Ultra Racing Underbody Lower Chassis Brace Kit for BMW F2x F20 F21 F22 1 & 2 Series - Subframe/Cross/Belly/Floor Pan Brace - Fits M135i M140i M235i M240i - Underfloor Reinforcement Bar ULTRA-RL-3885

Lower Chassis Reinforcement for BMW F20 F21 F22

Unlock sharper steering, improved stability and greater confidence with this Ultra Racing lower bracing package for the BMW F2x platform. This underfloor reinforcement links key points in the undercarriage to cut flex and keep geometry consistent under load. The result is crisper turn in, better mid-corner composure and a more planted feel on both fast road and track days. Ideal for remapped and suspension-tuned cars that demand extra rigidity.

We have installed this setup on our own demonstrators and for many customers. Feedback has been consistently positive, praising the tighter front end response and the calm, predictable behaviour over rough B-roads. It is a genuine bolt-on handling upgrade that complements coilovers, uprated anti-roll bars and performance tyres.

Why this chassis brace

• Bolt-on upgrade supplied with complete mounting hardware. Nothing else to buy
• Engineered specifically for the F20, F21 and F22 floorpan for precise fitment
• Exhaust friendly profile sits a touch lower to clear performance systems and larger centre sections
• Reduces underbody flex for more precise alignment control under braking and cornering
• Enhances steering feel, traction and high speed stability without compromising daily usability

Included in the kit

• Ultra Racing Underfloor Brace, part number ULTRA-RL-3885
• Pushrod left, BMW reference 33326793651
• Pushrod right, BMW reference 33326793652
• Torx bolt x2, BMW reference 33306861221
• Expanding plastic rivet x2, BMW reference 51118174185
• White plastic parts x2, BMW reference 07147201307

Vehicle applications

• BMW 1 Series F20 and F21 M135i 2012 onwards
• BMW 1 Series F20 and F21 M140i 2015 onwards
• BMW 2 Series F22 all variants except cabriolet

Also searched as BMW F20 chassis brace, BMW F21 lower brace, BMW F22 subframe brace, F2x cross brace, M135i reinforcement bar, M140i underfloor brace, M235i lower bar, M240i stability brace, F2x belly brace, F2x floor pan brace and F2x undercar bracing.

Installation and support

Straightforward bolt-on fitting using the supplied hardware. For professional installation and geometry setup, we can help. Book in with MJ Modifications in Warwickshire or request a fitting quote via info@mjmodifications.co.uk.