The BMW E60 M5 CSL has always captivated the hearts of S85 owners with the showcase being the single piece carbon plenum with larger side inlets running AlphaN software.
It was never available as a part to purchase. 

We did not want to make just make another carbon plenum which replaces the OEM for noise alone.
Like the rest of our range we wanted to give the market something very special for what is essentially one of the last of the truly great naturally aspirated engines.

Infinity Design therefore went out of it’s way to give the enthusiast S85 owners something very special.

The 100% pre preg carbon fibre plenum was designed in CAD software using accurate 3D scans of the engine bay without the OEM plenum in place, 3D scans of both of the individual OEM plenums and then combined together to make a singular larger volume system.

The induction sound is beyond what has been achieved by the market.
Mutiple reports of the intial pre production batch have shown more usable torque and improved 60-130mph times as well as improved power on dyno testing.

Under bonnet looks are sensational.

At the core of the design is the modularity. This is key both to the functionality, how the system is fitted, the multiple upgrade paths and also a lower price. No other product throughout the BMW aftermarket exists which is this complex and at the same time gives so many options and advantages.

There are 4 main components:
Main Plenum 
Throttle body bosses
Velocity stacks
Side inlets
Lid

Fitment
The fundamental problem with one piece plenums is that they are very difficult to fit as the throttle bodies are at a 120 degrees angle to one another unlike the S65 engine where they are at a 180 degree angle and the plenum fits directly downwards on top of them. A solid one-piece plenum causes major issues when attempting to fit with the rubber boots not seating correctly onto the adaptors on the plenum which lead to major air leaks. The system also requires considerable force to seat correctly.
The Infinity Design plenum allows the throttle body bosses to first be attached to the rubber boots, the main plenum is placed onto the adapters, the velocity stacks are then attached, side inlets installed and lid installed leading to a leak free and simple process.

By keeping the main frame, throttle body bosses, velocity stacks, side inlets and lid separate a logical and simple process can be taken to fit the system giving no risk of overlapping of the throttle body boots which leads to air leaks and having to force the plenum into position

Upgradability
By allowing all of the parts to be separate it allows the end user to change the velocity stacks to shorter types to give a higher rpm biased power delivery.
The side inlets can be changed from the OEM style to the CSL Style which give a significantly larger opening leading to a large volume high flow intake system.

Resistence to Failure
It has been long known that carbon plenums suffer from internal failures. The most common issue is the velocity stacks break away as they are often glued. Over time the adhesive weakens with heat cycles and vibrations. Not only is the entire plenum wasted but can cause major catastrophic engine damage as the broken carbon shards entire into the combustion chamber.
The Infinity Design system has one piece velocity stacks which are bolted through the plenum into the throttle body bosses. There is no chance of failure.

Lower Cost
Since all of the parts of the plenum are individually manufactured and supplied there is no expense of assembly which poses a significant cost in carbon parts. Jigs are required for exact placement of parts with adhesive, drying times and cleaning required which all add time to the manufacturing process leading to a higher overall price.
Given how complex our system is, the cost is very reasonable.

The velocity stacks were lightly redesigned with a larger and longer opening with them all facing the significantly larger side openings rather than away from the path of the air.

Specifications

• Pre-preg & autoclave carbon fiber construction
• Modular design for fitment and upgrades
• Available in Gloss or Matt clear coated finish
• Improved throttle response
• Plug & Play fitment 
• Monstrous Induction Noise

Components

• Main Carbon Plenum
• 10 x Pre Preg Carbon Velocity Stacks
• 10 x CNC Machined Alumimum throttle body bosses
• Right and Left CSL Style Side Inlets
• Right and Left CSL Inlet Tubes
• Right and Left CSL Lower Air Filter Housings
• Lid
• 2 x High Flow Air Filters
• 2 x Silicone Couplers
• 4 x SS-304 Clips
• 2 x Black SS304 V Band Clamps
• 20 x M5x16mm Stainless Steel Black Bolts
• 27 x M4x12mm Stainless Steel Black Bolts.

Installation