The project begins...

Right then, a blog.

I have never really been one to write things down, but having recently read a blog featuring the engineering adventures of a friend, I decided that having a go myself might be a nice idea - particularly as I embark on a new project to learn some new skills and realise an idea I have for the centerpiece of my next car project. In the past I've never written things down and months/years down the line I forget what I've done or how I did it, so perhaps this will be a nice chronicle for the future. If it helps a few like minded tinkerers out then all the better! So on to my new project...

I have owned my TVR Chimaera for about 13 years this year, and have always been bothered to some degree or other of the little or large niggles with it. TVR of course didn't design a fantastically well engineered car to begin with, and on top of that years of shake rattle and rust generate further work still. Having fixed, upgraded, enhanced and developed the car, I always felt like I wanted to start from a completely known basis, and to see how far the car could be pushed if given a clean sheet of paper and a proper go at it.

The Before Shot...

Perhaps fortunately this year I was posted to live and work in Malaysia for a couple of years and while putting much of my home life on hiatus, I would need to put the car into long term storage. This was the perfect opportunity, and I realised that if I was ever going to rebuild the car from the ground up, this was the time. So off we go.

My first step was to map out in my head what was I actually thinking of when deciding to restore the car, and I think I first started mapping things out in my head around about October 2018. I decided that the chassis was the place to start. TVR developed their base chassis design over the years before and since the Chimaera, and the later models achieved both significantly better handling characteristics and higher torsional rigidity than the Chimaera, and even more so than those that came before it. Fortunately for me Ian Davies, owner of Sportmotive in Staffordshire had already crossed this bridge several years earlier and designed a far superior chassis together with bespoke uprights and suspension components - the full works. Known as the Evolution chassis it is a thing of beauty, and takes the design right up to and beyond the last Wheeler era TVR chassis designs (excluding of course the very last where carbon composite was used in conjunction with the tubular space frame to further improve rigidity - perhaps a little out of my price range!).

Sportmotive Evo Chassis

To swap my car's body onto this evolved chassis however, it would need to be cut and adjusted to suit the evo chassis' wider engine bay chassis rails and revised pickup points. To cut a long story short, it quickly became clear that doing this (and what else I had in my head) would mean fully disassembling my car and rebuilding it onto a new chassis. With my car being in good health and a generally well sorted example of a TVR, it seemed counterproductive to effectively destroy it and start from scratch so the decision was made to source a donor body and chassis. Oh boy here we go.

Donor body and its happy new owner

LT4 6.2L Supercharged V8 Engine

So the decision was made, and the chassis put on order, along with the new drive train from the states. Given that it would take a long while for both of these things to be ready, I shifted my focus onto areas I could develop myself.

So now that I was planning out what was now to be the actualisation of my vision of a dream TVR, I decided that I should think a little outside the box. I've always loved the later model TVRs and in particular their interiors. TVR made a lot of great interiors, but in my opinion the Sagaris/T350/Tamora is the most attractive and best functioning of them all. Most of the fibreglass molds are still available to make the general dash pieces, but the TVR bespoke electrical components are rather more difficult to acquire.

TVR T-Car Interior

Having decided I was mad enough to create a bespoke interior in my resto-mod Chimaera project, I began to hunt for parts. Finding the switchgear and beautiful aluminium trim parts wasn't too hard (although extremely lucky as I seem to have found the last of each component for sale at time of writing), though the dash control unit and main instrument cluster were not so easy. Hens teeth in fact, and eye-wateringly expensive if you can find them, which I couldn't. On top of that, they have a bit of a poor reputation of failing; particularly the LCD screens within the dash pod (which I didn't particularly like anyway). It seemed that I might have to either give up on the idea or put in conventional gauges.

Never! Having a half baked set of instruments in my dream TVR right in front of my face would not wash. I would have to use some effort on this one.

TVR Original T-Car Design

Stillborn TVR Dash Design

Almost at exactly the right moment, Dom Trickett from TVR Power posted a teaser picture of a gauge layout similar to the Sagaris pod I desired, though without the ugly LCD screen and some analogue style gauges instead. Upon asking, Dom told me that this was in fact a stillborn design from TVR in its final months for the Sagaris MkII and Typhon, though of course the company wound up and that was that. What a fantastic idea though - and one that perhaps wouldn't require the dash ECU...

I fired up my laptop and some cad software to sketch out what my ideal gauge cluster might look like. A couple of iterations later and I had something that I really liked the look of. But having 4 analogue style gauges so close together would mean a custom job. How to make it?

Version 1

My first call was to Caerbont Automotive Instruments in Wales - the OEM TVR gauge manufacturer along with Smiths gauges and many many other classic cars from the Ford GT40 to the original Mini to the VW Camper. I spoke at length with their lead engineer and showed him my sketch and  rendered design and explained how I envisioned it would function. "Give me a few days..." he said, "...but it's not going to be cheap. This will require a one off custom designed PCB and a custom housing". I tried to remain optimistic but feared that this might not work, and may also be why Dom explained that it couldn't be done.

My heart was already set on it though. Can't be done? Bollocks to that!

CAI although they couldn't help me, kindly put me in touch with their ex-engineering manager Rodney, who after a lovely long chat explained how instruments are prototyped, designed and built, and that he had access to CAI out of hours and could therefore help build the physical unit, but admitted that the PCB design and coding to support the bespoke design would be the financial killer.

Thanking Rodney and after thinking of CAI's talk of PCBs and digital instruments, I looked at some projects that others had done on YouTube and found a particularly interesting chap named John. John  had used a couple of Arduinos to read a the OBD-II port of his Emerald K6 ECU in an old MG RV8 and display some of the digital data on a tiny OLED screen that he had mounted inside the Tacho unit. Along with this he had used the Arduino PWM output to drive the needle servo its self, turning the gauge into a fully digital unit. Very interesting indeed!

Arduino Inspiration

A quick Google found his blog posts of the project, including some of the source code he had written to control the Arduinos. It was a daunting task, but perhaps I could design and build the internals myself, and then have Rodney simply assemble the components into a nice binnacle with a professionally printed backing decal. This would be much more doable.