N54 INTERCOOLER BUYER'S GUIDE

 

With several different FMIC options available for the N54 BMW's it can be difficult to decide which one is best for your build.  In this article we discuss the benefits and disadvantages of the three most popular FMIC styles for the N54, the 5", 7", and 1K (7.5").  At ARM we offer several different options so you can get the perfect FMIC paired with your build.  Here is a quick guide for appropriately sizing an FMIC for your N54 project.

The most common question we get regarding FMIC size is why not just get the biggest most massive intercooler available?  There are several reasons as illustrated on the chart below.  While the positive aspect of cooling performance does increase with a larger FMIC, the other three negative aspects also increase (psi drop, installation, and price).  For the moment let's assume we're willing to modify our N54's to any extent and pay any price for an FMIC to get those IAT's icy cold.  There's still the very real pressure drop that is associated with installing the 7.5" FMIC on your N54 with the stock turbos. 

 

The best FMIC for an N54 on the stock turbos is the 7" FMIC.  Why?  It is the best balance between cooling performance and pressure drop. Despite this being a non-stepped design, the ARM 7" FMIC is measurably larger than the 5" FMIC.  While the ARM 5" FMIC comes in at 625cu.in., the ARM 7" FMIC is a significantly larger at 805cu.in.  That's 29% larger than the 5" FMIC, all without the stepped lip.  



On a back to back comparison between the ARM 7" FMIC and 5" FMIC, our Stage 2+ N54 test car was able to pick up an additional 10whp and 10wtq with the ARM 7" FMIC over the ARM 5" FMIC. 



As you can see peak boost comes on at exactly the same time, 2900 RPM, indicating there is no measurable difference in turbo lag between the 5" and 7" FMIC.  Add to that a higher peak hp and torque and you have a clear winner for the N54 on stock turbos.  In conclusion, your N54 will make more power with the ARM 7" FMIC over the 5" FMIC in every scenario.

The downside is that the 7" FMIC does require some trimming and it is slightly more expensive.  If neither of those aspects are an issue for you, then the 7" FMIC is the perfect intercooler for your build.  If offers the best balance between cooling performance and pressure drop on stock turbo N54 cars.  Running the 7" FMIC on a stock turbo N54, you will see close to ambient temperatures, and only approximately 1-2psi of pressure drop.

THE N54 FMIC WITH THE EASIEST INSTALLATION

Both the ARM 5" and 7" FMIC's are compatible with the stock intercooler piping.  However, if you want to get the most out of your ARM FMIC we strongly recommend adding the ARM Hose Upgrade. The ARM Hose Upgrade will replace the OEM intercooler piping with steel reinforced 5-layer silicone which is 50% larger, allowing more airflow for the charge air.

THE BEST FMIC FOR AN N54 WITH UPGRADED TWINS OR SINGLE TURBO

SUMMING IT UP

In conclusion, there is no universal "best" FMIC for your N54, but there is a best for your N54 and what you goals are for the project.  The N54 benefits tremendously from an FMIC upgrade, much more so than the average turbocharged car, but selecting the correct FMIC for your N54 based on what you plan on doing with it is one of the more important decisions you can make for your build.  Which is why we offer 3 variations of the N54 FMIC to suit your needs.