BMW N63 Intercooler/Heat Exchanger Upgrade Guide
Meet Austin
Austin graduated from the University of Colorado Denver in 2021 with a degree in technical writing and remains in the Denver area. Austin brings tons of automotive knowledge and experience to the table. Austin worked as a Technical Product Specialist at BMW for over 5 years and drives a heavily modified E30 325i with a stroker kit, all of which he built from the ground up.
The BMW N63 has been BMW’s premier non-M V8 engine for over 15 years now. The N63’s unique “hot-vee” design, with twin-turbochargers sitting between the cylinder banks of the engine, was innovative if not a bit problematic in the engine’s earlier years, with excessive heat – unsurprisingly – being one of the N63’s biggest problems. That’s where upgraded N63 intercoolers come into play, as larger and improved intercoolers can significantly reduce charge air temperatures, improving power, torque, and overall engine performance.
While there aren’t a ton of options as far as upgraded N63 intercoolers are concerned, there are a couple of very solid options. In this guide, we’ll cover upgraded N63 intercoolers in detail and discuss their performance benefits.
Factory Intercooler/Heat Exchanger Setup
Like many other modern BMW engine technologies, the N63 has a pretty complicated cooling system. It would actually be more accurate to say cooling systems, plural, as the N63 has both low and high-temperature cooling circuits, with the high-temperature circuit for primary engine cooling and the low-temperature circuit for cooling charge air.
To cool the charge air, the N63 uses two air-to-coolant heat exchangers/intercoolers, one for each turbo. Since the low-temperature cooling system is separate from the main engine cooling circuit, the intercoolers and relatively small, compact, and close to the turbos themselves. The shorter pipe length to the intercoolers decreases pressure loss and improves power and throttle response as a result. BMW claims that the factory intercoolers can cool the charge air by up to 80°C.
Ultimately, the main goal of the N63’s intercoolers is to cool the charge air as much as possible. The cooler the air, the more dense it is, which is better for combustion overall. Engine power is directly impacted by charge air temperature, so the cooler the better. Additionally, cooler charge air temperatures reduce the risk of engine knock and pre-detonation, improving engine safety. While the factory intercoolers do a decent job, there is still room for improvement.
Upgraded N63 Intercooler/Heat Exchanger Benefits
- Up to 25 horsepower increase
- Up to 15 lb-ft of torque increase
- Decreased chance of heat soak
- Increased engine knock protection
- Better engine efficiency
- Marginally improved fuel economy
The benefits of upgrading to more efficient heat exchangers are pretty numerous. Since the temperature of the charge air plays such a big role in the N63’s overall operation, upgraded heat exchangers make a big difference in terms of efficiency. Power and torque gains are the most notable benefit. The cooler and denser air provided to the combustion chamber as a result of upgraded exchangers allows for better combustion, leading to a potential increase of 25 horsepower and 15 lb-ft of torque which isn’t insignificant.
In addition to the additional power and torque, upgraded heat exchangers also have a pretty big effect on engine safety and efficiency. For example, heat soak is a common issue on the N63, especially if you are pushing it to its limits for an extended period of time i.e. on the track. Heat soak is when the engine’s intake air temperatures reach a high level, decreasing the performance of the engine. With more efficient exchangers, that isn’t an issue, making them a good modification for N63 owners who need consistent performance from their engine.
Increased engine safety is another pro, as cooler charge air temperatures reduce the risk of engine knock or a pre-detonation event caused by high intake air temperatures. That means you can push your turbochargers a bit further, via a tune, while remaining in a safe operating window. The increased combustion efficiency also leads to slightly better fuel economy.
Upgraded Intercooler/Heat Exchanger Options
Despite being a good modification for the BMW N63, there aren’t too many options as far as upgraded heat exchangers are concerned. Ultimately, you only have two options. Fortunately, they are both high-quality and proven options.
The first option is a kit provided by DINAN, so you know that it’s a good one. DINAN is known for their partnership with BMW in providing some of the highest quality aftermarket upgrades for pretty much every BMW engine ever made. Their N63 kit is no exception. It features two upgraded air-to-water intercoolers that are 23 percent bigger than the factory units, providing a dramatically larger internal surface area for the charge air to pass through. In addition to the intercoolers themselves, the kit also comes with all of the necessary hardware to replace the factory intercooler accessories including the silicone hoses, coolant lines, and mounting hardware.
Outside of the DINAN kit, the only other intercooler upgrade option for the N63 comes from Alpina. Like DINAN, Alpina truly doesn’t need an introduction. The Alpina B6 was one of the most exciting OEM+ BMWs in recent years and featured an upgraded N63 to put it in a league of its own. The B6 received larger turbochargers and larger intercoolers as a result, which can be modified slightly to fit regular N63 and N63TU engines. The Alpina intercoolers are 35 percent larger in volume than the OEM intercoolers which makes a big difference in terms of performance.
Neither option is cheap, though. The DINAN upgrade kit is widely available from their website for $2,999.00. Alpina doesn’t sell the B6 intercoolers directly, making them a bit difficult to find, but they pop up on eBay from time to time.
Is an N63 Intercooler Upgrade Worth It?
In all honesty, it really depends on how you use your N63-powered BMW. If you rarely find yourself pushing your car to its limit for an extended period of time, like during a track day, there isn’t really a reason to upgrade your intercoolers. While the moderate power and torque gains are significant, there are far easier and cheaper ways of getting an additional 20-25 horsepower out of an N63.
However, if you are building a dedicated N63 track car or have already installed extensive modifications, upgrading your intercoolers might be the next logical step. If you have already maxed out your engine with all of the go-to bolt-on modifications and are pushing significantly higher-than-stock power and torque, intercooler upgrades are worth it for the engine safety benefits and reduced heat soak properties alone. With an aggressive tune and downpipes, upgraded intercoolers will ensure that you can effectively put that additional power to the ground consistently while also keeping your charge air cool and keeping performance consistent.
Since there are only two upgraded intercooler options, with the DINAN kit costing an arm and a leg and the Alpina B6 intercoolers remaining a unicorn, it is hard to justify upgrading them unless you’ve already done pretty much every other N63 performance mod first.
If you are interested in learning more about other N63 modifications that might be a better band for your buck in terms of performance, take a look at our How to Build a 500+WHP BMW N63 for Under $1,500 Guide. Let us know if you think that N63 intercooler upgrades are worth it below.
