FSPE - RGR "Ultra" NA/NB Rear Diffuser

$495.00 - $595.00


Designed, engineered, and fabricated in collaboration with FS Performance Engineering, our NA/NB Diffuser is the product of many hours of work and fine-tuning.

We have taken the original FSPE "Monstrosity Junior" and taken it to the next level.

With the help of CFD and string testing validation, we have managed to design a diffuser that is extremely easy to install without compromising on efficiency.

Our diffuser offers unique solutions like our engineered end plates that separate dirty air coming from the rear tires and create an even low-pressure zone all across the width of the diffuser. Other features include a rear mounting bracket with threaded inserts that allows the diffuser to be installed in 3 easy steps, and the ability to adjust the height of the diffuser so it can work with cars with a variety of rear bumpers.

Our diffuser offers bolt-on, adjustable downforce like nothing else on the market.

Available either in raw aluminum or powder coated in black.

Each diffuser is made to order right here in the US. Please allow 3 to 5 weeks for processing time.

For shipping outside of the US, please contact us beforehand.

Instructions are available here: