Starting my build the next week. I plan on doing MOST of this myself a local shop is going to do the head inspection and clutch work because IDK wtf i’m looking at when it comes to that.

These are basically my notes with some extra explanations.

If a typical supporting mod isn’t listed it’s because it’s been done already (ie. fuel pump).


Step 1

Use new gaskets wherever possible (head, intake, etc.) <- bought a full OEM set

Clutch - ACT clutch that’s rated at 400wtq

ARP studs install

exhaust cam gear install (check on intake gear effectiveness)

^ people say the exhaust cam gear does a lot, intake not so much. Trying to confirm.

Clean AAC and Idle Air Control valves.

Check camshaft wear and valves etc. If camshaft looks bad i’ll have to find replacement. <- don’t know shit about this kind of thing. Need to do it because I will not be opening it up again for QUITE a while. Probably if ever barring failure or servicing.

Step 2 - prep for next step and tuning.

Test Power FC and FC Datalogit software. <- Regular consumer APEXi software doesn’t work with RB20 Power FC. FC Datalogit is more powerful anyways.

Test with Z32 AFM

Check about Tuning. Church Automotive or Pitstop AZ.


Final Shakedown autocross <- autocrossing this car has helped me find/fix a few issues. I will not being doing this with the untuned powerfc in obviously.

^ Pitstop said they would tune the car and they rebuilt my front end as well as driver side frame rail. However they are in Phoenix where Church comes to Vegas. Church is popular with the Subaru community here and did my WRX when I owned it.

Step 3 - car will need tuning after I do this.

Install injectors.


Turbo install (Hypergear SS1.5, still waiting on delivery... will be a while. Aluminum ball bearing turbo made in Australia. Comparable roughly to GT2871R but with better response)

Get turbo intake pipes, take one to a shop that will weld an vacuum line nipple on. <- stock plastic will not take well to the level of air that will flow.

Make sure to bring extra parts like coils to the tuner just in case. Have had some misfiring issues, hopefully fixed. (was MAF and now water temp sensor, runs good.... for now)

When this is done I will make minimum 300whp, the question is what I will make over that with pump 91 as any similar builds are foreign using what we would call 93 or higher.

List of RB20 builds.