Modern Automotive Performance
Modern Automotive Performance
fmic vs tmic

2015 Subaru WRX Front Mount vs Top Mount Intercoolers

We get tons of questions when it comes to chosing a top mount or front mount 2015 Subaru WRX intercooler, and it's all in good reason. It's one of the most common 2015 Subuaru WRX mods for owners planning on making big power. Truth be told, there is a bit of unneccessary controversy surrounding the two mods, and with the upcoming release of our own 2015 Subaru WRX top mount intercooler, we hope to lay some of it to rest. The most common questions we get are:

  • Does a TMIC have less lag than a FMIC?
  • Does a FMIC cool charge temps better than TMIC's?
  • Does a FMIC have better airflow properties than a TMIC?
  • I have 'X' mods, should I run 'Y' intercooler?

While these are all legitimate questions, and some you should certainly be asking yourself and retailers if you're in the market for a Subaru TMIC or FMIC mod. Lets discuss!

Which has more turbo lag, a FMIC or TMIC?

front mount vs top mount intercooler

The difference here is dependant on a few factors, most of which relating to the supporting mods also installed on the car. In most cases, a 2015 WRX top mount intercooler will see less turbo lag given the close proximity to both the turbocharger outlet and the throttle body, whereas a front mount has considerably more distance to travel between both. While you wont feel the difference in the seat of your pants on WOT pull, the difference is measurable with more advanced tools. With that said, the difference is practically negligible, so use the information presented below to help form your buying decisions.

Does a FMIC cool more than a TMIC?

Quite possibly the most definitive question, but still worthy of discussion. A top mount intercooler is located in arguably the hottest position on the car, right above the engine. Thoughtfully, Subuaru gave their turbcharged cars a large scoop to take in fresh, cooler air while the vehicle is moving. But this doesn't do much for the car when sitting at a stoplight or staging on the track, where heat soak slowly becomes a factor. Even while moving, if the ambient air is hot enough, a top mount 2015 WRX intercooler just wont be able to keep up with cooling charge temps when compared to a front mount intercooler. Add a few heat producing performance modifications into the picture, and you've got enough heat under the hook to cook an egg on the intercooler. This is not good for performance, so a front mount intercooler gets the nod in this category.

Which Subaru intercooler has better airflow?

tmic vs fmic

Overall, an aftermarket intercooler of either type with have substaintially better flow characteristics than the stock top mount intercooler offered by Subaru. In stock form, the top mount has a ton of design flaws that lead to poor airflow exiting the turbo, entering and exiting the intercooler, before finally being put to use at the throttle body.

From an airflow efficiency standpoint, a top mount intercooler will be more efficient than a front mount given the shorter path from turbo to intake. You'll be moving air quicker. But don't confuse the longer path with turbo lag, as the system is already pressurized. Also consider the use of mandrel bends on a front mount intercooler kit, which are much better for flow than the restrictive factory piping. We suggest running a 2015 WRX top mount intercooler to see the best airflow properties.

What Subaru WRX mods work best with either intercooler type?

This is a tricky question to answer, but just like every other modification you make should be made in consideration of your goals. All out track machines will benefit more from a front mount intercooler, where a daily driven Suburu may benefit from either depending on the amount of work the owner wants to perform. But in most cases, a top mount is best paired with cars planning on making less than 500whp.

Front mount intercoolers typically cost more, require modification to fit, as well as additional aftermarket parts. Kits are readily available which make the process easier, but there is no avoiding the cutting and modifications you'll need to do to get it to fit. When running an aftermarket turbo, we recommend a front mount to handle the extra head discharged from the turbocharger. However, for most customers a top mount 2015 WRX intercooler will do a well enough job even with aftermarket turbochargers.

2015 WRX TMIC and FMIC