Radium Engineering Coolant Expansion Tank for Lotus Elise & Exige (2006-2011)

If you own a 2006-2011 Lotus Elise or Exige equipped with the Toyota 2ZZ-GE engine, whether it’s naturally aspirated or supercharged, you’re in for a treat with the Radium Engineering Coolant Expansion Tank. This kit is designed to fit seamlessly into your vehicle, providing a reliable and efficient solution for your cooling system.

Key Features

The Radium Coolant Expansion Swirl Tank comes with three ports that utilize -6AN male adapters, ensuring a positive and secure seal (no tapered pipe threads here!). Crafted from high-quality billet aluminum, the tank features a two-piece design that is both durable and functional.

The two halves of the tank are bolted together, complemented by a CNC-machined aluminum cap receiver that fits any standard 32mm "Type-A" style pressure cap. What sets this tank apart is its innovative swirl feature. By sending pressurized coolant into a vortex chamber tangentially, it accelerates the coolant's rotation, effectively helping to eliminate air bubbles in the system. This is a classic hot rod technique that’s proven to work!

Why Upgrade?

Your S2 Lotus Elise and Exige models typically come with a Denso coolant expansion tank, the same plastic tank found in other Toyota 2ZZ-GE vehicles. While this tank does the job, it can be prone to failure, and replacements can be pricey. Radium has simplified the design by creating two separate mounts and enhancing it with a robust aluminum tank, while still allowing you to use the factory hoses adapted to -6AN fittings.

Installation is a breeze! The mount utilizes all factory threaded holes, meaning no drilling or modifications are necessary. An average mechanic can handle the installation, and everything remains accessible with the rear clam intact. Plus, aluminum push lock hose ends are included to easily convert your factory coolant hoses to -6AN.

What’s Included?

• Billet Aluminum Coolant Tank (Anodized Black)
• Nickel Plated Sight Tube Fittings
• Aluminum 6AN Male Adapter Fittings (Anodized Black)
• Aluminum 6AN Hose Ends (Anodized Black)
• Laser Cut Aluminum Tank Bracket (Powder Coated Black)
• Laser Cut Aluminum Hot-Soak Water Pump Bracket (Anodized)
• Rubber Isolation Coolant Tank Grommets
• Hot-Soak Water Pump Cushion Clamp
• Mounting Hardware

Optional Upgrades

If you're looking to take your cooling system to the next level, consider the optional Radium Engineering pressure caps (sold separately). These caps allow you to select a range of pressures that the Denso tank couldn’t offer. With a higher pressure cap, you can increase the boiling point in your cooling system, which enhances cooling efficiency—perfect for those intense track days! Each cap is made from stainless steel and features a race-proven high-pressure valve. For more details, check out the options here.

Important Note

The OEM Lotus pressure cap is rated at 1.1 Bar.

Fitment

• Lotus Elise (2006-2011)
• Lotus Exige (2006-2011)