DOC Race B58 Top Mount Turbo Kit with Precision Turbo – BMW F & G Chassis (B58 Gen 1 / Gen 2)

OVERVIEW

DOC Race top-mount single turbo kits for the BMW B58 — the Gen 1 kit for F-chassis cars and the Gen 2 kit for the 2020–2024 G-chassis M340i and M240i. Both use a stainless tubular T4 twin-scroll manifold, a Precision turbo, twin Turbosmart wastegates with external dump tubes, and a 3.5" stainless downpipe.

Choose the 1.25 Schedule 40 runner (industry standard, known to support well over 1,200 hp, with an investment-cast collector) or the larger 1.5 Schedule 40 runner for lower exhaust back pressure.

SPECS

• Chassis options: F Series (B58 Gen 1) or G Series (B58 Gen 2)
• F Series turbo options: PTE 6266 journal bearing, Gen2 6266 / 6466 / 6870 / 7275 ball bearing, Next Gen 6266 / 6466 / 6670 / 6870 / 6875 / 7275, Comp 6871, or supply your own PTE turbo
• G Series turbo options: PTE Next Gen 6466 / 6670 / 6870 / 6875 / 7275, Comp 6871, or supply your own PTE turbo
• Runner options: 1.25 Sch 40 (1.66" OD) or 1.5 Sch 40 (1.90" OD)
• Stainless tubular T4 twin-scroll manifold
• Twin Turbosmart wastegates (40mm F Series / 45mm G Series) with 2 x external dump tubes
• 3.5" stainless downpipe
• Exhaust parts supplied polished (ceramic coating is a separate DOC Race service)
• Precision (PTE) turbochargers only — DOC Race warns other turbos will not fit correctly
• Built to order; approximately 4 weeks lead time
• The price shown on the "supply my own turbo" option does not include a turbocharger.

PARTS INCLUDED

• Precision turbocharger (unless "supply my own" is selected)
• 2 x Turbosmart wastegates
• Stainless tubular T4 twin-scroll manifold
• 3.5" stainless downpipe
• 2 x wastegate dump tubes
• 2 x charge pipes (turbo to throttle body)
• Silicone couplers and clamps
• Stainless oil drain line kit
• Stainless oil feed line kit
• Stainless coolant bypass line kit
• T4 gasket, turbo studs and nuts
• Exhaust V-band clamp
• 4" turbo screen
• Heat shield
• 1/4" nylon tubing and fittings for wastegate routing
• Valve cover vent filter
• 2 x 3/4" boost caps

TECH RESOURCES

Required Additional Parts

• Tuning (required) by an experienced B58 tuner: Bootmod3 B58 Tune, MHD Super License – B58, JB4 Tuner – B58 Gen1 & Gen2.
• ECU unlock is required before a locked B58 DME can be flashed: Speed Logic ECU Unlock Service.
• Supporting fueling, intercooling, clutch and drivetrain sized for your power target — e.g. JB4 Fuel Pressure Upgrade Kit.
• Catch can (recommended): Black Market Race B58 Gen 1 Catch Can Kit or Black Market Race Gen 2 B58 Catch Can Kit.

Installation

• DOC Race kit video: B58 top mount turbo kit (the video does not show the 2 charge pipes, which are included).
• Wastegate vacuum lines must be routed away from exhaust heat; the wastegates may need to be clocked to do this. Melted lines can cause over- or under-boost.
• DOC Race does not publish an installation manual for this kit. Contact Speed Logic for install support.

VEHICLE APPLICATIONS