Things are going well for me, but the BR1 project has been officially retired. It was a tremendous learning experience and I would never regret the time, money, and energy that went into the project, but after years of school and closing in on finishing my Motorsports Engineering degree, I also learned everything I did wrong the first time. I will (of course) finish rebuilding the V12, because I want a V12 in my life no matter whether it's in a car or on an engine stand. Today I just had my last final exam for the year, and I am now studying at Oxford Brookes University in England. Next year will be my last, and as such I was required to either select a thesis/final year project from a list or submit my own. I submitted my own: a design proposal for a modern day "microcar," or really just a very small car that can comfortably seat two 95th percentile males, offer more trunk space than a Smart car/Mini Cooper/ Fiat 500/etc., outperform more than a few sports cars sports, and introduce a new generation to the idea of lightweight, fast, and economical motoring. Meet the BR4.
As a future production model, this project is the development of the prototype. My thesis will likely revolve around crash structure design in ultra-compact city cars. Some performance metrics for the car:
- a variety of motorcycle engines offering from 120-200hp (depending on model), limited slip differential with integrated reverse gearbox
- Tubeframe chassis/ Fiberglass Body prototype
- 1200-1600 lb target weight, maximum 300hp/ton
- 40" tall
- >2m meter wheelbase
I'm working on this as a personal leisure project at the moment; it won't become official schoolwork until next year but I enjoy it and everything I do now will be useful later. Here's where I'm at so far:
- Market research comparing a wide variety of small cars: usability, performance, and consumer market metrics
- Concept designed, basic body style determined after considering several variations, engine layouts, etc. Front engined, rwd hatchback.
- Initial packaging layout completed, powertrain options considered
- Suspension specified (Yes, I am doing my own suspension this time! SLA wishbone front and rear. CAD model is Miata stuff for now to use for dimensioning/packaging)
- Tubeframe chassis designed (Another thing I learned since the BR1: how to properly design a chassis in Solidworks)
That's pretty much where I'm at! Today I focused on chassis stiffness, setting a goal for a deflection force of 20,000 Nm/degree. This value seemed to be about average for many smaller hardtop sports cars. (Convertible models of the same cars are usually only 50-60% as stiff as their hardtop counterpart.). After numerous iterations, torsional stiffness increased from 2400 Nm/deg to just under 29,000 Nm/deg, and weight decreased by ~10 pounds. For reference, a Lamborghini Gallardo has a stiffness of 23,000 Nm/deg, and a BMW-made (the kings of stiff bodies) Mini cooper is rated at 24,500 NM/deg. Porsche Carrera GT is 26,500 Nm/deg. With room to spare for mass reduction, the next step will be fine tuning! I also added a windshield and side glass to the model
Current iteration of chassis
Starting point (simplified, unoptimized structure)
So... I guess that's all for here! I just wanted to give some great supporters on this forum some "closure" and invite them to follow this new project at the Triumph forum http://www.triumphrat.net/daytona-delib ... ost9004001 or on my Facebook as I post briefer updates there. I could always continue updating this thread as well if people preferred that, but there is no E28 influence left in the project (for better or worse
).I have been incredibly grateful to the forum members here for their endless advice, and honored by all the individuals who volunteered to help me whenever it was needed. This is a fantastic forum and I may be an E34 owner but I still like to stop by every now and then!
Thanks again all,
Spence
