February 21st, 2020:
Fifth Generation Subaru Legacy GT Bypass Valve Upgrade

This write-up applies to 2010 – 2013 Legacy GT models with 2.5 turbocharged engine. A stock engine engine/tune is unlikely to benefit from changing you bypass valve.

Replacing the factory turbo Bypass Valve (aka blow-off valve or BOV) is far easier than I initially thought. Whether or not you should is hotly debated, but it’s really up to you. My custom tuned Cobb Stage II was leaking boost and this fixed it, but that may have been due to the age of the original more than the design. Here’s how you do it (since I couldn’t find any other overview):

Parts needed:
1.) New bypass valve. I went with the GFB Hybrid (T9233) because it allows me to use either hybrid or full recirculation easily.
2.) Spare plastic body fasteners. (You may break some during removal of the intake snorkel)
3.) Zip tie or small hose clamp (optional, see step 11)

Tools needed:
1.) 8mm socket or nut driver (snicker)
2.) 10mm (socket and ratchet)
3.) 12mm (socket and ratchet)
4.) Screwdriver or similar tool to pry fasteners and hoses
5.) Vice grips (recommended) or pliers

1.) Remove the 2 plastic fasteners for the cool air intake snorkel, then lift it out.
2.) Remove the passenger side radiator fan by disconnecting the electrical connector in the bottom corner. Then remove the 2 10mm bolts on the top. Lift the radiator fan straight up to remove.
3.) You can now easily access the Bypass Valve from above:

Factory Bypass Valve

4.) Slip the vacuum line off of the Bypass Valve.
5.) Use an 8mm socket or nut driver to loosen the upper hose clamp on the Bypass Valve.
6.) Wiggle the upper Bypass Valve tube out of the hose while gently prying the hose with a screwdriver. There’s a lot more flex in the lower hose than you expect. It will allow you to pull the upper hose off of the Bypass Valve and pull it aside to access the lower hose clamp.
7.) Use your vice grips to lock the spring-style lower hose clamp open… or try to do the same with pliers. Wiggle the lower hose off of the factory Bypass Valve.
8.) Compare the orientation of the inlet and outlet to your factory Bypass Valve. Also ensure that the vacuum line is aligned. Most aftermarket Bypass Valves allow you to rotate the vacuum line as needed if you remove a few screws. Follow the manufacturer’s instructions. The GFB Hybrid (T9233) did not require any adjustment.
9.) Insert the new Bypass Valve into the lower hose and align it with the upper hose. Remove your vice grips from the lower spring-style lower hose clamp.
10.) Insert the new Bypass Valve into the upper hose. Tighten the 8mm hose clamp so that it is snug. No need to go gorilla on it.
11.) Slip the vacuum line onto the vacuum inlet on the new Bypass Valve. A zip tie or small hose clamp may be necessary to ensure a good seal if the outer diameter of the inlet is smaller than the stock Bypass Valve.
12.) Install the passenger-side radiator fan: slide it straight down into place. Reinstall the 2 10mm bolts on the top. Re-connect the electrical connector on the lower corner of the fan.
13.) Re-install the intake snorkel and secure it with 2 plastic fasteners.
14.) If your Bypass Valve spring requires tuning, follow the instructions provided by the manufacturer. My throttle response benefited from a slightly tigher spring. It held boost without any adjustment, though.

Visibility Was Better With Fan Removed

Here’s how the hybrid sounds (not too loud) with a full Invidia exhaust:

2011 Subaru Legacy GT w/ GFB Bypass Valve Interior, Stationary
2011 Subaru Legacy GT w/ GFB Bypass Valve Exterior Rear, Stationary
2011 Subaru Legacy GT w/ GFB Bypass Valve Exterior Front, Stationary

- Duane

April 16th, 2012:
Ferndale Drama of 2012

Today rivaled the great blizzard drama of 2005. Gina and I originally planned to visit Hodges Subaru for some scheduled maintenance on both of our cars, visit the zoo and take a relaxing day off of work. It got a little more complicated than that.

We were up at 6, out the door at 7 and at Hodges by 8am. We dropped off our cars for service (mine was due for a lower control arm recall inspection and Gina needed to have her steering rack replaced). We walked to Toast for a savory breakfast treat, then headed back to Hodges to see where we stood. Not only did my lower control arms fail their punch test, but the subframe assembly was rusted out. Hodges service crew deemed my car unsafe to drive and in need of at least the LCA replacement. Gina and I decided that it was time to try to find a new car.

Bill Garcia, who hooked Gina up with her last two Imprezas, overheard our situation and we asked if he could help us find my dream car: 2012 Legacy GT with navigation. The catch? The GT is no longer available for order and the last time I checked there were none available anywhere in the US. That didn’t stop Bill: he called around until he found a lead on one in Texas. We applied for financing (and were approved), then got the quote for the new car. We were pretty sure all was good to go… and then headed out to the zoo with a loaner Forester from Hodges.

Just down the road is the Detroit Zoo (actually located in Royal Oak, MI… go figure). We figured we would burn a few hours while checking out the zoo. Though the zoo was without power in some buildings due to the high winds, we were still able to check out just about everything we could stand! Three hours later, we had lunch then headed back to Hodges for an update.

It seems that the winds were causing problems for more than just the zoo. The power was out at Hodges’ auxiliary service center and our cars wouldn’t be done for a bit longer… So, we headed of for an afternoon showing of The Hunger Games at the Royal Oak Emagine Theater.

Thoroughly entertained, we returned once again to Hodges. This time, the work on my car was complete… but Bill had some complications regarding the Texas-based source for my potential new car. Without boring you with the details, we’re not sure if the ’12 GT is going to happen, but I can’t thank Bill and the guys enough for all the work they’re putting into try to make it happen. The power was still unrestored to their auxiliary service location, so I assume my car was assembled without the help of a lift or airtools. Gina’s car, however, could not have the steering rack replaced without a lift.

Hodges made arrangements for a loaner and Gina headed off to get her parking pass from her car while I signed off on the work for mine. I picked up my car and called Gina to locate her. However, she didn’t answer the phone! A nice lady, Veronica, found Gina’s phone on Woodward and held onto it for us! Crazy! I found Gina, headed over to Marygrove College (where Veronica works) and picked up here phone. We returned to Hodges one more time to pick up Gina’s loaner then went home.

All in all, today was a collection of miscellaneous little things adding up to one big tangle of craziness. We’re still not sure if the Legacy GT is REALLY available in Texas and Gina needs to pick up her car from Hodges after their aux. service location power is restored and they get it up in the air.

At least there wasn’t any snow involved this time.

- Duane