All vehicles will lose some degree of performance due to heat soak under the right operating conditions.  Engine management systems constantly monitor operating conditions and modifying parameters based on sensor inputs. BMW integrated the intake air temp sensor in the MAF housing on models such as the E39 M5, and, being sandwiched behind a hot radiator and in some applications next to an even hotter valve cover, this is less than ideal for performance applications. Absorbing excess heat from its surroundings, the MAF can’t shed it fast enough, and the ECU reads an inaccurately high intake air temperature. Compensating for this false hot air measurement, the ECU pulls timing and runs a richer fuel mixture, resulting in a significant loss of torque.

What can you do?  Locate an intake air temp sensor in a location where it can properly measure incoming air temps and where it's less prone to heat soak. Mounting the sensor further away from the heat source and isolating it from the MAF housing, it can both resist the effects of heat soak longer and respond to temperature changes more quickly.  The result is you’ll experience reduced torque loss and more consistent power output when you’re pushing your engine hard. 

The Turner engineering team was initially skeptical of the claimed performance benefits of this modification. They first set out validate the functionality and performance benefit of a temp sensor relocation. Replicating stop-and-go traffic heat soak in a 2001 540i was a simple task in a controlled environment - their dynometer. First the car was heat soaked to simulate being stuck in traffic or moving at low speeds by running the car four times on the dyno with the dyno's cooling fans disabled. The fans were then turned on for three more runs to observe the recovery rate once air flow was reintroduced. The test: following this procedure once with a stock IAT, and once with their relocation kit in place. 

The result? Turner recovered 11lb-ft torque at 2500rpm through use of their relocation kit, with even greater recovery to be found for M5 owners. Here are the heat soak-related torque losses Turner experienced:

Stock IAT location:
18rwtq at 2500rpm
10rwtq at 3000rpm
9rwtq at 3700rpm

Turner IAT Relocation:
7rwtq at 2500rpm
5rwtq at 3000rpm
5rwtq at 3700rpm

**Click here for installation instructions**

The Turner engineering team designed a complete plug and play kit (unlike all other options on the market) that makes for quick, easy, and reversible installation. Weather-sealed connectors keep out the elements, while sheathed wiring offers a clean appearance underhood. With a harness nearly 3 feet long - the Turner IAT relocation kit offers flexibility in positioning, but not too long that you're left with unsightly excess wiring. Turner recommends positioning the sensor in a location away from engine heat, but still within the intake ducting to achieve accurate intake temp readings - such as the far side of the base of the airbox. Vehicles with cold air intakes with cone-style filters can even position the sensor in the end of the filter. Simply drill a hole in your (cool) location of choice and plug in the harness. More information including installation instructions and some good examples of sensor mounting locations can be found in our DIY PDF. 

We include everything you need to relocate your IAT, just select your desired sensor brand below - Genuine BMW or original equipment Beru.

Also the perfect plug-n-play option for anyone looking to upgrade their intake to utilize an Alpha-N tune!

Note for vehicles with M62 engine: applicable to 1999 and up

When we designed this catch we wanted to have the most function options available, the best separation method, and the easiest to service. The Turner engineered catch cans offer a pre-setup design based ion desired flow direction, however this does not limit you to this flow. The inner baffle orientation can be easily adjusted to flow in both directions in case you decide to move this catch can to a different vehicle. A 4 chamber system  baffle system inside the catch can was engineered to create multiple changes in the direction of airflow within the separator to cause oil droplets to fall out of suspension before exiting the catch can. Having a closed / recirculated design reduces oil ingestion and promotes cleaner emissions and odor-less operation.

Our catch can was also designed with the idea that the cans fill level can easily be checked with a top mounted dipstick and an optional use bottom drain hole. The drain hole can be used with a valve and hose to be mounted at a lower area of the vehicle so when you're doing an oil change you can drain the catch can.

Features:

• 6061-T6 billet machined body, anodized black for lasting protection and appearance
• Strategically positioned 4 chamber baffle system maximizes oil / air separation 
• Knurled and black anodized oil dipstick makes inspecting oil volume of reservoir clean and simple
• Sealed with a pre-installed viton O-Ring
• Includes 2.5mm allen key to remove baffle plates for cleaning
• Engineered to create multiple changes in the direction of airflow within the separator to cause oil droplets to fall out of suspension before exiting the catch can
• Closed / recirculated design reduces oil ingestion and promotes cleaner emissions and odor-less operation
• Optional use drain hole (valve and hose sold separately, watch for our model specific drain kits!)

Any time a valve service must be performed or there is valve damage, it is recommended to replace the hydraulic lifters to keep the valve train in top condition. 

OEM Schaeffler (INA, LuK, & FAG) is an engineering company that focuses on high-performance, precision manufacturing. With their individual brands INA, Luk, and FAG providing exceptionally high quality parts directly to BMW, as well as countless other automotive companies, their history of reliability and variety of offered parts makes Schaeffler a go-to replacement parts provider for all of us here at Turner Motorsport.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

This is an OEM INA Hydraulic Tensioner. It provides pressure to the Water Pump and Alternator belt to assure maximum performance and prevent the belt from slipping, causing decreased cooling or low charge rates from the alternator.

OEM Schaeffler (INA, LuK, & FAG) is an engineering company that focuses on high-performance, precision manufacturing. With their individual brands INA, Luk, and FAG providing exceptionally high quality parts directly to BMW, as well as countless other automotive companies, their history of reliability and variety of offered parts makes Schaeffler a go-to replacement parts provider for all of us here at Turner Motorsport.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform.

INA - Chain Tensioner Piston for BMW Engine Performance

INA - Chain Tensioner Piston is an essential component for maintaining the precision and reliability of your BMW engine. Designed to deliver superior performance, this OEM-grade part ensures optimal tension in the timing chain, preventing slack, excessive wear, and potential engine damage. Available through Turner Motorsport, this chain tensioner piston guarantees compatibility and lasting durability for a variety of BMW models.

Key Benefits:

• OEM-quality part engineered for BMW vehicles
• Enhances timing chain performance for smoother engine operation
• Reduces chain noise and prevents premature wear
• Built with high-strength materials for maximum durability
• Simplifies installation with an exact-fit design

Ensure your BMW operates at peak efficiency by upgrading to the INA - Chain Tensioner Piston, available at Turner Motorsport. This premium component is a must-have for engine repairs, regular maintenance, and improved vehicle performance.

This is the tensioner pulley assembly for the serpentine belts on E39 540i and E38 740u with M62 engine. This tensioner keeps the belt for the alternator, power steering and Air Conditioning taught to provide maximum performance of each system. OEM replacement for BMW part # 11281742858 and 11287503424.

OEM Schaeffler (INA, LuK, & FAG) is an engineering company that focuses on high-performance, precision manufacturing. With their individual brands INA, Luk, and FAG providing exceptionally high quality parts directly to BMW, as well as countless other automotive companies, their history of reliability and variety of offered parts makes Schaeffler a go-to replacement parts provider for all of us here at Turner Motorsport.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

This item fits the following BMWs:
4/1997-1998 E38 BMW 740i 740il 
1998 E39 BMW 540i