If you drive a BMW 135i with the N54 or N55 engine, upgrading the intake manifold is one of the most powerful bolt-on mods available. This guide explores the top contenders—EOSpeed, Phoenix Racing, Black Market Parts, Masata, Plazmaman—and helps you choose based on performance goals, budget, and reliability. You’ll get in-depth analysis, real-world feedback, and installation insights so you can make a confident decision.
Why Upgrade Your Stock Intake Manifold?
The stock plastic intake manifold in the BMW N54/N55 is prone to cracking, heat soak, and limited flow—especially when tuning or pushing boost. These weaknesses limit performance and can cause engine management issues.
Aftermarket aluminum intakes offer:
• Significantly higher flow rates
• Integrated port injection options
• Increased durability and reduced heat soak
• Expansion ports for boost gauges, BOVs, hobbs switches
As one user on Bimmerpost reported, an N54 aluminum manifold delivered “+23 hp and +16 ft·lb torque peak gains at 18 psi” compared to stock :contentReference[oaicite:0]{index=0}.
Top Intake Manifold Options
1. EOSpeed (EOS)
A fan-favorite in discussion forums. EOSpeed stands out with a strong cast aluminum build and integrated port injection. Owners prefer it for its balance of quality, value, and weight:
“EOS of the two… Plazaman is nice but… overpriced. EOS it is.” :contentReference[oaicite:1]{index=1}
Pros: OEM-location fit, port-injection ready, durable.
Cons: Still heavier than trimmed billet options, potential heat soak without spacer.
2. Phoenix Racing Port Injection (PRM)
Phoenix Racing brings high-performance with a full aluminum manifold, top-mounted PI bungs, and vacuum/boost expansion ports. Price: ~\$600. Owners note excellent airflow and build quality :contentReference[oaicite:2]{index=2}.
Pros: High flow, plug-and-play, strong build.
Cons: Pricey, no direct dyno figures shared.
3. Black Market Parts (BMP) N55 Stock-Location
BMP’s variant offers a cost-effective route: sheet-metal and billet intake with PI and four extra ports. It works with OEM O-rings and covers N55 platforms too. Price: \$650–1,280 :contentReference[oaicite:3]{index=3}.
Pros: OEM-fit, PI ready, injection options included.
Cons: Sheet metal manifold—less rigid than cast/billet.
4. Masata Aluminum Intake
Masata offers an aluminum manifold fully supported by bolt-on hardware and optional injectors, at a UK price of ~£670 (~\$800) :contentReference[oaicite:4]{index=4}.
Pros: Direct fit, lifetime warranty.
Cons: Mid-range pricing, lacks extensive real-world data.
5. Plazmaman Intake
The top-tier billet Plazmaman is praised for craftsmanship—but the price reflects it: around US\$2,500+ including injectors and shipping :contentReference[oaicite:5]{index=5}.
Pros: Premium billet build, velocity stacks.
Cons: Extremely costly, DIY injector install adds complexity.
Comparing Intake Manifolds
| Manifold | Material & Build | PI Option | Extra Ports | Price Range |
|---|---|---|---|---|
| EOSpeed | Cast aluminum | Yes | Yes | \$600–£700 |
| Phoenix Racing | Billet aluminum | Yes | Yes | \$600 |
| BMP N55 | Sheet-metal + billet | Yes | Yes (4 ports) | \$650–1,280 |
| Masata | Aluminum | Yes | Yes | £670 (~\$800) |
| Plazmaman | Billet aluminum | Yes (DIY) | Yes | \$2,500+ |
Performance Insights & User Feedback
- EOSpeed gains: Users praise its sharp throttle response and reliable fitment :contentReference[oaicite:6]{index=6}
- Phoenix Racing PI: Excellent airflow, quality build, but backed by few independent dynos :contentReference[oaicite:7]{index=7}
- BMP N55 Reviews: OEM-like fit, strong build, perfect for multi-port setups :contentReference[oaicite:8]{index=8}
- Forum testing: Users see 35 rwhp gains from billet “FabFactory” style manifolds :contentReference[oaicite:9]{index=9}
- Costs vs gain: Port injection excels on ethanol/tuned engines—stock turbo setups see modest flow gains :contentReference[oaicite:10]{index=10}
Who Should Choose What?
- Balanced performance & value: EOSpeed is reliable, cost-effective, and PI-ready.
- High-end durability: Phoenix Racing offers billet precision and a rugged build.
- OEM fit with PI: BMP N55 delivers function, ports, and flexibility.
- Direct warranty support: Masata ensures parts and service across UK/EU.
- Showcase builds: Plazmaman is for show-stoppers willing to invest heavily.
Installation & Tuning Tips
- Ensure the manifold is cool and disconnected from battery.
- Remove the stock manifold with care—keep grounds and sensors safe.
- Install phenolic spacer where heat soak is a concern.
- Torque bolts evenly in a star pattern.
- Fit port injectors and close unused ports with plugs.
- Bleed fuel lines and check PI plumbing thoroughly.
- Get a supporting tune—port injection requires tuning to achieve full gains.
- Monitor IATs and refine tuning over 100–200 miles.
- Inspect for leaks and retorque after initial heat cycles.
Tracking vs Street Use
- Track/High boost: Billet Phoenix Racing or Plazmaman shine with high RPM flow and precision.
- Street/Tuner builds: EOSpeed and BMP N55 strike a good balance between cost, reliability, and performance.
- Builds in UK/EU: Masata’s support and warranty is a strong asset.
Conclusion
Upgrading your BMW 135i intake manifold is a transformative step—boosting airflow, durability, and system flexibility. Here’s a recap:
- Best overall: EOSpeed offers excellent value and dependability.
- Best precision build: Phoenix Racing brings billet quality and performance.
- Best OEM-fit flexibility: BMP N55 integrates well with OEM systems and PI setups.
- Best local support: Masata is ideal for UK/EU builds with support and warranty.
- Best showpiece: Plazmaman stands out if budget is no object.
Choose the intake manifold that fits your build goals—from spirited daily-driving to full-blown track rigs. Have questions? Drop a comment and I’ll help you match your choice to your setup!