23
May 2012
Treadstone Sponsored STi in the Lime Light:
One of the Treadstone sponsored Subaru Impressa WRX STi was recently featured on Import Tuner Magazine
Jeff is sporting a Treadstone front mounted intercooler and piping kit matted to a Treadstone rotated turbo kit featuring the mighty Turbonetics GTK turbo
Jeff is sporting a Treadstone front mounted intercooler and piping kit matted to a Treadstone rotated turbo kit featuring the mighty Turbonetics GTK turbo

Wall thickness is 2mm, Inside diameter is as follows
-3.0" Size; 76.0mm OD Lip, 74mm ID
-3.5" Size; 88.9mm OD Lip, 85.9mm ID
-4.0" Size; 101.6mm Lip, 98.6 ID.
The Truth!
Not all high horse power applications need use of a large wastegate. Use this very simple formula to add in waste gate selection
Large Turbo + Low Boost = Large Wastegate
Large Turbo + High Boost = Smaller Wastegate
Small Turbo + High Boost = Smaller Wastegate
Small Turbo + Low Boost = Large Wastegate
In other words, if you have a 2.0 liter engine, and are using a turbo capable of 600hp, and only pushing 250 to the wheels, you may need a larger wastegate than normal to prevent boost spikes. If you are maxing out your turbo with the HP your pushing, then you may not even need a wastegate at all, so a small wastegate would be needed because the wastegate duty cycle would be very low.
Wastegate placement plays a roll in sizing also, bad placement would require use of a larger wastegate than normal
Ex. V8 applications using a T76, and pushing a close to 900whp, all you need is a properly placed 38mm wastegate. With the same set up, and only running 500whp, you will need a larger 44-60mm wastegate.