What's one of the most overlooked anti-flowing Subaru pieces you ask?? ...
The stock exhaust manifold crossover. 50% of your exhaust gasses are passing through this tiny tiny pipe and that is not good. Well here comes the solution for this problem.
Welcome the GrimmSpeed Version 2 Subaru Exhaust Manifold HiFlow Crossover.
Well they've decided to step it up a notch with the first revision of the crossover. Meet HiFlow Crossover v2. Immaculate welds, smooth as butter 2" stainless steel, thick 12mm stainless flanges. You can't beat this piece.
Customers have seen up to 15 HP INCREASE when combined with a PnP Subaru Exhaust Manifold. This unit is built from 2" 304 Stainless Steel throughout, maximizing exhaust flow from cylinders 1 and 4 to the manifold collector for faster turbo response. This unit has a flex in the center to allow for easier installation and for thermal expansion during hard driving.
Features
- Boost transition is improved over stock
- Helps airflow in the mid to high rpm range.
Notes:
- New gaskets and hardware will be included to make this crosspipe ready for the installation.
- NOT COMPATIBLE w/ 2006-2007 WRX & Forester XT Models due to clearance for Oil Cooler/Oil Filter Housing.
Fitment:
2004-2021 Subaru STI & Type-RA
2002-2005 Subaru WRX
2008-2014 Subaru WRX
2005-2009 Subaru Legacy GT
2005-2009 Subaru Outback XT
All EJ Series Stock Manifolds