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BMW Electrical Sensors, Switches, & Relays for BMW E90 M3 S65 4.0L

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Electrical gremlins can be very frustrating. Luckily your BMW's electrical system is better than most, even if it's 25 years old. Here you will find electrical relays, sensors, switches, and modules for the engine, camshaft, and crankshaft. Our parts are OEM, Genuine BMW, or approved aftermarket brands that we have an excellent track record with. There is no middle ground with electrical parts - it either works perfectly or not. And there's nothing more frustrating than a new part that fails right out of the box. So it's important to choose quality replacement parts over a cheap but faulty piece.

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Alternator - 180amp

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T#:26438185

Part#: 12317837981

In Stock

Sale - Save 15% $ 304.99

This product was last offered at the strikethrough price on
05-03-2026

$ 259.24 USD

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Sale - Save 15%

$ 304.99

This product was last offered at the strikethrough price on
05-03-2026

$ 259.24 USD

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Braille Lightweight Advanced AGM Battery - B3121 - 21lbs

T#:558042

Part#: B3121

Ships in 6 Business Days

$ 270.99 USD

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$ 270.99 USD

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When building a car for the track, one of the most important factors to consider is weight. Stock batteries can weigh up to almost 50 pounds and are unnecessarily large, designed to power a host of systems not normally used in a track car (radios, lighting, etc.). What can you do to cut weight the weight without affecting your car's operation? This is where Braille Battery comes in with their long line of performance lightweight battery options! Designed to provide the highest cranking power possible while being up to 75% lighter, Braille Battery is one of the foremost leaders in automotive racing batteries with nothing but high quality, high output batteries in mind! The B3121 battery from Braille is their lightest do-everything battery available, offering 1380 pulse cranking amps that can crank over V8 engines with ease while still coming in at under 22 pounds, half of the weight of a standard Group 34 battery! This is thanks to their Advanced AGM racing technology that allows them to put a ton of power into a very small package. Physical Specifications: BCI Group: All sizes Weight: 21lbs / 9.5kg Length: 6.6" / 168mm Width: 5.2" / 132mm Height: 6.8" / 173mm Polarity: Right Side Positive Terminal Type: Steel terminal block with M6 bolt Performance Specifications: Voltage: 12v Recharge Voltage: 14.4V – 14.6V Maintenance charge voltage: 13.8V 5s Pulse Cranking Amps (PCA): 1380 10s PDC: 124 Amp Hour (Ah): 31 Watt Hour (Wh): 372 Life Cycle @ 10% DOD: 3100 Charging Temperature 0C to 50C Discharge Temperature range -40C to +60C Storage temperature -40C to +60C *THIS BATTERY REQUIRES A CUSTOM MOUNTING SOLUTION. The size and weight are significantly smaller than a stock battery and will not be held in place by the stock battery mount*

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Braille Performance Intensity Carbon Lithium-ION Battery - i48CX - 10...

This item is classified as Hazardous Materials and requires special shipping and handling. We cannot ship this item out of the US or with priority shi

T#:558047

Part#: I48CX

Ships in 5 Business Days

$ 1,164.99 USD

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$ 1,164.99 USD

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The ultra-lightweight, standard height I48CX lithium-ION battery from Braille Battery is a popular choice among BMW enthusiasts looking for a drop-in replacement battery that shaves off a ton of weight, 35 pounds in total! Thanks to the Group 48 design of this battery, no modifications are needed for installation. This is perfect for anyone looking to drive their car both on and off of the track, without any negative side effects, and wants a battery with a 10-15 year life span!

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Bav Auto Intake Air Temperature Sensor - BMW E9X M3 S65

10X Entries Into Our F80 M3 Sweepstakes

T#:639824

Part#: 13627792203

Ships on Jan 11, 2027

$ 24.99 USD

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$ 24.99 USD

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This sensor provides your BMW's control unit with intake temperature readings in order to run optimally in any condition. If this sensor has failed, your BMW may be suffering from more performance loss than you realize. Replace your IAT sensor to ensure proper temperature readings and restore lost performance! From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.

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Braille Performance GreenLite Lithium-ION Battery - G30 - 5.5lbs ...

T#:558046

Part#: G30

Ships in 6 Business Days

$ 522.99 USD

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$ 522.99 USD

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The G30 lithium battery from Braille is designed for the Import Tuner market (4 and 6 cylinder) for track use and has enough power for small black V8 race cars and hot rods with light electrical demands/accessories and standard compression. The G30 comes in the popular ETX 30 Group size, just like the B3121 AGM, so it is small and light enough to mount in a variety of locations. Incorporated in this battery is the same technology used in their race winning batteries used by nearly every OEM developer in classes ranging from SCCA to Formula 1.

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Meyle Crankshaft Position Sensor - E31, E38, E39, E52, E60, E63, E64,...

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We Price Match - Give Us A Call or Chat!

T#:579358

Part#: 3148990000

Ships on Nov 3, 2026

$ 37.99 USD

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$ 37.99 USD

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Referred to as the speed sensor & reference sensor

Bav Auto Crankshaft Position Sensor - Multiple BMWs

10X Entries Into Our F80 M3 Sweepstakes

T#:639826

Part#: 13627525015

Special Order: No Guaranteed ETA

$ 67.99 USD

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$ 67.99 USD

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This crankshaft position sensor provides the ECU with the engine speed signal. It is mounted in either the engine block or the bell housing of the transmission on most cars. From 1974 to 2019, Bavarian Autosport was one of the premier vendors for BMW and MINI auto parts. We are happy to preserve the Bav Auto legacy by continuing to carry their high-quality products into the future. All Bav Auto parts will remain unchanged in design and sourced from the same OEM suppliers to ensure long-lasting reliability. We trust these parts, accessories, and upgrades so confidently that we back every Bavarian Autosport branded component with a 2-year warranty.

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Meyle Outdoor Temperature Sensor / Probe

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We Price Match - Give Us A Call or Chat!

T#:579266

Part#: 3009190001

Back Ordered

$ 44.99 USD

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$ 44.99 USD

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Common fix for incorrect OBC temperature readings

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