Fitment Information
- Subaru Forester XT (2004-2008)
- Intercooler and gaskets included, Y Pipe sold separately
Specs & Features
- Smooth End Tank Internal Contours – Designed for maximum flow
- Machined Throttle Body Connection – Tight, leak and trouble-free seal
- Machined Flange Faces and Internal Bores – Maximum pressure-tightness and unrestricted flow
- Permanent Mold End Tank Tooling and Casting – Allows much tighter tolerances and higher strength
- Stainless Steel Threaded Inserts – Prevent cross-threading or damaged threads
- High-Density, High-Flow Core – Optimizes heat transfer and minimizes flow restriction for turbo Subarus
- Cleaned, Inspected and Sealed Prior to Shipping – Prevent Engine Damage Due To Foreign Matter
Product Description
So, you probably already know that you want an intercooler with maximum cooling and minimum restriction, but when it comes to selecting the right one for the job, we think it’s important to understand why. As air is pressurized by your turbo, it heats up, not because of the heat of the turbocharger, but because of it being compressed, the atoms in the air are forced closer together and as a result, move faster and have more energy. That energy manifests itself as heat. The more heat we can remove from the system, the denser the air becomes and that’s what helps eliminate pre-detonation, or ‘knock’, allowing for increased output from your system. Your OEM TMIC does just fine at stock boost under normal use, but as soon as you start putting some real heat into it with higher boost or harder use, it heat-soaks beyond recovery.
Performance is a difficult subject when discussing a top mount intercooler that can be used in many different systems, often times with different goals. For that reason, we’ve opted to use primarily stock-turbo cars running higher boost. This particular 2.0l TD04 car is running full exhaust (catted), a GrimmSpeed EBCS and a 19psi tune. First, we tested pressure drop to ensure that our aggressive core design didn’t negate its benefits with a massive pressure drop. The graph below shows boost pressure in the inlet and outlet end tanks, as well as the calculated pressure drop and a trendline. Because of sampling rates and the nature of the pulsing system, you’ll notice that there is a great deal of noise in the pressure drop measurements. What’s important is the trend and as you can see, the maximum recorded pressure drop is just above .2psi with an average of around .1psi. Data was collected using a DATAQ DI-148U sampling a pair of ProSense pressure transmitters at 240Hz. Next, we tested inlet and outlet temperatures using a pair of K-type thermocouples and high frequency multimeters. What we found is that with a stock turbo, the OEM WRX TMIC seemed to keep up OK until 5000rpm or so. At that point, the efficiency of the OEM TMIC drops off very quickly. As we continued doing pulls, performance of the OEM TMIC degraded very quickly and the GrimmSpeed TMIC refused to budge, no matter how much heat we put into it. The graph below shows the post-IC temperatures for the GrimmSpeed TMIC vs. OEM TMIC. Note that these pulls were both completed after the same warm-up procedure (a series of shorter pulls) but before the OEM TMIC was fully heat soaked (and just about useless). Lastly, the third graph shows the calculated efficiency for these two top mounts based on temperatures taken from the same two pulls. This graph shows that even before it’s heat-soaked, efficiency of the OEM TMIC begins to drop significantly after 3800rpm.
TMIC Splitters
An intercooler functions by forcing the ambient air coming into your hoodscoop through the core, where it interfaces with the hot charge air and carries heat out the bottom. If your splitter doesn’t seal perfectly, ambient air is likely to take the path of least resistance and slip around the TMIC. We’ve found noticeable performance improvement when using a correctly-fitting TMIC Splitter compared to an incorrectly fitting splitter. We has designed and manufactured a wide range of splitters so that no matter your application, you have a custom splitter that will extract maximum performance from the GrimmSpeed Top Mount Intercooler. Follow this link to learn more and be sure to use the correct splitter for your vehicle and hood scoop.
