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Discussion Starter · #1 ·
I’m building an engine for my 04 wagon. I got an 06 STI case I’m running a 12 crank eagle H beams manly pistons and 12 STI heads. Bored 20 over and heads/deck have been planed. Stock valves radios valve job port and polish. I’m going to run my 2.0 intake and turbo for now. Until I can be sure the bottom end of the engine is good working order. Should I run the STI injectors out of the donor STI engine or should I run my OEM 2.0 injectors also what heat range plugs? I would like to run about 18-19 PSI eventually. Any advice would be great
 

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1. If you are running 2012 STI heads, you will need some way of controlling the AVCS. Are you running a standalone ECU?
2. Your OEM 2.0L injectors are not even close to being capable of supporting the fuel requirements of what you're trying to do. Neither are the STI injectors. Challenge being that you seem to have a 2006 donor with side-feed injectors. Keep the 2.0L TGVs and rails and run the ID1050x injectors.
3. You will need a higher-flow fuel pump. Check out the Walbro 255LPH.
4. Exactly what are you goals here? A TD04-13T on a built STI block is ludicrous. Why even bother? Do it right or don't do it at all IMO.
5. The heat range of plugs depends on what the end goal is here.
 

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Discussion Starter · #3 ·
I am running STI cams with 2.0 cam gears and getting the AVCS camshaft sensor delete plugs. Also I have tapped and plugged the oil galleries that feed the 2.5 cam gears(in the end of the camshaft itself). So I will be running the 2.0 ECU. End goal is a reliable 400-450 wheel horsepower. I had an idea of running 750cc injectors but again I’m not sure if that will do what I need. I read the OEM STI injectors are 450 but I’m not sure what that will be good for. The transmission will be changed soon. I am looking at larger turbos at the moment but I’m not sure where to go with that either. I was looking at the blousch 18gxt again not sure what to run any suggestions would be good
 

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I am running STI cams with 2.0 cam gears and getting the AVCS camshaft sensor delete plugs. Also I have tapped and plugged the oil galleries that feed the 2.5 cam gears(in the end of the camshaft itself). So I will be running the 2.0 ECU. End goal is a reliable 400-450 wheel horsepower. I had an idea of running 750cc injectors but again I’m not sure if that will do what I need. I read the OEM STI injectors are 450 but I’m not sure what that will be good for. The transmission will be changed soon. I am looking at larger turbos at the moment but I’m not sure where to go with that either. I was looking at the blousch 18gxt again not sure what to run any suggestions would be good
The OEM STI injectors are 550cc/min (2007 and later) or 540cc/min (2004-2006).

There is no reason not to invest in ID 1050x injectors. The superior spray pattern will improve low-load mixing. Even with the 16bit ECU, the better mixing will improve idle despite lower injector resolution. I had 750cc injectors on a 2.0L with 18G and eventually switched to ID1000s... saw better fuel control. The 1050x are better still.

The 18GXT will not get you close to 450whp even with Ethanol, unless the dyno is very optimistic. You should be looking at turbo in the mid-50s lbs/min flow. Blouch DOM3.0XT at minimum; you might even consider going rotated. The STI cams will begin holding you back. Anything over 400whp, most tuners will likely recommend mild PnP, a hotter set of cams, and perhaps larger valves. Who will be mapping your ECU anyhow?
 

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The STi injectors will work for the STi turbo on pump gas (and stock heat range NGK iridium plugs).. if you're wanting 400-450whp in the future I would do as Zach suggested and get some ID1050x injectors. Or maybe even ID1300s. What type of fuel are you planning on using to hit your power goal?

In my opinion, unless you already have all the supporting mods, with a goal over 400whp you should just go with a rotated turbo setup and be done with it. For that power range I would want a twinscroll GTX3071r (.82 A/R hotside). It should be able to do 400whp on 93 octane and 450whp on e85. If you're wanting to hit 450whp on 93 octane then I would think about going a size up (GTX3576r). Maybe look into the similarly sized Forced Performance Xona Rotor turbos as well.
 

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Discussion Starter · #6 ·
I will only be running 93 octane. The closest e85 pump is almost 2 hours from me. I will look into the ID1050x injectors too. This engine is from scratch getting put together so I don’t have any of the supporting mods yet the heads are almost finished and should be on by the end of the week
 
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