"Hood doesent shake at above 80mph now due to no air piling in the back of the scoop ontop of that it perfectly seals to the top mount and throws a bunch of air over the aos lines and turbo itself"
OEM Splitter choking your TMIC? Fix that.
These have both been a long time in the making and as the popularity of GrimmSpeed intercooler offerings has skyrocketed, we've had a massive amount of demand for splitter options that maximize performance of our Top Mount Intercooler on the 04-08 FXT platform, with some users producing 600-700whp with them. These splitters are designed to seal perfectly with your GrimmSpeed TMIC, ensuring that the system works as efficiently as possible. With the dense cores that we use, forcing ambient air through the core with a properly fitting splitter is more important than ever and these splitters will allow you to do that with ease.
For FXT and STI owners that are currently using a GrimmSpeed TMIC, this is a must have.
QUICK SPECS:
- 70% Increase in flow capacity to your TMIC - Massively improves your TMIC's ability to remove heat
- Maximizes TMIC Efficiency - Lowers TMIC outlet temps, enables more aggressive tuning
- Designed for even flow distribution - Forces entire core work to cool the hot charge air
- CAD design and simulation - Ensures both fitment and function
- CNC Laser Cut 5052 Aluminum - Resists fatigue due to heat and vibration
- Durable DuPont Black Powdercoat - Protects splitter with an OEM finish
- Custom EPDM Rubber Gasket - Provides excellent seal and longevity
- 3x Intercooler Sprayer Ports - Utilize your STI TMIC sprayer or add one if you'd like
Our cars, with even mild modification, create some serious heat. As the turbo compresses your intake air, it heats up and it’s not unusual to see air temperatures of over 400* F entering your intercooler. For that reason, you’ve probably upgraded to a larger, more capable top mount. That intercooler uses ambient air flowing over your hood and through your scoop to cool the hot compressed air and if you’re still using the OEM FXT size splitter, you’re not getting the most out of your TMIC. The GrimmSpeed line of splitters increases the size of the opening by 70% to your larger TMIC. Larger TMICs can increase your internal core volume by as much as 200% and you’re going to need every bit of that additional ambient air to keep things cool.

DESIGN:
Each of these splitters has been designed to make the best possible use of the air entering your scoop and we offer a fitment for every 02-07 Impreza with a WRX or STI scoop. We’ve opened up the bottom of the splitter to better fit your STI or big GrimmSpeed TMIC and we’ve redesigned the vanes that direct air from your scoop down to your intercooler. In addition, we’ve added features for up to three intercooler water sprayers to each splitter. Each splitter was designed in CAD and tested via flow simulation prior to production. Extra air diversion vanes were added to the splitters where there was space. Where there wasn’t space (due to a smaller scoop), vanes were re-designed to more evenly distribute airflow.

MATERIALS:
You’ll also find that the GrimmSpeed splitters are very lightweight. We’ve tested some of ‘the other guys’ splitters and have found that they’ve chosen stainless steel instead of aluminum. The reason for this is likely as a band-aid, to ensure stiffness so that the splitter holds its shape. Instead of selecting a stiffer material, we’ve stiffened the design, which has allowed us to use 20 gauge 5052 aluminum and drop the weight of these splitters by 300% over the competition. Instead of welding the assemblies, we’ve opted to use flathead rivets. These offer the same mechanical joint but without stressing the material and because of that, you don’t have to worry about breaking welds or your splitter cracking. With each splitter, we’ll be including a length of a custom designed extrusion gasket, made from the same EPDM rubber as the OEM gasket, but better suited to fit our splitter. Pre-punched for split-shank rivets, you can be sure that you’ll get a great seal with no worries of failing adhesive or brittle rubber.
FITMENT:
- 2004-08 Subaru Forester XT (equipped with a GrimmSpeed or OEM STI TMIC)
INSTALLATION:
This installation guide is currently being updated to reflect some small design changes. You'll notice that some kits will ship with a bulb style gasket. For these kits, start applying the gasket in the center of one of the four flanges and work your way around. The gasket will flex enough to follow around the bends. As you approach the end, you'll notice that you have a few extra inches of gasket depending on how tightly you've stretched it. Trim it to length at this time. If you'd like, you can make relief cuts in the bulb on the corners. A more detailed installation guide will be posted shortly. Please feel free to be in touch with questions.
Subaru Top Mount Intercooler Splitter Install InstructionsOverall rating: 5.0 / 5 from 6 reviews.
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Review topics: ["quality","design","install"].
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Reviews
2004 XT with STI JDM TMIC
"This fit perfectly with my 2004 XT with an STI JDM V7 TMIC. No adjustment needed."
A++ Expected GrimmSpeed Quality
"I installed this on my 2007 Forester XT Limited and the build quality and finish is exceptional. It fits perfect as well. The previous owner had a different aftermarket splitter installed and I couldn't remove it fast enough. It was rusting out and way heavier than the GrimmSpeed splitter. I highly recommend this product to anyone running a larger TMIC and/or hood scoop. Thank you GrimmSpeed for continuing to extend your product line to these Foresters!"
Exact Fitment for Forester XT 2008
"Let me start by saying Grimmspeed's customer service is on point. They know heir products, the fittment and designed a high quality product for my year/make/model. The lightweight design of the splitter is stellar and matches up exceedingly well with the OEM STI intercooler. It even matches up better with the OEM STI 02-03 JDM hoodscoop. This project went without a hitch, I was in and out of the hood in under 30min and on to enjoying my new upgrade. The little design elements in this product make it phenomenal and I would highly recommend this to anyone doing a similar upgrade."
Quality work!
"Recently installed this on my FXT with an 07 STI intercooler. As usual GrimmSpeed quality speaks for itself, the piece is flawless and looks sharp under the hood. The product fit as described and was an easy install."
Nice!
"I had the stock rubber piece that was not up to par with the Grimspeed TMIC... Quality of material far exceeds stock or other similar products. Ease of installation is a strong point reusing stock fasteners, everything lined up perfectly."