May 22, 2016
May 19, 2016
Twin external wastegate F20C. Look at the size of the turbo in comparison to the engine.
May 18, 2016
It’s almost over, just a couple of things to finish up. Finally took the car out for a drive today after 6 months of working on it, and it was great to be back in this hard, uncomfortable and ridiculously loud car. The exhaust note has changed drastically from before; I’m not sure if it’s the cams or the tubular manifold or a bit of both but it’s high pitch and raspy, oh and so much louder. It’s almost embarrassingly loud when above 3000 rpm.
The splitter is on, but needs some additional mounting and refinement. I’ve already scraped it, and I haven’t got my scrape plates on it yet.
May 15, 2016
The final preparations are being carried out on the car before I can give it a test drive, so in the meantime I thought I would highlight all the engine specs and parts for those interested (parts not mentioned are OE, and I’m sure I’ve missed things):
ACL Race crank bearings
ACL Race big-end bearings
Apex Performance conrods
Wossner 86.5mm 8:1 pistons
Tomei 256 Poncams intake and exhaust
Custom rocker shims
Cometic 1.1mm head gasket
Apex Performance rocker arm stoppers
Front mount intercooler with custom piping
Apexi Power Intake filter
Garrett GT2871R turbo 0.64AR
XS Power tubular manifold
3.5″ catback with decat
Walbro 255 fuel pump
Nismo 740cc (JECS) injectors
AEM fuel pressure regulator
Billet oil sandwich plate
Thermostatic oil filter relocation block
Mocal oil cooler
Driftworks Supercool alu radiator
Apex Performance alu pulley kit
ACT Performance clutch kit
AH Fabrications oil catch tank
Apex Performance short shifter
After the mapping session I also checked the valve clearances again as everything has bedded in a bit and should have settled. Unfortunately the clearances are a bit higher than I would like which explains the elevated valvetrain noise, and will no doubt cause accelerated wear on the cams. Valvetrain is something that I have limited experience with and have a lot to learn; I assumed that the clearances would close up a bit after the valves have set in their seats but instead the clearances opened up a bit which means other parts have settled.
Also, I had to change the fuel pressure regulator to an AEM unit, as the “Aeromotive” unit started leaking. It was probably some Chinese knock-off unit, despite it not being that cheap. The good thing is that AEM unit is much smaller and nicer.
May 14, 2016
I didn’t really think there would be so many parts to this, but it’s getting close. After running the engine for a bit I took it to a tuner to get it mapped properly. Luckily I found Preparazioni Soretti, which had worked with the SR20, the Apexi PowerFC and D-Jetro version before, despite being a Subaru specialist.
There were a couple of things he wanted to sort out before mapping the car; these were mainly vacuum and oil lines. With the new tubular manifold, it gets very close to the intake tube and vacuum lines so he recommended moving the rubber joint on the intake pipe and the vacuum line away. The intercooler piping was cut and welded to the turbo outlet and an additional joint added (in blue). Then the vacuum line on the turbo inlet was completely moved away and under the tube, meaning it clears the manifolds completely.
The final result from the mapping session was 343hp (at the crank) and 428 Nm at 1.3bar. I quite happy with the result considering that the pressure isn’t too high and it will be a big difference to my previous setup.
May 2, 2016
The car is off to the tuner today so this weekend I’ve been getting everything ready for him. After a bit of fault finding I managed to get the car running on the Apexi PowerFC. The problem was that the original Zenki loom that I cut the plug off actually had a CAS pin missing (don’t know how it ran on the original car!), so I stole a pin from elsewhere and wired it in; then I also discovered I had wired an injector incorrectly.
I then sorted out some of the crank case ventilation items I didn’t like. With the added boost I will run, vaporised oil will increase and so I will need to manage it a bit better than before. So to limit the amount of oil that will be sprayed into the intake system I am now running a catch can system from the valve cover. The right hand side vent still sucks into the plenum but at least the turbo and intercooler will be kept much more clean and keep the octane higher too.
The only spot I could find for the catch tank was under the intercooler piping on the LH side of the engine bay.
Pretty much ready to be tuned, but will need some tidying before we finally drive it.