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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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OEM Valeo Alternator - 180amp - E9X M3 S65

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T#:377508

Part#: 12317837981

In Stock

$ 630.99

This product was last offered at the strikethrough price on
05-07-2026

$ 404.99 USD

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$ 404.99 USD

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This is a NEW alternator from the OEM manufacturer, Valeo. No core charge applies. Valeo is an OEM manufacturer for many BMW alternators - save money by buying the same alternator in a different box!

Braille Performance Endurance AGM Battery - B10049 - 58lbs

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#:558078

Part#: B10049

Ships in 8 Business Days

$ 446.99 USD

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$ 446.99 USD

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This Group 49 Endurance AGM battery is an ideal upgrade from the factory battery, offering higher cranking power and a longer battery life for less waste and lower cost to the customer. Plus, this battery is maintenance free and won't eat holes in the battery tray and surrounding areas of your car. Endurance AGM batteries from Braille are a drop-in OEM replacement that requires no modifications to be made for installation, has the highest cranking power and longest run times in their class, and also feature AGM internal racing technology developed for their Advanced AGM and Carbon Fiber batteries.

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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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Innovate LC-2 Wideband O2 Controller Kit

T#:28836410

Part#: 38770

In Stock at Vendor

$ 212.99 USD

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$ 212.99 USD

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Features & Benefits:

Two configurable linear 0-5V analog outputs Ability to calibrate O2 sensors for maximum accuracy Includes LC-2 controller and Bosch wideband O2 sensor Comes with a program cable, manual, and a 10 ft. sensor cable Includes a 1-inch mild steel exhaust bung Innovate MTS serial in/out capability Integrated dual-color status LED (green/red) Patented DirectDigital™ wideband sensor control Positive lock connectors for all connections Real-time display data on screen or with the powerful LogWorks software Range:

AFR (Air-Fuel Ratio) range from 7.4:1 to 22.4:1 (0.5 to 1.5 lambda)

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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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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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Endurance Series AGM Battery - B48-H6-L3

T#:36947237

Part#: B48-H6-L3

Ships in 4 Business Days

$ 398.99 USD

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$ 398.99 USD

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Battery Tender Plus Advanced Battery Charging System

T#:49892371

Part#: BTT0210128

In Stock at Vendor

$ 69.99 USD

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$ 69.99 USD

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Hitachi Engine Crankshaft Position Sensor - BMW N52 N54 S85 S65 S63 ...

T#:48815471

Part#: 13627525015

Ships in 6 Business Days

$ 66.99 USD

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$ 66.99 USD

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The crankshaft position sensor transmits the crankshaft's position to the computer. This helps the computer to calculate proper spark and fuel control. If you're struggling with CELs, hard starts or no starts, stalling, and/or a rough idle, you may need to replace the crank position sensor.

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Morimoto Standalone Can-Bus Wiring Harness - H4 / 9003 - Priced Each ...

T#:54388428

Part#: H240

Ships in 4 Business Days

$ 21.99 USD

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$ 21.99 USD

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