Tom Nasca's profile
STI Rebuild by a Non-Mechanic
“Do you know anyone who would be interested in a cheap STI?”

“Sure, me!”
-me, December 2021, needing a project while my regular shop tools were packed away in boxes from a move. 

*I am not a mechanic - just an industrial designer with a good head for self instruction.
Cosmetically rough, riddled with rust, ignition and headgasket issues, and a moldy, mouse-uriney interior.  Hardly worth it, but I'm a sucker for a project I can learn on.
Engine out! I removed every component to clean, inspect, and repair as needed. 
The culprit for this engine out service - from my research, these graphite-coated head gaskets get eroded by the coolant, and are no good. Replaced with a multi-layer stainless steel gasket. 
While researching this engine, I discovered many aftermarket solutions for Subaru’s design flaws. Pictured here is a better designed oil pan baffle system with an improved oil suction tube. One of many improvements I made to the engine’s oiling and cooling systems. 
I resealed, polished, and adjusted the valves that provide air intake and exhaust. 
Reassembled short block and heads. 
Full motor assembly with intake, exhaust, fueling, and timing belt - ready to drop back in. 
Since I modified the fueling system, intake system, turbo, and exhaust, I had to have the car professionally dyno-tuned to run correctly. EFI Logics was the highest recommended shop in my area.  I requested a conservative tune, so the motor has plenty of headroom and isn’t running close to a high-stress failure. 
290 AWD horsepower
340 ft/lb torque
A modest but respectable improvement over stock. 
Removing the rear end to address the worst of the rust. 
Removing the fuel tank, which had a massive leak from a rusted seam weld. 
With the rear end “empty”, I ground off the surface rust, used phosphoric acid to convert any leftover rust to iron phosphate, and coated the car in cosmoline to prevent future rot. 
I purchased a used fuel tank from a wrecked Texas car, replaced some hoses and cables, and coated the tank in cosmoline. 
I purchased a subframe, axles, and suspension linkages for separate wrecked California cars to assemble a rust-free rear end. Coated in cosmoline, of course. I pre-assembled these parts to simply lift up into the vehicle. 
Mechanically sorted!
I stripped the interior to address the mold, interior rust, and rodent damage. 
The rubber sound deadening was time-hardened and harboring mouse urine, so I used dry ice to make it brittle enough to be hammered out with a rubber mallet. 
I then used a Chlorine Dioxide vapor generator to remove the remaining rodent odors and sanitize the car. I loosely put all of the interior components in the car during its 24hr treatment, then aired it out for another 24hrs before continuing work. 
Individually cleaned and detailed all interior panels, and all of the switches, knobs, dials, and controls were also fully disassembled and cleaned. The mouse urine ran deep.
Since I removed all of the gross old sound deadening, I replaced it with new butyl rubber mat - with a thermal layer for improved insulation. 
Work in Progress - the interior will be reinstalled during the month of July 2023, after I resolve a small roof leak and run interior wiring.

Future projects will be repairing body dents, repainting small areas, and refinishing the carbon fiber hood.  The front suspension and steering systems will eventually see replacement as well.
STI Rebuild by a Non-Mechanic


STI Rebuild by a Non-Mechanic