S58 Charge Pipe Install: Y-Pipe and Hot Side for the M2, M3, M4, X3 M and X4 M

Short answer: The S58's factory charge pipe is a plastic Y-pipe. It joins a pipe from each turbo and feeds the throttle body. A full Y-pipe swap is a big job. Following Mishimoto's G80 instructions, you take off the underbody trays, drain coolant, and remove the strut braces, intakes, radiator support, core support bar and fan shroud to get the Y-pipe out from the front. A hot-side-only kit, like FTP's Lite pipe, replaces just the turbo outlet section, and FTP says the fan stays in. Plan on a full day for the full Y-pipe and no lift needed, though you'll want the car on stands. Most S58s at Stage 1 don't need one. It's insurance for high boost and ethanol.

I'm Gleb Blekher. I run B58 Racing out of Dallas, TX. The S58 charge pipe gets a lot of attention online, but almost nobody publishes how to fit one. The most complete set of instructions we found is Mishimoto's for the G80 M3 and G82 M4. It includes the factory torque values for the braces, trays and core support you'll remove, so this guide leans on it, with notes from do88, FTP and owners. Where I couldn't confirm something, I say so.

Who this guide is for, and who needs a charge pipe

Car	Chassis	Pipes we carry that fit
M3	G80 (G81)	FTP aluminum, FTP 2-in-1, FTP Lite, do88, Wagner
M4	G82/G83	FTP aluminum, FTP 2-in-1, FTP Lite, do88
M2	G87	FTP aluminum, FTP 2-in-1, FTP Lite, do88
X3 M, X4 M	F97/F98	FTP aluminum, FTP Lite

Do you need one? The sources disagree on how fragile the stock pipe is:

• do88 says the plastic Y-pipe can crack from the extra heat and pressure on tuned cars, and that a failure can damage the engine.
• FTP calls it a known weak point that can pop off or split under boost. It says the turbo outlet section is the part most likely to fail.
• OneFastShop says it found no owner documenting a cracked S58 pipe. It reports one G80 M3 owner running about 30 psi on E50 at roughly 700 whp on the stock pipe.

My take: at Stage 1 on pump gas, leave it alone. At Stage 2 with ethanol, upgraded turbos or water-methanol, an aluminum pipe is reasonable insurance, and the bungs are handy for methanol or a boost sensor. A charge pipe isn't a power part on its own.

Y-pipe vs hot side: what each kit replaces

Mishimoto's G80 instructions describe the factory layout:

• A plastic Y-pipe bolted to the engine with four 10 mm bolts, two on top and two underneath. Its outlet holds the MAP sensor and the charge air temperature sensor, next to the A/C compressor.
• A rear turbo outlet pipe, held by a 10 mm bolt and a quick-connect clamp.
• A front turbo elbow on a quick-connect clamp.
• An elbow to the throttle body, also on a quick-connect, and a throttle body adapter held by three T30 bolts.

Kits replace different parts of that run:

• Full Y-pipe kits: FTP Motorsport S58 aluminum charge pipe, FTP Motorsport S58 2-in-1 charge pipe (round-section tubing instead of the oval stock shape), do88 S58 charge pipe (cast aluminum Y with machined turbo and throttle adapters), and the Wagner Tuning boost pipe kit (G80 M3). Wagner describes its kit as one aluminum boost pipe in the factory location, so check which factory pieces it replaces.
• Hot side only: FTP Motorsport S58 turbo outlet hot-side pipe (Lite). FTP says this is roughly half of its full kit and the simpler install: the fan stays in, and you move the filter housing and its pipe aside and remove the undertray.

Check your kit's contents against this list before you start, so you know which factory pieces stay. Shop all charge pipes (S58 parts are listed there too) or the S58 parts page.

Difficulty, time and whether you need a lift

• Difficulty: 4 out of 5 for a full Y-pipe, about 2 to 3 out of 5 for a hot-side-only kit. Mishimoto rates its kit "medium." I rate the full job higher because you drain and refill coolant and remove the front structure.
• Time: we couldn't find a published install time from Mishimoto, do88 or FTP. Based on the number of steps in Mishimoto's guide, plan on a full day for a first-timer doing a full Y-pipe, including the coolant fill. A hot-side-only kit should be a fraction of that. That's our estimate, not a published figure.
• Lift: not required. Mishimoto says you need access to both the engine bay and the underside, with the front wheels off, on jack stands or a lift.
• X3 M / X4 M: we couldn't find a published step-by-step for the F97/F98. Mishimoto's product page lists F97 and F98 chassis codes, but its instructions are written for the G80 and G82. The X3 M's front end is different, so follow your kit's own sheet.
• G87 M2: the pipes are shared with the M3 and M4, but we didn't find M2-specific steps. Expect the same layout and check the torque values for your car.

Tools

This is the tool list from Mishimoto's G80 M3/M4 instructions:

• 1/4", 3/8" and 1/2" ratchets, and a breaker bar
• Sockets: 8 mm, 10 mm, 13 mm, 15 mm, 16 mm, 21 mm
• 10 mm wrench
• 17 mm 12-point wrench or deep socket (charge air temperature sensor)
• E18 external Torx (core support bar)
• T20, T30 and T40 internal Torx
• Various extensions
• Pick tool and trim removal tool
• Torque wrenches (1/4" and 3/8" drive)
• Bucket for coolant, and a vacuum coolant fill kit
• Jack and jack stands, or a lift

Add a flat screwdriver for worm-gear clamps, O-ring lube, and masking tape to mark bolt positions.

Step-by-step: full S58 Y-pipe install (G80/G82)

These steps follow Mishimoto's G80 M3/M4 instructions (MMICP-G80-21). Torque values below are the ones Mishimoto lists for factory fasteners on these cars. For your new pipe's clamps, bolts and sensors, torque to the value in the instructions supplied with your part. Other kits mount differently. do88's instructions, for example, attach its pipe to the rear turbo with the factory 10 mm bolt and leave the throttle-body hose clamp loose until the Y-pipe is in place.

Stage 1: prep

1. Disconnect the negative battery terminal. The G80 battery is in the trunk.
2. Raise the front of the car on stands or a lift and remove the front wheels.
3. Remove the front diffuser (eleven 10 mm bolts) and the front and side plastic undertrays (10 mm screws, including three in each wheel well).
4. Remove the large aluminum underbody tray. It has two 10 mm screws in each wheel well, two 21 mm bolts at the rear and eleven 16 mm bolts. Have a helper hold it.
5. Drain the coolant. Remove the reservoir cap, then disconnect the lower hose from each auxiliary radiator and drain into a container.

Stage 2: removal

6. Remove the strut braces and engine cover. Mishimoto removes the upper cross brace and V-brace with four 15 mm fasteners and one 13 mm bolt.
7. Remove both intakes and airboxes. Each has a worm-gear clamp at the airbox and a quick disconnect at the turbo. Remove the two pop clips that hold the front turbo intake to the core support.
8. Remove the hood seal and the plastic panel above the radiator support (six pop clips).
9. Remove the radiator support panel. It's held by six 13 mm bolts, four silver T40 bolts and five black T30 bolts. Move the hood latch cable out of its clips, then remove the four pop clips behind the bumper that hold the radiator shroud.
10. Remove the core support bar. Unclip the two fan shroud harness clips, then remove four E18 bolts, four T30 bolts and the center 13 mm bolt for the lower V-brace. Mark the bolt outlines so it goes back in the same place.
11. Remove the upper radiator pipe and its two small hoses, the small overflow line to the reservoir, the lower radiator hose and the fan shroud harness.
12. Remove the fan shroud. Take out three T30 screws, unlatch it and lift it out.
13. Remove the lower V-brace (two 16 mm bolts). Unclip the coolant hose from its driver's side first.
14. Move the auxiliary water pump. It sits next to the alternator. Remove one 10 mm nut and lift it off its mount for room.
15. Unbolt the Y-pipe (four 10 mm bolts, two on top and two underneath; the bottom two are easier from below).
16. Unplug the MAP and charge air temperature sensors at the Y-pipe outlet. Pull back the white locking tabs first.
17. Disconnect the pipes from the Y. Pull each quick-disconnect clip back on both sides until it locks open, then pull the pipe off. The outlet is easier from underneath. Lift out the Y-pipe.
18. Remove the turbo and throttle body pieces your kit replaces. That means the rear turbo pipe (10 mm bolt plus quick-connect), the front turbo elbow, the throttle body elbow and the throttle body adapter (three T30 bolts).

Stage 3: install

19. Move the sensors to the new pipe. The air temperature sensor comes out with the 17 mm 12-point. The MAP sensor is held by a T20 screw. Torque them to your kit's values.
20. Fit any new mounting hardware your kit supplies. Mishimoto's kit adds grommets and swaps a spacer at the lower right Y-pipe mount.
21. Install the throttle body adapter on the factory bolts and fit the throttle body boot loosely.
22. Fit the turbo-side pieces. Push the front turbo adapter on until the wire clip clicks. Fit the rear turbo pipe so its bracket sits on top of the car's bracket. Lube O-rings before they go on.
23. Fit the couplers loosely, with clamps started but not tight.
24. Lower the Y-pipe in. Connect the outlet to the throttle body boot first, then the front and rear turbo boots. Fit the four Y-pipe bolts. Mishimoto tightens them to about 10 Nm (7 lb-ft) and the rear turbo pipe bracket bolt to about 10 Nm.
25. Seat and tighten every coupler now. Make sure each clamp is behind the bead on the pipe. Mishimoto warns its clamps can't be reached from the engine bay once everything is back together.
26. Reconnect and lock both sensor connectors.

Stage 4: reassembly and after the install

27. Refit the auxiliary water pump. The 10 mm nut takes 8 Nm (about 6 lb-ft).
28. Refit the lower V-brace. The two 16 mm bolts take 56 Nm (41 lb-ft).
29. Refit the fan shroud and its connector. The three T30 screws take about 6.5 Nm.
30. Reconnect the radiator hoses. Lube the O-ring inside each hose with coolant and push until it clicks. Reconnect both auxiliary radiator lower hoses and the small vent line to the reservoir.
31. Refit the core support bar. Loosely fit the upper V-brace to line it up. Hand-start every bolt. Then tighten the lower V-brace 13 mm bolt to 56 Nm, the four E18 bolts to 56 Nm and the four T30 hood-latch bolts to 12 Nm (9 lb-ft).
32. Refit the radiator support panel. Clips first, then hand-start all bolts. Torque the three black T30 bolts that hold the bumper to the panel to 4.6 Nm. Torque the six 13 mm bolts and four silver T40 bolts to 28 Nm and the remaining two black T30 bolts to 12 Nm. Refit the hood latch cable and the fan shroud wiring clips.
33. Refit the top panel, hood seal, intakes, engine cover and strut braces. The brace's 13 mm bolt takes 56 Nm (41 lb-ft) and the 15 mm nuts take 28 Nm (21 lb-ft).
34. Refit the aluminum underbody tray. The 21 mm bolts take 100 Nm (74 lb-ft) and the 16 mm bolts take 56 Nm (41 lb-ft). Then refit the plastic trays and the diffuser.
35. Refill and bleed the cooling system. Mishimoto strongly recommends a vacuum fill tool. Refit the reservoir cap.
36. Reconnect the battery and check for leaks. Look for coolant at every hose you disconnected. Listen for a boost leak under load. If in doubt, smoke-test the intake.
37. Scan for codes. Boost-deviation or sensor codes usually mean an unplugged sensor or a leaking coupler or clip.
38. Tune. A charge pipe alone doesn't need a tune change. If you use the bungs for water-methanol or a boost sensor, your tune has to support it.
39. Recheck clamps and bung plugs after a week of driving.

Hot-side-only (FTP Lite) install notes

FTP doesn't publish a full step list that we could find. Its notes say the fan stays in, and you reach the pipe by moving the filter housing and its pipe aside and removing the undertray. The disconnects at each end are the same quick-connect style described above. Follow the sheet in the box, lube the O-ring, and listen for the clip to click.

Common mistakes and how to avoid them

• Couplers or clamps not fully seated before reassembly. On the full Y-pipe, you can't reach them once the front end is back on. Check every one twice, behind the bead.
• Dry or reused O-rings. Lube them, and replace any that are flat or nicked. FTP includes an O-ring, seal and C-clip with its aluminum pipe.
• Clips not locked. Each quick-connect should click. Pull on every joint to test it.
• Forgotten coolant connections. Mishimoto specifically calls out the auxiliary radiator lower hoses and the small vent line to the reservoir.
• Air left in the cooling system. Use a vacuum fill and bleed it properly. Don't drive it hard until temperatures are stable.
• Rear turbo pipe bracket on the wrong side. Mishimoto says the pipe's bracket goes on top of the vehicle's bracket.
• Core support misaligned. Mark the bolt outlines and line it up with the upper V-brace before torquing.
• Loose bung plugs. Seal and snug any unused 1/8" NPT plugs and recheck them.
• Buying the wrong kit for an X3 M or X4 M. Only some S58 pipes list F97/F98 fitment. Check the listing.

FAQ

Do I need an S58 charge pipe?

Not at Stage 1 on pump gas. do88 and FTP both call the plastic Y-pipe a weak point once boost and heat go up. OneFastShop found no owner reports of a cracked stock pipe. It's sensible insurance for high boost, ethanol or methanol.

How hard is it to install an S58 charge pipe?

A full Y-pipe kit is a big job. Mishimoto's G80 procedure drains coolant and removes the braces, radiator support, core support bar and fan shroud. A hot-side-only kit is much simpler. FTP says the fan stays in.

What's the difference between the S58 Y-pipe and hot-side pipe?

The Y-pipe joins both turbo outlets and feeds the throttle body. The hot-side pipe is the turbo outlet section, which FTP says is the part most likely to fail. Full kits replace both. Lite kits replace only the hot side.

Do I need to drain coolant to change the S58 charge pipe?

For a full Y-pipe kit following Mishimoto's procedure, yes, because the radiator hoses and fan shroud come out. Refill with a vacuum fill tool. FTP's hot-side Lite kit doesn't require removing the fan.

Does an S58 charge pipe need a tune?

No, not on its own. You only need tune support if you add water-methanol injection or another sensor to the bungs.

Do S58 charge pipes fit the X3 M?

Some do. FTP's aluminum pipe and Lite hot-side pipe list the F97 X3 M and F98 X4 M. The do88 and Wagner pipes we carry are for the G8x cars.

Doing downpipes at the same time? See the S58 downpipe install guide.

Sources

• Full procedure, factory layout, tool list and factory fastener torque values for the G80/G82: Mishimoto MMICP-G80-21 install guide, Mishimoto product page (chassis codes, difficulty)
• do88 mounting notes (rear turbo 10 mm screw, loose throttle-body clamp until fitted; via search excerpt of the PDF, which blocked direct download): do88 TR-420 installation instruction
• Failure risk, hot-side Lite install access, included O-ring/seal/C-clip, X3 M/X4 M fitment: FTP Motorsport and do88 product information on our listings
• Owner record and the 30 psi / E50 report: OneFastShop charge pipe guide (onefastshop.com)