Project Prytaneia: 1989 Eunos Roadster – The Story So Far

Sometimes, cars come into your lives in the most unexpected of ways. This was definitely the case with Prytaneia. At the time, I had sold the XJR, just had Synthia and Aethyia, and on the whole, I felt like I had a very complete garage for most of my needs. A small nimble roadster to take around country lanes, and a larger 4wd wagon to take on longer trips or when I needed more space.

During a trip to Budapest for work, I was in my hotel room one evening, slightly inebriated after a delicious dinner where I may have overindulged in some very fine Hungarian wine, and I thought to browse my phone before settling down for the night. I happened to come across a post from a chap who had purchased a silver Eunos Roadster, and had then realised it required too much work to be worth his while to fix and he was looking to break it for parts.

The silver Roadster in the picture was looking in a bit of a sad state, with body panels which were all slightly different shades of silver, and there were various parts of interior trim missing, so she was definitely looking a bit sorry for herself. But underneath the cosmetic issues, she seemed to be in decent condition.

I’m sure you can guess where this is going dear reader, and you’re right. A quick message to the previous owner and bank transfer secured the car for me that very same night. I simply could not allow such an old example of these cars to be discarded in this way and knew she had to be saved. As things had quickly escalated on Synthia, I also felt like it would be good to have a fun car to run around in and work on more slowly with the view to potentially selling her when I had brought her up to a good condition.

A note on chronology at this stage, this post is written before part 3 of Synthia’s story, but much of the modifications and work done on this car was impacted by that part of Synthia’s story. To this end, I will only touch on the parts pertinent to Prytaneia, leaving the main conversation to its own post.

I booked a ticket to Didcot, in Oxford, shortly after my return back from Budapest and on the 27th of September 2019 I found myself in possession of my second MX5, and my fourth overall. Prytaneia is the first silver one that I’ve owned, the previous three having all been BRG. On the drive home, it was immediately apparent that I had made a great decision. She had been clearly unloved but the engine, gearbox and handling were one of the best of all that I have had the pleasure of driving.

For the first few months, not a lot was really done to her except for a good wash by my good friend and car detailer, Gareth of Calverts Car Clean, who gave her a thorough wash on the outside and inside, and I just enjoyed driving her. However, some problems did come to light during this time that would need addressing at some point.

While she was mostly mechanically sound, it was obvious that someone had fettled with the cooling system at some point as the radiator fans were not connected to the thermostat, but instead to a switch in the dashboard. This meant that she did not heat up properly and would require fan management to keep the car cool but not too cool. This more than likely pointed to an issue with the thermostat that would need addressing. Additionally, the head unit which was wired in was not done very well and much of the wiring inside the car had been cut and connected together using incorrect fixings. There were also various pieces of interior trim that were missing or broken. Potentially the biggest issue was that the car was sat on questionably quality suspension, with 1 of the springs being mounted upside down. Finally, the power windows were not working correctly on the passenger side.

I had decided during this time, that as I was heavily modifying Synthia, I would keep Prytaneia as original as possible, with my ethos being to upgrade all the parts to an OEM+ standard which to me meant using the best versions of parts that were either originally available on MX5s, or were very close to the spirit of the originally available parts. This was in part due to the upgrades being done to Synthia meant she became a stunning fast car to drive, but did reduce slightly from the daily drivability of the car for various reasons. I will cover these in more detail within part 3 of Synthia’s story.

The first port of call was to contact Autolink and acquire replacements for the various pieces of interior trim that needed replacing, and that done the interior of the car was ready to accept a new headhunt. Unlike Synthia and Aethyia, I decided to go with a more traditional looking head unit, but one that would still allow me to still connect via Bluetooth for my audio needs. To this end, I settled for a Kenwood DPX-7100DAB which is a simple, affordable, and easy to use unit. I decided to take her to a specialist for the wiring due to the previously mentioned wiring issues when I had taken out the old head unit to investigate. I also took the opportunity to purchase a Jass Performance bolt in black aluminium double din head unit cage as I am not a fan of the slide in cages which are included with these stereos.

I discovered a car audio specialist near to me in Nxt Gen Autos, and they were able to easily fit the head unit for me and fix the wiring. While there, I discovered that they also took on more car electronic work, which would come in very handy when I had to fix the mess that was the radiator fans. Before this could be done however, the thermostat had to be fixed. I ordered a thermostat and gasket from MX5Parts and decided to do the relatively easy fix of changing the thermostat myself.

Now you’ll notice that I said relatively easy, famous last words. Easy it was not. In high hopes, I set about taking off the two 12mm bolts which hold the thermostat in place and they both decided to snap off in situ. This lead to much unbolting of parts to work out where the thermostat housing could be removed to be replaced. Turns out this requires taking apart much of the engine, and going some of the way through I decided this was best left to the experts. I called my friend Paul at Arrow5, who is an MX5 specialist and enthusiast, and asked him to pick up Prytaneia with his tow truck and take her away for some much needed TLC.

I decided to use this time to upgrade the suspension since the car was with Paul anyway, as well as to give the car a major service to include timing belt, and engine gaskets. In keeping with the OEM+ ethos, I decided to use Bilstein suspension as used in the special editions, alongside stock replacement springs from Autolink which lead to a slight lowering of the car by 10mm, and a firmer more sporty ride. I also used the mark 2 MX5 bump stops and dust covers since these were a better performing item compared to the ones that were fitted to the mark 1. I had done this with Synthia as well when fitting the lowering springs on her, where the suspension would be more likely to bottom out due to the lowering.

As the car wasn’t significantly lowered, I can still comfortably drive over speed bumps and the stiffer suspension leads to a better handling overall as the tyre is making more contact with the road, more of the time with a less “bouncy” ride as weight transfer is better controlled. As with Synthia, I also used this opportunity to fit the R Limited track rod ends to counter bump steer from lowering the car.

While the car had been at Arrow5, I had found a pair of fixed back Momo bucket seats to replace the frankly badly covered original seats which were in the car, so with these in hand, I grabbed a lift down to Arrow5 in Winchester and, to my surprise, Paul had managed to fix the leaking exhaust, and the windows, while the car had been with him. I installed the seats into a considerably happier Prytaneia and headed on back home.

The journey home was slightly damp, and this further brought to my attention the awful tyres on her so off to eBay I went. By pure chance, I uncovered some 15×7 et35 Enkei Racing RP01 wheels which were a very close match to the Enkei wheels available on one of the special edition later MX5s. These were perfect for keeping with the OEM+ ethos and came with brand new 195/50/15 Uniroyal Rainsport 3 tyres so these were ordered and fitted to replace the standard 14″ wheels and budget tyres the car had come with. The Enkei alloys, as well as being very attractive wheels, are also incredibly light for their size which is very important on a low power, handling focused car. They also give more space for bigger brakes to be fitted in the future.

I decided to take the car back to Wheels in Motion, so that Joe could adjust the wheel alignment after the suspension work but it seemed that Prytaneia had some fight left in her after the “easy” thermostat change. While adjusting the alignment, the rear camber bolt seized inside the wishbone and required Joe to cut out the bolt from the wishbone. As this was being done, I decided to polybush the rear wishbones. Rubber bushes, over time, deteriorate and allow for movement which prevents alignment from being consistent as the car is in motion, so stiffer polybushes help to prevent this issue and offer more consistent handling. There is a minor tradeoff for more vibrations being prominent especially through harsher roads but it’s a small price to pay for the handling benefits if it is not your daily car. Polybushes also last almost indefinitely and do not wear out the same way rubber bushes do.

As the car would have to be with Wheels in Motion for a few days, I decided it made sense to upgrade the door bushes as with Synthia, and also ordered a full set of rear braces to mount around the wishbone to greatly stiffen the rear end of the car. This was done partially as an experiment since the car was in the workshop. I wanted to see the effectiveness of the bracing before I decided to do the same with Synthia. With the parts all fitted, and suspension aligned, the car headed off to Nxt Gen Autos to have the thermostat fitted, and to have a unique mod fitted which I will be writing about separately.

That brings us up to date with the story so far on Prytaneia and with it, the end of this post. The unique mod is one which I did to both of the roadsters, and I will write about in its own brief post as I’m sure other Eunos enthusiasts may wish to do the same to their own cars.

I hope you enjoyed reading this as much as I did writing it. There are many modifications planned for Prytaneia which I will write about as time goes on, so this story is far from over, but for now, I thank you for reading my post and as always I look forward to your comments and questions.

#Arrow5#Autolink#Bracing#Bucket Seats#Calverts#Door Bushes#Enkei#Eunos#I.C.E.#Jass Performance#Kenwood#Maintenance#Mazda#Modifications#Momo#MX-5#MX5-Parts#Nxt Gen Autos#OEM+#Polybushes#Prytaneia#Roadster#RWD#Wheels & Tyres#Wheels in Motion

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