Forge Recirc Valve vs Subaru OE Recirc Valve Dyno Test by Pure Tuning.
We still get Subaru WRX / STI owners today that say “the original equipment turbo recirc valve is adequate for any turbo or boost level so why should I change it”. What a better way to prove if this was true or not then on a stock car.
For this test the valve in question is the Forge Motorsport Recirc valve that sells for around $170. This is a direct bolt on replacement valve that uses the adapter from the OE valve to recirculate the exhaled air back to the induction hose.
The car tested was a bone stock 06 STI with mid 20k on the odometer. Looking at the dynograph you can see the difference in power before peak boost is reached at 3800rpm. The OE valve hangs open a little which is primarily for smooth transition between shifts so where this is great for Granny it’s not what we are after. The Forge valve shuts immediately giving the engine all the boost and air volume as the turbo is providing it. The peak number didn’t change as the target boost is the same but the increase in boost pressure below 3800rpm netted 10whp at 3270rpm and 17ft/lbs at 3300rpm.
That is defiantly usable everyday performance!