Rawr... My 2011 STi Build Log by Heide264

By diyauto
( 4 )

4 minute(s) of a 64 minute read


Alright guys... Planning the next round of stuff. Looking for any input as I'm venturing a bit past my "comfort envelope" on this one.

In a nutshell, I'm looking to do everything I can while the intake manifold is off. So far I'm at the following:

  • TGV Deletes

  • PnP Throttle Body & Intake Manifold (Possibly)

  • KS Tech Phenolic Spacers - 3mm

  • Air Pump Delete (KS Tech Plates)

  • Aeromotive Fuel Rails

  • Hard Inlet (AP Racing, I knowww)

  • Anything Else?

TGV Deletes:

I have the KS Tech block off plates for these. I think combined with my IR burr grinder bits (Thank you Ingersoll Rand closeout deals) and my harbor freight die grinder, I think this should be fairly straightforward once I get them out. I kinda want to get my HF metal saw working before doing this, but I'm not sure if that will happen or not. I may also spray these down with ceramic spray paint while I am down there.

PnP Throttle Body & Intake Manifold:

This will depend on the success of everything else. It may just come down to whether or not I have time to do this.

Fuel Rails:

I am looking for a bit of input on these... Or at least a confirmation.

My intended setup (until I get a FPR):

I have found that the Aeromotive rails use an -8 sized ORB (o-ring boss) type fitting on them. The banjo bolts that aeromotive sells for them are about $40-60/PER FITTING!!! On the other hand, ORB fittings are commonly used in industries that use a JIC specification fitting in place of an AN spec fitting. The fittings are compatible (under these pressure levels) as long as you get the correct flare (37 degrees). The 90 degree fittings I found ran about $4 each. I gave it some thought, and balanced it against the price, but I think I am sticking with barbed fittings & oetiker clamps instead of the fancy reusable AN type hose connections. For the fuel line itself, I found that frozenboost now sells it's own fuel line that is PTFE (untrademarked teflon) lined and doesn't look like a smurf that made love to a cardinal. 

Hard Inlet:

I'm scared of this guy. I am expecting nothing to line up and to have to reroute many (non-reroutable) lines. It's a cheap off-brand, AP Racing, and even the higher quality brands seem to be a PITA to install. I think I may find some nice ceramic spray paint of sorts and hit this with it first... or possibly even use some of my left over DEI titanium wrap on it.


Install is complete. I'll post up some pictures of it later. I stopped taking pictures after day two or three in isolation. Long story short, it's done. Car feels pretty strong now even without the tuning.

Tuning process started. I opened up closed loop correction so I could drive on it easily. As you can see, it needs some work:

That is a 'pivot graph' of my A/F Correction (Short Term Fuel Trim / STFT / AFC) added to my A/F Learning (Long Term Fuel Trim / LTFT / AFL) over the MAF(V) range of my car, over the course of my 30 minute drive to work this morning. It's sorted into the various learning ranges, A/B/C/D. The spreadsheet wasn't too bad to make, and I can help out if anybody wants. It basically does a bucket sort with a VLOOKUP command (makes the pivot chart useful), then plots it in a pivot table (which can be a pain to figure out, at least for myself).

What to take from the graph:

  • This is why closed loop scaling doesn't work well all the time - your AFL ranges may encompass both a peak and valley (as does my D range). You should move your AFL ranges around time to time.

  • I need to adjust my MAF across the voltage range, ideally by what is shown in this graph. I need to remember the math for this.

  • If used correctly, pivot charts are actually useful

My car is moving again =)