FSPE - RGR "ULTRA" NA/NB REAR DIFFUSER

Designed, engineered, and fabricated in collaboration with FS Performance Engineering, the RGR NA/NB Diffuser builds upon the FSPE “Monstrosity Junior,” taking it to the next level. With extensive CFD analysis and validation through string testing, this diffuser balances ease of installation with unmatched aerodynamic efficiency.

The diffuser features custom-engineered end plates that separate turbulent air from the rear tires, creating a consistent low-pressure zone across its width. A unique rear mounting bracket with threaded inserts allows for a quick, three-step installation, while adjustable height settings ensure compatibility with various rear bumper designs.

This diffuser offers bolt-on, adjustable downforce like no other solution on the market.

Available Finishes:

• Raw Aluminum
• Black Powder Coated

Product Details:

• Made to order in the USA; allow 3 to 5 weeks for processing
• For international shipping, please contact beforehand

Installation Guide:
For instructions, refer here.

Product Overview Video:
View a detailed look at the diffuser on Flyin' Miata.

Achieve professional-grade downforce with the RGR Diffuser—engineered to elevate your Miata’s performance and style.