Underdog

They don’t seem to be flying off the shelf so let me know!

Thanks Mike. I have a gauge in the cabin and its 45-47PSI on cold start, then settles right in at 35PSI after the FPDC% comes down to 33%. It definitely still misses during that initial 100% FPDC period, but it seems worse at 33%. Also today only cylinder #1 is having the consistent miss, with cylinder #2 occasionally racking up low-mid single digits. #3 and 4 are quiet today. I put in some chemtool B12 , as a diagnostic indicator rather than a solution. I also noticed that if I bring it up to 2500-3000 rpm and then let it come back down it idles nicely for a little bit before the misfires start again. Curious. I'd love to get another set of ID1000s so I could try swapping in a new one for troubleshooting, but they've been replaced by the 1050x which will require tuning adjustments.

Well I guess the car decided to give me one last kick in the head... or maybe it's a last ditch attempt to get me to fall back in love with it? After replacing the battery I needed to run out to get some oil and a few other odds and ends. Fired up the car for the first time in a while and had erratic strings of misfires on cylinders 1 and 3. Seemed to be at idle only, and smoothed out at 2k+ rpm. Occasional individual misfires on cylinders 2 and 4. Eventually threw a CEL and misfire codes only. On initial starts it purrs like a kitten, it's only after 30 seconds or so it starts to act up. - Swapped in a new spare coilpack - no change. - Pull all four plugs and they look clean. - Compression and leakdown shows 130PSI and 4-6% across the board. - Boost leak test revealed tiny leak from EPDM cap on one of the unused ports on turbo inlet. Replaced and verified leak was resolved. No change in misfires. - Swapped OCVs to see if problem followed to bank 2, no change. - Oil and coolant look good. - Engine ground straps are in great shape. - Drained the couple months-old fuel and added 4 fresh gallons of 93 with seafoam. After some rough idling things seemed to smooth out a bit. Took the car out for a loop and the misfire gradually settled down to very infrequent individual misses at idle. Figured it was just sticky injectors from sitting for a while. - Went to start it up two days later and erratic strings of misfires have returned, perhaps even more frequent than before. I'm now wondering if my front O2 sensor is getting wonky. Still feel like the injectors (ID1000s) could need a proper cleaning, but it doesn't make sense to me that that specific problem would yield intermittent symptoms. I may start with the O2 sensor as it is likely easier than pulling the injectors, on account of the injector cover brackets used on the STI manifold. The BRZ/GR86 is looking better by the moment.

Repost from WDYDTY4G: Swapped in a new battery and tidied up the wiring a bit to make the next swap easier. This involved putting a marine terminal on the negative post and re-terminating the negative cable with a 5/16” ring (which fits through the hole I drilled for the grommet - unlike the original battery lug). I also moved the fuel pump fuse to the exterior of the box so it isn’t in the way when you’re trying to remove/install the battery. Original post detailing the battery relocation can be found here. I got 11 years out of the last Deka AGM, here’s hoping this one lasts the same.

Keep in mind I have the STI intake manifold swap, so you wouldn’t do the same thing for the plastic LGT manifold. The throttle body isn’t talked about much because of diminishing returns but Grimmspeed used to offer the service, and of course TGV deletes often include removing the internal dividers, plugging the holes, and polishing the walls. Those types of mods are all about reducing losses, and so they benefit any turbo. However those loses increase exponentially with flow velocity, so if your set up is designed around low-RPM torque then the benefit is very small, maybe even negligible within the noise of other variables. If I were in your shoes, and wanted a car to drive on twisty backroads, get me around town, and occasionally toss around on a track in a non-competitive manner, I would strongly consider embracing the relative simplicity of the vf52 and mild bolt-ons. Sure you could sink more money into chasing higher power, but that money is probably better spent elsewhere in the chassis, or on consumables. As far as your motor - there is nothing wrong with having more shortblock than strictly needed for a power level, as long as the piston-to-wall clearance/ring gaps/bearing clearance are all designed around how it will actually be used.

Here you go. Excellent write-up by @Harrimat - there is a walkthrough pdf under the video in the original post.

I swear I just saw a thread somewhere where a person had adapted the 4-point load sensor seat to the later bladder-style ODS car. I’ll be sure to send you the link if I remember where I saw it.

Wow thanks for the kind words - I really appreciate that. I’ve certainly learned a lot throughout my ownership of the car and even now there’s a long list of things I still want to do with it. It’s encouraging to see folks like yourself who continue to invest in these cars for the awesome vehicles that they are.

Yeah I think shralp ran into this recently, albeit before actually trying to install. He was under the impression IAG included physical adapters for both the 05-06 and 07+ hardware, but regardless we’ve since confirmed the polarity difference between styles, which is not easily resolved (i.e. you can’t just swap the positive and negative, the open/closed position is mapped inversely on the 5V scale). I could make a prototype TGV emulator module for either style with relays and resistors, but we’d be better off with more robust solution. That conversation has been ongoing here.

Yeah, it sucks. Those of us with 05-06 can’t even use that since the sensor polarity of the 07+ motor/sensor is different. I’ve been looking at circuitry to emulate the TGVs, but need an EE with some PCB design experience to take it to the next step.

Thanks man. Yeah it’s a limited 5MT red/black, so if the sunroof and leather aren’t a dealbreaker for you. Hoping to list it up within the next week or so, but finding it very difficult to pull the trigger!

There wasn’t much first-hand user experience about the poncams back in ‘13 when I started spec’ing this build either. If I remember correctly @08Legacy08used them on his build, so there may be some breadcrumbs, although I don’t remember what turbo setup he went with. I think it was an STI style turbo however, as he had the PW TMIC and vaguely remember an adapter hose. As you mentioned, they are advertised as a very mild cam in terms of additional lift and duration. My car idles like stock* and there is no sponginess at low RPM. I do feel they have contributed towards getting more top end out of my TS 1.5XTR, with the twinscroll turbine housing and my OEM STI TMIC being the current bottlenecks. In the pursuit of volumetric efficiency I also went with Grimmspeed PnP’d throttle body, intake manifold, and TGVs, as well as DIYing some bowl/runner cleanup in the B25 heads. My overall goal on that build was to make the car feel like it has a classic turbocharged engine, where power builds all the way to redline, rather than a stand-in for the low end punch of a larger displacement N/A which is how most modern turbo 4s in this class are set up. I chose the twinscroll route to mitigate some of the trade-offs, but I would not say it was worth it due to other factors (availability of parts, tuning challenges due to O2 sensor location). All of this is to say that I paired the cams with a turbo that would target the power band I was aiming for. I didn't want the stock-turbo feel where there was a mountain of torque at low-mid RPM that fell off quickly, but I didn’t want to go so far the other way that the power was confined to a narrow band in the upper RPM range. This balance will be different for everyone and will also take into account other factors like fueling, gearing, and other design constraints (I wanted to stay TMIC, for example). * One challenge of the twinscroll route is that that front O2 sensor is moved to the DP, and the ECU can not compensate fully for the delay. This can cause the car to hunt for stoich on cold start, which makes the idle sound a little lopey. It settles down within a minute or two however.

I have the twinscroll Dom 1.5XTR, and it's not so much that the larger turbo would benefit from the cams but rather that they work together to make the powerband you are looking for. Stock cams and a VF52 are great for low end responsiveness and a heap of midrange torque, but that will fall off as RPMs increase. Putting a cam with more lift and overlap will allow the engine to breathe better at higher RPM, but the turbo may not be running as efficiently trying to hold the same boost targets at a higher flow rate, which would add heat and reduce power. Happy to take the convo to PM or another thread so as not to derail WRX USA's build thread.

I also have the Tomei poncams in my motor and have been very happy with them, but I wanted to trade off some low end for more mid/upper range. I feel like they would be an odd choice with a vf52-based setup, but I’ve never seen it tried.

MAF sensor and BPV have sold

Swapped in a new battery and tidied up the wiring a bit to make the next swap easier. This involved putting a marine terminal on the negative post and re-terminating the negative cable with a 5/16” ring (which fits through the hole I drilled for the grommet - unlike the original battery lug terminal). I also moved the fuel pump fuse to the exterior of the box so it isn’t in the way when you’re trying to remove/install the battery. I got 11 years out of the last Deka AGM, here’s hoping this one lasts the same for the next owner (whoever you are).

I was looking at a new CTR recently as well - really nice cars. Dealers near me were putting a 20k markup on them! Would have jumped at msrp. I’ll just mod my ‘19 Accord 2.0T instead.

It always surprises me how crappy the cam caps look in any ej25 I take apart. Hopefully the machine shop can recondition them for you. The only “tricky” part of assembling the long block is torquing down the head bolts (or studs if you’re going that route). Just follow the instructions and you’ll be fine. Otherwise having it assembled by the shop just makes it heavier to move. IMO, it takes considerably more time and attention to do everything after assembling the long block. None of it is overly complex, just go slow and triple check your work. Disassembly and cleaning was always my least favorite part of the job; reassembly is where the fun is.

MAF and pigtail from my 06 LGT. I don’t recall if it’s the original MAF but if so it would have about 80k on it. I swapped to the STI style so no longer able to use it as a spare.

The ‘15 STI rack should bolt right in for your 2.5i wagon. Might need to look at upgrading the pump for good measure. The knuckles will not affect your steering ratio.

No new content, just bumping the thread so it's easier to find.

Finally tossed the front swaybar but still have the endlinks and bushings of those are usable to anyone. Endlinks are tight and the bushings seem in good shape.

STI y-pipe sold on NASIOC

Glad to hear no injuries and sounds very fixable, although inconvenient. Good luck with the repair!

Oof sorry to hear that. Is everyone ok?