Biturbo downpipes · Welded in Phoenix, AZ

Downpipes that let the turbos breathe.

On a biturbo Mercedes, the factory downpipes are the tightest point in the exhaust. MBH downpipes open it up with large 3-inch tubing (3.5-inch on the W213 E63 S), hand-built from 16-gauge T-304 American stainless. Most bolt on in about an hour.

Shop M157 · 5.5LShop M177 / M178 · 4.0L
Downpipes that let the turbos breathe.
  • 3-inch and upHigh-flow tubing
  • 16-gauge T-304American stainless steel
  • About 1 hourBolt-on install, hand tools
  • Lifetime warrantyOn USA-made downpipes

Fastest way

Find downpipes for your Mercedes

Why downpipes make power

Backpressure is the enemy of boost.

  1. The choke point

    Right after the turbos, the factory downpipes squeeze the exhaust through small pipes and catalytic converters. That backpressure holds the whole engine back.

  2. Faster spool

    Bigger, smoother pipes let exhaust leave the turbines freely. The turbos spool faster and the engine breathes easier at every RPM.

  3. The tune cashes it in

    With more flow available, a matched MBH tune can ask for more boost and timing. That is where the 100+ horsepower gains come from.

M157 · 5.5L biturbo V8

The 5.5L biturbo 63s

The M157 makes huge torque from the factory, but small downpipes keep it from using all of it. Our 3-inch downpipes remove that restriction on everything from the E63 and S63 to the G63 and GL63. On the G63 we use flanges CNC-machined from solid billet stainless so they never warp under biturbo heat.

+140 / +175WHP / WTQ with MBH tune (ML63, GL63, GLE63)
3-inchHigh-flow piping, up from factory
~1 hourBolt-on install, no cutting
  • Fits:
  • E63 (W212)
  • S63 (W221 / W222)
  • S63 Coupe
  • CL63
  • CLS63
  • G63
  • ML63
  • GLE63
  • GL63 / GLS63
The 5.5L biturbo 63s

Shop M157 downpipes

M177 · M178 · 4.0L biturbo V8

The 4.0L biturbo AMGs

The hot-V 4.0L puts the turbos inside the V, so the downpipes do a lot of work in a small space. Ours use as much large-diameter tubing as the car allows, TIG welded from 16-gauge 304 stainless, so the turbos spool faster and the engine runs cooler and more efficiently.

+100 / +120WHP / WTQ with MBH tune (C63 W205)
+100 / +150WHP / WTQ with MBH tune (AMG GT)
3.5-inchTubing on the W213 E63 S
  • Fits:
  • C63 / C63 S (W205)
  • E63 S (W213)
  • GLC63
  • AMG GT
The 4.0L biturbo AMGs

Shop 4.0L downpipes

C63S AMG W205 Heatshield Downpipes
On a budget? W205 C63 SFlowsport heatshield downpipesOur lower-cost line: heatshield-wrapped 304 stainless, TIG welded, 5-year warranty.
$781.00 $831.00 View Flowsport
M278 · 4.7L biturbo V8

The 550s

The 4.7L biturbo in the 550 models has far more in it than Mercedes lets out. With our downpipes and a matched tune, a CL550 can pass factory CL63 power while keeping all the comfort of the car.

+108 / +138HP / TQ with MBH tune (CL550)
+80WHP with MBH tune (GL550)
3-inchHigh-flow piping
  • Fits:
  • E550
  • S550 (W221 / W222)
  • S550 Coupe
  • CLS550
  • CL550
  • GL550
  • GLS550
The 550s

Shop M278 downpipes

Downpipes + tune

The tune is where the power is.

Our in-house tuner writes every biturbo calibration around MBH downpipes. On the M157 that means up to +140 WHP.

See MBH tuning

Downpipe questions

Do downpipes need a tune?

To get the big numbers, yes. The gains we list are with a matched MBH tune, which is what puts the extra flow to work.

How hard is the install?

Most of our downpipes are a direct bolt-on that takes about an hour with basic hand tools. No cutting or welding.

What's the warranty?

USA-made MBH downpipes carry a lifetime warranty. Flowsport downpipes carry a 5-year warranty.

Gains are from MBH dyno testing. Results vary with dyno type, weather, fuel and the condition of the car. Catless downpipes are sold for off-road and competition use.