Adding an aftermarket Up Pipe is one of the first things you should do to your Subaru. Arguably one of the best $/HP ratios. Our goal was to make a premium heavy duty Up Pipe for you.
We designed this Up Pipe using our in-house FARO Arm along with the latest and greatest Solidworks CAD software. This assures that we can offer you the most precise and best fitting Up Pipe on the market. In short, OEM exhaust manifold pieces are inconsisent so we used our reverse engineering hardware/software to scan countless OEM pieces to determine the range of best fitments for our aftermarket pipe. This allows us to be very confident that your flanges will be leak free and the Up Pipe will fit nicely.
Our 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. Our 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). We also put a nice bevel on the edge of the flange so you don't cut yourself. You're welcome. The insides of our flanges are "cut-back" to allow the pipe to rest inside the flange which gives you a nice flush mating surface thus allowing optimal flow through the pipe. Heck, we started as a Porting company afterall....we take pride in exhaust flow quality through our pipes. All fabrication is completed by our Welder/Fabricator who is certified in Aerospace Welding...yeah, he knows his stuff. A bit of overkill using an Aerospace Welder you say? Well the Up Pipe is put through some very harsh environments so we wanted the best for the job.
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
Continually striving for perfection, it's what you can expect from GrimmSpeed™
Posted by Steve
I installed this on my 1994 WRX Sti ej20g motor and it fit perfectly...the design and finish of the part are superior to the original and the included gaskets are substantially thicker as well. Grimmspeed definitely does a great job with their products and craftsmanship. I got the option for ceramic coating and it was worth every penny in my opinion.
Posted by Brad
First off, the package came very well padded on the inside - the part arrived with the ceramic coating flawless.
Next, the installation - everyone talks about how horrible it is to do the installation of an up pipe. It wasn't bad, it would've been about 4.5 hours if the rear downpipe bolt hadn't been horribly siezed in the mount, requiring some creativity to get loose. I did pull the passenger side manifold and the crossover tube at that side, and then jacked up the motor slightly, and the OE up pipe came out easily. Installation was really straightforward - the only note is that the new manifold to up-pipe bolts have a 17mm head on them, and the nut on the other side is only 14mm. When you install the upper bolt that passes near the front O2 sensor, make sure you put the head of the bolt AWAY from the O2 sensor or you won't be able to get the sensor installed!
Aside from that, fitment was great, the studs and nuts are high quality, and I'm looking forward to the slightly quicker spool!
Posted by Unknown
Awesome up pipe looks great ! Welds look good . Flanges look great