of 2-pin sensor on ECU diagram)... Unfortunately my old crossover pipe is already somewhere in the box in new garage.
Anyway, hope to solve it soon and hope it's the problem keeping car from starting. Because car needs to drive to its new home by the end of this week in any case.
 
#158 ·
Problem fixed, but car is not starting... I just pulled one wire from connector under the dash that was supplying 12v to ECU pin as per correct V2 car schematic. In V4 car this specific wire was not present. ECU now works fine and responds to sensors (like rad fans kicked in when I forgot to plug in temp sensor).

So, what do we have today...
To run it needs compression, fuel and spark.
Compression seems to be there - I can feel it from cranking engine manually and by the sound starter makes.
For fuel and spark we need ECU... Here comes the fun part.
ECU is stock 3-plug 1S ECU for 440cc injectors, and some VF turbo, I believe. Right what I have in car now.

In any case, my other car being stock V4 STi works on this ECU flawlessly. In fact, it really helps that I can switch parts back and forth between the cars to test anything.

All the chassis harness is stock V2 except for ignitor deleted because I converted car back in the days to run newage coils.
All the changes to adopt wiring harness to another ECU are done in separate patch harness.
Engine gas 6-tooth crank pulley, which I believe is what it needs - I couldn't remove crank sensor from my other car to confirm... Cam pulleys are also correct, (black plastic with 7 magnets) - I can't imagine that I messed up that bad and somehow put wrong ones or did that incorrectly.
I tested crank sensor wiring tapping signal wire with test light connected to 12v and fuel pump starts working with boost solenoid clicking after I stop. Similar things happen when I just crank the car, so I assume that crank sensor itself, it's wiring and ECU are working as intended.
Car has no maf sensor and map sensor is incorrect for this ECU (V2 and V4 are different, I planned to fix this later in ESL ECU or replace it with GM sensor) but I believe that it shouldn't affect startup because I stared black car on this ECU with both of them fully disconnected. Car just dies after 5 sec of working, I assume because cranking and starting routine is over. But starts perfectly.
Ignition is a bit customized, this ECU is meant to control coil pack with two channels, but car has newage COP ignition using all old COP wiring.
This mod is well documented and quite common - two coils are connected in parallel and I will check the wiring once again, but two of four pins of ignition control in original COP wiring are not changed at all, so I assume that in worst case if there's a problem, at least two cylinders should sort of fire up but it's not happening, there's no sign of any combustion events...
I also checked +12v at coils feed and it's ok, power is there (At least at ign on, probably need to check that at cranking)
I haven't done any checks for injectors yet. But wiring in general was checked several times, which doesn't mean that I couldn't miss something.
I have custom fuel lines with aeromotive FPR and pressure gauge showing around 3 bar, so some pressure is there.
I spend last week trying to sort it out and found couple of issues and oversights, but now is sort of "should be working", but it doesn't.
Maybe you can advise me something?
I need to confirm cam sensor signal and timing sync at ECU somehow. What is the best way to do it?
Also I plan to re-check wiring of ignition and injectors circuits but I don't feel any of them firing now. Will probably also take one coil out and put old spark plug in to see it better, maybe it's firing after all...
But something tells me issue may be no ECU sync.
I swapped cam sensors between cars and my other car starts every time without any problems, still need to try to start it with cam sensor disconnected just to check...
Also worth noting that fuel in the car is from 2015, but I tried adding 5 liters of this fuel to my other cars and I didn't noticed any changes. In one case other car had really low fuel lever so whatever I filled in definitely burns.. after that I considered that it's not worth draining fuel tank completely and I decided to try to start it as is.. Maybe it's worth adding up some fresh fuel? But again, considering that there are no slight signs of combustion events at all, I believe that problem is elsewhere...
 
#160 ·
Lack of combustion event could very well be bad gas. Being as cold as it is up where I am, I have to deal with bad gas after a car sits for 6 months. Ethanol likes to collect moisture. Get 5-10gallons of good gas, a bottle of heat or any other moisture preventitive and dump that in the tank before trying to find a problem that doesn't exist. Crank it over a fair amount so you can pump all the nasty gas out of the rails and lines.

If it doesn't start then, pull your plugs and compression test it. Yes it sucks, but again, no need to chase a wiring problem if you have a few dead cylinders. Odds are good it isn't this as most low compression cars still fire on the good cylinders.

Assuming you have done both of those, back probe or stick a noid light on an injector. If you see a signal and they are not clogged carry on.

Pull a plug and a coil pack and ground it on the block, turn over and check for a spark.

As for the cam sensor, which should fire your injectors in this case, the best way to test this would be an oscilloscope. A multimeter will show a switching signal (depending on the tooth count ) but an o-scope would be more accurate.

Sent from my SM-N920V using Tapatalk
 
#162 ·
Lack of combustion event could very well be bad gas. Being as cold as it is up where I am, I have to deal with bad gas after a car sits for 6 months. Ethanol likes to collect moisture. Get 5-10gallons of good gas, a bottle of heat or any other moisture preventitive and dump that in the tank before trying to find a problem that doesn't exist. Crank it over a fair amount so you can pump all the nasty gas out of the rails and lines.
I'm in Cyprus, it's around 10-12 deg C during the nights here right now.. So not cold at all to have cold start problems.. Anyways, fresh fuel might help...

If it doesn't start then, pull your plugs and compression test it. Yes it sucks, but again, no need to chase a wiring problem if you have a few dead cylinders. Odds are good it isn't this as most low compression cars still fire on the good cylinders.
Car was running fine three years back. I changed timing belt and valve shims. Timing assembled according to manual, engine spins freely with noticed evenly spaced compression phases, everything seems to be OK. On the electrical and control side of things there's much more stuff changed. New style inlet manifold, all sensors, ECU. That's why I mainly focused on this...


Assuming you have done both of those, back probe or stick a noid light on an injector. If you see a signal and they are not clogged carry on.

Pull a plug and a coil pack and ground it on the block, turn over and check for a spark.

As for the cam sensor, which should fire your injectors in this case, the best way to test this would be an oscilloscope. A multimeter will show a switching signal (depending on the tooth count ) but an o-scope would be more accurate.

Sent from my SM-N920V using Tapatalk
Thanks! Will try to spend some time testing today.
 
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