Adding an aftermarket Up Pipe is one of the first things you should do to your Subaru. Arguably one of the best $/HP ratios. GrimmSpeeds goal was to make a premium heavy duty Up Pipe.
GrimmSpeed designed this Up Pipe using in-house FARO Arm along with the latest and greatest Solidworks CAD software. This assures that GrimmSpeed can offer the most precise and best fitting Up Pipe on the market. In short, OEM exhaust manifold pieces are inconsisent so GrimmSpeed used their reverse engineering hardware/software to scan countless OEM pieces to determine the range of best fitments for the aftermarket pipe. This allows GrimmSpeed to be very confident that your flanges will be leak free and the Up Pipe will fit nicely.
The Up Pipe has been made with beefy local raw materials. The flex joint is 321 Stainless Steel w/ an Interlocking Liner and tubing is a heavy duty 14 Gauge 304 Stainless Steel(competitors use thinner 16 GA) that has been CNC Mandrel Bent and finished up with a nice brushed finish. GrimmSpeed flanges are made out of 1/2″ 304 Stainless Steel and are fully machined on all sides(competitors typically just laser cut flanges for cost reductions). GrimmSpeed also put a nice bevel on the edge of the flange so you don’t cut yourself. The insides of GrimmSpeed flanges are “cut-back” to allow the pipe to rest inside the flange which gives a nice flush mating surface thus allowing optimal flow through the pipe.
Flow Bench Results vs. OEM at 28″ WC
OEM Catless – 244.6 CFM
OEM Catted – 164.7 CFM
GrimmSpeed – 292.6 CFM
Application specific but generally you will see 300-400rpm quicker spool up
Application specific but generally you will see 8-10HP increase
Gaskets Included – Heavy Duty GrimmSpeed Gaskets
Flex Joint – 321 Stainless Steel “Tuned-Bellow”
Tubing Thickness- 14 Gauge Piping Thickness – 33% thicker than most competitors
Pipe to Flange Connection – Cut-Back flange allows much smoother connection. Piping is ported flush with flange so there is no step into the pipe.
Flanges – 1/2″ 304 Stainless Steel CNC Milled – All 3 sides are milled for precise tolerances in manufacturing
Increased HP by ~10hp
Reduce turbo lag
Also includes required bolts, new Grimmspeed up-pipe to turbo gasket (024001) and new Grimmspeed exhaust manifold to up pipe gasket (026001).