Some other threads on Passion Performance, here and elsewhere, have questioned or speculated about teaming and development of the 5 speed unit. Below is some background. Found this link and I included the verbiage for posterity:
5SR BY GFI
Our Story
The A855 Five Speed Project
The story starts with Garrett-Fuss Inc providing a Hemi 4 speed overdrive gear set for Passon Performance in the Early 2000s. The Set was a success and Passon Performance was able to develop a following for overdrive gear sets. A few years rolled by and William Fuss, Founder of GFI and Engineer behind the 5SR Project, asked the question "would a 5 speed overdrive have any interest?" Jamie Passon of Passon Performance answered with a resounding "yes" and the project was put into motion starting with a feasibility study and given the name 5 Speed Retro or 5SR Project.
Many hours were then spent with GFI and Passon Performance, working out the parameters of the new gear box. The main goal was to provide a transmissions that would fit without modifications of the car. Jamie Passon provided information on desirable ratios, fitment issues between platforms, desired torque handling capabilities and from there the A855 concept was born. William Fuss then went to work designing a gear set that would handle substantially more torque than the stock Hemi trans with the added bonus of a fifth gear that would fit inside the small space of an A833. The result, after several months, was a low helix angle gear set with carbon fiber synchronizer/blocker rings that maintains the period correct A833 look of the early 60's, 70's, and 80's Mopars, and as a bonus, will handle over 700 foot pounds of torque.
Next on the Agenda was many months of CAD work to produce final drawings of the cases, components, and fit them together on the screen. A prototype assembly was developed and went to manufacturing for 10 initial units. Testing started with much success and a list of improvements was generated. After 2 years of road testing, revisions to the design were made, and the first production lot of 50 transmissions was manufactured, with almost all of the parts coming from right here in Pennsylvania, which they still do to this day!
Process development and tooling used up several months delaying production of the first lot, which finished in about 10 months. The units went out and customers response was even better than anticipated. After extensive testing and valuable suggestions from the end user, we were able to discover improvements that we implemented into the product design.
In 2015 John Huff of Yellowstone Garage was implemented into the project as an investor. As an avid Mopar builder and collector he has gone far above and beyond his expected involvement and is now in charge of final testing and shipping of the finished product, making him a very important part of the project. Every transmission goes to his shop and is road tested under various driving conditions including speed tests on the interstate. His involvement even goes beyond testing as he has become a major part of sales as of early 2018 and his insight and expertise are extremely valuable.
As of 2023, 13 years have passed, some of those years being very challenging, we are currently in the 6th lot of production totaling several hundred units since the start of production in 2012. The 5SR project is expected to expand to GM designs, calling our GM 5SR the M25, you could say it's the M22 Rock Crusher's Big Brother. We have already prototyped our M25 for C2 and C3 Corvettes along with the Camaro and the Nova with the same goal of a transmission that fits the car without modification or the addition of costly adapters and components. Nobody likes to cut a pristine car and now you don't have to.
So, thats the story of the 5SR, a transmission that fits the car without modification and can handle big horsepower. Look for other enhancements to the project in the future such as short throw shifting, road course gear ratios, and a dog ring (otherwise known as clutchless) version of both the A855 and the M25.
