N20 Intercooler Upgrade Guide
We believe upgraded front mount intercoolers (FMIC’s) are one of the most under-rated mods for the BMW N20. Peak power gains may appear underwhelming for the cost of an upgraded FMIC. However, upgraded intercoolers are excellent on tuned and modded N20 engines. In this guide, we will discuss the many benefits of running an upgraded FMIC as well as sizing and the top options on the market.
N20 Upgraded FMIC Performance Benefits
- Lower IAT’s
- More power
- Higher boost targets
- Better ignition timing
- Reduce chance of knock/pre-detonation
Turbochargers spool and build boost from free-flowing exhaust gases. Of course, there is an inherent downside to that. Turbos run at incredibly hot temperatures. The cool, fresh air pulled in by the engine is rapidly heated as it flows through the turbo. Enter an air-to-air front mount intercooler. An intercooler is tasked with the job of cooling the compressed air once it leaves the turbocharger. The factory N20 FMIC is successful at cooling the air during modest driving or short one gear pulls. However, the inefficient design falls flat on its face when tasked with long pulls or back to back pulls. This is where an upgraded N20 intercooler comes into play.
As stated initially, peak power gains with upgraded FMIC’s may not seem appealing. On glory runs and short pulls an FMIC may only provide 5whp for the N20 engine. This is because the turbos are not generating enough heat to overwhelm the factory intercooler. However, after several minutes of aggressive driving or back-to-back pulls the factory intercooler becomes an issue. IAT’s (intake air temperatures) skyrocket and the factory N20 FMIC has trouble keeping temperatures in check. Warmer air is less dense which ultimately saps power. In these scenarios, an upgraded FMIC has the ability to gain as much as 20-30whp over the stock N20 FMIC. We should specify, an upgraded FMIC technically isn’t “gaining” that power. However, it’s preventing the N20 from losing the power.
N20 FMIC Intake Air Temps (IAT’s)
IAT’s are the name of the game for upgraded intercoolers. Their efficient designs are intended to provide a significant advantage in cooling the compressed air. The below image highlights the benefits of an upgraded intercooler:
*The image is for an example only. It shows an N54/N55 OEM FMIC vs upgraded VRSF FMIC
Although the above image is for the N54/N55 the concept remains on the N20 engine as well. An upgraded N20 FMIC will drastically improve intake air temperatures. Keeping the air temps down assists in ensuring the engine is running on denser air which creates more power. Ultimately, cooler air also reduces the risk of engine knocks. Warmer air is prone to igniting without a spark and causing engine knock. Keep temperatures down and you can target better ignition timing leading to further performance benefits.
N20 Upgraded FMIC Sizes
Most N20 intercoolers are available in sizes ranging from 5″ to 6.5″. The right intercooler for you depends on your mods and goals. Regardless of exact sizing, an upgraded FMIC is still a big upgrade over the factory N20 design. Below we’ll discuss who should opt for what size intercooler:
N20 5-6″ FMIC
A 5 or 6″ upgraded FMIC core is typically in the ballpark of 80-95% larger than the factory intercooler. Despite smaller size, these intercoolers are still a considerable upgrade. These intercoolers are best for stock turbo cars and modest aggressive driving. A 5-6″ intercooler will provide plenty of cooling benefits and keep IAT’s low even after multiple back to back pulls. However, for N20’s running larger turbos or going to the track often these options may be a little small, especially the 5″.
You may be asking, “why not just opt for the largest offering?” Great question. It can’t hurt too much to go with an over-sized FMIC, however there are a few downsides. For one, the larger core will take longer to fill with the compressed air. This will cause a little bit of additional turbo lag. Additionally, the larger core will cause a minor loss in boost pressure. Stick to a 6″ or smaller intercooler if you’re N20 is on stock turbos and not tracked too often.
N20 6.5″+ FMIC
These N20 upgraded intercoolers are going to have the largest cores and best cooling capacity. It will be nearly impossible to truly heat soak these intercoolers on the stock turbo. They will handle whatever a stock turbo N20 can handle. Great option for those who are tracking their N20’s frequently, running an upgraded turbo, or driving very aggressively on the norm.
For most N20 owners, the 6.5″ intercoolers are probably on the overkill side. If you want the absolute best cooling then there is nothing wrong with opting for these larger intercoolers. Again, just expect a little extra turbo lag and a minor loss in boost pressure. It’s not too drastic but it may be pointless if the 5″ or 6″ offerings can handle the job anyways.
N20 Upgraded FMIC Options
Below we’ll touch on a few of the popular N20 FMIC options. Please note – it is not an exhaustive list of all intercoolers available. However, these are among the most proven, high quality intercoolers on the market for the N20.
N20 VRSF 5″ and 6.5″ FMIC
You can’t go wrong with VRSF. In our opinion, they offer the best balance of price and quality on the market. VRSF products are highly tested and proven not only on N20 engines, but also on just about every turbo BMW engine. With 5″ and 6.5″ stepped FMIC designs you’ve got perfect options to satisfy your needs. Again, we recommend opting for the 5″ stepped intercooler for most N20 owners. Upgrade to the larger 6.5″ if you’re on an upgraded turbo or plan to track your N20 frequently.
Price: $379 (5″) or $479 (6.5″)
Buy Here: N20 VRSF FMIC
N20 CSF Racing FMIC
CSF racing has been in the BMW cooling business for a long time. Their radiators and other cooling system products are top notch. They recently entered the FMIC space and their intercoolers are already earning top praises and a lot of respect. At $599 the CSF N20 intercooler comes in around the mid-range pricing wise. Ultimately, we love VRSF for their quality and pricing. However, CSF Racing is a close second. If you want the utmost quality from a company that’s been building phenomenal cooling system products for ages then CSF is a great choice.
Buy Here: BMW N20 CSF Racing FMIC
N20 Wagner EVO FMIC’s
Wagner Tuning builds some excellent FMIC’s for top dollar. Expect these intercoolers to have top-tier, elite performance with a price tag to match. They offer the EVO I Competition, EVO II Performance, and EVO II Competition. These intercoolers, especially the larger EVO II options, are excellent for N20’s tasked with heavy track duties and/or an upgraded turbo. Again, the price is on the extreme end so we only recommend these FMIC’s for demanding N20’s. Otherwise, stick with VRSF or CSF.
Buy Here: N20 Wagner EVO FMIC
BMW N20 Upgraded FMIC Summary
Upgraded intercoolers are one of the best mods for not only the N20, but also any modded turbo engine. They assist in providing consistent performance by eliminating heat-soak and keeping temperatures in check. Expect 5-10whp gains on one off glory runs, but up to 30whp on back-to-back pulls. Cooler intake temps also reduce the change of engine knocks, allow for higher boost targets, and more aggressive ignition timing. 5-6″ FMIC’s are likely best for most N20’s. However, those pushing the limits may consider opting for the larger 6.5″ offerings.
VRSF, CSF, and Wagner Tuning all make excellent FMIC’s for the N20 engine. There are tons of options on the market, but these 3 offer a great balance of quality, performance, and price. Wagner FMIC’s are on the pricey side so we recommend those only for the die hard N20’s. Nonetheless, you cannot go wrong with any proven upgraded FMIC on the N20.