Project GD STI – Improving the Fuel System with Injector Dynamics and Other Details


The Fluidampr has a sealed smooth outer housing.  The ring inside is free to move.  On the stock damper at right, you can see the rubber that isolates the outer ring from the inner hub.  The Fluidampr is heavier than the stock pulley.  Fluidampr says this is better for absorbing vibrations.  Unfortunately I realized it would have been interesting to weigh the two pulleys after it was already installed on the car.  Whoops, sorry.
Looking at the backside of the two dampers you can see how the Fluidampr on the left is flatter.  This means you have to sightly modify the timing belt cover or you will crack it.  Don’t ask me how I know this.
We ground the flange off the end of the timing belt cover with a die grinder.  This was pretty easy.  We stuffed a rag into the hole to prevent plastic shavings from falling into the cover.
The balancer in place.  We dynoed the Fluidampr and unfortunately we did not experience any gains on the Cobb Mustang dyno.  However we felt a huge reduction in vibration.  Even vibration at idle was greatly reduced!  The engine is so smooth you can barely tell it’s running.  Subie engines have an odd vibration that feels like they are dropping a cylinder.  This was almost completely gone.  The vibrations were damped so well, the engine note was slightly different!  The engine felt like it was freer revving and slightly more responsive but it was nothing we could record on the dyno.  The difference in vibration was so great that the Fluidampr must do something to increase engine life.  Perhaps at higher power levels it will reveal a power increase.  Perhaps on an inertial dyno like a Dynojet we might see a difference.  We may not have gained any power but we were still very impressed with the Fluidampr.

Our latest round of modifications has left Project STI a much improved car.  The engine is much more responsive with better driveability and much less turbo lag than stock.  There is a lot more power and the car is much more fun to drive.  There are no downsides to any of this.  The only slight quirk we have noticed is that the engine runs very slightly rougher for a few seconds after a completely cold start after a long cold soak.  This is probably due to the removal of the TGV valves and is hardly noticeable.

Cobb’s no lift to shift and launch control work great.  You can build a little boost off the line and slide the clutch smoothly to really get a good launch without hurting things and you can shift with your foot to the floor with no boost drop off in between shifts.  It is kinda scary at first to trust the ECU but it works fine.  It is easier on the drivetrain as well as long as you don’t slam it into the next gear.

The Perrin MC brace has given us a rock hard easy to modulate pedal.  The awesome brakes are now more awesome.  It is amazing how much this small inexpensive part has improved things.  We feel that this is a must even with stock brakes.

The Fluidampr has made the engine a lot smoother and we now have plenty of fuel headspace for more mods.  On a down note the increase in power has made our clutch start to slip.  In our next segments we will discuss further suspension work and a new clutch and flywheel.

Read more about Project GD STI here!


Injector Dynamics

Perrin Performance

Crawford Performance



Koyo Cooling Systems

HPS Silicone Hose

Cobb Tuning

Cobb Tuning So Cal

Synapse Engineering

Afterhours Automotive


KW Suspension

Mackin Industries Advan Wheels

Falken Tires

West End Alignment



PLX Devices – Kiwi Bluetooth

Palmer DashCommand

3M Window Films (Renewable Energy Division)

Frank Garrido – Owner
Tint Factory Solar Concepts Inc – 3M Authorized Dealer
2033 South La Cienega Blvd.
Los Angeles, CA 90034


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