Tag Archives: subaru

How To Do a Boost Leak Test

Here I Teach How to Do a Boost Leak Test. This Is the Most Important Thing to Know How to Do If You Own a Turbo Car.

If Your Turbo Vehicle Has a Boost Leak It is Rob You of Your Horsepower, Fuel Economy, and Can Potentially Cause You to Blow Up Your Engine by Burning a Valve, Running too Rich and Washing the Cylinders, and Blowing Your Headgasket from Throwing off Your Tune.

Boost Leaks Will Cause a Rich Condition, The Car can Also Experience Stalling, Rough and High Idle, Loss of Power, Bad Fuel Mileage, and Loss of Turbo Spool up. This is the Single Most Important Thing that You can Learn About Turbochargers.

Here is an Easy to Read Itemized List of Symptoms of Boost Leaks:

  • Vehicle Lacks Power and is Slow
  • Turbo is Very Laggy, (Spool Up is Slow)
  • Bad Gas Mileage
  • Rough Idle
  • High Idle
  • Engine Stalling

Make Sure You Buy The Appropriate Boost Leak Tester For Your Application. (1″, 2″, 3″, 4″, 5″ etc)

Here are Some Boost Leak Testers Already Made that You can Purchase.

Common Leaks That You Cannot See Are Often Found In Conditions Like:

  • Corroded Intercooler Pipe
  • Corroded Intercooler (Common for DSM)
  • Not Properly Sealed Intercooler Core. ( I saw this on a New Jeep Liberty Turbo Diesel Once)
  • Leaking Blow Off Valve (Common with Greedy, Blitz, and Factory BOV)
  • Holes in Vacuum Lines
  • Broken Seal Intake Manifold Gaskets
  • Dry Rotted Fuel Injector Seals

Steps Too Boost Leak Testing Your Car:

  • Install Boost Leak Tester On TurboCharger Inlet
  • Fill Up Boost Leak Tester Tire Valve With Air Chuck Until You Reach Your Boost Level (25 psi+)
  • Spray Soapy Water All Over Charge Pipes, Vacuum Lines, and Where Every Boost May Go.
  • Search For Bubbles to find Leaks


Subaru STI WRX Legacy GT Turbo Upgrade EJ20 EJ25 Options

Subaru STI WRX Legacy GT Turbo Upgrade Options

Most Common Upgrade Options Are:

350 to 415 hp

  • 16g 48.3 x 68mm Compressor and 49 x 56mm Turbine
  • 18g 50mm x 68mm Compressor and 49 x 56mm Turbin
  • 20g 52.6mm x 68mm Compressor and 49 x 56mm Turbine

450 hp

  • SL2 20g 52.6mm x 68mm Compressor and 54 x 61mm Turbine
  • SL2 EF3 56 x 76mm Compressor and 54 x 61mm Turbine (9 Blade)
  • TDO6 EF3 56 x 76mm Compressor and 55 x 65mm Turbine (12 Blade)

500 – 625 HP

  • TDO6H GTX3076R 58mm x 76mm and 58.8 x 67.2 Turbine (9 or 11 blade) (550HP)
  • TDO6H EF4 60.27 x 82 x 83mm 7blade and 58.8 x 67.2 Turbine (9 or 11 blade) (580 +HP)
  • TDO6H 25g 60.5 x 78 x 83mm (5, 6, or 11 blade) and 58.8 x 67.2 Turbine (9 or 11 blade)580+HP
  • TDO6H GTX3582R 62.35 x 82 x 86mm 11 blade and 58.8 x 67.2 Turbine (9 or 11 blade)600+HP

To Install this Turbo You May Need TDO5 Coolant Line Install Kit, Because The thread Pitch of the TDO4 and VF turbos for the Coolant is Different than the MHI TDO5 TDO6 Which is M14 x 1.5. You can buy this coolant kit on ebay Here. (turbo oil feed line water pipe install gasket kit for subaru EJ20 EJ25)

NOTE: 2011+ Year STI Requires Rotation kit to install the turbo upgrade with the 3″ inlet compressor Housing. You must use the 3″ compressor housing for the Compressor wheels 56mm and Larger.

If You would like for us to build you a turbo like this you can contact us at turbolabamerica@gmail.com